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authorUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
committerUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
commita334319f6530564d22e775935d9c91663623a1b4 (patch)
treeb5877475619e4c938e98757d518bb1e9cbead751 /linuxthreads/signals.c
parent0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (diff)
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(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.
Diffstat (limited to 'linuxthreads/signals.c')
-rw-r--r--linuxthreads/signals.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/linuxthreads/signals.c b/linuxthreads/signals.c
new file mode 100644
index 0000000000..50f55995a3
--- /dev/null
+++ b/linuxthreads/signals.c
@@ -0,0 +1,213 @@
+/* Linuxthreads - a simple clone()-based implementation of Posix        */
+/* threads for Linux.                                                   */
+/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
+/*                                                                      */
+/* This program 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 program 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.                 */
+
+/* Handling of signals */
+
+#include <errno.h>
+#include <signal.h>
+#include "pthread.h"
+#include "internals.h"
+#include "spinlock.h"
+#include <ucontext.h>
+
+
+int pthread_sigmask(int how, const sigset_t * newmask, sigset_t * oldmask)
+{
+  sigset_t mask;
+
+  if (newmask != NULL) {
+    mask = *newmask;
+    /* Don't allow __pthread_sig_restart to be unmasked.
+       Don't allow __pthread_sig_cancel to be masked. */
+    switch(how) {
+    case SIG_SETMASK:
+      sigaddset(&mask, __pthread_sig_restart);
+      sigdelset(&mask, __pthread_sig_cancel);
+      if (__pthread_sig_debug > 0)
+	sigdelset(&mask, __pthread_sig_debug);
+      break;
+    case SIG_BLOCK:
+      sigdelset(&mask, __pthread_sig_cancel);
+      if (__pthread_sig_debug > 0)
+	sigdelset(&mask, __pthread_sig_debug);
+      break;
+    case SIG_UNBLOCK:
+      sigdelset(&mask, __pthread_sig_restart);
+      break;
+    }
+    newmask = &mask;
+  }
+  if (sigprocmask(how, newmask, oldmask) == -1)
+    return errno;
+  else
+    return 0;
+}
+
+int pthread_kill(pthread_t thread, int signo)
+{
+  pthread_handle handle = thread_handle(thread);
+  int pid;
+
+  __pthread_lock(&handle->h_lock, NULL);
+  if (invalid_handle(handle, thread)) {
+    __pthread_unlock(&handle->h_lock);
+    return ESRCH;
+  }
+  pid = handle->h_descr->p_pid;
+  __pthread_unlock(&handle->h_lock);
+  if (kill(pid, signo) == -1)
+    return errno;
+  else
+    return 0;
+}
+
+union sighandler __sighandler[NSIG] =
+  { [1 ... NSIG - 1] = { (arch_sighandler_t) SIG_ERR } };
+
+/* The wrapper around sigaction.  Install our own signal handler
+   around the signal. */
+int __pthread_sigaction(int sig, const struct sigaction * act,
+			struct sigaction * oact)
+{
+  struct sigaction newact;
+  struct sigaction *newactp;
+  __sighandler_t old = SIG_DFL;
+
+  if (sig == __pthread_sig_restart ||
+      sig == __pthread_sig_cancel ||
+      (sig == __pthread_sig_debug && __pthread_sig_debug > 0))
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+  if (sig > 0 && sig < NSIG)
+    old = (__sighandler_t) __sighandler[sig].old;
+  if (act)
+    {
+      newact = *act;
+      if (act->sa_handler != SIG_IGN && act->sa_handler != SIG_DFL
+	  && sig > 0 && sig < NSIG)
+	{
+	  if (act->sa_flags & SA_SIGINFO)
+	    newact.sa_handler = (__sighandler_t) __pthread_sighandler_rt;
+	  else
+	    newact.sa_handler = (__sighandler_t) __pthread_sighandler;
+	  if (old == SIG_IGN || old == SIG_DFL || old == SIG_ERR)
+	    __sighandler[sig].old = (arch_sighandler_t) act->sa_handler;
+	}
+      newactp = &newact;
+    }
+  else
+    newactp = NULL;
+  if (__libc_sigaction(sig, newactp, oact) == -1)
+    {
+      if (act)
+	__sighandler[sig].old = (arch_sighandler_t) old;
+      return -1;
+    }
+  if (sig > 0 && sig < NSIG)
+    {
+      if (oact != NULL
+	  /* We may have inherited SIG_IGN from the parent, so return the
+	     kernel's idea of the signal handler the first time
+	     through.  */
+	  && old != SIG_ERR)
+	oact->sa_handler = old;
+      if (act)
+	/* For the assignment it does not matter whether it's a normal
+	   or real-time signal.  */
+	__sighandler[sig].old = (arch_sighandler_t) act->sa_handler;
+    }
+  return 0;
+}
+#ifdef SHARED
+strong_alias(__pthread_sigaction, __sigaction)
+strong_alias(__pthread_sigaction, sigaction)
+#endif
+
+/* sigwait -- synchronously wait for a signal */
+int __pthread_sigwait(const sigset_t * set, int * sig)
+{
+  volatile pthread_descr self = thread_self();
+  sigset_t mask;
+  int s;
+  sigjmp_buf jmpbuf;
+  struct sigaction sa;
+
+  /* Get ready to block all signals except those in set
+     and the cancellation signal.
+     Also check that handlers are installed on all signals in set,
+     and if not, install our dummy handler.  This is conformant to
+     POSIX: "The effect of sigwait() on the signal actions for the
+     signals in set is unspecified." */
+  sigfillset(&mask);
+  sigdelset(&mask, __pthread_sig_cancel);
+  for (s = 1; s < NSIG; s++) {
+    if (sigismember(set, s) &&
+        s != __pthread_sig_restart &&
+        s != __pthread_sig_cancel &&
+        s != __pthread_sig_debug) {
+      sigdelset(&mask, s);
+      if (__sighandler[s].old == (arch_sighandler_t) SIG_ERR ||
+          __sighandler[s].old == (arch_sighandler_t) SIG_DFL ||
+          __sighandler[s].old == (arch_sighandler_t) SIG_IGN) {
+        sa.sa_handler = __pthread_null_sighandler;
+        sigfillset(&sa.sa_mask);
+        sa.sa_flags = 0;
+        sigaction(s, &sa, NULL);
+      }
+    }
+  }
+  /* Test for cancellation */
+  if (sigsetjmp(jmpbuf, 1) == 0) {
+    THREAD_SETMEM(self, p_cancel_jmp, &jmpbuf);
+    if (! (THREAD_GETMEM(self, p_canceled)
+	   && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE)) {
+      /* Reset the signal count */
+      THREAD_SETMEM(self, p_signal, 0);
+      /* Say we're in sigwait */
+      THREAD_SETMEM(self, p_sigwaiting, 1);
+      /* Unblock the signals and wait for them */
+      sigsuspend(&mask);
+    }
+  }
+  THREAD_SETMEM(self, p_cancel_jmp, NULL);
+  /* The signals are now reblocked.  Check for cancellation */
+  pthread_testcancel();
+  /* We should have self->p_signal != 0 and equal to the signal received */
+  *sig = THREAD_GETMEM(self, p_signal);
+  return 0;
+}
+#ifdef SHARED
+strong_alias (__pthread_sigwait, sigwait)
+#endif
+
+/* Redefine raise() to send signal to calling thread only,
+   as per POSIX 1003.1c */
+int __pthread_raise (int sig)
+{
+  int retcode = pthread_kill(pthread_self(), sig);
+  if (retcode == 0)
+    return 0;
+  else {
+    errno = retcode;
+    return -1;
+  }
+}
+#ifdef SHARED
+strong_alias (__pthread_raise, raise)
+#endif
+
+/* This files handles cancellation internally.  */
+LIBC_CANCEL_HANDLED ();