svn commit: r484674 - /incubator/stdcxx/trunk/util/exec.cpp

[ablack]

Author: ablack
Date: Fri Dec  8 09:58:21 2006
New Revision: 484674

URL: http://svn.apache.org/viewvc?view=rev&rev=484674
Log:
2006-12-07  Andrew Black  <[EMAIL PROTECTED]>

        * exec.cpp (alarm_timeout) [!_WIN32]: Update documentation.
        (kill_signal) [!WIN32]: Add file local variable to track signal used to 
        kill process.
        (handle_term_signal) [!_WIN32]: Add new callback function...
        (wait_for_child) [!_WIN32]: ... Used here for SIGHUP, SIGINT, SIGQUIT, 
        and SIGTERM signals (via sigaction).  Handlers are cleared if 
        kill_signal is set and the signal contained within is raise()ed.

Modified:
    incubator/stdcxx/trunk/util/exec.cpp

Modified: incubator/stdcxx/trunk/util/exec.cpp
URL: 
http://svn.apache.org/viewvc/incubator/stdcxx/trunk/util/exec.cpp?view=diff&rev=484674&r1=484673&r2=484674
==============================================================================
--- incubator/stdcxx/trunk/util/exec.cpp (original)
+++ incubator/stdcxx/trunk/util/exec.cpp Fri Dec  8 09:58:21 2006
@@ -64,10 +64,19 @@
    Value is 1 when alarm has been triggered and hasn't been handled
 
    @see handle_alrm
+   @see handle_term_signal
 */
 static int alarm_timeout;
 
 /**
+   Record of fatal signal recieved.  Used to raise() the signal again after
+   child process has been killed.
+
+   @see handle_term_signal
+*/
+static int kill_signal;
+
+/**
     Utility macro to generate a signal number/name pair.
     
     @parm val 'short' signal name (no leading SIG) to generate pair for.
@@ -360,6 +369,22 @@
         alarm_timeout = 1;
 }
 
+/**
+   Callback used to gracefully terminate the utility if signaled to do so
+   while running a target
+
+   @param signo the signal recieved (should be in {SIGHUP, SIGINT, SIGQUIT, 
+   SIGTERM})
+   @see alarm_timeout
+
+*/
+static void
+handle_term_signal (int signo)
+{
+    kill_signal = signo;
+    alarm_timeout = 1;
+}
+
 typedef void (*alarm_handler)(int);
 
 #ifdef __cplusplus
@@ -428,6 +453,19 @@
 
     sigaction (SIGALRM, &act, 0);
     
+    /* Set handlers for SIGHUP, SIGINT, SIGQUIT, SIGTERM so we can kill the
+       child process prior to dieing.
+    */
+    kill_signal = 0;
+
+    phandler = handle_term_signal;
+    memcpy (&act.sa_handler, &phandler, sizeof act.sa_handler);
+
+    sigaction (SIGHUP, &act, 0);
+    sigaction (SIGINT, &act, 0);
+    sigaction (SIGQUIT, &act, 0);
+    sigaction (SIGTERM, &act, 0);
+
     if (timeout > 0)
         alarm (timeout);
 
@@ -557,6 +595,20 @@
     while (siginx < sigcount && 0 == kill (-child_pid, signals [siginx])) {
         ++siginx;
         sleep (1);
+    }
+
+    /* Check if we were signaled to quit. */
+    if (kill_signal) {
+        /* Reset the handlers to normal */
+        act.sa_handler = SIG_DFL;
+        sigaction (SIGHUP, &act, 0);
+        sigaction (SIGINT, &act, 0);
+        sigaction (SIGQUIT, &act, 0);
+        sigaction (SIGTERM, &act, 0);
+
+        if (0 > raise (kill_signal))
+            terminate (1, "raise(%s) failed: %s\n",
+                       get_signame (kill_signal), strerror (errno));
     }
 }