| /* Copyright (C) 2001-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@redhat.com>, 2001. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <netdb.h> |
| #include <pthread.h> |
| #include <stdlib.h> |
| #include <gai_misc.h> |
| |
| |
| struct notify_func |
| { |
| void (*func) (sigval_t); |
| sigval_t value; |
| }; |
| |
| static void * |
| notify_func_wrapper (void *arg) |
| { |
| gai_start_notify_thread (); |
| struct notify_func *const n = arg; |
| void (*func) (sigval_t) = n->func; |
| sigval_t value = n->value; |
| free (n); |
| (*func) (value); |
| return NULL; |
| } |
| |
| |
| int |
| __gai_notify_only (struct sigevent *sigev, pid_t caller_pid) |
| { |
| int result = 0; |
| |
| /* Send the signal to notify about finished processing of the request. */ |
| if (sigev->sigev_notify == SIGEV_THREAD) |
| { |
| /* We have to start a thread. */ |
| pthread_t tid; |
| pthread_attr_t attr, *pattr; |
| |
| pattr = (pthread_attr_t *) sigev->sigev_notify_attributes; |
| if (pattr == NULL) |
| { |
| pthread_attr_init (&attr); |
| pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED); |
| pattr = &attr; |
| } |
| |
| /* SIGEV may be freed as soon as we return, so we cannot let the |
| notification thread use that pointer. Even though a sigval_t is |
| only one word and the same size as a void *, we cannot just pass |
| the value through pthread_create as the argument and have the new |
| thread run the user's function directly, because on some machines |
| the calling convention for a union like sigval_t is different from |
| that for a pointer type like void *. */ |
| struct notify_func *nf = malloc (sizeof *nf); |
| if (nf == NULL) |
| result = -1; |
| else |
| { |
| nf->func = sigev->sigev_notify_function; |
| nf->value = sigev->sigev_value; |
| if (pthread_create (&tid, pattr, notify_func_wrapper, nf) < 0) |
| { |
| free (nf); |
| result = -1; |
| } |
| } |
| } |
| else if (sigev->sigev_notify == SIGEV_SIGNAL) |
| /* We have to send a signal. */ |
| if (__gai_sigqueue (sigev->sigev_signo, sigev->sigev_value, caller_pid) |
| < 0) |
| result = -1; |
| |
| return result; |
| } |
| |
| |
| void |
| __gai_notify (struct requestlist *req) |
| { |
| struct waitlist *waitlist; |
| |
| /* Now also notify possibly waiting threads. */ |
| waitlist = req->waiting; |
| while (waitlist != NULL) |
| { |
| struct waitlist *next = waitlist->next; |
| |
| if (waitlist->sigevp == NULL) |
| { |
| #ifdef DONT_NEED_GAI_MISC_COND |
| GAI_MISC_NOTIFY (waitlist); |
| #else |
| /* Decrement the counter. */ |
| --*waitlist->counterp; |
| |
| pthread_cond_signal (waitlist->cond); |
| #endif |
| } |
| else |
| /* This is part of an asynchronous `getaddrinfo_a' operation. If |
| this request is the last one, send the signal. */ |
| if (--*waitlist->counterp == 0) |
| { |
| __gai_notify_only (waitlist->sigevp, waitlist->caller_pid); |
| /* This is tricky. See getaddrinfo_a.c for the reason why |
| this works. */ |
| free ((void *) waitlist->counterp); |
| } |
| |
| waitlist = next; |
| } |
| } |