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| author | Guenter Bartsch <guenter@users.sourceforge.net> | 2003-04-20 16:42:06 +0000 |
|---|---|---|
| committer | Guenter Bartsch <guenter@users.sourceforge.net> | 2003-04-20 16:42:06 +0000 |
| commit | ce4f3efd78c110c015c54eab05f201d1caac5f8d (patch) | |
| tree | 668c555d5de70518b93426f45fe3e44d7f06663c /win32/contrib/pthreads/signal.c | |
| parent | 80f6215b607f0ed76f7f75deaf4e4668bc6f244d (diff) | |
| download | xine-lib-ce4f3efd78c110c015c54eab05f201d1caac5f8d.tar.gz xine-lib-ce4f3efd78c110c015c54eab05f201d1caac5f8d.tar.bz2 | |
importing win32 contrib sources and msvc build environment
CVS patchset: 4641
CVS date: 2003/04/20 16:42:06
Diffstat (limited to 'win32/contrib/pthreads/signal.c')
| -rw-r--r-- | win32/contrib/pthreads/signal.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/win32/contrib/pthreads/signal.c b/win32/contrib/pthreads/signal.c new file mode 100644 index 000000000..867dc4cc7 --- /dev/null +++ b/win32/contrib/pthreads/signal.c @@ -0,0 +1,172 @@ +/*
+ * signal.c
+ *
+ * Description:
+ * Thread-aware signal functions.
+ *
+ * Pthreads-win32 - POSIX Threads Library for Win32
+ * Copyright (C) 1998
+ *
+ * This 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.
+ *
+ * This 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 this library; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA
+ */
+
+/*
+ * Strategy for implementing pthread_kill()
+ * ========================================
+ *
+ * Win32 does not implement signals.
+ * Signals are simply software interrupts.
+ * pthread_kill() asks the system to deliver a specified
+ * signal (interrupt) to a specified thread in the same
+ * process.
+ * Signals are always asynchronous (no deferred signals).
+ * Pthread-win32 has an async cancelation mechanism.
+ * A similar system can be written to deliver signals
+ * within the same process (on ix86 processors at least).
+ *
+ * Each thread maintains information about which
+ * signals it will respond to. Handler routines
+ * are set on a per-process basis - not per-thread.
+ * When signalled, a thread will check it's sigmask
+ * and, if the signal is not being ignored, call the
+ * handler routine associated with the signal. The
+ * thread must then (except for some signals) return to
+ * the point where it was interrupted.
+ *
+ * Ideally the system itself would check the target thread's
+ * mask before possibly needlessly bothering the thread
+ * itself. This could be done by pthread_kill(), that is,
+ * in the signaling thread since it has access to
+ * all pthread_t structures. It could also retrieve
+ * the handler routine address to minimise the target
+ * threads response overhead. This may also simplify
+ * serialisation of the access to the per-thread signal
+ * structures.
+ *
+ * pthread_kill() eventually calls a routine similar to
+ * ptw32_cancel_thread() which manipulates the target
+ * threads processor context to cause the thread to
+ * run the handler launcher routine. pthread_kill() must
+ * save the target threads current context so that the
+ * handler launcher routine can restore the context after
+ * the signal handler has returned. Some handlers will not
+ * return, eg. the default SIGKILL handler may simply
+ * call pthread_exit().
+ *
+ * The current context is saved in the target threads
+ * pthread_t structure.
+ */
+
+#include "pthread.h"
+#include "implement.h"
+
+#if HAVE_SIGSET_T
+
+static void
+ptw32_signal_thread()
+{
+}
+
+static void
+ptw32_signal_callhandler()
+{
+}
+
+int
+pthread_sigmask(int how, sigset_t const *set, sigset_t *oset)
+{
+ pthread_t thread = pthread_self();
+
+ if (thread == NULL)
+ {
+ return ENOENT;
+ }
+
+ /* Validate the `how' argument.*/
+ if (set != NULL)
+ {
+ switch (how)
+ {
+ case SIG_BLOCK:
+ break;
+ case SIG_UNBLOCK:
+ break;
+ case SIG_SETMASK:
+ break;
+ default:
+ /* Invalid `how' argument. */
+ return EINVAL;
+ }
+ }
+
+ /* Copy the old mask before modifying it. */
+ if (oset != NULL)
+ {
+ memcpy(oset, &(thread->sigmask), sizeof(sigset_t));
+ }
+
+ if (set != NULL)
+ {
+ unsigned int i;
+
+ /* FIXME: this code assumes that sigmask is an even multiple of
+ the size of a long integer. */
+
+ unsigned long *src = (unsigned long const *) set;
+ unsigned long *dest = (unsigned long *) &(thread->sigmask);
+
+ switch (how)
+ {
+ case SIG_BLOCK:
+ for (i = 0; i < (sizeof(sigset_t) / sizeof(unsigned long)); i++)
+ {
+ /* OR the bit field longword-wise. */
+ *dest++ |= *src++;
+ }
+ break;
+ case SIG_UNBLOCK:
+ for (i = 0; i < (sizeof(sigset_t) / sizeof(unsigned long)); i++)
+ {
+ /* XOR the bitfield longword-wise. */
+ *dest++ ^= *src++;
+ }
+ case SIG_SETMASK:
+ /* Replace the whole sigmask. */
+ memcpy(&(thread->sigmask), set, sizeof(sigset_t));
+ break;
+ }
+ }
+
+ return 0;
+}
+
+int pthread_kill(pthread_t thread,
+ int signo)
+{
+}
+
+int sigwait(const sigset_t *set,
+ int *sig)
+{
+}
+
+int sigaction(int signum,
+ const struct sigaction *act,
+ struct sigaction *oldact)
+{
+}
+
+#endif /* HAVE_SIGSET_T */
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