Add thread pool class
Added a thread pool class loosely based on google3 code.
Modified the compiler to have a single thread pool instead of creating new threads in ForAll.
Moved barrier to be in top level directory as it is not GC specific code.
Performance Timings:
Reference:
boot.oat: 14.306596s
time mm oat-target:
real 2m33.748s
user 10m23.190s
sys 5m54.140s
Thread pool:
boot.oat: 13.111049s
time mm oat-target:
real 2m29.372s
user 10m3.130s
sys 5m46.290s
The speed increase is probably just noise.
Change-Id: If3c1280cbaa4c7e4361127d064ac744ea12cdf49
diff --git a/src/barrier.h b/src/barrier.h
new file mode 100644
index 0000000..342890b
--- /dev/null
+++ b/src/barrier.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_SRC_BARRIER_H_
+#define ART_SRC_BARRIER_H_
+
+#include "../src/mutex.h"
+#include "locks.h"
+#include "UniquePtr.h"
+
+namespace art {
+
+class Barrier {
+ public:
+ Barrier();
+ virtual ~Barrier();
+
+ // Pass through the barrier, decrements the count but does not block.
+ void Pass(Thread* self);
+
+ // Wait on the barrier, decrement the count.
+ void Wait(Thread* self);
+
+ // Set the count to a new value, if the value is 0 then everyone waiting on the condition
+ // variable is resumed.
+ void Init(Thread* self, int count);
+
+ // Increment the count by delta, wait on condition if count is non zero.
+ void Increment(Thread* self, int delta);
+
+ private:
+ void SetCountLocked(Thread* self, int count) EXCLUSIVE_LOCKS_REQUIRED(lock_);
+
+ // Counter, when this reaches 0 all people blocked on the barrier are signalled.
+ int count_ GUARDED_BY(lock_);
+
+ Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
+ ConditionVariable condition_ GUARDED_BY(lock_);
+};
+
+} // namespace art
+#endif // ART_SRC_GC_BARRIER_H_
+