[Aptitude-svn-commit] r4101 - in branches/aptitude-0.3/aptitude: . src/generic

[Daniel Burrows]

Author: dburrows
Date: Fri Sep 16 22:00:00 2005
New Revision: 4101

Modified:
   branches/aptitude-0.3/aptitude/ChangeLog
   branches/aptitude-0.3/aptitude/src/generic/resolver_manager.cc
Log:
Don't segfault or deadlock when shutting down the resolver thread if the resolver was discarded.

Modified: branches/aptitude-0.3/aptitude/ChangeLog
==============================================================================
--- branches/aptitude-0.3/aptitude/ChangeLog	(original)
+++ branches/aptitude-0.3/aptitude/ChangeLog	Fri Sep 16 22:00:00 2005
@@ -1,3 +1,19 @@
+2005-09-16  Daniel Burrows  <dburrows at debian.org>
+
+	* src/generic/resolver_manager.cc:
+
+	  Make a thread-kill override all other control messages, so that
+	  the program doesn't deadlock trying to shut the background
+	  thread down.  What would happen was that if, e.g., the resolver
+	  was null and the foreground thread tried to kill the background
+	  thread, the background thread would sit there waiting for the
+	  resolver to be non-null.
+
+	* src/generic/resolver_manager.cc:
+
+	  Fix a segfault that occurred when shutting down the resolver
+	  thread.
+
 2005-09-15  Daniel Burrows  <dburrows at debian.org>
 
 	* src/generic/problemresolver/Makefile.am:

Modified: branches/aptitude-0.3/aptitude/src/generic/resolver_manager.cc
==============================================================================
--- branches/aptitude-0.3/aptitude/src/generic/resolver_manager.cc	(original)
+++ branches/aptitude-0.3/aptitude/src/generic/resolver_manager.cc	Fri Sep 16 22:00:00 2005
@@ -100,8 +100,8 @@
 
   while(1)
     {
-      while(background_thread_suspend_count > 0 || resolver_null ||
-	    (!background_thread_killed && pending_jobs.empty()))
+      while((background_thread_suspend_count > 0 || resolver_null || pending_jobs.empty()) &&
+	    !background_thread_killed)
 	background_control_cond.wait(l);
 
       if(background_thread_killed)
@@ -173,7 +173,8 @@
     {
       threads::mutex::lock control_lock(background_control_mutex);
 
-      resolver->cancel_solver();
+      if(resolver != NULL)
+	resolver->cancel_solver();
       background_thread_killed = true;
       background_control_cond.wake_all();
 
@@ -204,7 +205,8 @@
 
   threads::mutex::lock control_lock(background_control_mutex);
 
-  resolver->cancel_solver();
+  if(resolver != NULL)
+    resolver->cancel_solver();
 
   ++background_thread_suspend_count;
   background_control_cond.wake_all();
@@ -212,7 +214,8 @@
   while(background_thread_in_resolver)
     background_resolver_cond.wait(control_lock);
 
-  resolver->uncancel_solver();
+  if(resolver != NULL)
+    resolver->uncancel_solver();
 }
 
 void resolver_manager::unsuspend_background_thread()