nptl/pthread_tryjoin.c - master - githubmirror/glibc

nptl/pthread_tryjoin.c
47 строк2 KB
Paul Eggert
Update copyright dates with scripts/update-copyrights
02 янв 2026, 00:42
02 янв 2026, 00:4266f3e92
/* Copyright (C) 2002-2026 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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
   <https://www.gnu.org/licenses/>.  */

#include "pthreadP.h"
#include <shlib-compat.h>

int
__pthread_tryjoin_np (pthread_t threadid, void **thread_return)
{
  /* The joinable state (THREAD_STATE_JOINABLE) is straightforward: the thread
     hasn't finished yet, so trying to join might block.

     The exiting thread (THREAD_STATE_EXITING) also might result in a blocking
     call: a detached thread might change its state to exiting, and an exiting
     thread might take some time to exit (and thus let the kernel set the
     state to THREAD_STATE_EXITED).

     The ‘joinstate’ does not change during the thread lifetime once the
     kernel sets it to THREAD_STATE_EXITED.  The __pthread_clockjoin_ex will
     only call the cancellable futex if state is not THREAD_STATE_EXITED, so
     calling it should be safe wrt not making pthread_tryjoin_np a
     cancellable entrypoint (since it is marked as __THROW).  */

  struct pthread *pd = (struct pthread *) threadid;
  return atomic_load_acquire (&pd->joinstate) != THREAD_STATE_EXITED
	 ? EBUSY
	 : __pthread_clockjoin_ex (threadid, thread_return, 0, NULL, false);
}
versioned_symbol (libc, __pthread_tryjoin_np, pthread_tryjoin_np, GLIBC_2_34);

#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_3_3, GLIBC_2_34)
compat_symbol (libc, __pthread_tryjoin_np, pthread_tryjoin_np, GLIBC_2_3_3);
#endif