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+/*
+ * signal.c
+ *
+ * Description:
+ * Thread-aware signal functions.
+ *
+ * --------------------------------------------------------------------------
+ *
+ * Pthreads-win32 - POSIX Threads Library for Win32
+ * Copyright(C) 1998 John E. Bossom
+ * Copyright(C) 1999,2005 Pthreads-win32 contributors
+ *
+ * Contact Email: rpj@callisto.canberra.edu.au
+ *
+ * The current list of contributors is contained
+ * in the file CONTRIBUTORS included with the source
+ * code distribution. The list can also be seen at the
+ * following World Wide Web location:
+ * http://sources.redhat.com/pthreads-win32/contributors.html
+ *
+ * This 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 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library in the file COPYING.LIB;
+ * if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+/*
+ * Possible future 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.p == 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.p->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.p->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.p->sigmask), set, sizeof (sigset_t));
+ break;
+ }
+ }
+
+ return 0;
+}
+
+int
+sigwait (const sigset_t * set, int *sig)
+{
+ /* This routine is a cancellation point */
+ pthread_test_cancel();
+}
+
+int
+sigaction (int signum, const struct sigaction *act, struct sigaction *oldact)
+{
+}
+
+#endif /* HAVE_SIGSET_T */