R6.6 is the Xorg base-lineXORG-MAIN

1 files changed, 251 insertions, 0 deletions

diff --git a/signals.c b/signals.c
new file mode 100644
index 0000000..ec73792
--- /dev/null
+++ b/signals.c
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+/* $Xorg: signals.c,v 1.4 2001/02/09 02:06:01 xorgcvs Exp $ */
+/******************************************************************************
+
+Copyright 1994, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from The Open Group.
+******************************************************************************/
+
+#include <X11/Xos.h>
+#include <X11/Xfuncs.h>
+
+#include <X11/SM/SMlib.h>
+
+#ifdef USG
+#ifndef __TYPES__
+#include <sys/types.h>			/* forgot to protect it... */
+#define __TYPES__
+#endif /* __TYPES__ */
+#else
+#if defined(_POSIX_SOURCE) && defined(MOTOROLA)
+#undef _POSIX_SOURCE
+#include <sys/types.h>
+#define _POSIX_SOURCE
+#else
+#include <sys/types.h>
+#endif
+#endif /* USG */
+
+#ifdef X_POSIX_C_SOURCE
+#define _POSIX_C_SOURCE X_POSIX_C_SOURCE
+#include <signal.h>
+#include <sys/wait.h>
+#undef _POSIX_C_SOURCE
+#else
+#if defined(X_NOT_POSIX) || defined(_POSIX_SOURCE)
+#include <signal.h>
+#include <sys/wait.h>
+#else
+#define _POSIX_SOURCE
+#include <signal.h>
+#include <sys/wait.h>
+#undef _POSIX_SOURCE
+#endif
+#endif
+
+#if defined(X_NOT_POSIX) && defined(SIGNALRETURNSINT)
+#define SIGVAL int
+#else
+#define SIGVAL void
+#endif
+
+#ifndef X_NOT_POSIX
+#define USE_POSIX_WAIT
+#endif
+
+#if defined(linux) || defined(SYSV)
+#define USE_SYSV_SIGNALS
+#endif
+
+#if defined(SCO) || defined(ISC)
+#undef SIGTSTP			/* defined, but not the BSD way */
+#endif
+
+#if defined(X_NOT_POSIX) && defined(SYSV)
+#define SIGNALS_RESET_WHEN_CAUGHT
+#endif
+
+#ifndef NULL
+#define NULL 0
+#endif
+
+int checkpoint_from_signal = 0;
+
+extern Bool wantShutdown;
+
+
+SIGVAL (*Signal (sig, handler))()
+    int sig;
+    SIGVAL (*handler)();
+{
+#ifndef X_NOT_POSIX
+    struct sigaction sigact, osigact;
+    sigact.sa_handler = handler;
+    sigemptyset(&sigact.sa_mask);
+    sigact.sa_flags = 0;
+    sigaction(sig, &sigact, &osigact);
+    return osigact.sa_handler;
+#else
+    return signal(sig, handler);
+#endif
+}
+
+
+void
+sig_child_handler ()
+
+{
+    int pid;
+
+#if !defined(USE_POSIX_WAIT) && (defined(USE_SYSV_SIGNALS) && \
+    (defined(CRAY) || !defined(SIGTSTP)))
+    wait (NULL);
+#endif
+
+#ifdef SIGNALS_RESET_WHEN_CAUGHT
+    Signal (SIGCHLD, sig_child_handler);
+#endif
+
+    /*
+     * The wait() above must come before re-establishing the signal handler.
+     * In between this time, a new child might have died.  If we can do
+     * a non-blocking wait, we can check for this race condition.  If we
+     * don't have non-blocking wait, we lose.
+     */
+
+    do
+    {
+#ifdef USE_POSIX_WAIT
+	pid = waitpid (-1, NULL, WNOHANG);
+#else
+#if defined(USE_SYSV_SIGNALS) && (defined(CRAY) || !defined(SIGTSTP))
+	/* cannot do non-blocking wait */
+	pid = 0;
+#else
+	union wait status;
+
+	pid = wait3 (&status, WNOHANG, (struct rusage *)NULL);
+#endif
+#endif /* USE_POSIX_WAIT else */
+    }
+    while (pid > 0);
+}
+
+
+void
+sig_term_handler ()
+
+{
+    wantShutdown = 1;
+    checkpoint_from_signal = 1;
+    DoSave (SmSaveLocal, SmInteractStyleNone, 1 /* fast */);
+}
+
+
+void
+sig_usr1_handler ()
+
+{
+    wantShutdown = 0;
+    checkpoint_from_signal = 1;
+    DoSave (SmSaveLocal, SmInteractStyleNone, 0 /* fast */);
+}
+
+
+
+void
+register_signals ()
+
+{
+    /*
+     * Ignore SIGPIPE
+     */
+
+    Signal (SIGPIPE, SIG_IGN);
+
+
+    /*
+     * If child process dies, call our handler
+     */
+
+    Signal (SIGCHLD, sig_child_handler);
+
+
+    /*
+     * If we get a SIGTERM, do shutdown, fast, local, no interact
+     */
+
+    Signal (SIGTERM, sig_term_handler);
+
+
+    /*
+     * If we get a SIGUSR1, do checkpoint, local, no interact
+     */
+
+    Signal (SIGUSR1, sig_usr1_handler);
+}
+
+
+
+int
+execute_system_command (s)
+
+char *s;
+
+{
+    int stat;
+
+#ifdef X_NOT_POSIX
+    /*
+     * Non-POSIX system() uses wait().  We must disable our sig child
+     * handler because if it catches the signal, system() will block
+     * forever in wait().
+     */
+
+    int pid;
+
+    Signal (SIGCHLD, SIG_IGN);
+#endif
+
+    stat = system (s);
+
+#ifdef X_NOT_POSIX
+    /*
+     * Re-enable our sig child handler.  We might have missed some signals,
+     * so do non-blocking waits until there are no signals left.
+     */
+
+    Signal (SIGCHLD, sig_child_handler);
+
+#if !(defined(USE_SYSV_SIGNALS) && (defined(CRAY) || !defined(SIGTSTP)))
+    do
+    {
+	union wait status;
+
+	pid = wait3 (&status, WNOHANG, (struct rusage *)NULL);
+    } while (pid > 0);
+#endif
+#endif   /* X_NOT_POSIX */
+
+    return (stat);
+}
+
+