Google Git Google Git
Sign in
third-party-mirror/openjdk/jdk25u/HEAD/./src/hotspot/os/aix/os_aix.cpp
blob: 50a219f0824e0d168bffbc606db9fe113f8fdc4b [file]
/*
* Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2025 SAP SE. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "classfile/vmSymbols.hpp"
#include "code/vtableStubs.hpp"
#include "compiler/compileBroker.hpp"
#include "interpreter/interpreter.hpp"
#include "jvm.h"
#include "jvmtifiles/jvmti.h"
#include "libperfstat_aix.hpp"
#include "libodm_aix.hpp"
#include "loadlib_aix.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "memory/allocation.inline.hpp"
#include "misc_aix.hpp"
#include "oops/oop.inline.hpp"
#include "os_aix.inline.hpp"
#include "os_posix.hpp"
#include "porting_aix.hpp"
#include "prims/jniFastGetField.hpp"
#include "prims/jvm_misc.hpp"
#include "runtime/arguments.hpp"
#include "runtime/atomic.hpp"
#include "runtime/globals.hpp"
#include "runtime/globals_extension.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/javaCalls.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/objectMonitor.hpp"
#include "runtime/os.hpp"
#include "runtime/osInfo.hpp"
#include "runtime/osThread.hpp"
#include "runtime/perfMemory.hpp"
#include "runtime/safefetch.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/threads.hpp"
#include "runtime/timer.hpp"
#include "runtime/vm_version.hpp"
#include "services/attachListener.hpp"
#include "services/runtimeService.hpp"
#include "signals_posix.hpp"
#include "utilities/align.hpp"
#include "utilities/checkedCast.hpp"
#include "utilities/debug.hpp"
#include "utilities/decoder.hpp"
#include "utilities/defaultStream.hpp"
#include "utilities/events.hpp"
#include "utilities/growableArray.hpp"
#include "utilities/permitForbiddenFunctions.hpp"
#include "utilities/vmError.hpp"
#if INCLUDE_JFR
#include "jfr/support/jfrNativeLibraryLoadEvent.hpp"
#endif
// put OS-includes here (sorted alphabetically)
#include <alloca.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <poll.h>
#include <procinfo.h>
#include <pthread.h>
#include <pwd.h>
#include <semaphore.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/ipc.h>
#include <sys/mman.h>
// sys/mman.h defines MAP_ANON_64K beginning with AIX7.3 TL1
#ifndef MAP_ANON_64K
#define MAP_ANON_64K 0x400
#else
STATIC_ASSERT(MAP_ANON_64K == 0x400);
#endif
#include <sys/resource.h>
#include <sys/select.h>
#include <sys/shm.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/sysinfo.h>
#include <sys/systemcfg.h>
#include <sys/time.h>
#include <sys/times.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <sys/vminfo.h>
#ifndef _LARGE_FILES
#error Hotspot on AIX must be compiled with -D_LARGE_FILES
#endif
// Missing prototypes for various system APIs.
extern "C"
int mread_real_time(timebasestruct_t *t, size_t size_of_timebasestruct_t);
#if !defined(_AIXVERSION_610)
extern "C" int getthrds64(pid_t, struct thrdentry64*, int, tid64_t*, int);
extern "C" int getprocs64(procentry64*, int, fdsinfo*, int, pid_t*, int);
extern "C" int getargs(procsinfo*, int, char*, int);
#endif
#define MAX_PATH (2 * K)
// for multipage initialization error analysis (in 'g_multipage_error')
#define ERROR_MP_OS_TOO_OLD 100
#define ERROR_MP_EXTSHM_ACTIVE 101
#define ERROR_MP_VMGETINFO_FAILED 102
#define ERROR_MP_VMGETINFO_CLAIMS_NO_SUPPORT_FOR_64K 103
// excerpts from sys/systemcfg.h that might be missing on older os levels
#ifndef PV_8
#define PV_8 0x300000 /* Power PC 8 */
#endif
#ifndef PV_8_Compat
#define PV_8_Compat 0x308000 /* Power PC 8 */
#endif
#ifndef PV_9
#define PV_9 0x400000 /* Power PC 9 */
#endif
#ifndef PV_9_Compat
#define PV_9_Compat 0x408000 /* Power PC 9 */
#endif
#ifndef PV_10
#define PV_10 0x500000 /* Power PC 10 */
#endif
#ifndef PV_10_Compat
#define PV_10_Compat 0x508000 /* Power PC 10 */
#endif
#ifndef PV_11
#define PV_11 0x600000 /* Power PC 11 */
#endif
#ifndef PV_11_Compat
#define PV_11_Compat 0x608000 /* Power PC 11 */
#endif
static address resolve_function_descriptor_to_code_pointer(address p);
static void vmembk_print_on(outputStream* os);
////////////////////////////////////////////////////////////////////////////////
// global variables (for a description see os_aix.hpp)
julong os::Aix::_physical_memory = 0;
pthread_t os::Aix::_main_thread = ((pthread_t)0);
// 0 = uninitialized, otherwise 32 bit number:
// 0xVVRRTTSS
// VV - major version
// RR - minor version
// TT - tech level, if known, 0 otherwise
// SS - service pack, if known, 0 otherwise
uint32_t os::Aix::_os_version = 0;
// -1 = uninitialized, 0 - no, 1 - yes
int os::Aix::_xpg_sus_mode = -1;
// -1 = uninitialized, 0 - no, 1 - yes
int os::Aix::_extshm = -1;
////////////////////////////////////////////////////////////////////////////////
// local variables
static volatile jlong max_real_time = 0;
// Process break recorded at startup.
static address g_brk_at_startup = nullptr;
// This describes the state of multipage support of the underlying
// OS. Note that this is of no interest to the outsize world and
// therefore should not be defined in AIX class.
//
// AIX supports four different page sizes - 4K, 64K, 16MB, 16GB. The
// latter two (16M "large" resp. 16G "huge" pages) require special
// setup and are normally not available.
//
// AIX supports multiple page sizes per process, for:
// - Stack (of the primordial thread, so not relevant for us)
// - Data - data, bss, heap, for us also pthread stacks
// - Text - text code
// - shared memory
//
// Default page sizes can be set via linker options (-bdatapsize, -bstacksize, ...)
// and via environment variable LDR_CNTRL (DATAPSIZE, STACKPSIZE, ...).
//
// For shared memory, page size can be set dynamically via
// shmctl(). Different shared memory regions can have different page
// sizes.
//
// More information can be found at AIBM info center:
// http://publib.boulder.ibm.com/infocenter/aix/v6r1/index.jsp?topic=/com.ibm.aix.prftungd/doc/prftungd/multiple_page_size_app_support.htm
//
static struct {
size_t pagesize; // sysconf _SC_PAGESIZE (4K)
size_t datapsize; // default data page size (LDR_CNTRL DATAPSIZE)
size_t shmpsize; // default shared memory page size (LDR_CNTRL SHMPSIZE)
size_t pthr_stack_pagesize; // stack page size of pthread threads
size_t textpsize; // default text page size (LDR_CNTRL STACKPSIZE)
bool can_use_64K_pages; // True if we can alloc 64K pages dynamically with Sys V shm.
bool can_use_16M_pages; // True if we can alloc 16M pages dynamically with Sys V shm.
bool can_use_64K_mmap_pages; // True if we can alloc 64K pages dynamically with mmap.
int error; // Error describing if something went wrong at multipage init.
} g_multipage_support = {
(size_t) -1,
(size_t) -1,
(size_t) -1,
(size_t) -1,
(size_t) -1,
false, false, false,
0
};
// We must not accidentally allocate memory close to the BRK - even if
// that would work - because then we prevent the BRK segment from
// growing which may result in a malloc OOM even though there is
// enough memory. The problem only arises if we shmat() or mmap() at
// a specific wish address, e.g. to place the heap in a
// compressed-oops-friendly way.
static bool is_close_to_brk(address a) {
assert0(g_brk_at_startup != nullptr);
if (a >= g_brk_at_startup &&
a < (g_brk_at_startup + MaxExpectedDataSegmentSize)) {
return true;
}
return false;
}
julong os::free_memory() {
return Aix::available_memory();
}
julong os::available_memory() {
return Aix::available_memory();
}
julong os::Aix::available_memory() {
os::Aix::meminfo_t mi;
if (os::Aix::get_meminfo(&mi)) {
return mi.real_free;
} else {
return ULONG_MAX;
}
}
jlong os::total_swap_space() {
perfstat_memory_total_t memory_info;
if (libperfstat::perfstat_memory_total(nullptr, &memory_info, sizeof(perfstat_memory_total_t), 1) == -1) {
return -1;
}
return (jlong)(memory_info.pgsp_total * 4 * K);
}
jlong os::free_swap_space() {
perfstat_memory_total_t memory_info;
if (libperfstat::perfstat_memory_total(nullptr, &memory_info, sizeof(perfstat_memory_total_t), 1) == -1) {
return -1;
}
return (jlong)(memory_info.pgsp_free * 4 * K);
}
julong os::physical_memory() {
return Aix::physical_memory();
}
size_t os::rss() { return (size_t)0; }
// Cpu architecture string
#if defined(PPC32)
static char cpu_arch[] = "ppc";
#elif defined(PPC64)
static char cpu_arch[] = "ppc64";
#else
#error Add appropriate cpu_arch setting
#endif
// Given an address, returns the size of the page backing that address.
size_t os::Aix::query_pagesize(void* addr) {
vm_page_info pi;
pi.addr = (uint64_t)addr;
if (::vmgetinfo(&pi, VM_PAGE_INFO, sizeof(pi)) == 0) {
return pi.pagesize;
} else {
log_warning(pagesize)("vmgetinfo(VM_PAGE_INFO) failed (errno: %d)", errno);
assert(false, "vmgetinfo failed to retrieve page size");
return 4*K;
}
}
void os::Aix::initialize_system_info() {
// Get the number of online(logical) cpus instead of configured.
os::_processor_count = sysconf(_SC_NPROCESSORS_ONLN);
assert(_processor_count > 0, "_processor_count must be > 0");
// Retrieve total physical storage.
os::Aix::meminfo_t mi;
if (!os::Aix::get_meminfo(&mi)) {
assert(false, "os::Aix::get_meminfo failed.");
}
_physical_memory = (julong) mi.real_total;
}
// Helper function for tracing page sizes.
static const char* describe_pagesize(size_t pagesize) {
switch (pagesize) {
case 4*K : return "4K";
case 64*K: return "64K";
case 16*M: return "16M";
case 16*G: return "16G";
default:
assert(false, "surprise");
return "??";
}
}
// Probe OS for multipage support.
// Will fill the global g_multipage_support structure.
// Must be called before calling os::large_page_init().
static void query_multipage_support() {
guarantee(g_multipage_support.pagesize == (size_t)-1,
"do not call twice");
g_multipage_support.pagesize = ::sysconf(_SC_PAGESIZE);
// This really would surprise me.
assert(g_multipage_support.pagesize == 4*K, "surprise!");
// Query default data page size (default page size for C-Heap, pthread stacks and .bss).
// Default data page size is defined either by linker options (-bdatapsize)
// or by environment variable LDR_CNTRL (suboption DATAPSIZE). If none is given,
// default should be 4K.
{
void* p = permit_forbidden_function::malloc(16*M);
g_multipage_support.datapsize = os::Aix::query_pagesize(p);
permit_forbidden_function::free(p);
}
// Query default shm page size (LDR_CNTRL SHMPSIZE).
// Note that this is pure curiosity. We do not rely on default page size but set
// our own page size after allocated.
{
const int shmid = ::shmget(IPC_PRIVATE, 1, IPC_CREAT | S_IRUSR | S_IWUSR);
assert(shmid != -1, "shmget failed");
if (shmid != -1) {
void* p = ::shmat(shmid, nullptr, 0);
::shmctl(shmid, IPC_RMID, nullptr);
assert(p != (void*) -1, "shmat failed");
if (p != (void*) -1) {
g_multipage_support.shmpsize = os::Aix::query_pagesize(p);
::shmdt(p);
}
}
}
// Before querying the stack page size, make sure we are not running as primordial
// thread (because primordial thread's stack may have different page size than
// pthread thread stacks). Running a VM on the primordial thread won't work for a
// number of reasons so we may just as well guarantee it here.
guarantee0(!os::is_primordial_thread());
// Query pthread stack page size. Should be the same as data page size because
// pthread stacks are allocated from C-Heap.
{
int dummy = 0;
g_multipage_support.pthr_stack_pagesize = os::Aix::query_pagesize(&dummy);
}
// Query default text page size (LDR_CNTRL TEXTPSIZE).
{
address any_function =
resolve_function_descriptor_to_code_pointer((address)describe_pagesize);
g_multipage_support.textpsize = os::Aix::query_pagesize(any_function);
}
// Now check which page sizes the OS claims it supports, and of those, which actually can be used.
{
const int MAX_PAGE_SIZES = 4;
psize_t sizes[MAX_PAGE_SIZES];
const int num_psizes = ::vmgetinfo(sizes, VMINFO_GETPSIZES, MAX_PAGE_SIZES);
if (num_psizes == -1) {
log_warning(pagesize)("vmgetinfo(VMINFO_GETPSIZES) failed (errno: %d), disabling multipage support.", errno);
g_multipage_support.error = ERROR_MP_VMGETINFO_FAILED;
goto query_multipage_support_end;
}
guarantee(num_psizes > 0, "vmgetinfo(.., VMINFO_GETPSIZES, ...) failed.");
assert(num_psizes <= MAX_PAGE_SIZES, "Surprise! more than 4 page sizes?");
log_info(pagesize)("vmgetinfo(.., VMINFO_GETPSIZES, ...) returns %d supported page sizes: ", num_psizes);
for (int i = 0; i < num_psizes; i ++) {
trcVerbose(" %s ", describe_pagesize(sizes[i]));
}
// Can we use 64K, 16M pages?
for (int i = 0; i < num_psizes; i ++) {
const size_t pagesize = sizes[i];
if (pagesize != 64*K && pagesize != 16*M) {
continue;
}
bool can_use = false;
trcVerbose("Probing support for %s pages...", describe_pagesize(pagesize));
const int shmid = ::shmget(IPC_PRIVATE, pagesize,
IPC_CREAT | S_IRUSR | S_IWUSR);
assert(shmid != -1, "shmget failed");
if (shmid != -1) {
// Try to set pagesize.
struct shmid_ds shm_buf = { };
shm_buf.shm_pagesize = pagesize;
if (::shmctl(shmid, SHM_PAGESIZE, &shm_buf) != 0) {
const int en = errno;
::shmctl(shmid, IPC_RMID, nullptr); // As early as possible!
log_warning(pagesize)("shmctl(SHM_PAGESIZE) failed with errno=%d", errno);
} else {
// Attach and double check pageisze.
void* p = ::shmat(shmid, nullptr, 0);
::shmctl(shmid, IPC_RMID, nullptr); // As early as possible!
assert(p != (void*) -1, "shmat failed");
if (p != (void*) -1) {
const size_t real_pagesize = os::Aix::query_pagesize(p);
if (real_pagesize != pagesize) {
log_warning(pagesize)("real page size (0x%zx) differs.", real_pagesize);
} else {
can_use = true;
}
::shmdt(p);
}
}
}
trcVerbose("Can use: %s", (can_use ? "yes" : "no"));
if (pagesize == 64*K) {
g_multipage_support.can_use_64K_pages = can_use;
} else if (pagesize == 16*M) {
g_multipage_support.can_use_16M_pages = can_use;
}
}
// Can we use mmap with 64K pages? (Should be available with AIX7.3 TL1)
{
void* p = mmap(nullptr, 64*K, PROT_READ | PROT_WRITE, MAP_ANON_64K | MAP_ANONYMOUS | MAP_SHARED, -1, 0);
assert(p != (void*) -1, "mmap failed");
if (p != (void*) -1) {
g_multipage_support.can_use_64K_mmap_pages = (64*K == os::Aix::query_pagesize(p));
munmap(p, 64*K);
}
}
} // end: check which pages can be used for shared memory
query_multipage_support_end:
trcVerbose("base page size (sysconf _SC_PAGESIZE): %s",
describe_pagesize(g_multipage_support.pagesize));
trcVerbose("Data page size (C-Heap, bss, etc): %s",
describe_pagesize(g_multipage_support.datapsize));
trcVerbose("Text page size: %s",
describe_pagesize(g_multipage_support.textpsize));
trcVerbose("Thread stack page size (pthread): %s",
describe_pagesize(g_multipage_support.pthr_stack_pagesize));
trcVerbose("Can use 64K pages with mmap memory: %s",
(g_multipage_support.can_use_64K_mmap_pages ? "yes" :"no"));
trcVerbose("Default shared memory page size: %s",
describe_pagesize(g_multipage_support.shmpsize));
trcVerbose("Can use 64K pages dynamically with shared memory: %s",
(g_multipage_support.can_use_64K_pages ? "yes" :"no"));
trcVerbose("Can use 16M pages dynamically with shared memory: %s",
(g_multipage_support.can_use_16M_pages ? "yes" :"no"));
trcVerbose("Multipage error details: %d",
g_multipage_support.error);
// sanity checks
assert0(g_multipage_support.pagesize == 4*K);
assert0(g_multipage_support.datapsize == 4*K || g_multipage_support.datapsize == 64*K);
assert0(g_multipage_support.textpsize == 4*K || g_multipage_support.textpsize == 64*K);
assert0(g_multipage_support.pthr_stack_pagesize == g_multipage_support.datapsize);
assert0(g_multipage_support.shmpsize == 4*K || g_multipage_support.shmpsize == 64*K);
}
void os::init_system_properties_values() {
#ifndef OVERRIDE_LIBPATH
#define DEFAULT_LIBPATH "/lib:/usr/lib"
#else
#define DEFAULT_LIBPATH OVERRIDE_LIBPATH
#endif
#define EXTENSIONS_DIR "/lib/ext"
// Buffer that fits several snprintfs.
// Note that the space for the trailing null is provided
// by the nulls included by the sizeof operator.
const size_t bufsize =
MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
(size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR)); // extensions dir
char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
// sysclasspath, java_home, dll_dir
{
char *pslash;
os::jvm_path(buf, bufsize);
// Found the full path to libjvm.so.
// Now cut the path to <java_home>/jre if we can.
pslash = strrchr(buf, '/');
if (pslash != nullptr) {
*pslash = '\0'; // Get rid of /libjvm.so.
}
pslash = strrchr(buf, '/');
if (pslash != nullptr) {
*pslash = '\0'; // Get rid of /{client|server|hotspot}.
}
Arguments::set_dll_dir(buf);
if (pslash != nullptr) {
pslash = strrchr(buf, '/');
if (pslash != nullptr) {
*pslash = '\0'; // Get rid of /lib.
}
}
Arguments::set_java_home(buf);
if (!set_boot_path('/', ':')) {
vm_exit_during_initialization("Failed setting boot class path.", nullptr);
}
}
// Where to look for native libraries.
// On Aix we get the user setting of LIBPATH.
// Eventually, all the library path setting will be done here.
// Get the user setting of LIBPATH.
const char *v = ::getenv("LIBPATH");
const char *v_colon = ":";
if (v == nullptr) { v = ""; v_colon = ""; }
// Concatenate user and invariant part of ld_library_path.
// That's +1 for the colon and +1 for the trailing '\0'.
size_t pathsize = strlen(v) + 1 + sizeof(DEFAULT_LIBPATH) + 1;
char *ld_library_path = NEW_C_HEAP_ARRAY(char, pathsize, mtInternal);
os::snprintf_checked(ld_library_path, pathsize, "%s%s" DEFAULT_LIBPATH, v, v_colon);
Arguments::set_library_path(ld_library_path);
FREE_C_HEAP_ARRAY(char, ld_library_path);
// Extensions directories.
os::snprintf_checked(buf, bufsize, "%s" EXTENSIONS_DIR, Arguments::get_java_home());
Arguments::set_ext_dirs(buf);
FREE_C_HEAP_ARRAY(char, buf);
#undef DEFAULT_LIBPATH
#undef EXTENSIONS_DIR
}
// retrieve memory information.
// Returns false if something went wrong;
// content of pmi undefined in this case.
bool os::Aix::get_meminfo(meminfo_t* pmi) {
assert(pmi, "get_meminfo: invalid parameter");
memset(pmi, 0, sizeof(meminfo_t));
// dynamically loaded perfstat library is used to retrieve memory statistics
perfstat_memory_total_t psmt;
memset (&psmt, '\0', sizeof(psmt));
const int rc = libperfstat::perfstat_memory_total(nullptr, &psmt, sizeof(psmt), 1);
if (rc == -1) {
log_warning(os)("perfstat_memory_total() failed (errno=%d)", errno);
assert(0, "perfstat_memory_total() failed");
return false;
}
assert(rc == 1, "perfstat_memory_total() - weird return code");
// The fields of perfstat_memory_total_t:
// u_longlong_t virt_total Total virtual memory (in 4 KB pages).
// u_longlong_t real_total Total real memory (in 4 KB pages).
// u_longlong_t real_free Free real memory (in 4 KB pages).
// u_longlong_t pgsp_total Total paging space (in 4 KB pages).
// u_longlong_t pgsp_free Free paging space (in 4 KB pages).
pmi->virt_total = psmt.virt_total * 4096;
pmi->real_total = psmt.real_total * 4096;
pmi->real_free = psmt.real_free * 4096;
pmi->pgsp_total = psmt.pgsp_total * 4096;
pmi->pgsp_free = psmt.pgsp_free * 4096;
return true;
} // end os::Aix::get_meminfo
//////////////////////////////////////////////////////////////////////////////
// create new thread
// Thread start routine for all newly created threads
static void *thread_native_entry(Thread *thread) {
thread->record_stack_base_and_size();
const pthread_t pthread_id = ::pthread_self();
const tid_t kernel_thread_id = ::thread_self();
LogTarget(Info, os, thread) lt;
if (lt.is_enabled()) {
address low_address = thread->stack_end();
address high_address = thread->stack_base();
lt.print("Thread is alive (tid: %zu, kernel thread id: %zu"
", stack [" PTR_FORMAT " - " PTR_FORMAT " (%zuk using %luk pages)).",
os::current_thread_id(), (uintx) kernel_thread_id, p2i(low_address), p2i(high_address),
(high_address - low_address) / K, os::Aix::query_pagesize(low_address) / K);
}
// Normally, pthread stacks on AIX live in the data segment (are allocated with malloc()
// by the pthread library). In rare cases, this may not be the case, e.g. when third-party
// tools hook pthread_create(). In this case, we may run into problems establishing
// guard pages on those stacks, because the stacks may reside in memory which is not
// protectable (shmated).
if (thread->stack_base() > ::sbrk(0)) {
log_warning(os, thread)("Thread stack not in data segment.");
}
// Try to randomize the cache line index of hot stack frames.
// This helps when threads of the same stack traces evict each other's
// cache lines. The threads can be either from the same JVM instance, or
// from different JVM instances. The benefit is especially true for
// processors with hyperthreading technology.
static int counter = 0;
int pid = os::current_process_id();
alloca(((pid ^ counter++) & 7) * 128);
thread->initialize_thread_current();
OSThread* osthread = thread->osthread();
// Thread_id is pthread id.
osthread->set_thread_id(pthread_id);
// .. but keep kernel thread id too for diagnostics
osthread->set_kernel_thread_id(kernel_thread_id);
// Initialize signal mask for this thread.
PosixSignals::hotspot_sigmask(thread);
// Initialize floating point control register.
os::Aix::init_thread_fpu_state();
assert(osthread->get_state() == RUNNABLE, "invalid os thread state");
// Call one more level start routine.
thread->call_run();
// Note: at this point the thread object may already have deleted itself.
// Prevent dereferencing it from here on out.
thread = nullptr;
log_info(os, thread)("Thread finished (tid: %zu, kernel thread id: %zu).",
os::current_thread_id(), (uintx) kernel_thread_id);
return 0;
}
bool os::create_thread(Thread* thread, ThreadType thr_type,
size_t req_stack_size) {
assert(thread->osthread() == nullptr, "caller responsible");
// Allocate the OSThread object.
OSThread* osthread = new (std::nothrow) OSThread();
if (osthread == nullptr) {
return false;
}
// Initial state is ALLOCATED but not INITIALIZED
osthread->set_state(ALLOCATED);
thread->set_osthread(osthread);
// Init thread attributes.
pthread_attr_t attr;
int rslt = pthread_attr_init(&attr);
if (rslt != 0) {
thread->set_osthread(nullptr);
delete osthread;
return false;
}
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
// Make sure we run in 1:1 kernel-user-thread mode.
guarantee(pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) == 0, "???");
guarantee(pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED) == 0, "???");
// Start in suspended state, and in os::thread_start, wake the thread up.
guarantee(pthread_attr_setsuspendstate_np(&attr, PTHREAD_CREATE_SUSPENDED_NP) == 0, "???");
// Calculate stack size if it's not specified by caller.
size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
// JDK-8187028: It was observed that on some configurations (4K backed thread stacks)
// the real thread stack size may be smaller than the requested stack size, by as much as 64K.
// This very much looks like a pthread lib error. As a workaround, increase the stack size
// by 64K for small thread stacks (arbitrarily chosen to be < 4MB)
if (stack_size < 4096 * K) {
stack_size += 64 * K;
}
// On Aix, pthread_attr_setstacksize fails with huge values and leaves the
// thread size in attr unchanged. If this is the minimal stack size as set
// by pthread_attr_init this leads to crashes after thread creation. E.g. the
// guard pages might not fit on the tiny stack created.
int ret = pthread_attr_setstacksize(&attr, stack_size);
if (ret != 0) {
log_warning(os, thread)("The %sthread stack size specified is invalid: %zuk",
(thr_type == compiler_thread) ? "compiler " : ((thr_type == java_thread) ? "" : "VM "),
stack_size / K);
thread->set_osthread(nullptr);
delete osthread;
pthread_attr_destroy(&attr);
return false;
}
// Save some cycles and a page by disabling OS guard pages where we have our own
// VM guard pages (in java threads). For other threads, keep system default guard
// pages in place.
if (thr_type == java_thread || thr_type == compiler_thread) {
ret = pthread_attr_setguardsize(&attr, 0);
}
ResourceMark rm;
pthread_t tid = 0;
if (ret == 0) {
int trials_remaining = 4;
useconds_t next_delay = 1000;
while (true) {
ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
if (ret != EAGAIN) {
break;
}
if (--trials_remaining <= 0) {
break;
}
log_debug(os, thread)("Failed to start native thread (%s), retrying after %dus.", os::errno_name(ret), next_delay);
::usleep(next_delay);
next_delay *= 2;
}
}
if (ret == 0) {
char buf[64];
log_info(os, thread)("Thread \"%s\" started (pthread id: %zu, attributes: %s). ",
thread->name(), (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
} else {
char buf[64];
log_warning(os, thread)("Failed to start thread \"%s\" - pthread_create failed (%d=%s) for attributes: %s.",
thread->name(), ret, os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
// Log some OS information which might explain why creating the thread failed.
log_warning(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
log_warning(os, thread)("Checking JVM parameter MaxExpectedDataSegmentSize (currently %zuk) might be helpful", MaxExpectedDataSegmentSize/K);
LogStream st(Log(os, thread)::info());
os::Posix::print_rlimit_info(&st);
os::print_memory_info(&st);
}
pthread_attr_destroy(&attr);
if (ret != 0) {
// Need to clean up stuff we've allocated so far.
thread->set_osthread(nullptr);
delete osthread;
return false;
}
// OSThread::thread_id is the pthread id.
osthread->set_thread_id(tid);
// child thread synchronization is not done here on AIX, a thread is started in suspended state
return true;
}
/////////////////////////////////////////////////////////////////////////////
// attach existing thread
// bootstrap the main thread
bool os::create_main_thread(JavaThread* thread) {
assert(os::Aix::_main_thread == pthread_self(), "should be called inside main thread");
return create_attached_thread(thread);
}
bool os::create_attached_thread(JavaThread* thread) {
#ifdef ASSERT
thread->verify_not_published();
#endif
// Allocate the OSThread object
OSThread* osthread = new (std::nothrow) OSThread();
if (osthread == nullptr) {
return false;
}
const pthread_t pthread_id = ::pthread_self();
const tid_t kernel_thread_id = ::thread_self();
// OSThread::thread_id is the pthread id.
osthread->set_thread_id(pthread_id);
// .. but keep kernel thread id too for diagnostics
osthread->set_kernel_thread_id(kernel_thread_id);
// initialize floating point control register
os::Aix::init_thread_fpu_state();
// Initial thread state is RUNNABLE
osthread->set_state(RUNNABLE);
thread->set_osthread(osthread);
// initialize signal mask for this thread
// and save the caller's signal mask
PosixSignals::hotspot_sigmask(thread);
log_info(os, thread)("Thread attached (tid: %zu, kernel thread id: %zu"
", stack: " PTR_FORMAT " - " PTR_FORMAT " (%zuK) ).",
os::current_thread_id(), (uintx) kernel_thread_id,
p2i(thread->stack_base()), p2i(thread->stack_end()), thread->stack_size() / K);
return true;
}
void os::pd_start_thread(Thread* thread) {
int status = pthread_continue_np(thread->osthread()->pthread_id());
assert(status == 0, "thr_continue failed");
}
// Free OS resources related to the OSThread
void os::free_thread(OSThread* osthread) {
assert(osthread != nullptr, "osthread not set");
// We are told to free resources of the argument thread, but we can only really operate
// on the current thread. The current thread may be already detached at this point.
assert(Thread::current_or_null() == nullptr || Thread::current()->osthread() == osthread,
"os::free_thread but not current thread");
// Restore caller's signal mask
sigset_t sigmask = osthread->caller_sigmask();
pthread_sigmask(SIG_SETMASK, &sigmask, nullptr);
delete osthread;
}
////////////////////////////////////////////////////////////////////////////////
// time support
double os::elapsedVTime() {
struct rusage usage;
int retval = getrusage(RUSAGE_THREAD, &usage);
if (retval == 0) {
return usage.ru_utime.tv_sec + usage.ru_stime.tv_sec + (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000.0 * 1000);
} else {
// better than nothing, but not much
return elapsedTime();
}
}
// We use mread_real_time here.
// On AIX: If the CPU has a time register, the result will be RTC_POWER and
// it has to be converted to real time. AIX documentations suggests to do
// this unconditionally, so we do it.
//
// See: https://www.ibm.com/support/knowledgecenter/ssw_aix_61/com.ibm.aix.basetrf2/read_real_time.htm
//
jlong os::javaTimeNanos() {
timebasestruct_t time;
int rc = mread_real_time(&time, TIMEBASE_SZ);
if (rc != RTC_POWER) {
rc = time_base_to_time(&time, TIMEBASE_SZ);
assert(rc != -1, "error calling time_base_to_time()");
}
return jlong(time.tb_high) * NANOSECS_PER_SEC + jlong(time.tb_low);
}
void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
info_ptr->max_value = all_bits_jlong;
// mread_real_time() is monotonic (see 'os::javaTimeNanos()')
info_ptr->may_skip_backward = false;
info_ptr->may_skip_forward = false;
info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
}
intx os::current_thread_id() {
return (intx)pthread_self();
}
int os::current_process_id() {
return getpid();
}
// DLL functions
// This must be hard coded because it's the system's temporary
// directory not the java application's temp directory, ala java.io.tmpdir.
const char* os::get_temp_directory() { return "/tmp"; }
void os::prepare_native_symbols() {
LoadedLibraries::reload();
}
// Check if addr is inside libjvm.so.
bool os::address_is_in_vm(address addr) {
// Input could be a real pc or a function pointer literal. The latter
// would be a function descriptor residing in the data segment of a module.
loaded_module_t lm;
if (LoadedLibraries::find_for_text_address(addr, &lm)) {
return lm.is_in_vm;
} else if (LoadedLibraries::find_for_data_address(addr, &lm)) {
return lm.is_in_vm;
} else {
return false;
}
}
// Resolve an AIX function descriptor literal to a code pointer.
// If the input is a valid code pointer to a text segment of a loaded module,
// it is returned unchanged.
// If the input is a valid AIX function descriptor, it is resolved to the
// code entry point.
// If the input is neither a valid function descriptor nor a valid code pointer,
// null is returned.
static address resolve_function_descriptor_to_code_pointer(address p) {
if (LoadedLibraries::find_for_text_address(p, nullptr)) {
// It is a real code pointer.
return p;
} else if (LoadedLibraries::find_for_data_address(p, nullptr)) {
// Pointer to data segment, potential function descriptor.
address code_entry = (address)(((FunctionDescriptor*)p)->entry());
if (LoadedLibraries::find_for_text_address(code_entry, nullptr)) {
// It is a function descriptor.
return code_entry;
}
}
return nullptr;
}
bool os::dll_address_to_function_name(address addr, char *buf,
int buflen, int *offset,
bool demangle) {
if (offset) {
*offset = -1;
}
// Buf is not optional, but offset is optional.
assert(buf != nullptr, "sanity check");
buf[0] = '\0';
// Resolve function ptr literals first.
addr = resolve_function_descriptor_to_code_pointer(addr);
if (!addr) {
return false;
}
return AixSymbols::get_function_name(addr, buf, buflen, offset, nullptr, demangle);
}
bool os::dll_address_to_library_name(address addr, char* buf,
int buflen, int* offset) {
if (offset) {
*offset = -1;
}
// Buf is not optional, but offset is optional.
assert(buf != nullptr, "sanity check");
buf[0] = '\0';
// Resolve function ptr literals first.
addr = resolve_function_descriptor_to_code_pointer(addr);
if (!addr) {
return false;
}
address base = nullptr;
if (!AixSymbols::get_module_name_and_base(addr, buf, buflen, &base)
|| base == nullptr) {
return false;
}
assert(addr >= base && addr <= base + INT_MAX, "address not in library text range");
if (offset != nullptr) {
*offset = addr - base;
}
return true;
}
static void* dll_load_library(const char *filename, int *eno, char *ebuf, int ebuflen) {
log_info(os)("attempting shared library load of %s", filename);
if (ebuf && ebuflen > 0) {
ebuf[0] = '\0';
ebuf[ebuflen - 1] = '\0';
}
if (!filename || strlen(filename) == 0) {
if (ebuf != nullptr && ebuflen > 0) {
::strncpy(ebuf, "dll_load: empty filename specified", ebuflen - 1);
}
return nullptr;
}
// RTLD_LAZY has currently the same behavior as RTLD_NOW
// The dl is loaded immediately with all its dependants.
int dflags = RTLD_LAZY;
// check for filename ending with ')', it indicates we want to load
// a MEMBER module that is a member of an archive.
int flen = strlen(filename);
if (flen > 0 && filename[flen - 1] == ')') {
dflags |= RTLD_MEMBER;
}
void* result;
const char* error_report = nullptr;
JFR_ONLY(NativeLibraryLoadEvent load_event(filename, &result);)
result = Aix_dlopen(filename, dflags, eno, &error_report);
if (result != nullptr) {
Events::log_dll_message(nullptr, "Loaded shared library %s", filename);
// Reload dll cache. Don't do this in signal handling.
LoadedLibraries::reload();
log_info(os)("shared library load of %s was successful", filename);
return result;
} else {
// error analysis when dlopen fails
if (error_report == nullptr) {
error_report = "dlerror returned no error description";
}
if (ebuf != nullptr && ebuflen > 0) {
snprintf(ebuf, ebuflen - 1, "%s, LIBPATH=%s, LD_LIBRARY_PATH=%s : %s",
filename, ::getenv("LIBPATH"), ::getenv("LD_LIBRARY_PATH"), error_report);
}
Events::log_dll_message(nullptr, "Loading shared library %s failed, %s", filename, error_report);
log_info(os)("shared library load of %s failed, %s", filename, error_report);
JFR_ONLY(load_event.set_error_msg(error_report);)
}
return nullptr;
}
// Load library named <filename>
// If filename matches <name>.so, and loading fails, repeat with <name>.a.
void *os::dll_load(const char *filename, char *ebuf, int ebuflen) {
void* result = nullptr;
const char old_extension[] = ".so";
const char new_extension[] = ".a";
// First try to load the existing file.
int eno = 0;
result = dll_load_library(filename, &eno, ebuf, ebuflen);
// If the load fails, we try to reload by changing the extension to .a for .so files only.
// Shared object in .so format dont have braces, hence they get removed for archives with members.
if (result == nullptr && eno == ENOENT) {
const char* pointer_to_dot = strrchr(filename, '.');
if (pointer_to_dot != nullptr && strcmp(pointer_to_dot, old_extension) == 0) {
STATIC_ASSERT(sizeof(old_extension) >= sizeof(new_extension));
char* tmp_path = os::strdup(filename);
size_t prefix_size = pointer_delta(pointer_to_dot, filename, 1);
os::snprintf(tmp_path + prefix_size, sizeof(old_extension), "%s", new_extension);
result = dll_load_library(tmp_path, &eno, ebuf, ebuflen);
os::free(tmp_path);
}
}
return result;
}
void os::print_dll_info(outputStream *st) {
st->print_cr("Dynamic libraries:");
LoadedLibraries::print(st);
}
void os::get_summary_os_info(char* buf, size_t buflen) {
// There might be something more readable than uname results for AIX.
struct utsname name;
uname(&name);
snprintf(buf, buflen, "%s %s", name.release, name.version);
}
int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
if (!LoadedLibraries::for_each(callback, param)) {
return -1;
}
return 0;
}
void os::print_os_info_brief(outputStream* st) {
uint32_t ver = os::Aix::os_version();
st->print_cr("AIX kernel version %u.%u.%u.%u",
(ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
os::Posix::print_uname_info(st);
// Linux uses print_libversion_info(st); here.
}
void os::print_os_info(outputStream* st) {
st->print_cr("OS:");
os::Posix::print_uname_info(st);
uint32_t ver = os::Aix::os_version();
st->print_cr("AIX kernel version %u.%u.%u.%u",
(ver >> 24) & 0xFF, (ver >> 16) & 0xFF, (ver >> 8) & 0xFF, ver & 0xFF);
os::Posix::print_uptime_info(st);
os::Posix::print_rlimit_info(st);
os::Posix::print_load_average(st);
// _SC_THREAD_THREADS_MAX is the maximum number of threads within a process.
long tmax = sysconf(_SC_THREAD_THREADS_MAX);
st->print_cr("maximum #threads within a process:%ld", tmax);
// print wpar info
libperfstat::wparinfo_t wi;
if (libperfstat::get_wparinfo(&wi)) {
st->print_cr("wpar info");
st->print_cr("name: %s", wi.name);
st->print_cr("id: %d", wi.wpar_id);
st->print_cr("type: %s", (wi.app_wpar ? "application" : "system"));
}
VM_Version::print_platform_virtualization_info(st);
}
void os::print_memory_info(outputStream* st) {
st->print_cr("Memory:");
st->print_cr(" Base page size (sysconf _SC_PAGESIZE): %s",
describe_pagesize(g_multipage_support.pagesize));
st->print_cr(" Data page size (C-Heap, bss, etc): %s",
describe_pagesize(g_multipage_support.datapsize));
st->print_cr(" Text page size: %s",
describe_pagesize(g_multipage_support.textpsize));
st->print_cr(" Thread stack page size (pthread): %s",
describe_pagesize(g_multipage_support.pthr_stack_pagesize));
st->print_cr(" Can use 64K pages with mmap memory: %s",
(g_multipage_support.can_use_64K_mmap_pages ? "yes" :"no"));
st->print_cr(" Default shared memory page size: %s",
describe_pagesize(g_multipage_support.shmpsize));
st->print_cr(" Can use 64K pages dynamically with shared memory: %s",
(g_multipage_support.can_use_64K_pages ? "yes" :"no"));
st->print_cr(" Can use 16M pages dynamically with shared memory: %s",
(g_multipage_support.can_use_16M_pages ? "yes" :"no"));
st->print_cr(" Multipage error: %d",
g_multipage_support.error);
st->cr();
st->print_cr(" os::vm_page_size: %s", describe_pagesize(os::vm_page_size()));
// print out LDR_CNTRL because it affects the default page sizes
const char* const ldr_cntrl = ::getenv("LDR_CNTRL");
st->print_cr(" LDR_CNTRL=%s.", ldr_cntrl ? ldr_cntrl : "<unset>");
// Print out EXTSHM because it is an unsupported setting.
const char* const extshm = ::getenv("EXTSHM");
st->print_cr(" EXTSHM=%s.", extshm ? extshm : "<unset>");
if ( (strcmp(extshm, "on") == 0) || (strcmp(extshm, "ON") == 0) ) {
st->print_cr(" *** Unsupported! Please remove EXTSHM from your environment! ***");
}
// Print out AIXTHREAD_GUARDPAGES because it affects the size of pthread stacks.
const char* const aixthread_guardpages = ::getenv("AIXTHREAD_GUARDPAGES");
st->print_cr(" AIXTHREAD_GUARDPAGES=%s.",
aixthread_guardpages ? aixthread_guardpages : "<unset>");
st->cr();
os::Aix::meminfo_t mi;
if (os::Aix::get_meminfo(&mi)) {
st->print_cr("physical total : %zu", mi.real_total);
st->print_cr("physical free : %zu", mi.real_free);
st->print_cr("swap total : %zu", mi.pgsp_total);
st->print_cr("swap free : %zu", mi.pgsp_free);
}
st->cr();
// Print program break.
st->print_cr("Program break at VM startup: " PTR_FORMAT ".", p2i(g_brk_at_startup));
address brk_now = (address)::sbrk(0);
if (brk_now != (address)-1) {
st->print_cr("Program break now : " PTR_FORMAT " (distance: %zuk).",
p2i(brk_now), (size_t)((brk_now - g_brk_at_startup) / K));
}
st->print_cr("MaxExpectedDataSegmentSize : %zuk.", MaxExpectedDataSegmentSize / K);
st->cr();
// Print segments allocated with os::reserve_memory.
st->print_cr("internal virtual memory regions used by vm:");
vmembk_print_on(st);
}
// Get a string for the cpuinfo that is a summary of the cpu type
void os::get_summary_cpu_info(char* buf, size_t buflen) {
// read _system_configuration.version
switch (_system_configuration.version) {
case PV_11:
strncpy(buf, "Power PC 11", buflen);
break;
case PV_10:
strncpy(buf, "Power PC 10", buflen);
break;
case PV_9:
strncpy(buf, "Power PC 9", buflen);
break;
case PV_8:
strncpy(buf, "Power PC 8", buflen);
break;
case PV_8_Compat:
strncpy(buf, "PV_8_Compat", buflen);
break;
case PV_9_Compat:
strncpy(buf, "PV_9_Compat", buflen);
break;
case PV_10_Compat:
strncpy(buf, "PV_10_Compat", buflen);
break;
case PV_11_Compat:
strncpy(buf, "PV_11_Compat", buflen);
break;
default:
strncpy(buf, "unknown", buflen);
}
}
void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
// Nothing to do beyond of what os::print_cpu_info() does.
}
static char saved_jvm_path[MAXPATHLEN] = {0};
// Find the full path to the current module, libjvm.so.
void os::jvm_path(char *buf, jint buflen) {
// Error checking.
if (buflen < MAXPATHLEN) {
assert(false, "must use a large-enough buffer");
buf[0] = '\0';
return;
}
// Lazy resolve the path to current module.
if (saved_jvm_path[0] != 0) {
strcpy(buf, saved_jvm_path);
return;
}
Dl_info dlinfo;
int ret = dladdr(CAST_FROM_FN_PTR(void *, os::jvm_path), &dlinfo);
assert(ret != 0, "cannot locate libjvm");
char* rp = os::realpath((char *)dlinfo.dli_fname, buf, buflen);
assert(rp != nullptr, "error in realpath(): maybe the 'path' argument is too long?");
// If executing unit tests we require JAVA_HOME to point to the real JDK.
if (Arguments::executing_unit_tests()) {
// Look for JAVA_HOME in the environment.
char* java_home_var = ::getenv("JAVA_HOME");
if (java_home_var != nullptr && java_home_var[0] != 0) {
// Check the current module name "libjvm.so".
const char* p = strrchr(buf, '/');
if (p == nullptr) {
return;
}
assert(strstr(p, "/libjvm") == p, "invalid library name");
stringStream ss(buf, buflen);
rp = os::realpath(java_home_var, buf, buflen);
if (rp == nullptr) {
return;
}
assert((int)strlen(buf) < buflen, "Ran out of buffer room");
ss.print("%s/lib", buf);
if (0 == access(buf, F_OK)) {
// Use current module name "libjvm.so"
ss.print("/%s/libjvm%s", Abstract_VM_Version::vm_variant(), JNI_LIB_SUFFIX);
assert(strcmp(buf + strlen(buf) - strlen(JNI_LIB_SUFFIX), JNI_LIB_SUFFIX) == 0,
"buf has been truncated");
} else {
// Go back to path of .so
rp = os::realpath((char *)dlinfo.dli_fname, buf, buflen);
if (rp == nullptr) {
return;
}
}
}
}
strncpy(saved_jvm_path, buf, sizeof(saved_jvm_path));
saved_jvm_path[sizeof(saved_jvm_path) - 1] = '\0';
}
////////////////////////////////////////////////////////////////////////////////
// Virtual Memory
// We need to keep small simple bookkeeping for os::reserve_memory and friends.
#define VMEM_MAPPED 1
#define VMEM_SHMATED 2
struct vmembk_t {
int type; // 1 - mmap, 2 - shmat
char* addr;
size_t size; // Real size, may be larger than usersize.
size_t pagesize; // page size of area
vmembk_t* next;
bool contains_addr(char* p) const {
return p >= addr && p < (addr + size);
}
bool contains_range(char* p, size_t s) const {
return contains_addr(p) && contains_addr(p + s - 1);
}
void print_on(outputStream* os) const {
os->print("[" PTR_FORMAT " - " PTR_FORMAT "] (%zu"
" bytes, %ld %s pages), %s",
p2i(addr), p2i(addr) + size - 1, size, size / pagesize, describe_pagesize(pagesize),
(type == VMEM_SHMATED ? "shmat" : "mmap")
);
}
// Check that range is a sub range of memory block (or equal to memory block);
// also check that range is fully page aligned to the page size if the block.
void assert_is_valid_subrange(char* p, size_t s) const {
if (!contains_range(p, s)) {
fatal(RANGEFMT " is not a sub range of " RANGEFMT, RANGEFMTARGS(p, s),
RANGEFMTARGS(addr, size));
}
if (!is_aligned_to(p, pagesize) || !is_aligned_to(p + s, pagesize)) {
fatal("range " RANGEFMT " is not aligned to pagesize (%lu)",
RANGEFMTARGS(p, s), (unsigned long)pagesize);
}
}
};
static struct {
vmembk_t* first;
MiscUtils::CritSect cs;
} vmem;
static void vmembk_add(char* addr, size_t size, size_t pagesize, int type) {
vmembk_t* p = (vmembk_t*) permit_forbidden_function::malloc(sizeof(vmembk_t));
assert0(p);
if (p) {
MiscUtils::AutoCritSect lck(&vmem.cs);
p->addr = addr; p->size = size;
p->pagesize = pagesize;
p->type = type;
p->next = vmem.first;
vmem.first = p;
}
}
static vmembk_t* vmembk_find(char* addr) {
MiscUtils::AutoCritSect lck(&vmem.cs);
for (vmembk_t* p = vmem.first; p; p = p->next) {
if (p->addr <= addr && (p->addr + p->size) > addr) {
return p;
}
}
return nullptr;
}
static void vmembk_remove(vmembk_t* p0) {
MiscUtils::AutoCritSect lck(&vmem.cs);
assert0(p0);
assert0(vmem.first); // List should not be empty.
for (vmembk_t** pp = &(vmem.first); *pp; pp = &((*pp)->next)) {
if (*pp == p0) {
*pp = p0->next;
permit_forbidden_function::free(p0);
return;
}
}
assert0(false); // Not found?
}
static void vmembk_print_on(outputStream* os) {
MiscUtils::AutoCritSect lck(&vmem.cs);
for (vmembk_t* vmi = vmem.first; vmi; vmi = vmi->next) {
vmi->print_on(os);
os->cr();
}
}
// Reserve and attach a section of System V memory.
// If <requested_addr> is not null, function will attempt to attach the memory at the given
// address. Failing that, it will attach the memory anywhere.
// If <requested_addr> is null, function will attach the memory anywhere.
static char* reserve_shmated_memory (size_t bytes, char* requested_addr) {
trcVerbose("reserve_shmated_memory %zu bytes, wishaddress "
PTR_FORMAT "...", bytes, p2i(requested_addr));
// We must prevent anyone from attaching too close to the
// BRK because that may cause malloc OOM.
if (requested_addr != nullptr && is_close_to_brk((address)requested_addr)) {
log_info(os, map)("Wish address " PTR_FORMAT
" is too close to the BRK segment.",
p2i(requested_addr));
// Since we treat an attach to the wrong address as an error later anyway,
// we return null here
return nullptr;
}
// Align size of shm up to 64K to avoid errors if we later try to change the page size.
const size_t size = align_up(bytes, 64*K);
// Reserve the shared segment.
int shmid = shmget(IPC_PRIVATE, size, IPC_CREAT | S_IRUSR | S_IWUSR);
if (shmid == -1) {
ErrnoPreserver ep;
log_trace(os, map)("shmget(.., %zu, ..) failed (errno=%s).",
size, os::strerror(ep.saved_errno()));
return nullptr;
}
// Important note:
// It is very important that we, upon leaving this function, do not leave a shm segment alive.
// We must right after attaching it remove it from the system. System V shm segments are global and
// survive the process.
// So, from here on: Do not assert, do not return, until we have called shmctl(IPC_RMID) (A).
struct shmid_ds shmbuf;
memset(&shmbuf, 0, sizeof(shmbuf));
shmbuf.shm_pagesize = 64*K;
if (shmctl(shmid, SHM_PAGESIZE, &shmbuf) != 0) {
assert(false,
"Failed to set page size (need %zu"
" 64K pages) - shmctl failed. (errno=%s).",
size / (64 * K), os::strerror(os::get_last_error()));
}
// Now attach the shared segment.
// Note that we deliberately *don't* pass SHM_RND. The contract of os::attempt_reserve_memory_at() -
// which invokes this function with a request address != nullptr - is to map at the specified address
// excactly, or to fail. If the caller passed us an address that is not usable (aka not a valid segment
// boundary), shmat should not round down the address, or think up a completely new one.
// (In places where this matters, e.g. when reserving the heap, we take care of passing segment-aligned
// addresses on Aix. See, e.g., ReservedHeapSpace.
char* const addr = (char*) shmat(shmid, requested_addr, 0);
const int errno_shmat = errno;
// (A) Right after shmat and before handing shmat errors delete the shm segment.
if (::shmctl(shmid, IPC_RMID, nullptr) == -1) {
ErrnoPreserver ep;
log_trace(os, map)("shmctl(%u, IPC_RMID) failed (errno=%s)\n",
shmid,
os::strerror(ep.saved_errno()));
assert(false, "failed to remove shared memory segment!");
}
// Handle shmat error. If we failed to attach, just return.
if (addr == (char*)-1) {
ErrnoPreserver ep;
log_trace(os, map)("Failed to attach segment at " PTR_FORMAT " (errno=%s).",
p2i(requested_addr),
os::strerror(ep.saved_errno()));
return nullptr;
}
// Just for info: query the real page size. In case setting the page size did not
// work (see above), the system may have given us something other then 4K (LDR_CNTRL).
const size_t real_pagesize = os::Aix::query_pagesize(addr);
if (real_pagesize != (size_t)shmbuf.shm_pagesize) {
log_trace(os, map)("pagesize is, surprisingly, %zu",
real_pagesize);
}
if (addr) {
log_trace(os, map)("shm-allocated succeeded: " RANGEFMT
" (%zu %s pages)",
RANGEFMTARGS(addr, size),
size / real_pagesize,
describe_pagesize(real_pagesize));
} else {
if (requested_addr != nullptr) {
log_trace(os, map)("shm-allocate failed: " RANGEFMT,
RANGEFMTARGS(requested_addr, size));
} else {
log_trace(os, map)("failed to shm-allocate %zu"
" bytes at any address.",
size);
}
}
// book-keeping
vmembk_add(addr, size, real_pagesize, VMEM_SHMATED);
assert0(is_aligned_to(addr, os::vm_page_size()));
return addr;
}
static bool release_shmated_memory(char* addr, size_t size) {
trcVerbose("release_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
p2i(addr), p2i(addr + size - 1));
bool rc = false;
// TODO: is there a way to verify shm size without doing bookkeeping?
if (::shmdt(addr) != 0) {
ErrnoPreserver ep;
log_trace(os, map)("shmdt failed: " RANGEFMT " errno=(%s)",
RANGEFMTARGS(addr, size),
os::strerror(ep.saved_errno()));
} else {
log_trace(os, map)("shmdt succeded: " RANGEFMT,
RANGEFMTARGS(addr, size));
rc = true;
}
return rc;
}
static bool uncommit_shmated_memory(char* addr, size_t size) {
trcVerbose("uncommit_shmated_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
p2i(addr), p2i(addr + size - 1));
const int rc = disclaim64(addr, size, DISCLAIM_ZEROMEM);
if (rc != 0) {
ErrnoPreserver ep;
log_warning(os)("disclaim64(" PTR_FORMAT ", %zu) failed, %s\n", p2i(addr), size, os::strerror(ep.saved_errno()));
return false;
}
return true;
}
//////////////////////////////// mmap-based routines /////////////////////////////////
// Reserve memory via mmap.
// If <requested_addr> is given, an attempt is made to attach at the given address.
// Failing that, memory is allocated at any address.
static char* reserve_mmaped_memory(size_t bytes, char* requested_addr) {
trcVerbose("reserve_mmaped_memory %zu bytes, wishaddress " PTR_FORMAT "...",
bytes, p2i(requested_addr));
if (requested_addr && !is_aligned_to(requested_addr, os::vm_page_size()) != 0) {
log_trace(os, map)("Wish address " PTR_FORMAT
" not aligned to page boundary.",
p2i(requested_addr));
return nullptr;
}
// We must prevent anyone from attaching too close to the
// BRK because that may cause malloc OOM.
if (requested_addr != nullptr && is_close_to_brk((address)requested_addr)) {
log_trace(os, map)("Wish address " PTR_FORMAT
" is too close to the BRK segment.",
p2i(requested_addr));
// Since we treat an attach to the wrong address as an error later anyway,
// we return null here
return nullptr;
}
// In 64K mode, we lie and claim the global page size (os::vm_page_size()) is 64K
// (complicated story). This mostly works just fine since 64K is a multiple of the
// actual 4K lowest page size. Only at a few seams light shines thru, e.g. when
// calling mmap. mmap will return memory aligned to the lowest pages size - 4K -
// so we must make sure - transparently - that the caller only ever sees 64K
// aligned mapping start addresses.
const size_t alignment = os::vm_page_size();
// Size shall always be a multiple of os::vm_page_size (esp. in 64K mode).
const size_t size = align_up(bytes, os::vm_page_size());
// alignment: Allocate memory large enough to include an aligned range of the right size and
// cut off the leading and trailing waste pages.
assert0(alignment != 0 && is_aligned_to(alignment, os::vm_page_size())); // see above
const size_t extra_size = size + alignment;
// Note: MAP_SHARED (instead of MAP_PRIVATE) needed to be able to
// later use msync(MS_INVALIDATE) (see os::uncommit_memory).
int flags = MAP_ANONYMOUS | MAP_SHARED;
if (os::vm_page_size() == 64*K && g_multipage_support.can_use_64K_mmap_pages) {
flags |= MAP_ANON_64K;
}
// MAP_FIXED is needed to enforce requested_addr - manpage is vague about what
// it means if wishaddress is given but MAP_FIXED is not set.
//
// Important! Behaviour differs depending on whether SPEC1170 mode is active or not.
// SPEC1170 mode active: behaviour like POSIX, MAP_FIXED will clobber existing mappings.
// SPEC1170 mode not active: behaviour, unlike POSIX, is that no existing mappings will
// get clobbered.
if (requested_addr != nullptr) {
if (!os::Aix::xpg_sus_mode()) { // not SPEC1170 Behaviour
flags |= MAP_FIXED;
}
}
char* addr = (char*)::mmap(requested_addr, extra_size,
PROT_READ|PROT_WRITE|PROT_EXEC, flags, -1, 0);
if (addr == MAP_FAILED) {
ErrnoPreserver ep;
log_trace(os, map)("mmap failed: " RANGEFMT " errno=(%s)",
RANGEFMTARGS(requested_addr, size),
os::strerror(ep.saved_errno()));
return nullptr;
} else if (requested_addr != nullptr && addr != requested_addr) {
log_trace(os, map)("mmap succeeded: " RANGEFMT
", but at a different address than"
"requested (" PTR_FORMAT "), will unmap",
RANGEFMTARGS(requested_addr, size),
p2i(addr));
::munmap(addr, extra_size);
return nullptr;
}
// Handle alignment.
char* const addr_aligned = align_up(addr, alignment);
const size_t waste_pre = addr_aligned - addr;
char* const addr_aligned_end = addr_aligned + size;
const size_t waste_post = extra_size - waste_pre - size;
if (waste_pre > 0) {
::munmap(addr, waste_pre);
}
if (waste_post > 0) {
::munmap(addr_aligned_end, waste_post);
}
addr = addr_aligned;
trcVerbose("mmap-allocated " PTR_FORMAT " .. " PTR_FORMAT " (%zu bytes)",
p2i(addr), p2i(addr + bytes), bytes);
// bookkeeping
if (os::vm_page_size() == 64*K && g_multipage_support.can_use_64K_mmap_pages) {
vmembk_add(addr, size, 64*K, VMEM_MAPPED);
} else {
vmembk_add(addr, size, 4*K, VMEM_MAPPED);
}
// Test alignment, see above.
assert0(is_aligned_to(addr, os::vm_page_size()));
return addr;
}
static bool release_mmaped_memory(char* addr, size_t size) {
assert0(is_aligned_to(addr, os::vm_page_size()));
assert0(is_aligned_to(size, os::vm_page_size()));
trcVerbose("release_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
p2i(addr), p2i(addr + size - 1));
bool rc = false;
if (::munmap(addr, size) != 0) {
ErrnoPreserver ep;
log_trace(os, map)("munmap failed: " RANGEFMT " errno=(%s)",
RANGEFMTARGS(addr, size),
os::strerror(ep.saved_errno()));
rc = false;
} else {
log_trace(os, map)("munmap succeeded: " RANGEFMT,
RANGEFMTARGS(addr, size));
rc = true;
}
return rc;
}
static bool uncommit_mmaped_memory(char* addr, size_t size) {
assert0(is_aligned_to(addr, os::vm_page_size()));
assert0(is_aligned_to(size, os::vm_page_size()));
trcVerbose("uncommit_mmaped_memory [" PTR_FORMAT " - " PTR_FORMAT "].",
p2i(addr), p2i(addr + size - 1));
bool rc = false;
// Uncommit mmap memory with msync MS_INVALIDATE.
if (::msync(addr, size, MS_INVALIDATE) != 0) {
ErrnoPreserver ep;
log_trace(os, map)("msync failed: " RANGEFMT " errno=(%s)",
RANGEFMTARGS(addr, size),
os::strerror(ep.saved_errno()));
rc = false;
} else {
log_trace(os, map)("msync succeeded: " RANGEFMT,
RANGEFMTARGS(addr, size));
rc = true;
}
return rc;
}
#ifdef PRODUCT
static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
int err) {
warning("INFO: os::commit_memory(" PTR_FORMAT ", %zu, %d) failed; error='%s' (errno=%d)",
p2i(addr), size, exec, os::errno_name(err), err);
}
#endif
void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
const char* mesg) {
assert(mesg != nullptr, "mesg must be specified");
if (!pd_commit_memory(addr, size, exec)) {
// Add extra info in product mode for vm_exit_out_of_memory():
PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
}
}
bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
assert(is_aligned_to(addr, os::vm_page_size()),
"addr " PTR_FORMAT " not aligned to vm_page_size (%zu)",
p2i(addr), os::vm_page_size());
assert(is_aligned_to(size, os::vm_page_size()),
"size " PTR_FORMAT " not aligned to vm_page_size (%zu)",
size, os::vm_page_size());
vmembk_t* const vmi = vmembk_find(addr);
guarantee0(vmi);
vmi->assert_is_valid_subrange(addr, size);
log_info(os)("commit_memory [" PTR_FORMAT " - " PTR_FORMAT "].", p2i(addr), p2i(addr + size - 1));
if (UseExplicitCommit) {
// AIX commits memory on touch. So, touch all pages to be committed.
for (char* p = addr; p < (addr + size); p += 4*K) {
*p = '\0';
}
}
return true;
}
bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, bool exec) {
return pd_commit_memory(addr, size, exec);
}
void os::pd_commit_memory_or_exit(char* addr, size_t size,
size_t alignment_hint, bool exec,
const char* mesg) {
// Alignment_hint is ignored on this OS.
pd_commit_memory_or_exit(addr, size, exec, mesg);
}
bool os::pd_uncommit_memory(char* addr, size_t size, bool exec) {
assert(is_aligned_to(addr, os::vm_page_size()),
"addr " PTR_FORMAT " not aligned to vm_page_size (%zu)",
p2i(addr), os::vm_page_size());
assert(is_aligned_to(size, os::vm_page_size()),
"size " PTR_FORMAT " not aligned to vm_page_size (%zu)",
size, os::vm_page_size());
// Dynamically do different things for mmap/shmat.
const vmembk_t* const vmi = vmembk_find(addr);
guarantee0(vmi);
vmi->assert_is_valid_subrange(addr, size);
if (vmi->type == VMEM_SHMATED) {
return uncommit_shmated_memory(addr, size);
} else {
return uncommit_mmaped_memory(addr, size);
}
}
bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
// Do not call this; no need to commit stack pages on AIX.
ShouldNotReachHere();
return true;
}
bool os::remove_stack_guard_pages(char* addr, size_t size) {
// Do not call this; no need to commit stack pages on AIX.
ShouldNotReachHere();
return true;
}
void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
}
void os::pd_disclaim_memory(char *addr, size_t bytes) {
}
size_t os::pd_pretouch_memory(void* first, void* last, size_t page_size) {
return page_size;
}
void os::numa_make_global(char *addr, size_t bytes) {
}
void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
}
bool os::numa_topology_changed() {
return false;
}
size_t os::numa_get_groups_num() {
return 1;
}
int os::numa_get_group_id() {
return 0;
}
size_t os::numa_get_leaf_groups(uint *ids, size_t size) {
if (size > 0) {
ids[0] = 0;
return 1;
}
return 0;
}
int os::numa_get_group_id_for_address(const void* address) {
return 0;
}
bool os::numa_get_group_ids_for_range(const void** addresses, int* lgrp_ids, size_t count) {
return false;
}
// Reserves and attaches a shared memory segment.
char* os::pd_reserve_memory(size_t bytes, bool exec) {
// Always round to os::vm_page_size(), which may be larger than 4K.
bytes = align_up(bytes, os::vm_page_size());
// In 4K mode always use mmap.
// In 64K mode allocate with mmap if it supports 64K pages, otherwise use 64K shmatted.
if (os::vm_page_size() == 4*K || g_multipage_support.can_use_64K_mmap_pages) {
return reserve_mmaped_memory(bytes, nullptr /* requested_addr */);
} else {
return reserve_shmated_memory(bytes, nullptr /* requested_addr */);
}
}
bool os::pd_release_memory(char* addr, size_t size) {
// Dynamically do different things for mmap/shmat.
vmembk_t* const vmi = vmembk_find(addr);
guarantee0(vmi);
vmi->assert_is_valid_subrange(addr, size);
// Always round to os::vm_page_size(), which may be larger than 4K.
size = align_up(size, os::vm_page_size());
addr = align_up(addr, os::vm_page_size());
bool rc = false;
bool remove_bookkeeping = false;
if (vmi->type == VMEM_SHMATED) {
// For shmatted memory, we do:
// - If user wants to release the whole range, release the memory (shmdt).
// - If user only wants to release a partial range, uncommit (disclaim) that
// range. That way, at least, we do not use memory anymore (bust still page
// table space).
if (addr == vmi->addr && size == vmi->size) {
rc = release_shmated_memory(addr, size);
remove_bookkeeping = true;
} else {
rc = uncommit_shmated_memory(addr, size);
}
} else {
// In mmap-mode:
// - If the user wants to release the full range, we do that and remove the mapping.
// - If the user wants to release part of the range, we release that part, but need
// to adjust bookkeeping.
assert(is_aligned(size, 4 * K), "Sanity");
rc = release_mmaped_memory(addr, size);
if (addr == vmi->addr && size == vmi->size) {
remove_bookkeeping = true;
} else {
if (addr == vmi->addr && size < vmi->size) {
// Chopped from head
vmi->addr += size;
vmi->size -= size;
} else if (addr + size == vmi->addr + vmi->size) {
// Chopped from tail
vmi->size -= size;
} else {
// releasing a mapping in the middle of the original mapping:
// For now we forbid this, since this is an invalid scenario
// (the bookkeeping is easy enough to fix if needed but there
// is no use case for it; any occurrence is likely an error.
ShouldNotReachHere();
}
}
}
// update bookkeeping
if (rc && remove_bookkeeping) {
vmembk_remove(vmi);
}
return rc;
}
static bool checked_mprotect(char* addr, size_t size, int prot) {
// Little problem here: if SPEC1170 behaviour is off, mprotect() on AIX will
// not tell me if protection failed when trying to protect an un-protectable range.
//
// This means if the memory was allocated using shmget/shmat, protection won't work
// but mprotect will still return 0:
//
// See http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf1/mprotect.htm
Events::log_memprotect(nullptr, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
bool rc = ::mprotect(addr, size, prot) == 0 ? true : false;
if (!rc) {
const char* const s_errno = os::errno_name(errno);
warning("mprotect(" PTR_FORMAT "-" PTR_FORMAT ", 0x%X) failed (%s).", p2i(addr), p2i(addr) + size, prot, s_errno);
return false;
}
// mprotect success check
//
// Mprotect said it changed the protection but can I believe it?
//
// To be sure I need to check the protection afterwards. Try to
// read from protected memory and check whether that causes a segfault.
//
if (!os::Aix::xpg_sus_mode()) {
const bool read_protected =
(SafeFetch32((int*)addr, 0x12345678) == 0x12345678 &&
SafeFetch32((int*)addr, 0x76543210) == 0x76543210) ? true : false;
if (prot & PROT_READ) {
rc = !read_protected;
} else {
rc = read_protected;
}
}
assert(rc == true, "mprotect failed.");
return rc;
}
// Set protections specified
bool os::protect_memory(char* addr, size_t size, ProtType prot, bool is_committed) {
unsigned int p = 0;
switch (prot) {
case MEM_PROT_NONE: p = PROT_NONE; break;
case MEM_PROT_READ: p = PROT_READ; break;
case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
default:
ShouldNotReachHere();
}
// is_committed is unused.
return checked_mprotect(addr, size, p);
}
bool os::guard_memory(char* addr, size_t size) {
return checked_mprotect(addr, size, PROT_NONE);
}
bool os::unguard_memory(char* addr, size_t size) {
return checked_mprotect(addr, size, PROT_READ|PROT_WRITE|PROT_EXEC);
}
// Large page support
static size_t _large_page_size = 0;
// Enable large page support if OS allows that.
void os::large_page_init() {
return; // Nothing to do. See query_multipage_support and friends.
}
char* os::pd_reserve_memory_special(size_t bytes, size_t alignment, size_t page_size, char* req_addr, bool exec) {
fatal("os::reserve_memory_special should not be called on AIX.");
return nullptr;
}
bool os::pd_release_memory_special(char* base, size_t bytes) {
fatal("os::release_memory_special should not be called on AIX.");
return false;
}
size_t os::large_page_size() {
return _large_page_size;
}
bool os::can_commit_large_page_memory() {
// Does not matter, we do not support huge pages.
return false;
}
char* os::pd_attempt_map_memory_to_file_at(char* requested_addr, size_t bytes, int file_desc) {
assert(file_desc >= 0, "file_desc is not valid");
char* result = nullptr;
// Always round to os::vm_page_size(), which may be larger than 4K.
bytes = align_up(bytes, os::vm_page_size());
result = reserve_mmaped_memory(bytes, requested_addr);
if (result != nullptr) {
if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == nullptr) {
vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
}
}
return result;
}
// Reserve memory at an arbitrary address, only if that area is
// available (and not reserved for something else).
char* os::pd_attempt_reserve_memory_at(char* requested_addr, size_t bytes, bool exec) {
char* addr = nullptr;
// Always round to os::vm_page_size(), which may be larger than 4K.
bytes = align_up(bytes, os::vm_page_size());
// In 4K mode always use mmap.
// In 64K mode allocate with mmap if it supports 64K pages, otherwise use 64K shmatted.
if (os::vm_page_size() == 4*K || g_multipage_support.can_use_64K_mmap_pages) {
return reserve_mmaped_memory(bytes, requested_addr);
} else {
return reserve_shmated_memory(bytes, requested_addr);
}
return addr;
}
size_t os::vm_min_address() {
// On AIX, we need to make sure we don't block the sbrk. However, this is
// done at actual reservation time, where we honor a "no-mmap" area following
// the break. See MaxExpectedDataSegmentSize. So we can return a very low
// address here.
assert(is_aligned(_vm_min_address_default, os::vm_allocation_granularity()), "Sanity");
return _vm_min_address_default;
}
////////////////////////////////////////////////////////////////////////////////
// thread priority support
// From AIX manpage to pthread_setschedparam
// (see: http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?
// topic=/com.ibm.aix.basetechref/doc/basetrf1/pthread_setschedparam.htm):
//
// "If schedpolicy is SCHED_OTHER, then sched_priority must be in the
// range from 40 to 80, where 40 is the least favored priority and 80
// is the most favored."
//
// (Actually, I doubt this even has an impact on AIX, as we do kernel
// scheduling there; however, this still leaves iSeries.)
//
int os::java_to_os_priority[CriticalPriority + 1] = {
54, // 0 Entry should never be used
55, // 1 MinPriority
55, // 2
56, // 3
56, // 4
57, // 5 NormPriority
57, // 6
58, // 7
58, // 8
59, // 9 NearMaxPriority
60, // 10 MaxPriority
60 // 11 CriticalPriority
};
static int prio_init() {
if (ThreadPriorityPolicy == 1) {
if (geteuid() != 0) {
if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy) && !FLAG_IS_JIMAGE_RESOURCE(ThreadPriorityPolicy)) {
warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
"e.g., being the root user. If the necessary permission is not " \
"possessed, changes to priority will be silently ignored.");
}
}
}
if (UseCriticalJavaThreadPriority) {
os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
}
return 0;
}
OSReturn os::set_native_priority(Thread* thread, int newpri) {
if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
pthread_t thr = thread->osthread()->pthread_id();
int policy = SCHED_OTHER;
struct sched_param param;
param.sched_priority = newpri;
int ret = pthread_setschedparam(thr, policy, &param);
if (ret != 0) {
log_warning(os)("Could not change priority for thread %d to %d (error %d, %s)",
(int)thr, newpri, ret, os::errno_name(ret));
}
return (ret == 0) ? OS_OK : OS_ERR;
}
OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
*priority_ptr = java_to_os_priority[NormPriority];
return OS_OK;
}
pthread_t thr = thread->osthread()->pthread_id();
int policy = SCHED_OTHER;
struct sched_param param;
int ret = pthread_getschedparam(thr, &policy, &param);
*priority_ptr = param.sched_priority;
return (ret == 0) ? OS_OK : OS_ERR;
}
// To install functions for atexit system call
extern "C" {
static void perfMemory_exit_helper() {
perfMemory_exit();
}
}
static void set_page_size(size_t page_size) {
OSInfo::set_vm_page_size(page_size);
OSInfo::set_vm_allocation_granularity(page_size);
}
// This is called _before_ the most of global arguments have been parsed.
void os::init(void) {
// This is basic, we want to know if that ever changes.
// (Shared memory boundary is supposed to be a 256M aligned.)
assert(SHMLBA == ((uint64_t)0x10000000ULL)/*256M*/, "unexpected");
// Record process break at startup.
g_brk_at_startup = (address) ::sbrk(0);
assert(g_brk_at_startup != (address) -1, "sbrk failed");
// First off, we need to know the OS level we run on.
os::Aix::initialize_os_info();
// Scan environment (SPEC1170 behaviour, etc).
os::Aix::scan_environment();
// Probe multipage support.
query_multipage_support();
// Act like we only have one page size by eliminating corner cases which
// we did not support very well anyway.
// We have two input conditions:
// 1) Data segment page size. This is controlled by linker setting (datapsize) on the
// launcher, and/or by LDR_CNTRL environment variable. The latter overrules the linker
// setting.
// Data segment page size is important for us because it defines the thread stack page
// size, which is needed for guard page handling, stack banging etc.
// 2) The ability to allocate 64k pages dynamically. If this is a given, java heap can
// and should be allocated with 64k pages.
//
// So, we do the following:
// LDR_CNTRL can_use_64K_pages_dynamically(mmap or shm) what we do remarks
// 4K no 4K old systems (aix 5.2) or new systems with AME activated
// 4k yes 64k (treat 4k stacks as 64k) different loader than java and standard settings
// 64k no --- AIX 5.2 ? ---
// 64k yes 64k new systems and standard java loader (we set datapsize=64k when linking)
// We explicitly leave no option to change page size, because only upgrading would work,
// not downgrading (if stack page size is 64k you cannot pretend its 4k).
if (g_multipage_support.datapsize == 4*K) {
// datapsize = 4K. Data segment, thread stacks are 4K paged.
if (g_multipage_support.can_use_64K_pages || g_multipage_support.can_use_64K_mmap_pages) {
// .. but we are able to use 64K pages dynamically.
// This would be typical for java launchers which are not linked
// with datapsize=64K (like, any other launcher but our own).
//
// In this case it would be smart to allocate the java heap with 64K
// to get the performance benefit, and to fake 64k pages for the
// data segment (when dealing with thread stacks).
//
// However, leave a possibility to downgrade to 4K, using
// -XX:-Use64KPages.
if (Use64KPages) {
trcVerbose("64K page mode (faked for data segment)");
set_page_size(64*K);
} else {
trcVerbose("4K page mode (Use64KPages=off)");
set_page_size(4*K);
}
} else {
// .. and not able to allocate 64k pages dynamically. Here, just
// fall back to 4K paged mode and use mmap for everything.
trcVerbose("4K page mode");
set_page_size(4*K);
FLAG_SET_ERGO(Use64KPages, false);
}
} else {
// datapsize = 64k. Data segment, thread stacks are 64k paged.
// This normally means that we can allocate 64k pages dynamically.
// (There is one special case where this may be false: EXTSHM=on.
// but we decided to not support that mode).
assert0(g_multipage_support.can_use_64K_pages || g_multipage_support.can_use_64K_mmap_pages);
set_page_size(64*K);
trcVerbose("64K page mode");
FLAG_SET_ERGO(Use64KPages, true);
}
// For now UseLargePages is just ignored.
FLAG_SET_ERGO(UseLargePages, false);
_page_sizes.add(os::vm_page_size());
// debug trace
trcVerbose("os::vm_page_size %s", describe_pagesize(os::vm_page_size()));
// Next, we need to initialize libperfstat
os::Aix::initialize_libperfstat();
// Reset the perfstat information provided by ODM.
libperfstat::perfstat_reset();
// Now initialize basic system properties. Note that for some of the values we
// need libperfstat etc.
os::Aix::initialize_system_info();
// _main_thread points to the thread that created/loaded the JVM.
Aix::_main_thread = pthread_self();
os::Posix::init();
}
// This is called _after_ the global arguments have been parsed.
jint os::init_2(void) {
// This could be set after os::Posix::init() but all platforms
// have to set it the same so we have to mirror Solaris.
DEBUG_ONLY(os::set_mutex_init_done();)
os::Posix::init_2();
trcVerbose("processor count: %d", os::_processor_count);
trcVerbose("physical memory: %lu", Aix::_physical_memory);
// Initially build up the loaded dll map.
LoadedLibraries::reload();
if (Verbose) {
trcVerbose("Loaded Libraries: ");
LoadedLibraries::print(tty);
}
if (PosixSignals::init() == JNI_ERR) {
return JNI_ERR;
}
// Check and sets minimum stack sizes against command line options
if (set_minimum_stack_sizes() == JNI_ERR) {
return JNI_ERR;
}
// Not supported.
FLAG_SET_ERGO(UseNUMA, false);
FLAG_SET_ERGO(UseNUMAInterleaving, false);
if (MaxFDLimit) {
// Set the number of file descriptors to max. print out error
// if getrlimit/setrlimit fails but continue regardless.
struct rlimit nbr_files;
int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
if (status != 0) {
log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
} else {
nbr_files.rlim_cur = nbr_files.rlim_max;
status = setrlimit(RLIMIT_NOFILE, &nbr_files);
if (status != 0) {
log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
}
}
}
if (PerfAllowAtExitRegistration) {
// Only register atexit functions if PerfAllowAtExitRegistration is set.
// At exit functions can be delayed until process exit time, which
// can be problematic for embedded VM situations. Embedded VMs should
// call DestroyJavaVM() to assure that VM resources are released.
// Note: perfMemory_exit_helper atexit function may be removed in
// the future if the appropriate cleanup code can be added to the
// VM_Exit VMOperation's doit method.
if (atexit(perfMemory_exit_helper) != 0) {
warning("os::init_2 atexit(perfMemory_exit_helper) failed");
}
}
// initialize thread priority policy
prio_init();
return JNI_OK;
}
int os::active_processor_count() {
// User has overridden the number of active processors
if (ActiveProcessorCount > 0) {
log_trace(os)("active_processor_count: "
"active processor count set by user : %d",
ActiveProcessorCount);
return ActiveProcessorCount;
}
int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
return online_cpus;
}
void os::set_native_thread_name(const char *name) {
// Not yet implemented.
return;
}
////////////////////////////////////////////////////////////////////////////////
// debug support
bool os::find(address addr, outputStream* st) {
st->print(PTR_FORMAT ": ", p2i(addr));
loaded_module_t lm;
if (LoadedLibraries::find_for_text_address(addr, &lm) ||
LoadedLibraries::find_for_data_address(addr, &lm)) {
st->print_cr("%s", lm.path);
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// misc
// This does not do anything on Aix. This is basically a hook for being
// able to use structured exception handling (thread-local exception filters)
// on, e.g., Win32.
void
os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method,
JavaCallArguments* args, JavaThread* thread) {
f(value, method, args, thread);
}
// This code originates from JDK's sysOpen and open64_w
// from src/solaris/hpi/src/system_md.c
int os::open(const char *path, int oflag, int mode) {
if (strlen(path) > MAX_PATH - 1) {
errno = ENAMETOOLONG;
return -1;
}
// AIX 7.X now supports O_CLOEXEC too, like modern Linux; but we have to be careful, see
// IV90804: OPENING A FILE IN AFS WITH O_CLOEXEC FAILS WITH AN EINVAL ERROR APPLIES TO AIX 7100-04 17/04/14 PTF PECHANGE
int oflag_with_o_cloexec = oflag | O_CLOEXEC;
int fd = ::open(path, oflag_with_o_cloexec, mode);
if (fd == -1) {
// we might fail in the open call when O_CLOEXEC is set, so try again without (see IV90804)
fd = ::open(path, oflag, mode);
if (fd == -1) {
return -1;
}
}
// If the open succeeded, the file might still be a directory.
{
struct stat buf64;
int ret = ::fstat(fd, &buf64);
int st_mode = buf64.st_mode;
if (ret != -1) {
if ((st_mode & S_IFMT) == S_IFDIR) {
errno = EISDIR;
::close(fd);
return -1;
}
} else {
::close(fd);
return -1;
}
}
// All file descriptors that are opened in the JVM and not
// specifically destined for a subprocess should have the
// close-on-exec flag set. If we don't set it, then careless 3rd
// party native code might fork and exec without closing all
// appropriate file descriptors (e.g. as we do in closeDescriptors in
// UNIXProcess.c), and this in turn might:
//
// - cause end-of-file to fail to be detected on some file
// descriptors, resulting in mysterious hangs, or
//
// - might cause an fopen in the subprocess to fail on a system
// suffering from bug 1085341.
// Validate that the use of the O_CLOEXEC flag on open above worked.
static sig_atomic_t O_CLOEXEC_is_known_to_work = 0;
if (O_CLOEXEC_is_known_to_work == 0) {
int flags = ::fcntl(fd, F_GETFD);
if (flags != -1) {
if ((flags & FD_CLOEXEC) != 0) {
O_CLOEXEC_is_known_to_work = 1;
} else { // it does not work
::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
O_CLOEXEC_is_known_to_work = -1;
}
}
} else if (O_CLOEXEC_is_known_to_work == -1) {
int flags = ::fcntl(fd, F_GETFD);
if (flags != -1) {
::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
}
}
return fd;
}
// current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
// are used by JVM M&M and JVMTI to get user+sys or user CPU time
// of a thread.
//
// current_thread_cpu_time() and thread_cpu_time(Thread*) returns
// the fast estimate available on the platform.
jlong os::current_thread_cpu_time() {
// return user + sys since the cost is the same
const jlong n = os::thread_cpu_time(Thread::current(), true /* user + sys */);
assert(n >= 0, "negative CPU time");
return n;
}
jlong os::thread_cpu_time(Thread* thread) {
// consistent with what current_thread_cpu_time() returns
const jlong n = os::thread_cpu_time(thread, true /* user + sys */);
assert(n >= 0, "negative CPU time");
return n;
}
jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
const jlong n = os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
assert(n >= 0, "negative CPU time");
return n;
}
static bool thread_cpu_time_unchecked(Thread* thread, jlong* p_sys_time, jlong* p_user_time) {
bool error = false;
jlong sys_time = 0;
jlong user_time = 0;
// Reimplemented using getthrds64().
//
// Works like this:
// For the thread in question, get the kernel thread id. Then get the
// kernel thread statistics using that id.
//
// This only works of course when no pthread scheduling is used,
// i.e. there is a 1:1 relationship to kernel threads.
// On AIX, see AIXTHREAD_SCOPE variable.
pthread_t pthtid = thread->osthread()->pthread_id();
// retrieve kernel thread id for the pthread:
tid64_t tid = 0;
struct __pthrdsinfo pinfo;
// I just love those otherworldly IBM APIs which force me to hand down
// dummy buffers for stuff I dont care for...
char dummy[1];
int dummy_size = sizeof(dummy);
if (pthread_getthrds_np(&pthtid, PTHRDSINFO_QUERY_TID, &pinfo, sizeof(pinfo),
dummy, &dummy_size) == 0) {
tid = pinfo.__pi_tid;
} else {
tty->print_cr("pthread_getthrds_np failed, errno: %d.", errno);
error = true;
}
// retrieve kernel timing info for that kernel thread
if (!error) {
struct thrdentry64 thrdentry;
if (getthrds64(getpid(), &thrdentry, sizeof(thrdentry), &tid, 1) == 1) {
sys_time = thrdentry.ti_ru.ru_stime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_stime.tv_usec * 1000LL;
user_time = thrdentry.ti_ru.ru_utime.tv_sec * 1000000000LL + thrdentry.ti_ru.ru_utime.tv_usec * 1000LL;
} else {
tty->print_cr("getthrds64 failed, errno: %d.", errno);
error = true;
}
}
if (p_sys_time) {
*p_sys_time = sys_time;
}
if (p_user_time) {
*p_user_time = user_time;
}
if (error) {
return false;
}
return true;
}
jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
jlong sys_time;
jlong user_time;
if (!thread_cpu_time_unchecked(thread, &sys_time, &user_time)) {
return -1;
}
return user_sys_cpu_time ? sys_time + user_time : user_time;
}
void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
info_ptr->max_value = all_bits_jlong; // will not wrap in less than 64 bits
info_ptr->may_skip_backward = false; // elapsed time not wall time
info_ptr->may_skip_forward = false; // elapsed time not wall time
info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
}
void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
info_ptr->max_value = all_bits_jlong; // will not wrap in less than 64 bits
info_ptr->may_skip_backward = false; // elapsed time not wall time
info_ptr->may_skip_forward = false; // elapsed time not wall time
info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
}
bool os::is_thread_cpu_time_supported() {
return true;
}
// System loadavg support. Returns -1 if load average cannot be obtained.
// For now just return the system wide load average (no processor sets).
int os::loadavg(double values[], int nelem) {
guarantee(nelem >= 0 && nelem <= 3, "argument error");
guarantee(values, "argument error");
// AIX: use libperfstat
libperfstat::cpuinfo_t ci;
if (libperfstat::get_cpuinfo(&ci)) {
for (int i = 0; i < nelem; i++) {
values[i] = ci.loadavg[i];
}
} else {
return -1;
}
return nelem;
}
bool os::is_primordial_thread(void) {
if (pthread_self() == (pthread_t)1) {
return true;
} else {
return false;
}
}
// OS recognitions (OS level) call this before calling Aix::os_version()
void os::Aix::initialize_os_info() {
assert(_os_version == 0, "already called.");
struct utsname uts;
memset(&uts, 0, sizeof(uts));
strcpy(uts.sysname, "?");
if (::uname(&uts) == -1) {
log_warning(os)("uname failed (%d)", errno);
guarantee(0, "Could not determine uname information");
} else {
log_info(os)("uname says: sysname \"%s\" version \"%s\" release \"%s\" "
"node \"%s\" machine \"%s\"\n",
uts.sysname, uts.version, uts.release, uts.nodename, uts.machine);
const int major = atoi(uts.version);
assert(major > 0, "invalid OS version");
const int minor = atoi(uts.release);
assert(minor > 0, "invalid OS release");
_os_version = (major << 24) | (minor << 16);
char ver_str[20] = {0};
const char* name_str = "unknown OS";
if (strcmp(uts.sysname, "AIX") == 0) {
// We run on AIX. We do not support versions older than AIX 7.1.
// Determine detailed AIX version: Version, Release, Modification, Fix Level.
odmWrapper::determine_os_kernel_version(&_os_version);
if (os_version_short() < 0x0701) {
log_warning(os)("AIX releases older than AIX 7.1 are not supported.");
assert(false, "AIX release too old.");
}
name_str = "AIX";
jio_snprintf(ver_str, sizeof(ver_str), "%u.%u.%u.%u",
major, minor, (_os_version >> 8) & 0xFF, _os_version & 0xFF);
} else {
assert(false, "%s", name_str);
}
log_info(os)("We run on %s %s", name_str, ver_str);
}
guarantee(_os_version, "Could not determine AIX release");
} // end: os::Aix::initialize_os_info()
// Scan environment for important settings which might effect the VM.
// Trace out settings. Warn about invalid settings and/or correct them.
//
// Must run after os::Aix::initialue_os_info().
void os::Aix::scan_environment() {
char* p;
int rc;
// Warn explicitly if EXTSHM=ON is used. That switch changes how
// System V shared memory behaves. One effect is that page size of
// shared memory cannot be change dynamically, effectivly preventing
// large pages from working.
// This switch was needed on AIX 32bit, but on AIX 64bit the general
// recommendation is (in OSS notes) to switch it off.
p = ::getenv("EXTSHM");
trcVerbose("EXTSHM=%s.", p ? p : "<unset>");
if (p && strcasecmp(p, "ON") == 0) {
_extshm = 1;
log_warning(os)("*** Unsupported mode! Please remove EXTSHM from your environment! ***");
if (!AllowExtshm) {
// We allow under certain conditions the user to continue. However, we want this
// to be a fatal error by default. On certain AIX systems, leaving EXTSHM=ON means
// that the VM is not able to allocate 64k pages for the heap.
// We do not want to run with reduced performance.
vm_exit_during_initialization("EXTSHM is ON. Please remove EXTSHM from your environment.");
}
} else {
_extshm = 0;
}
// SPEC1170 behaviour: will change the behaviour of a number of POSIX APIs.
// Not tested, not supported.
//
// Note that it might be worth the trouble to test and to require it, if only to
// get useful return codes for mprotect.
//
// Note: Setting XPG_SUS_ENV in the process is too late. Must be set earlier (before
// exec() ? before loading the libjvm ? ....)
p = ::getenv("XPG_SUS_ENV");
trcVerbose("XPG_SUS_ENV=%s.", p ? p : "<unset>");
if (p && strcmp(p, "ON") == 0) {
_xpg_sus_mode = 1;
log_warning(os)("Unsupported setting: XPG_SUS_ENV=ON");
// This is not supported. Worst of all, it changes behaviour of mmap MAP_FIXED to
// clobber address ranges. If we ever want to support that, we have to do some
// testing first.
guarantee(false, "XPG_SUS_ENV=ON not supported");
} else {
_xpg_sus_mode = 0;
}
p = ::getenv("LDR_CNTRL");
trcVerbose("LDR_CNTRL=%s.", p ? p : "<unset>");
p = ::getenv("AIXTHREAD_GUARDPAGES");
trcVerbose("AIXTHREAD_GUARDPAGES=%s.", p ? p : "<unset>");
} // end: os::Aix::scan_environment()
void os::Aix::initialize_libperfstat() {
if (!libperfstat::init()) {
log_warning(os)("libperfstat initialization failed.");
assert(false, "libperfstat initialization failed");
} else {
trcVerbose("libperfstat initialized.");
}
}
bool os::Aix::supports_64K_mmap_pages() {
return g_multipage_support.can_use_64K_mmap_pages;
}
/////////////////////////////////////////////////////////////////////////////
// thread stack
// Get the current stack base and size from the OS (actually, the pthread library).
// Note: base usually not page aligned.
// Returned size is such that (base - size) is always aligned to page size.
void os::current_stack_base_and_size(address* stack_base, size_t* stack_size) {
AixMisc::stackbounds_t bounds;
bool rc = AixMisc::query_stack_bounds_for_current_thread(&bounds);
guarantee(rc, "Unable to retrieve stack bounds.");
*stack_base = bounds.base;
// Align the reported stack size such that the stack low address
// is aligned to page size (Note: base is usually not and we do not care).
// We need to do this because caller code will assume stack low address is
// page aligned and will place guard pages without checking.
address low = bounds.base - bounds.size;
address low_aligned = (address)align_up(low, os::vm_page_size());
*stack_size = bounds.base - low_aligned;
}
// Get the default path to the core file
// Returns the length of the string
int os::get_core_path(char* buffer, size_t bufferSize) {
const char* p = get_current_directory(buffer, bufferSize);
if (p == nullptr) {
assert(p != nullptr, "failed to get current directory");
return 0;
}
jio_snprintf(buffer, bufferSize, "%s/core or core.%d",
p, current_process_id());
return checked_cast<int>(strlen(buffer));
}
bool os::start_debugging(char *buf, int buflen) {
int len = (int)strlen(buf);
char *p = &buf[len];
jio_snprintf(p, buflen -len,
"\n\n"
"Do you want to debug the problem?\n\n"
"To debug, run 'dbx -a %d'; then switch to thread tid %zd, k-tid %zd\n"
"Enter 'yes' to launch dbx automatically (PATH must include dbx)\n"
"Otherwise, press RETURN to abort...",
os::current_process_id(),
os::current_thread_id(), thread_self());
bool yes = os::message_box("Unexpected Error", buf);
if (yes) {
// yes, user asked VM to launch debugger
jio_snprintf(buf, buflen, "dbx -a %d", os::current_process_id());
os::fork_and_exec(buf);
yes = false;
}
return yes;
}
static inline time_t get_mtime(const char* filename) {
struct stat st;
int ret = os::stat(filename, &st);
assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
return st.st_mtime;
}
int os::compare_file_modified_times(const char* file1, const char* file2) {
time_t t1 = get_mtime(file1);
time_t t2 = get_mtime(file2);
return primitive_compare(t1, t2);
}
bool os::supports_map_sync() {
return false;
}
void os::print_memory_mappings(char* addr, size_t bytes, outputStream* st) {}
#if INCLUDE_JFR
void os::jfr_report_memory_info() {}
#endif // INCLUDE_JFR