* posix/Makefile (tests): Add tst-fork.
2000-05-28 Ulrich Drepper <drepper@redhat.com>
+ * posix/Makefile (tests): Add tst-fork.
+
* resolv/inet_pton.c: Loose __P.
2000-05-21 Jakub Jelinek <jakub@redhat.com>
+2000-05-28 Ulrich Drepper <drepper@redhat.com>
+
+ * Makefile (tests): Add ex8.
+ * Examples/ex8.c: New file.
+
+2000-05-12 Kaz Kylheku <kaz@ashi.footprints.net>
+
+ Bugfix: The pthread_atfork mechanism now takes care of its
+ own internal mutex at fork time.
+
+ * ptfork.c (__fork): Revised so that the mutex is held across
+ the fork operation and while the handlers are called, and so that
+ the child resets the mutex.
+ Added calls to new functions __flockallfiles and __funlockallfiles.
+
+ * linuxthreads.texi: Updated pthread_atfork documentation to make
+ it clear that fork and pthread_atfork can't be reentered from
+ atfork handlers, that pthread_atfork and fork are mutually atomic,
+ and that the handlers are inherited by the child process.
+
2000-05-24 Ulrich Drepper <drepper@redhat.com>
* Makefile (libpthread-routines): Add pspinlock.
--- /dev/null
+/* Tests for fork in multi-threaded environment.
+ Copyright (C) 2000 Free Software Foundation, Inc.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
+
+ 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 <error.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <wait.h>
+
+enum
+{
+ PREPARE_BIT = 1,
+ PARENT_BIT = 2,
+ CHILD_BIT = 4
+};
+
+static int var;
+
+static void
+prepare (void)
+{
+ var |= PREPARE_BIT;
+}
+
+static void
+parent (void)
+{
+ var |= PARENT_BIT;
+}
+
+static void
+child (void)
+{
+ var |= CHILD_BIT;
+}
+
+
+static void *thread (void *arg);
+
+
+int
+main (void)
+{
+ pthread_t th;
+ void *res;
+
+ pthread_atfork (prepare, parent, child);
+
+ if (pthread_create (&th, NULL, thread, NULL) != 0)
+ error (EXIT_FAILURE, 0, "cannot create thread");
+
+ pthread_join (th, &res);
+
+ return (int) res;
+}
+
+
+static void *
+thread (void *arg)
+{
+ int status;
+ pid_t pid;
+
+ pid = fork ();
+ if (pid == 0)
+ {
+ /* We check whether the `prepare' and `child' function ran. */
+ exit (var != (PREPARE_BIT | CHILD_BIT));
+ }
+ else if (pid == (pid_t) -1)
+ error (EXIT_FAILURE, errno, "cannot fork");
+
+ if (waitpid (pid, &status, 0) != pid)
+ error (EXIT_FAILURE, errno, "wrong child");
+
+ if (WTERMSIG (status) != 0)
+ error (EXIT_FAILURE, 0, "Child terminated incorrectly");
+ status = WEXITSTATUS (status);
+
+ if (status == 0)
+ status = var != (PREPARE_BIT | PARENT_BIT);
+
+ return (void *) status;
+}
oldsemaphore events getcpuclockid pspinlock
vpath %.c Examples
-tests = ex1 ex2 ex3 ex4 ex5 ex6 ex7
+tests = ex1 ex2 ex3 ex4 ex5 ex6 ex7 ex8
include ../Rules
$(objpfx)ex5: $(libpthread)
$(objpfx)ex6: $(libpthread)
$(objpfx)ex7: $(libpthread)
+$(objpfx)ex8: $(libpthread)
If there is insufficient memory available to register the handlers,
@code{pthread_atfork} fails and returns @code{ENOMEM}. Otherwise it
returns 0.
+
+The functions @code{fork} and @code{pthread_atfork} must not be regarded as
+reentrant from the context of the handlers. That is to say, if a
+@code{pthread_atfork} handler invoked from within @code{fork} calls
+@code{pthread_atfork} or @code{fork}, the behavior is undefined.
+
+Registering a triplet of handlers is an atomic operation with respect to fork.
+If new handlers are registered at about the same time as a fork occurs, either
+all three handlers will be called, or none of them will be called.
+
+The handlers are inherited by the child process, and there is no
+way to remove them, short of using @code{exec} to load a new
+pocess image.
+
@end deftypefun
To understand the purpose of @code{pthread_atfork}, recall that
pid_t __fork(void)
{
pid_t pid;
- struct handler_list * prepare, * child, * parent;
pthread_mutex_lock(&pthread_atfork_lock);
- prepare = pthread_atfork_prepare;
- child = pthread_atfork_child;
- parent = pthread_atfork_parent;
- pthread_mutex_unlock(&pthread_atfork_lock);
- pthread_call_handlers(prepare);
+
+ pthread_call_handlers(pthread_atfork_prepare);
__pthread_once_fork_prepare();
+
pid = __libc_fork();
+
if (pid == 0) {
__pthread_reset_main_thread();
+
__fresetlockfiles();
- pthread_call_handlers(child);
__pthread_once_fork_child();
+ pthread_call_handlers(pthread_atfork_child);
+
+ pthread_mutex_init(&pthread_atfork_lock, NULL);
} else {
- pthread_call_handlers(parent);
__pthread_once_fork_parent();
+ pthread_call_handlers(pthread_atfork_parent);
+
+ pthread_mutex_unlock(&pthread_atfork_lock);
}
+
return pid;
}
tests := tstgetopt testfnm runtests runptests \
tst-preadwrite tst-preadwrite64 test-vfork regexbug1 \
tst-getlogin tst-mmap tst-getaddrinfo tst-truncate \
- tst-truncate64
+ tst-truncate64 tst-fork
ifeq (yes,$(build-shared))
test-srcs := globtest
tests += wordexp-test
--- /dev/null
+/* Tests for fork.
+ Copyright (C) 2000 Free Software Foundation, Inc.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
+
+ 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 <error.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <wait.h>
+
+
+static const char testdata[] = "This is a test";
+static const char testdata2[] = "And here we go again";
+
+
+int
+main (void)
+{
+ const char *tmpdir = getenv ("TMPDIR");
+ char buf[100];
+ size_t tmpdirlen;
+ char *name;
+ int fd;
+ pid_t pid;
+ off_t off;
+ int status;
+
+ if (tmpdir == NULL || *tmpdir == '\0')
+ tmpdir = "/tmp";
+ tmpdirlen = strlen (tmpdir);
+
+ name = (char *) malloc (tmpdirlen + strlen ("/forkXXXXXX") + 1);
+ if (name == NULL)
+ error (EXIT_FAILURE, errno, "cannot allocate file name");
+
+ mempcpy (mempcpy (name, tmpdir, tmpdirlen),
+ "/forkXXXXXX", sizeof ("/forkXXXXXX"));
+
+ /* Open our test file. */
+ fd = mkstemp (name);
+ if (fd == -1)
+ error (EXIT_FAILURE, errno, "cannot open test file `%s'", name);
+
+ /* Make sure it gets removed. */
+ unlink (name);
+
+ /* Write some data. */
+ if (write (fd, testdata, strlen (testdata)) != strlen (testdata))
+ error (EXIT_FAILURE, errno, "cannot write test data");
+
+ /* Get the position in the stream. */
+ off = lseek (fd, 0, SEEK_CUR);
+ if (off == (off_t) -1 || off != strlen (testdata))
+ error (EXIT_FAILURE, errno, "wrong file position");
+
+ /* Now fork of the process. */
+ pid = fork ();
+ if (pid == 0)
+ {
+ /* This is the child. First get the position of the descriptor. */
+ off = lseek (fd, 0, SEEK_CUR);
+ if (off == (off_t) -1 || off != strlen (testdata))
+ error (EXIT_FAILURE, errno, "wrong file position in child");
+
+ /* Reset the position. */
+ if (lseek (fd, 0, SEEK_SET) != 0)
+ error (EXIT_FAILURE, errno, "cannot reset position in child");
+
+ /* Read the data. */
+ if (read (fd, buf, sizeof buf) != strlen (testdata))
+ error (EXIT_FAILURE, errno, "cannot read data in child");
+
+ /* Compare the data. */
+ if (memcmp (buf, testdata, strlen (testdata)) != 0)
+ error (EXIT_FAILURE, 0, "data comparison failed in child");
+
+ /* Reset position again. */
+ if (lseek (fd, 0, SEEK_SET) != 0)
+ error (EXIT_FAILURE, errno, "cannot reset position again in child");
+
+ /* Write new data. */
+ if (write (fd, testdata2, strlen (testdata2)) != strlen (testdata2))
+ error (EXIT_FAILURE, errno, "cannot write new data in child");
+
+ /* Close the file. This must not remove it. */
+ close (fd);
+
+ _exit (0);
+ }
+ else if (pid < 0)
+ /* Something went wrong. */
+ error (EXIT_FAILURE, errno, "cannot fork");
+
+ /* Wait for the child. */
+ if (waitpid (pid, &status, 0) != pid)
+ error (EXIT_FAILURE, 0, "Oops, wrong test program terminated");
+
+ if (WTERMSIG (status) != 0)
+ error (EXIT_FAILURE, 0, "Child terminated incorrectly");
+ status = WEXITSTATUS (status);
+
+ if (status == 0)
+ {
+ /* Test whether the child wrote the right data. First test the
+ position. It must be the same as in the child. */
+ if (lseek (fd, 0, SEEK_CUR) != strlen (testdata2))
+ error (EXIT_FAILURE, 0, "file position not changed");
+
+ if (lseek (fd, 0, SEEK_SET) != 0)
+ error (EXIT_FAILURE, errno, "cannot reset file position");
+
+ if (read (fd, buf, sizeof buf) != strlen (testdata2))
+ error (EXIT_FAILURE, errno, "cannot read new data");
+
+ if (memcmp (buf, testdata2, strlen (testdata2)) != 0)
+ error (EXIT_FAILURE, 0, "new data not read correctly");
+ }
+
+ return status;
+}
projects / platform / upstream / glibc.git / commitdiff