From cf6b495d8f6d8f08fd6603c5ba2ec7a6acf7ac01 Mon Sep 17 00:00:00 2001
From: Ian Lynagh <igloo@earth.li>
Date: Mon, 11 Dec 2006 13:10:04 +0000
Subject: [PATCH] Add freeScheduler/freeTaskManager and call it later than
 exitScheduler We were freeing the tasks in exitScheduler
 (stopTaskManager) before exitStorage (stat_exit), but the
 latter needs to walk down the list printing stats. Resulted
 in segfaults with commands like     ghc -v0 -e main q.hs
 -H32m -H32m +RTS -Sstderr (where q.hs is trivial), but very
 sensitive to exact commandline and libc version or
 something.

---
 rts/RtsStartup.c |    3 +++
 rts/Schedule.c   |    6 ++++++
 rts/Schedule.h   |    1 +
 rts/Task.c       |   20 +++++++++++++++++---
 rts/Task.h       |    1 +
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/rts/RtsStartup.c b/rts/RtsStartup.c
index 5bb9806..937334b 100644
--- a/rts/RtsStartup.c
+++ b/rts/RtsStartup.c
@@ -438,6 +438,9 @@ hs_exit(void)
     // also outputs the stats (+RTS -s) info.
     exitStorage();
     
+    /* free the tasks */
+    freeScheduler();
+
     /* free shared Typeable store */
     exitTypeableStore();
 
diff --git a/rts/Schedule.c b/rts/Schedule.c
index cf62c5a..77dcf41 100644
--- a/rts/Schedule.c
+++ b/rts/Schedule.c
@@ -2582,6 +2582,12 @@ exitScheduler( void )
 #endif
 }
 
+void
+freeScheduler( void )
+{
+    freeTaskManager();
+}
+
 /* ---------------------------------------------------------------------------
    Where are the roots that we know about?
 
diff --git a/rts/Schedule.h b/rts/Schedule.h
index 2afedee..ba5efc2 100644
--- a/rts/Schedule.h
+++ b/rts/Schedule.h
@@ -19,6 +19,7 @@
  */
 void initScheduler (void);
 void exitScheduler (void);
+void freeScheduler (void);
 
 // Place a new thread on the run queue of the current Capability
 void scheduleThread (Capability *cap, StgTSO *tso);
diff --git a/rts/Task.c b/rts/Task.c
index 588d414..0e51dbf 100644
--- a/rts/Task.c
+++ b/rts/Task.c
@@ -68,19 +68,33 @@ initTaskManager (void)
 void
 stopTaskManager (void)
 {
-    Task *task, *next;
+    Task *task;
 
     debugTrace(DEBUG_sched, 
 	       "stopping task manager, %d tasks still running",
 	       tasksRunning);
 
     ACQUIRE_LOCK(&sched_mutex);
-    for (task = task_free_list; task != NULL; task = next) {
-        next = task->next;
+    for (task = task_free_list; task != NULL; task = task->next) {
 #if defined(THREADED_RTS)
         closeCondition(&task->cond);
         closeMutex(&task->lock);
 #endif
+    }
+    RELEASE_LOCK(&sched_mutex);
+}
+
+
+void
+freeTaskManager (void)
+{
+    Task *task, *next;
+
+    debugTrace(DEBUG_sched, "freeing task manager");
+
+    ACQUIRE_LOCK(&sched_mutex);
+    for (task = task_free_list; task != NULL; task = next) {
+        next = task->next;
         stgFree(task);
     }
     task_free_list = NULL;
diff --git a/rts/Task.h b/rts/Task.h
index cc450a7..3b7a08e 100644
--- a/rts/Task.h
+++ b/rts/Task.h
@@ -170,6 +170,7 @@ extern Task *all_tasks;
 //
 void initTaskManager (void);
 void stopTaskManager (void);
+void freeTaskManager (void);
 
 // Create a new Task for a bound thread
 // Requires: sched_mutex.
-- 
1.7.10.4