Merge "media.bufferpool2: Ensure uniqueness of connection id" into main

media/bufferpool/aidl/default/Accessor.cpp

@@ -16,6 +16,8 @@
 #define LOG_TAG "AidlBufferPoolAcc"
 //#define LOG_NDEBUG 0
 
+#include <android-base/no_destructor.h>
+
 #include <sys/types.h>
 #include <stdint.h>
 #include <time.h>
@@ -41,7 +43,25 @@ static constexpr uint32_t kSeqIdVndkBit = 0;
 #endif
 
 static constexpr uint32_t kSeqIdMax = 0x7fffffff;
-uint32_t Accessor::sSeqId = time(nullptr) & kSeqIdMax;
+
+Accessor::ConnectionIdGenerator::ConnectionIdGenerator() {
+    mSeqId = static_cast<uint32_t>(time(nullptr) & kSeqIdMax);
+    mPid = static_cast<int32_t>(getpid());
+}
+
+ConnectionId Accessor::ConnectionIdGenerator::getConnectionId() {
+    uint32_t seq;
+    {
+        std::lock_guard<std::mutex> l(mLock);
+        seq = mSeqId;
+        if (mSeqId == kSeqIdMax) {
+            mSeqId = 0;
+        } else {
+            ++mSeqId;
+        }
+    }
+    return (int64_t)mPid << 32 | seq | kSeqIdVndkBit;
+}
 
 namespace {
 // anonymous namespace
@@ -239,13 +259,14 @@ BufferPoolStatus Accessor::connect(
         uint32_t *pMsgId,
         StatusDescriptor* statusDescPtr,
         InvalidationDescriptor* invDescPtr) {
+    static ::android::base::NoDestructor<ConnectionIdGenerator> sConIdGenerator;
     std::shared_ptr<Connection> newConnection = ::ndk::SharedRefBase::make<Connection>();
     BufferPoolStatus status = ResultStatus::CRITICAL_ERROR;
     {
         std::lock_guard<std::mutex> lock(mBufferPool.mMutex);
         if (newConnection) {
             int32_t pid = getpid();
-            ConnectionId id = (int64_t)pid << 32 | sSeqId | kSeqIdVndkBit;
+            ConnectionId id = sConIdGenerator->getConnectionId();
             status = mBufferPool.mObserver.open(id, statusDescPtr);
             if (status == ResultStatus::OK) {
                 newConnection->initialize(ref<Accessor>(), id);
@@ -255,11 +276,6 @@ BufferPoolStatus Accessor::connect(
                 mBufferPool.mConnectionIds.insert(id);
                 mBufferPool.mInvalidationChannel.getDesc(invDescPtr);
                 mBufferPool.mInvalidation.onConnect(id, observer);
-                if (sSeqId == kSeqIdMax) {
-                   sSeqId = 0;
-                } else {
-                    ++sSeqId;
-                }
             }
 
         }

media/bufferpool/aidl/default/Accessor.h

@@ -189,7 +189,14 @@ struct Accessor : public BnAccessor {
 private:
     // ConnectionId = pid : (timestamp_created + seqId)
     // in order to guarantee uniqueness for each connection
-    static uint32_t sSeqId;
+    struct ConnectionIdGenerator {
+        int32_t mPid;
+        uint32_t mSeqId;
+        std::mutex mLock;
+
+        ConnectionIdGenerator();
+        ConnectionId getConnectionId();
+    };
 
     const std::shared_ptr<BufferPoolAllocator> mAllocator;
     nsecs_t mScheduleEvictTs;

media/bufferpool/aidl/default/Android.bp

@@ -29,6 +29,9 @@ cc_library {
     export_include_dirs: [
         "include",
     ],
+    header_libs: [
+        "libbase_headers",
+    ],
     shared_libs: [
         "libbinder_ndk",
         "libcutils",