Steel Bank Common Lisp

Update of /cvsroot/sbcl/sbcl/src/runtime
In directory sc8-pr-cvs8.sourceforge.net:/tmp/cvs-serv4605/src/runtime

Modified Files:
	interrupt.c 
Log Message:
1.0.4.3: interrupt and GC issues
 * Add WITHOUT-INTERRUPTS to WITHOUT-GCING.
 * Warn if WITH-INTERRUPTS nested in WITHOUT-GCING.
 * Make sure that SIG_STOP_FOR_GC and SIG_RESUME_FROM_GC are enabled on
   threaded builds before calling into SUB-GC from the runtime.
 * Better WITHOUT-GCING, WITHOUT-INTERRUPTS, and WITH-INTERRUPTS
   documentation.
 * Internals documentation about POSIX signal safety rules.


Index: interrupt.c
===================================================================
RCS file: /cvsroot/sbcl/sbcl/src/runtime/interrupt.c,v
retrieving revision 1.121
retrieving revision 1.122
diff -u -d -r1.121 -r1.122
--- interrupt.c	3 Mar 2007 00:42:02 -0000	1.121
+++ interrupt.c	26 Mar 2007 10:30:30 -0000	1.122
@@ -123,7 +123,7 @@
 #endif
 
 void
-check_blockables_blocked_or_lose()
+check_blockables_blocked_or_lose(void)
 {
 #if !defined(LISP_FEATURE_WIN32)
     /* Get the current sigmask, by blocking the empty set. */
@@ -138,6 +138,41 @@
 #endif
 }
 
+void
+check_gc_signals_unblocked_or_lose(void)
+{
+#ifdef LISP_FEATURE_SB_THREAD
+# if !defined(LISP_FEATURE_WIN32)
+    /* Get the current sigmask, by blocking the empty set. */
+    sigset_t empty,current;
+    sigemptyset(&empty);
+    thread_sigmask(SIG_BLOCK, &empty, &current);
+    if (sigismember(&current, SIG_STOP_FOR_GC))
+        lose("SIG_STOP_FOR_GC blocked in thread %p at a bad place\n",
+             arch_os_get_current_thread());
+#  if defined(SIG_RESUME_FROM_GC)
+    if (sigismember(&current, SIG_RESUME_FROM_GC))
+        lose("SIG_RESUME_FROM_GC blocked in thread %p at a bad place\n",
+             arch_os_get_current_thread());
+#  endif
+# endif
+#endif
+}
+
+void
+unblock_gc_signals(void)
+{
+#ifdef LISP_FEATURE_SB_THREAD
+    sigset_t new;
+    sigemptyset(&new);
+#if defined(SIG_RESUME_FROM_GC)
+    sigaddset(&new,SIG_RESUME_FROM_GC);
+#endif
+    sigaddset(&new,SIG_STOP_FOR_GC);
+    thread_sigmask(SIG_UNBLOCK,&new,0);
+#endif
+}
+
 inline static void
 check_interrupts_enabled_or_lose(os_context_t *context)
 {
@@ -1147,22 +1182,14 @@
      * outer context.
      */
 #ifndef LISP_FEATURE_WIN32
-    if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL)
+    if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL) {
         thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
-#ifdef LISP_FEATURE_SB_THREAD
-    else {
-        sigset_t new;
-        sigemptyset(&new);
-#if defined(SIG_RESUME_FROM_GC)
-        sigaddset(&new,SIG_RESUME_FROM_GC);
-#endif
-        sigaddset(&new,SIG_STOP_FOR_GC);
-        thread_sigmask(SIG_UNBLOCK,&new,0);
+        check_gc_signals_unblocked_or_lose();
     }
-#endif
+    else
+        unblock_gc_signals();
 #endif
     funcall0(SymbolFunction(SUB_GC));
-
     undo_fake_foreign_function_call(context);
     return 1;
 }