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88ff4759ac
2003-04-10 Ulrich Drepper <drepper@redhat.com> * sysdeps/unix/sysv/linux/fork.c (__libc_fork): Reset CPU clocks in child.
148 lines
3.6 KiB
C
148 lines
3.6 KiB
C
/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <assert.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sysdep.h>
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#include <libio/libioP.h>
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#include <tls.h>
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#include "fork.h"
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#include <hp-timing.h>
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#include <ldsodefs.h>
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#include <bits/stdio-lock.h>
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unsigned long int *__fork_generation_pointer;
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lll_lock_t __fork_lock = LLL_LOCK_INITIALIZER;
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LIST_HEAD (__fork_prepare_list);
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LIST_HEAD (__fork_parent_list);
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LIST_HEAD (__fork_child_list);
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static void
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fresetlockfiles (void)
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{
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_IO_ITER i;
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for (i = _IO_iter_begin(); i != _IO_iter_end(); i = _IO_iter_next(i))
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_IO_lock_init (*((_IO_lock_t *) _IO_iter_file(i)->_lock));
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}
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pid_t
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__libc_fork (void)
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{
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pid_t pid;
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list_t *runp;
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/* Get the lock so that the set of registered handlers is not
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inconsistent or changes beneath us. */
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lll_lock (__fork_lock);
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/* Run all the registered preparation handlers. In reverse order. */
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list_for_each_prev (runp, &__fork_prepare_list)
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{
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struct fork_handler *curp;
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curp = list_entry (runp, struct fork_handler, list);
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curp->handler ();
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}
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_IO_list_lock ();
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#ifndef NDEBUG
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pid_t ppid = THREAD_GETMEM (THREAD_SELF, tid);
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#endif
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#ifdef ARCH_FORK
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pid = ARCH_FORK ();
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#else
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# error "ARCH_FORK must be defined so that the CLONE_SETTID flag is used"
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pid = INLINE_SYSCALL (fork, 0);
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#endif
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if (pid == 0)
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{
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struct pthread *self = THREAD_SELF;
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assert (THREAD_GETMEM (self, tid) != ppid);
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if (__fork_generation_pointer != NULL)
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*__fork_generation_pointer += 4;
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#if HP_TIMING_AVAIL
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/* The CPU clock of the thread and process have to be set to zero. */
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hp_timing_t now;
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HP_TIMING_NOW (now);
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THREAD_SETMEM (self, cpuclock_offset, now);
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GL(dl_cpuclock_offset) = now;
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#endif
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/* Reset the file list. These are recursive mutexes. */
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fresetlockfiles ();
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/* Reset locks in the I/O code. */
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_IO_list_resetlock ();
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/* Run the handlers registered for the child. */
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list_for_each (runp, &__fork_child_list)
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{
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struct fork_handler *curp;
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curp = list_entry (runp, struct fork_handler, list);
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curp->handler ();
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}
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/* Initialize the fork lock. */
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__fork_lock = (lll_lock_t) LLL_LOCK_INITIALIZER;
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}
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else
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{
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assert (THREAD_GETMEM (THREAD_SELF, tid) == ppid);
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/* We execute this even if the 'fork' call failed. */
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_IO_list_unlock ();
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/* Run the handlers registered for the parent. */
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list_for_each (runp, &__fork_parent_list)
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{
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struct fork_handler *curp;
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curp = list_entry (runp, struct fork_handler, list);
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curp->handler ();
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}
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/* Release the for lock. */
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lll_unlock (__fork_lock);
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}
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return pid;
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}
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weak_alias (__libc_fork, __fork)
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libc_hidden_def (__fork)
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weak_alias (__libc_fork, fork)
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