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authorUlrich Drepper <drepper@redhat.com>2004-04-13 05:26:20 +0000
committerUlrich Drepper <drepper@redhat.com>2004-04-13 05:26:20 +0000
commite079c2285466ed0ddeed002a651c2e7ed7af5e8d (patch)
tree5d37a59b9ce2b94dea02d785e5cbe1b9348be0ff /linuxthreads/sysdeps/unix
parent1b82c6c77d566ce3977c83b7ca47f09aac31e525 (diff)
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Update.
2004-04-12 Ulrich Drepper <drepper@redhat.com> * rt/Makefile (tests): Add tst-timer3. * rt/tst-timer3.c: New file. By Roland McGrath.
Diffstat (limited to 'linuxthreads/sysdeps/unix')
-rw-r--r--linuxthreads/sysdeps/unix/sysv/linux/i386/sysdep-cancel.h16
-rw-r--r--linuxthreads/sysdeps/unix/sysv/linux/mq_notify.c285
2 files changed, 300 insertions, 1 deletions
diff --git a/linuxthreads/sysdeps/unix/sysv/linux/i386/sysdep-cancel.h b/linuxthreads/sysdeps/unix/sysv/linux/i386/sysdep-cancel.h
index baba152a77..ec21949a49 100644
--- a/linuxthreads/sysdeps/unix/sysv/linux/i386/sysdep-cancel.h
+++ b/linuxthreads/sysdeps/unix/sysv/linux/i386/sysdep-cancel.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2002.
@@ -95,6 +95,20 @@
# ifdef IS_IN_libpthread
# define CENABLE call __pthread_enable_asynccancel;
# define CDISABLE call __pthread_disable_asynccancel
+# elif defined IS_IN_librt
+# ifdef __PIC__
+# define CENABLE pushl %ebx; \
+ SETUP_PIC_REG(bx); \
+ call __librt_enable_asynccancel@PLT; \
+ popl %ebx;
+# define CDISABLE pushl %ebx; \
+ SETUP_PIC_REG(bx); \
+ call __librt_disable_asynccancel@PLT; \
+ popl %ebx;
+# else
+# define CENABLE call __librt_enable_asynccancel;
+# define CDISABLE call __librt_disable_asynccancel
+ #endif
# else
# define CENABLE call __libc_enable_asynccancel;
# define CDISABLE call __libc_disable_asynccancel
diff --git a/linuxthreads/sysdeps/unix/sysv/linux/mq_notify.c b/linuxthreads/sysdeps/unix/sysv/linux/mq_notify.c
new file mode 100644
index 0000000000..e231e591d1
--- /dev/null
+++ b/linuxthreads/sysdeps/unix/sysv/linux/mq_notify.c
@@ -0,0 +1,285 @@
+/* Copyright (C) 2004 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contribute by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <mqueue.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h>
+#include <sysdep.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <not-cancel.h>
+
+
+#ifdef __NR_mq_notify
+
+/* Defined in the kernel headers: */
+#define NOTIFY_COOKIE_LEN 32 /* Length of the cookie used. */
+#define NOTIFY_WOKENUP 1 /* Code for notifcation. */
+#define NOTIFY_REMOVED 2 /* Code for closed message queue
+ of de-notifcation. */
+
+
+/* Data structure for the queued notification requests. */
+union notify_data
+{
+ struct
+ {
+ void (*fct) (union sigval); /* The function to run. */
+ union sigval param; /* The parameter to pass. */
+ pthread_attr_t *attr; /* Attributes to create the thread with. */
+ /* NB: on 64-bit machines the struct as a size of 24 bytes. Which means
+ byte 31 can still be used for returning the status. */
+ };
+ char raw[NOTIFY_COOKIE_LEN];
+};
+
+
+/* Keep track of the initialization. */
+static pthread_once_t once = PTHREAD_ONCE_INIT;
+
+
+/* The netlink socket. */
+static int netlink_socket = -1;
+
+
+/* Barrier used to make sure data passed to the new thread is not
+ resused by the parent. */
+static pthread_barrier_t notify_barrier;
+
+
+/* Modify the signal mask. We move this into a separate function so
+ that the stack space needed for sigset_t is not deducted from what
+ the thread can use. */
+static int
+__attribute__ ((noinline))
+change_sigmask (int how, sigset_t *oss)
+{
+ sigset_t ss;
+ sigfillset (&ss);
+ return pthread_sigmask (how, &ss, oss);
+}
+
+
+/* The function used for the notification. */
+static void *
+notification_function (void *arg)
+{
+ /* Copy the function and parameter so that the parent thread can go
+ on with its life. */
+ volatile union notify_data *data = (volatile union notify_data *) arg;
+ void (*fct) (union sigval) = data->fct;
+ union sigval param = data->param;
+
+ /* Let the parent go. */
+ (void) pthread_barrier_wait (&notify_barrier);
+
+ /* Make the thread detached. */
+ (void) pthread_detach (pthread_self ());
+
+ /* The parent thread has all signals blocked. This is probably a
+ bit surprising for this thread. So we unblock all of them. */
+ (void) change_sigmask (SIG_UNBLOCK, NULL);
+
+ /* Now run the user code. */
+ fct (param);
+
+ /* And we are done. */
+ return NULL;
+}
+
+
+/* Helper thread. */
+static void *
+helper_thread (void *arg)
+{
+ while (1)
+ {
+ union notify_data data;
+
+ ssize_t n = recv (netlink_socket, &data, sizeof (data),
+ MSG_NOSIGNAL | MSG_WAITALL);
+ if (n < NOTIFY_COOKIE_LEN)
+ continue;
+
+ if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_WOKENUP)
+ {
+ /* Just create the thread as instructed. There is no way to
+ report a problem with creating a thread. */
+ pthread_t th;
+ if (__builtin_expect (pthread_create (&th, data.attr,
+ notification_function, &data)
+ == 0, 0))
+ /* Since we passed a pointer to DATA to the new thread we have
+ to wait until it is done with it. */
+ (void) pthread_barrier_wait (&notify_barrier);
+ }
+ else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED)
+ /* The only state we keep is the copy of the thread attributes. */
+ free (data.attr);
+ }
+}
+
+
+static void
+reset_once (void)
+{
+ once = PTHREAD_ONCE_INIT;
+}
+
+
+static void
+init_mq_netlink (void)
+{
+ /* This code might be called a second time after fork(). The file
+ descriptor is inherited from the parent. */
+ if (netlink_socket == -1)
+ {
+ /* Just a normal netlink socket, not bound. */
+ netlink_socket = socket (AF_NETLINK, SOCK_RAW, 0);
+ /* No need to do more if we have no socket. */
+ if (netlink_socket == -1)
+ return;
+
+ /* Make sure the descriptor is closed on exec. */
+ if (fcntl (netlink_socket, F_SETFD, FD_CLOEXEC) != 0)
+ goto errout;
+ }
+
+ int err = 1;
+
+ /* Initialize the barrier. */
+ if (__builtin_expect (pthread_barrier_init (&notify_barrier, NULL, 2) == 0,
+ 0))
+ {
+ /* Create the helper thread. */
+ pthread_attr_t attr;
+ (void) pthread_attr_init (&attr);
+ (void) pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
+ /* We do not need much stack space, the bare minimum will be enough. */
+ (void) pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN);
+
+ /* Temporarily block all signals so that the newly created
+ thread inherits the mask. */
+ sigset_t oss;
+ int have_no_oss = change_sigmask (SIG_BLOCK, &oss);
+
+ pthread_t th;
+ err = pthread_create (&th, &attr, helper_thread, NULL);
+
+ /* Reset the signal mask. */
+ if (!have_no_oss)
+ pthread_sigmask (SIG_SETMASK, &oss, NULL);
+
+ (void) pthread_attr_destroy (&attr);
+
+ if (err == 0)
+ {
+ static int added_atfork;
+
+ if (added_atfork == 0
+ && pthread_atfork (NULL, NULL, reset_once) != 0)
+ {
+ /* The child thread will call recv() which is a
+ cancellation point. */
+ (void) pthread_cancel (th);
+ err = 1;
+ }
+ else
+ added_atfork = 1;
+ }
+ }
+
+ if (err != 0)
+ {
+ errout:
+ close_not_cancel_no_status (netlink_socket);
+ netlink_socket = -1;
+ }
+}
+
+
+/* Register notification upon message arrival to an empty message queue
+ MQDES. */
+int
+mq_notify (mqd_t mqdes, const struct sigevent *notification)
+{
+ /* Make sure the type is correctly defined. */
+ assert (sizeof (union notify_data) == NOTIFY_COOKIE_LEN);
+
+ /* Special treatment needed for SIGEV_THREAD. */
+ if (notification == NULL || notification->sigev_notify != SIGEV_THREAD)
+ return INLINE_SYSCALL (mq_notify, 2, mqdes, notification);
+
+ /* The kernel cannot directly start threads. This will have to be
+ done at userlevel. Since we cannot start threads from signal
+ handlers we have to create a dedicated thread which waits for
+ notifications for arriving messages and creates threads in
+ response. */
+
+ /* Initialize only once. */
+ pthread_once (&once, init_mq_netlink);
+
+ /* If we cannot create the netlink socket we cannot provide
+ SIGEV_THREAD support. */
+ if (__builtin_expect (netlink_socket == -1, 0))
+ {
+ __set_errno (ENOSYS);
+ return -1;
+ }
+
+ /* Create the cookie. It will hold almost all the state. */
+ union notify_data data;
+ memset (&data, '\0', sizeof (data));
+ data.fct = notification->sigev_notify_function;
+ data.param = notification->sigev_value;
+
+ if (notification->sigev_notify_attributes != NULL)
+ {
+ /* The thread attribute has to be allocated separately. */
+ data.attr = (pthread_attr_t *) malloc (sizeof (pthread_attr_t));
+ if (data.attr == NULL)
+ return -1;
+
+ memcpy (data.attr, notification->sigev_notify_attributes,
+ sizeof (pthread_attr_t));
+ }
+
+ /* Construct the new request. */
+ struct sigevent se;
+ se.sigev_notify = SIGEV_THREAD;
+ se.sigev_signo = netlink_socket;
+ se.sigev_value.sival_ptr = &data;
+
+ /* Tell the kernel. */
+ int retval = INLINE_SYSCALL (mq_notify, 2, mqdes, &se);
+
+ /* If it failed, free the allocated memory. */
+ if (__builtin_expect (retval != 0, 0))
+ free (data.attr);
+
+ return retval;
+}
+
+#else
+# include <sysdeps/generic/mq_notify.c>
+#endif