# HG changeset patch
# User anoll
# Date 1399362758 -7200
# Node ID c47fcf523fff21b5964fd631d683b06dec731f6a
# Parent  0c0e68524c17709a71e9bbb4bcef9ab34581c7d4
8042428: CompileQueue::free_all() code is incorrect
Summary: Free task after getting next pointer of freelist.
Reviewed-by: kvn, adlertz

diff -r 0c0e68524c17 -r c47fcf523fff src/share/vm/compiler/compileBroker.cpp
--- a/src/share/vm/compiler/compileBroker.cpp	Wed May 07 22:06:42 2014 +0200
+++ b/src/share/vm/compiler/compileBroker.cpp	Tue May 06 09:52:38 2014 +0200
@@ -664,17 +664,27 @@
   lock()->notify_all();
 }
 
+/**
+ * Empties compilation queue by putting all compilation tasks onto
+ * a freelist. Furthermore, the method wakes up all threads that are
+ * waiting on a compilation task to finish. This can happen if background
+ * compilation is disabled.
+ */
 void CompileQueue::free_all() {
   MutexLocker mu(lock());
-  if (_first != NULL) {
-    for (CompileTask* task = _first; task != NULL; task = task->next()) {
-      // Wake up thread that blocks on the compile task.
-      task->lock()->notify();
-      // Puts task back on the freelist.
-      CompileTask::free(task);
-    }
-    _first = NULL;
+  CompileTask* next = _first;
+
+  // Iterate over all tasks in the compile queue
+  while (next != NULL) {
+    CompileTask* current = next;
+    next = current->next();
+    // Wake up thread that blocks on the compile task.
+    current->lock()->notify();
+    // Put the task back on the freelist.
+    CompileTask::free(current);
   }
+  _first = NULL;
+
   // Wake up all threads that block on the queue.
   lock()->notify_all();
 }