1 files changed, 90 insertions, 0 deletions
diff --git a/services/camera/libcameraservice/utils/AutoConditionLock.cpp b/services/camera/libcameraservice/utils/AutoConditionLock.cpp
new file mode 100644
index 0000000..c8ee965
--- /dev/null
+++ b/services/camera/libcameraservice/utils/AutoConditionLock.cpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#include "AutoConditionLock.h"
+
+namespace android {
+
+WaitableMutexWrapper::WaitableMutexWrapper(Mutex* mutex) : mMutex{mutex}, mState{false} {}
+
+WaitableMutexWrapper::~WaitableMutexWrapper() {}
+
+// Locks manager-owned mutex
+AutoConditionLock::AutoConditionLock(const std::shared_ptr<WaitableMutexWrapper>& manager) :
+        mManager{manager}, mAutoLock{manager->mMutex} {}
+
+// Unlocks manager-owned mutex
+AutoConditionLock::~AutoConditionLock() {
+    // Unset the condition and wake everyone up before releasing lock
+    mManager->mState = false;
+    mManager->mCondition.broadcast();
+}
+
+std::unique_ptr<AutoConditionLock> AutoConditionLock::waitAndAcquire(
+        const std::shared_ptr<WaitableMutexWrapper>& manager, nsecs_t waitTime) {
+
+    if (manager == nullptr || manager->mMutex == nullptr) {
+        // Bad input, return null
+        return std::unique_ptr<AutoConditionLock>{nullptr};
+    }
+
+    // Acquire scoped lock
+    std::unique_ptr<AutoConditionLock> scopedLock(new AutoConditionLock(manager));
+
+    // Figure out what time in the future we should hit the timeout
+    nsecs_t failTime = systemTime(SYSTEM_TIME_MONOTONIC) + waitTime;
+
+    // Wait until we timeout, or success
+    while(manager->mState) {
+        status_t ret = manager->mCondition.waitRelative(*(manager->mMutex), waitTime);
+        if (ret != NO_ERROR) {
+            // Timed out or whatever, return null
+            return std::unique_ptr<AutoConditionLock>{nullptr};
+        }
+        waitTime = failTime - systemTime(SYSTEM_TIME_MONOTONIC);
+    }
+
+    // Set the condition and return
+    manager->mState = true;
+    return scopedLock;
+}
+
+std::unique_ptr<AutoConditionLock> AutoConditionLock::waitAndAcquire(
+        const std::shared_ptr<WaitableMutexWrapper>& manager) {
+
+    if (manager == nullptr || manager->mMutex == nullptr) {
+        // Bad input, return null
+        return std::unique_ptr<AutoConditionLock>{nullptr};
+    }
+
+    // Acquire scoped lock
+    std::unique_ptr<AutoConditionLock> scopedLock(new AutoConditionLock(manager));
+
+    // Wait until we timeout, or success
+    while(manager->mState) {
+        status_t ret = manager->mCondition.wait(*(manager->mMutex));
+        if (ret != NO_ERROR) {
+            // Timed out or whatever, return null
+            return std::unique_ptr<AutoConditionLock>{nullptr};
+        }
+    }
+
+    // Set the condition and return
+    manager->mState = true;
+    return scopedLock;
+}
+
+}; // namespace android