glibc/sysdeps/nptl/libc_start_call_main.h
Wilco Dijkstra 4a07fbb689 Use C11 atomics instead of atomic_decrement_and_test
Replace atomic_decrement_and_test with atomic_fetch_add_relaxed.
These are simple counters which do not protect any shared data from
concurrent accesses. Also remove the unused file cond-perf.c.

Passes regress on AArch64.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-09-23 15:59:56 +01:00

76 lines
2.6 KiB
C

/* Invoking main from __libc_start_main. nptl version.
Copyright (C) 1998-2022 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 <atomic.h>
#include <pthreadP.h>
_Noreturn static void
__libc_start_call_main (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
int argc, char **argv
#ifdef LIBC_START_MAIN_AUXVEC_ARG
, ElfW(auxv_t) *auxvec
#endif
)
{
int result;
/* Memory for the cancellation buffer. */
struct pthread_unwind_buf unwind_buf;
int not_first_call;
DIAG_PUSH_NEEDS_COMMENT;
#if __GNUC_PREREQ (7, 0)
/* This call results in a -Wstringop-overflow warning because struct
pthread_unwind_buf is smaller than jmp_buf. setjmp and longjmp
do not use anything beyond the common prefix (they never access
the saved signal mask), so that is a false positive. */
DIAG_IGNORE_NEEDS_COMMENT (11, "-Wstringop-overflow=");
#endif
not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf);
DIAG_POP_NEEDS_COMMENT;
if (__glibc_likely (! not_first_call))
{
struct pthread *self = THREAD_SELF;
/* Store old info. */
unwind_buf.priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf);
unwind_buf.priv.data.cleanup = THREAD_GETMEM (self, cleanup);
/* Store the new cleanup handler info. */
THREAD_SETMEM (self, cleanup_jmp_buf, &unwind_buf);
/* Run the program. */
result = main (argc, argv, __environ MAIN_AUXVEC_PARAM);
}
else
{
/* Remove the thread-local data. */
__nptl_deallocate_tsd ();
/* One less thread. Decrement the counter. If it is zero we
terminate the entire process. */
result = 0;
if (atomic_fetch_add_relaxed (&__nptl_nthreads, -1) != 1)
/* Not much left to do but to exit the thread, not the process. */
while (1)
INTERNAL_SYSCALL_CALL (exit, 0);
}
exit (result);
}