From 121969b7e0d958092fae76226dc55fe8547a1da6 Mon Sep 17 00:00:00 2001
From: Chong Zhang <chz@google.com>
Date: Tue, 21 Oct 2014 14:12:25 -0700
Subject: release camera without holding CameraSource mutex

Bug: 17997578
Change-Id: Iba93848ad10ba84d2d836573da7ce242c761582f
---
 media/libstagefright/CameraSource.cpp | 99 ++++++++++++++++++++---------------
 1 file changed, 58 insertions(+), 41 deletions(-)

(limited to 'media/libstagefright/CameraSource.cpp')

diff --git a/media/libstagefright/CameraSource.cpp b/media/libstagefright/CameraSource.cpp
index 2b50763..f76aed6 100644
--- a/media/libstagefright/CameraSource.cpp
+++ b/media/libstagefright/CameraSource.cpp
@@ -677,63 +677,80 @@ void CameraSource::stopCameraRecording() {
 
 void CameraSource::releaseCamera() {
     ALOGV("releaseCamera");
-    if (mCamera != 0) {
+    sp<Camera> camera;
+    bool coldCamera = false;
+    {
+        Mutex::Autolock autoLock(mLock);
+        // get a local ref and clear ref to mCamera now
+        camera = mCamera;
+        mCamera.clear();
+        coldCamera = (mCameraFlags & FLAGS_HOT_CAMERA) == 0;
+    }
+
+    if (camera != 0) {
         int64_t token = IPCThreadState::self()->clearCallingIdentity();
-        if ((mCameraFlags & FLAGS_HOT_CAMERA) == 0) {
+        if (coldCamera) {
             ALOGV("Camera was cold when we started, stopping preview");
-            mCamera->stopPreview();
-            mCamera->disconnect();
+            camera->stopPreview();
+            camera->disconnect();
         }
-        mCamera->unlock();
-        mCamera.clear();
-        mCamera = 0;
+        camera->unlock();
         IPCThreadState::self()->restoreCallingIdentity(token);
     }
-    if (mCameraRecordingProxy != 0) {
-        mCameraRecordingProxy->asBinder()->unlinkToDeath(mDeathNotifier);
-        mCameraRecordingProxy.clear();
+
+    {
+        Mutex::Autolock autoLock(mLock);
+        if (mCameraRecordingProxy != 0) {
+            mCameraRecordingProxy->asBinder()->unlinkToDeath(mDeathNotifier);
+            mCameraRecordingProxy.clear();
+        }
+        mCameraFlags = 0;
     }
-    mCameraFlags = 0;
 }
 
 status_t CameraSource::reset() {
     ALOGD("reset: E");
-    Mutex::Autolock autoLock(mLock);
-    mStarted = false;
-    mFrameAvailableCondition.signal();
 
-    int64_t token;
-    bool isTokenValid = false;
-    if (mCamera != 0) {
-        token = IPCThreadState::self()->clearCallingIdentity();
-        isTokenValid = true;
-    }
-    releaseQueuedFrames();
-    while (!mFramesBeingEncoded.empty()) {
-        if (NO_ERROR !=
-            mFrameCompleteCondition.waitRelative(mLock,
-                    mTimeBetweenFrameCaptureUs * 1000LL + CAMERA_SOURCE_TIMEOUT_NS)) {
-            ALOGW("Timed out waiting for outstanding frames being encoded: %zu",
-                mFramesBeingEncoded.size());
+    {
+        Mutex::Autolock autoLock(mLock);
+        mStarted = false;
+        mFrameAvailableCondition.signal();
+
+        int64_t token;
+        bool isTokenValid = false;
+        if (mCamera != 0) {
+            token = IPCThreadState::self()->clearCallingIdentity();
+            isTokenValid = true;
+        }
+        releaseQueuedFrames();
+        while (!mFramesBeingEncoded.empty()) {
+            if (NO_ERROR !=
+                mFrameCompleteCondition.waitRelative(mLock,
+                        mTimeBetweenFrameCaptureUs * 1000LL + CAMERA_SOURCE_TIMEOUT_NS)) {
+                ALOGW("Timed out waiting for outstanding frames being encoded: %zu",
+                    mFramesBeingEncoded.size());
+            }
+        }
+        stopCameraRecording();
+        if (isTokenValid) {
+            IPCThreadState::self()->restoreCallingIdentity(token);
         }
-    }
-    stopCameraRecording();
-    releaseCamera();
-    if (isTokenValid) {
-        IPCThreadState::self()->restoreCallingIdentity(token);
-    }
 
-    if (mCollectStats) {
-        ALOGI("Frames received/encoded/dropped: %d/%d/%d in %" PRId64 " us",
-                mNumFramesReceived, mNumFramesEncoded, mNumFramesDropped,
-                mLastFrameTimestampUs - mFirstFrameTimeUs);
-    }
+        if (mCollectStats) {
+            ALOGI("Frames received/encoded/dropped: %d/%d/%d in %" PRId64 " us",
+                    mNumFramesReceived, mNumFramesEncoded, mNumFramesDropped,
+                    mLastFrameTimestampUs - mFirstFrameTimeUs);
+        }
 
-    if (mNumGlitches > 0) {
-        ALOGW("%d long delays between neighboring video frames", mNumGlitches);
+        if (mNumGlitches > 0) {
+            ALOGW("%d long delays between neighboring video frames", mNumGlitches);
+        }
+
+        CHECK_EQ(mNumFramesReceived, mNumFramesEncoded + mNumFramesDropped);
     }
 
-    CHECK_EQ(mNumFramesReceived, mNumFramesEncoded + mNumFramesDropped);
+    releaseCamera();
+
     ALOGD("reset: X");
     return OK;
 }
-- 
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