Changeset 11500

Timestamp:

Dec 11, 2008, 9:17:04 AM (12 years ago)

Author:

gb

Message:

Since SIQQUIT can be sent to the process, using a handler for it to
force threads to die somewhat cleanly leads to unexpected behavior
(e.g., kills whatever thread's unlucky enough to receive that
signal.)

Reorganize things a bit, to minimize references to SIGQUIT and
hopefully make it easier to use some signal that's not used by
the platform unless we can reliably differentiate between
signals sent thread-to-thread and those sent sent "to the process."
(So far, it seems that Linux and Solaris reliably identify signals
sent by pthread_kill and FreeBSD and Darwin don't; unfortunately,
it may be harder to find "unused but usable" signal numbers on
FreeBSD and Darwin.)

These changes shouldn't change the status quo, but may make it
easier to do so.

Location:

trunk/source/lisp-kernel

Files:

• Threads.h (modified) (1 diff)
• ppc-exceptions.c (modified) (1 diff)
• thread_manager.c (modified) (2 diffs)
• x86-exceptions.c (modified) (2 diffs)

trunk/source/lisp-kernel/Threads.h

@@ -240 +240 @@
 #endif
 
-extern int thread_suspend_signal, thread_resume_signal;
+
+#define SIG_KILL_THREAD  SIGQUIT   /* unless we can find something better */
+
+extern int thread_suspend_signal, thread_quit_signal;
 
 void *

trunk/source/lisp-kernel/ppc-exceptions.c

@@ -2206 +2206 @@
 {
   thread_suspend_signal = SIG_SUSPEND_THREAD;
+  thread_quit_signal = SIG_KILL_THREAD;
 
   install_signal_handler(thread_suspend_signal, (void *) suspend_resume_handler);

trunk/source/lisp-kernel/thread_manager.c

@@ -547 +547 @@
 
 
-int thread_suspend_signal = 0, thread_resume_signal = 0;
+int thread_suspend_signal = 0, thread_quit_signal = 0;
 
 
@@ -2021 +2021 @@
       }
 #else
-      if (pthread_kill((pthread_t)osid,SIGQUIT)) {
+      if (pthread_kill((pthread_t)osid,thread_quit_signal)) {
         result = false;
       }

trunk/source/lisp-kernel/x86-exceptions.c

@@ -2023 +2023 @@
   TCR *tcr = get_tcr(false);
   sigset_t mask;
-  
+
   sigemptyset(&mask);
 
   empty_tcr_stacks(tcr);
-  
+
   pthread_sigmask(SIG_SETMASK,&mask,NULL);
   pthread_exit(NULL);
@@ -2110 +2110 @@
 {
   thread_suspend_signal = SIG_SUSPEND_THREAD;
+  thread_quit_signal = SIG_KILL_THREAD;
 
   install_signal_handler(thread_suspend_signal, (void *)SUSPEND_RESUME_HANDLER);
-  install_signal_handler(SIGQUIT, (void *)QUIT_HANDLER);
+  install_signal_handler(thread_quit_signal, (void *)QUIT_HANDLER);
 }
 #endif