Index: content/common/shared_memory_seqlock_buffer.h |
diff --git a/content/common/shared_memory_seqlock_buffer.h b/content/common/shared_memory_seqlock_buffer.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..89a168f216e9751f255a34f5c29e307b6240351a |
--- /dev/null |
+++ b/content/common/shared_memory_seqlock_buffer.h |
@@ -0,0 +1,38 @@ |
+// Copyright (c) 2013 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#ifndef CONTENT_COMMON_SHARED_MEMORY_SEQLOCK_BUFFER_H_ |
+#define CONTENT_COMMON_SHARED_MEMORY_SEQLOCK_BUFFER_H_ |
+ |
+#include "content/common/one_writer_seqlock.h" |
+ |
+namespace content { |
+ |
+// This structure is stored in shared memory that's shared between the browser |
+// which does the hardware polling, and the consumers of the device motion |
scottmg
2013/06/24 23:24:38
being that this is currently device motion specifi
timvolodine
2013/06/25 03:36:07
Yes, the idea is to use this for the gamepad code
|
+// data, i.e. the renderers. The performance characteristics are that |
+// we want low latency (so would like to avoid explicit communication via IPC |
+// between producer and consumer) and relatively large data size. |
+// |
+// Writer and reader operate on the same buffer assuming contention is low, and |
+// contention is detected by using the associated SeqLock. |
+ |
+class SharedMemorySeqLockBufferBase { |
+ public: |
+ OneWriterSeqLock seqlock; |
+ |
+ // This boolean is used to indicate the state of the buffer, |
+ // it is not used for locking. |
+ bool is_ready_for_read; |
scottmg
2013/06/24 23:24:38
(unrelated to looking at gamepad changes, but) thi
timvolodine
2013/06/25 03:36:07
ok, I've moved this field to WebDeviceMotionData,
|
+}; |
+ |
+template<class Data> |
+class SharedMemorySeqLockBuffer : public SharedMemorySeqLockBufferBase { |
darin (slow to review)
2013/06/24 23:40:34
nit: Since there are no methods here, it seems lik
timvolodine
2013/06/25 03:36:07
The base buffer class is used by the shared_memory
|
+ public: |
+ Data data; |
+}; |
+ |
+} // namespace content |
+ |
+#endif // CONTENT_COMMON_SHARED_MEMORY_SEQLOCK_BUFFER_H_ |