src/hotspot/share/compiler/compilerEvent.cpp

/*
 * Copyright (c) 2020, 2025, Oracle and/or its affiliates. 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
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#include "ci/ciMethod.hpp"
#include "compiler/compilerEvent.hpp"
#include "jfr/jfr.hpp"
#include "jfr/jfrEvents.hpp"
#include "jfr/metadata/jfrSerializer.hpp"
#include "runtime/interfaceSupport.inline.hpp"
#include "runtime/javaThread.hpp"
#include "runtime/os.hpp"
#include "runtime/semaphore.inline.hpp"
#include "utilities/growableArray.hpp"

// Synchronizes access to phases_names.
class PhaseTypeGuard : public StackObj {
 private:
  static Semaphore _mutex_semaphore;
  bool _enabled;
 public:
  PhaseTypeGuard(bool enabled=true) {
    if (enabled) {
      _mutex_semaphore.wait();
      _enabled = true;
    } else {
      _enabled = false;
    }
  }
  ~PhaseTypeGuard() {
    if (_enabled) {
      _mutex_semaphore.signal();
    }
  }
};

Semaphore PhaseTypeGuard::_mutex_semaphore(1);

// Table for mapping compiler phases names to int identifiers.
static GrowableArray<const char*>* phase_names = nullptr;

class CompilerPhaseTypeConstant : public JfrSerializer {
 public:
  void serialize(JfrCheckpointWriter& writer) {
    PhaseTypeGuard guard;
    assert(phase_names != nullptr, "invariant");
    assert(phase_names->is_nonempty(), "invariant");
    const u4 nof_entries = phase_names->length();
    writer.write_count(nof_entries);
    for (u4 i = 0; i < nof_entries; i++) {
      writer.write_key(i);
      writer.write(phase_names->at(i));
    }
  }
};

static int lookup_phase(const char* phase_name) {
  for (int i = 0; i < phase_names->length(); i++) {
    const char* name = phase_names->at(i);
    if (strcmp(name, phase_name) == 0) {
      return i;
    }
  }
  return -1;
}

int CompilerEvent::PhaseEvent::get_phase_id(const char* phase_name, bool may_exist, bool use_strdup, bool sync) {
  int index;
  bool register_jfr_serializer = false;
  {
    PhaseTypeGuard guard(sync);
    if (phase_names == nullptr) {
      phase_names = new (mtInternal) GrowableArray<const char*>(100, mtCompiler);
      register_jfr_serializer = true;
    } else if (may_exist) {
      index = lookup_phase(phase_name);
      if (index != -1) {
        return index;
      }
    } else {
      assert((index = lookup_phase(phase_name)) == -1, "phase name \"%s\" already registered: %d", phase_name, index);
    }

    index = phase_names->length();
    phase_names->append(use_strdup ? os::strdup(phase_name) : phase_name);
  }
  if (register_jfr_serializer) {
    JfrSerializer::register_serializer(TYPE_COMPILERPHASETYPE, false, new CompilerPhaseTypeConstant());
  } else if (Jfr::is_recording()) {
    // serialize new phase.
    JfrCheckpointWriter writer;
    writer.write_type(TYPE_COMPILERPHASETYPE);
    writer.write_count(1);
    writer.write_key(index);
    writer.write(phase_name);
  }
  return index;
}

// As part of event commit, a Method* is tagged as a function of an epoch.
// Epochs evolve during safepoints. To ensure the event is tagged in the correct epoch,
// that is, to avoid a race, the thread will participate in the safepoint protocol
// by doing the commit while the thread is _thread_in_vm.
template <typename EventType>
static inline void commit(EventType& event) {
  JavaThread* thread = JavaThread::current();
  JavaThreadState state = thread->thread_state();
  if (state == _thread_in_native) {
    ThreadInVMfromNative transition(thread);
    event.commit();
  } else {
    assert(state == _thread_in_vm, "coming from wrong thread state %d", state);
    event.commit();
  }
 }

void CompilerEvent::CompilationEvent::post(EventCompilation& event, int compile_id, CompilerType compiler_type, Method* method,
    int compile_level, bool success, bool is_osr, int code_size,
    int inlined_bytecodes, size_t arenaBytes) {
  event.set_compileId(compile_id);
  event.set_compiler(compiler_type);
  event.set_method(method);
  event.set_compileLevel((short)compile_level);
  event.set_succeded(success);
  event.set_isOsr(is_osr);
  event.set_codeSize(code_size);
  event.set_inlinedBytes(inlined_bytecodes);
  event.set_arenaBytes(arenaBytes);
  commit(event);
}

void CompilerEvent::CompilationFailureEvent::post(EventCompilationFailure& event, int compile_id, const char* reason) {
  event.set_compileId(compile_id);
  event.set_failureMessage(reason);
  event.commit();
}

void CompilerEvent::PhaseEvent::post(EventCompilerPhase& event, const Ticks& start_time, int phase, int compile_id, int level) {
  event.set_starttime(start_time);
  event.set_phase((u1) phase);
  event.set_compileId(compile_id);
  event.set_phaseLevel((short)level);
  event.commit();
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, const JfrStructCalleeMethod& callee, bool success, const char* msg, int bci) {
  event.set_compileId(compile_id);
  event.set_caller(caller);
  event.set_callee(callee);
  event.set_succeeded(success);
  event.set_message(msg);
  event.set_bci(bci);
  commit(event);
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, Method* callee, bool success, const char* msg, int bci) {
  JfrStructCalleeMethod callee_struct;
  callee_struct.set_type(callee->klass_name()->as_utf8());
  callee_struct.set_name(callee->name()->as_utf8());
  callee_struct.set_descriptor(callee->signature()->as_utf8());
  post(event, compile_id, caller, callee_struct, success, msg, bci);
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, ciMethod* callee, bool success, const char* msg, int bci) {
  JfrStructCalleeMethod callee_struct;
  callee_struct.set_type(callee->holder()->name()->as_utf8());
  callee_struct.set_name(callee->name()->as_utf8());
  callee_struct.set_descriptor(callee->signature()->as_symbol()->as_utf8());
  post(event, compile_id, caller, callee_struct, success, msg, bci);
}