From: Stefan Ring <stefan@complang.tuwien.ac.at>
Date: Tue, 23 Jun 2009 13:13:04 +0000 (+0200)
Subject: Fixes PR131.
X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=cacao.git;a=commitdiff_plain;h=081b5d0c4965aa1507e975990f2f9ea95471f440

Fixes PR131.
* src/threads/lock.cpp: Remove lock records only after they have become
absolutely unreachable.
* src/threads/lock.hpp: Added lock_schedule_lockrecord_removal.
* src/vm/finalizer.cpp: Schedule lock record removal.
---

diff --git a/src/threads/lock.cpp b/src/threads/lock.cpp
index df007f1e8..ae7bb8740 100644
--- a/src/threads/lock.cpp
+++ b/src/threads/lock.cpp
@@ -459,7 +459,14 @@ static lock_record_t *lock_hashtable_get(java_handle_t* o)
 #if defined(ENABLE_GC_BOEHM)
 		/* register new finalizer to clean up the lock record */
 
-		GC_REGISTER_FINALIZER(LLNI_DIRECT(o), lock_record_finalizer, 0, 0, 0);
+		GC_finalization_proc ofinal = 0;
+		GC_REGISTER_FINALIZER_UNREACHABLE(LLNI_DIRECT(o), lock_record_finalizer, 0, &ofinal, 0);
+
+		/* There was a finalizer -- reinstall it. We do not want to disrupt the
+		   normal finalizer operation. We hold the monitor on this object, so
+		   this is thread-safe. */
+		if (ofinal)
+			GC_REGISTER_FINALIZER(LLNI_DIRECT(o), ofinal, 0, 0, 0);
 #endif
 
 		/* enter it in the hashtable */
@@ -483,6 +490,29 @@ static lock_record_t *lock_hashtable_get(java_handle_t* o)
 	return lr;
 }
 
+/* lock_schedule_lockrecord_removal ********************************************
+
+   Gives the locking system a chance to schedule the removal of an unused lock
+   record. This function is called after an object's finalizer has run.
+
+   IN:
+	  o....the object which has been finalized
+
+*******************************************************************************/
+
+#if defined(ENABLE_GC_BOEHM)
+void lock_schedule_lockrecord_removal(java_handle_t *o)
+{
+	Lockword* lockword = lock_lockword_get(o);
+	if (!lockword->is_fat_lock())
+		/* there is no lock record */
+		return;
+
+	/* register new finalizer to clean up the lock record */
+	GC_REGISTER_FINALIZER_UNREACHABLE(LLNI_DIRECT(o), lock_record_finalizer, 0, 0, 0);
+}
+#endif
+
 
 /* lock_hashtable_remove *******************************************************
 
@@ -578,11 +608,6 @@ static void lock_record_finalizer(void *object, void *p)
 	}
 #endif
 
-	/* check for a finalizer function */
-
-	if (c->finalizer != NULL)
-		finalizer_run(object, p);
-
 	/* remove the lock-record entry from the hashtable and free it */
 
 	lock_hashtable_remove(THREADOBJECT, o);
diff --git a/src/threads/lock.hpp b/src/threads/lock.hpp
index 87519d98e..07bd54b67 100644
--- a/src/threads/lock.hpp
+++ b/src/threads/lock.hpp
@@ -97,6 +97,10 @@ void lock_wait_for_object(java_handle_t *o, s8 millis, s4 nanos);
 void lock_notify_object(java_handle_t *o);
 void lock_notify_all_object(java_handle_t *o);
 
+#if defined(ENABLE_GC_BOEHM)
+void lock_schedule_lockrecord_removal(java_handle_t *o);
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/vm/finalizer.cpp b/src/vm/finalizer.cpp
index cd14c484e..7a4ecd471 100644
--- a/src/vm/finalizer.cpp
+++ b/src/vm/finalizer.cpp
@@ -34,6 +34,7 @@
 #include "threads/condition.hpp"
 #include "threads/mutex.hpp"
 #include "threads/thread.hpp"
+#include "threads/lock.hpp"
 
 #include "vm/jit/builtin.hpp"
 #include "vm/exceptions.hpp"
@@ -220,6 +221,10 @@ void finalizer_run(void *o, void *p)
 	/* if we had an exception in the finalizer, ignore it */
 
 	exceptions_clear_exception();
+
+#if defined(ENABLE_GC_BOEHM)
+    lock_schedule_lockrecord_removal(h);
+#endif
 }
 
 #if defined(__cplusplus)