1 #include <errno.h>
2
3 #include <bufferhub/BufferHubService.h>
4 #include <bufferhub/BufferNode.h>
5 #include <log/log.h>
6 #include <ui/GraphicBufferAllocator.h>
7
8 namespace android {
9 namespace frameworks {
10 namespace bufferhub {
11 namespace V1_0 {
12 namespace implementation {
13
initializeMetadata()14 void BufferNode::initializeMetadata() {
15 // Using placement new here to reuse shared memory instead of new allocation
16 // Initialize the atomic variables to zero.
17 BufferHubDefs::MetadataHeader* metadataHeader = mMetadata.metadataHeader();
18 mBufferState = new (&metadataHeader->bufferState) std::atomic<uint32_t>(0);
19 mFenceState = new (&metadataHeader->fenceState) std::atomic<uint32_t>(0);
20 mActiveClientsBitMask = new (&metadataHeader->activeClientsBitMask) std::atomic<uint32_t>(0);
21 // The C++ standard recommends (but does not require) that lock-free atomic operations are
22 // also address-free, that is, suitable for communication between processes using shared
23 // memory.
24 LOG_ALWAYS_FATAL_IF(!std::atomic_is_lock_free(mBufferState) ||
25 !std::atomic_is_lock_free(mFenceState) ||
26 !std::atomic_is_lock_free(mActiveClientsBitMask),
27 "Atomic variables in ashmen are not lock free.");
28 }
29
30 // Allocates a new BufferNode.
BufferNode(uint32_t width,uint32_t height,uint32_t layerCount,uint32_t format,uint64_t usage,size_t userMetadataSize,int id)31 BufferNode::BufferNode(uint32_t width, uint32_t height, uint32_t layerCount, uint32_t format,
32 uint64_t usage, size_t userMetadataSize, int id)
33 : mId(id) {
34 uint32_t outStride = 0;
35 // graphicBufferId is not used in GraphicBufferAllocator::allocate
36 // TODO(b/112338294) After move to the service folder, stop using the
37 // hardcoded service name "bufferhub".
38 int ret = GraphicBufferAllocator::get().allocate(width, height, format, layerCount, usage,
39 const_cast<const native_handle_t**>(
40 &mBufferHandle),
41 &outStride,
42 /*graphicBufferId=*/0,
43 /*requestor=*/"bufferhub");
44
45 if (ret != OK || mBufferHandle == nullptr) {
46 ALOGE("%s: Failed to allocate buffer: %s", __FUNCTION__, strerror(-ret));
47 return;
48 }
49
50 mBufferDesc.width = width;
51 mBufferDesc.height = height;
52 mBufferDesc.layers = layerCount;
53 mBufferDesc.format = format;
54 mBufferDesc.usage = usage;
55 mBufferDesc.stride = outStride;
56
57 mMetadata = BufferHubMetadata::create(userMetadataSize);
58 if (!mMetadata.isValid()) {
59 ALOGE("%s: Failed to allocate metadata.", __FUNCTION__);
60 return;
61 }
62 initializeMetadata();
63 }
64
~BufferNode()65 BufferNode::~BufferNode() {
66 // Free the handle
67 if (mBufferHandle != nullptr) {
68 status_t ret = GraphicBufferAllocator::get().free(mBufferHandle);
69 if (ret != OK) {
70 ALOGE("%s: Failed to free handle; Got error: %d", __FUNCTION__, ret);
71 }
72 }
73
74 // Free the id, if valid
75 if (mId >= 0) {
76 BufferHubIdGenerator::getInstance().freeId(mId);
77 }
78 }
79
getActiveClientsBitMask() const80 uint32_t BufferNode::getActiveClientsBitMask() const {
81 return mActiveClientsBitMask->load(std::memory_order_acquire);
82 }
83
addNewActiveClientsBitToMask()84 uint32_t BufferNode::addNewActiveClientsBitToMask() {
85 uint32_t currentActiveClientsBitMask = getActiveClientsBitMask();
86 uint32_t clientStateMask = 0U;
87 uint32_t updatedActiveClientsBitMask = 0U;
88 do {
89 clientStateMask =
90 BufferHubDefs::findNextAvailableClientStateMask(currentActiveClientsBitMask);
91 if (clientStateMask == 0U) {
92 ALOGE("%s: reached the maximum number of channels per buffer node: %d.", __FUNCTION__,
93 BufferHubDefs::kMaxNumberOfClients);
94 errno = E2BIG;
95 return 0U;
96 }
97 updatedActiveClientsBitMask = currentActiveClientsBitMask | clientStateMask;
98 } while (!(mActiveClientsBitMask->compare_exchange_weak(currentActiveClientsBitMask,
99 updatedActiveClientsBitMask,
100 std::memory_order_acq_rel,
101 std::memory_order_acquire)));
102 return clientStateMask;
103 }
104
removeClientsBitFromMask(const uint32_t & value)105 void BufferNode::removeClientsBitFromMask(const uint32_t& value) {
106 mActiveClientsBitMask->fetch_and(~value);
107 }
108
109 } // namespace implementation
110 } // namespace V1_0
111 } // namespace bufferhub
112 } // namespace frameworks
113 } // namespace android
114