# HG changeset patch
# User johnc
# Date 1321896296 28800
# Node ID b5a5f30c483d720e5aa4558cedb2b3a627a854fc
# Parent  d06a2d7fcd5bd27a834c2d0742110658e17790d3
7110173: GCNotifier::pushNotification publishes stale data.
Summary: GCNotifier::pushNotification() references GCMemoryManager::_last_gc_stat but is called from GCMemoryManager::gc_end() before GCMemoryManager::_last_gc_stat is set up using the values in GCMemoryManager::_current_gc_stat. As a result the GC notification code accesses unitialized or stale data. Move the notification call after GCMemoryManager::_las_gc_stat is set, but inside the same if-block.
Reviewed-by: poonam, dholmes, fparain, mchung

diff -r d06a2d7fcd5b -r b5a5f30c483d src/share/vm/services/memoryManager.cpp
--- a/src/share/vm/services/memoryManager.cpp	Mon Nov 21 07:47:34 2011 +0100
+++ b/src/share/vm/services/memoryManager.cpp	Mon Nov 21 09:24:56 2011 -0800
@@ -168,10 +168,8 @@
   // initialize the arrays for memory usage
   _before_gc_usage_array = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
   _after_gc_usage_array  = (MemoryUsage*) NEW_C_HEAP_ARRAY(MemoryUsage, num_pools);
-  size_t len = num_pools * sizeof(MemoryUsage);
-  memset(_before_gc_usage_array, 0, len);
-  memset(_after_gc_usage_array, 0, len);
   _usage_array_size = num_pools;
+  clear();
 }
 
 GCStatInfo::~GCStatInfo() {
@@ -304,12 +302,8 @@
       pool->set_last_collection_usage(usage);
       LowMemoryDetector::detect_after_gc_memory(pool);
     }
-    if(is_notification_enabled()) {
-      bool isMajorGC = this == MemoryService::get_major_gc_manager();
-      GCNotifier::pushNotification(this, isMajorGC ? "end of major GC" : "end of minor GC",
-                                   GCCause::to_string(cause));
-    }
   }
+
   if (countCollection) {
     _num_collections++;
     // alternately update two objects making one public when complete
@@ -321,6 +315,12 @@
       // reset the current stat for diagnosability purposes
       _current_gc_stat->clear();
     }
+
+    if (is_notification_enabled()) {
+      bool isMajorGC = this == MemoryService::get_major_gc_manager();
+      GCNotifier::pushNotification(this, isMajorGC ? "end of major GC" : "end of minor GC",
+                                   GCCause::to_string(cause));
+    }
   }
 }