Check atomics in shared memory are lock free
when they are created in bufferhub server side in BufferNode, and client
side in BufferHubBuffer.
Fix: 117849512
Test: BufferHub_test BufferHubServer_test
Change-Id: Ifc5b681a6a86fa02cb598b33bf68dfefc07a76f9
diff --git a/services/bufferhub/BufferNode.cpp b/services/bufferhub/BufferNode.cpp
index cc87e15..da19a6f 100644
--- a/services/bufferhub/BufferNode.cpp
+++ b/services/bufferhub/BufferNode.cpp
@@ -2,6 +2,7 @@
#include <bufferhub/BufferHubService.h>
#include <bufferhub/BufferNode.h>
+#include <log/log.h>
#include <ui/GraphicBufferAllocator.h>
namespace android {
@@ -18,6 +19,13 @@
fence_state_ = new (&metadata_header->fence_state) std::atomic<uint32_t>(0);
active_clients_bit_mask_ =
new (&metadata_header->active_clients_bit_mask) std::atomic<uint32_t>(0);
+ // The C++ standard recommends (but does not require) that lock-free atomic operations are
+ // also address-free, that is, suitable for communication between processes using shared
+ // memory.
+ LOG_ALWAYS_FATAL_IF(!std::atomic_is_lock_free(buffer_state_) ||
+ !std::atomic_is_lock_free(fence_state_) ||
+ !std::atomic_is_lock_free(active_clients_bit_mask_),
+ "Atomic variables in ashmen are not lock free.");
}
// Allocates a new BufferNode.