diff options
Diffstat (limited to 'resolv/getaddrinfo_a.c')
| -rw-r--r-- | resolv/getaddrinfo_a.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/resolv/getaddrinfo_a.c b/resolv/getaddrinfo_a.c new file mode 100644 index 0000000..1a077d1 --- /dev/null +++ b/resolv/getaddrinfo_a.c @@ -0,0 +1,168 @@ +/* Copyright (C) 2001 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <errno.h> +#include <netdb.h> +#include <pthread.h> +#include <stdlib.h> +#include <unistd.h> + +#include "gai_misc.h" + + +/* We need this special structure to handle asynchronous I/O. */ +struct async_waitlist + { + int counter; + struct sigevent sigev; + struct waitlist list[0]; + }; + + +int +getaddrinfo_a (int mode, struct gaicb *list[], int ent, struct sigevent *sig) +{ + struct sigevent defsigev; + struct requestlist *requests[ent]; + int cnt; + volatile int total = 0; + int result = 0; + + /* Check arguments. */ + if (mode != GAI_WAIT && mode != GAI_NOWAIT) + { + __set_errno (EINVAL); + return EAI_SYSTEM; + } + + if (sig == NULL) + { + defsigev.sigev_notify = SIGEV_NONE; + sig = &defsigev; + } + + /* Request the mutex. */ + pthread_mutex_lock (&__gai_requests_mutex); + + /* Now we can enqueue all requests. Since we already acquired the + mutex the enqueue function need not do this. */ + for (cnt = 0; cnt < ent; ++cnt) + if (list[cnt] != NULL) + { + requests[cnt] = __gai_enqueue_request (list[cnt]); + + if (requests[cnt] != NULL) + /* Successfully enqueued. */ + ++total; + else + /* Signal that we've seen an error. `errno' and the error code + of the gaicb will tell more. */ + result = EAI_SYSTEM; + } + else + requests[cnt] = NULL; + + if (total == 0) + { + /* We don't have anything to do except signalling if we work + asynchronously. */ + + /* Release the mutex. We do this before raising a signal since the + signal handler might do a `siglongjmp' and then the mutex is + locked forever. */ + pthread_mutex_unlock (&__gai_requests_mutex); + + if (mode == GAI_NOWAIT) + __gai_notify_only (sig, + sig->sigev_notify == SIGEV_SIGNAL ? getpid () : 0); + + return result; + } + else if (mode == GAI_WAIT) + { + pthread_cond_t cond = PTHREAD_COND_INITIALIZER; + struct waitlist waitlist[ent]; + int oldstate; + + total = 0; + for (cnt = 0; cnt < ent; ++cnt) + if (requests[cnt] != NULL) + { + waitlist[cnt].cond = &cond; + waitlist[cnt].next = requests[cnt]->waiting; + waitlist[cnt].counterp = &total; + waitlist[cnt].sigevp = NULL; + waitlist[cnt].caller_pid = 0; /* Not needed. */ + requests[cnt]->waiting = &waitlist[cnt]; + ++total; + } + + /* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancelation + points we must be careful. We added entries to the waiting lists + which we must remove. So defer cancelation for now. */ + pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate); + + while (total > 0) + pthread_cond_wait (&cond, &__gai_requests_mutex); + + /* Now it's time to restore the cancelation state. */ + pthread_setcancelstate (oldstate, NULL); + + /* Release the conditional variable. */ + if (pthread_cond_destroy (&cond) != 0) + /* This must never happen. */ + abort (); + } + else + { + struct async_waitlist *waitlist; + + waitlist = (struct async_waitlist *) + malloc (sizeof (struct async_waitlist) + + (ent * sizeof (struct waitlist))); + + if (waitlist == NULL) + result = EAI_AGAIN; + else + { + pid_t caller_pid = sig->sigev_notify == SIGEV_SIGNAL ? getpid () : 0; + total = 0; + + for (cnt = 0; cnt < ent; ++cnt) + if (requests[cnt] != NULL) + { + waitlist->list[cnt].cond = NULL; + waitlist->list[cnt].next = requests[cnt]->waiting; + waitlist->list[cnt].counterp = &waitlist->counter; + waitlist->list[cnt].sigevp = &waitlist->sigev; + waitlist->list[cnt].caller_pid = caller_pid; + requests[cnt]->waiting = &waitlist->list[cnt]; + ++total; + } + + waitlist->counter = total; + waitlist->sigev = *sig; + } + } + + /* Release the mutex. */ + pthread_mutex_unlock (&__gai_requests_mutex); + + return result; +} |