Fix capture stopping

When stopping the camera, the working thread should be stopped before sending
"stop" query to the emulator: we don't want "frame" queries to be floating around
while we're in the process of stopping the camera.

Change-Id: I16dc56ca1c2e304a07a074302001d2e27100f2ac

tools/emulator/system/camera/EmulatedCameraDevice.cpp

@@ -78,6 +78,7 @@ status_t EmulatedCameraDevice::startCapturing(int width,
 {
     LOGV("%s", __FUNCTION__);
 
+    Mutex::Autolock locker(&mObjectLock);
     /* Validate pixel format, and calculate framebuffer size at the same time. */
     switch (pix_fmt) {
         case V4L2_PIX_FMT_YVU420:
@@ -126,6 +127,7 @@ status_t EmulatedCameraDevice::stopCapturing()
 {
     LOGV("%s", __FUNCTION__);
 
+    Mutex::Autolock locker(&mObjectLock);
     /* Stop the camera. */
     const status_t res = stopDevice();
     if (res == NO_ERROR) {

tools/emulator/system/camera/EmulatedFakeCameraDevice.cpp

@@ -90,7 +90,6 @@ status_t EmulatedFakeCameraDevice::startDevice()
 {
     LOGV("%s", __FUNCTION__);
 
-    Mutex::Autolock locker(&mObjectLock);
     if (!isConnected()) {
         LOGE("%s: Fake camera device is not connected.", __FUNCTION__);
         return EINVAL;

tools/emulator/system/camera/EmulatedQemuCameraDevice.cpp

@@ -126,7 +126,6 @@ status_t EmulatedQemuCameraDevice::startDevice()
 {
     LOGV("%s", __FUNCTION__);
 
-    Mutex::Autolock locker(&mObjectLock);
     if (!isConnected()) {
         LOGE("%s: Qemu camera device is not connected.", __FUNCTION__);
         return EINVAL;
@@ -169,17 +168,16 @@ status_t EmulatedQemuCameraDevice::stopDevice()
 {
     LOGV("%s", __FUNCTION__);
 
-    Mutex::Autolock locker(&mObjectLock);
     if (!isCapturing()) {
         LOGW("%s: Qemu camera device is not capturing.", __FUNCTION__);
         return NO_ERROR;
     }
 
-    /* Stop the actual camera device. */
-    status_t res = mQemuClient.queryStop();
+    /* Stop the worker thread first. */
+    status_t res = stopWorkerThread();
     if (res == NO_ERROR) {
-        /* Stop the worker thread. */
-        res = stopWorkerThread();
+        /* Stop the actual camera device. */
+        res = mQemuClient.queryStop();
         if (res == NO_ERROR) {
             if (mPreviewFrame == NULL) {
                 delete[] mPreviewFrame;
@@ -187,10 +185,12 @@ status_t EmulatedQemuCameraDevice::stopDevice()
             }
             mState = ECDS_CONNECTED;
             LOGV("%s: Stopped", __FUNCTION__);
-        }
         } else {
             LOGE("%s: Stop failed", __FUNCTION__);
         }
+    } else {
+        LOGE("%s: Unable to stop worker thread", __FUNCTION__);
+    }
 
     return res;
 }

tools/emulator/system/camera/PreviewWindow.cpp

@@ -111,8 +111,6 @@ void PreviewWindow::onNextFrameAvailable(const void* frame,
                                          nsecs_t timestamp,
                                          EmulatedCameraDevice* camera_dev)
 {
-    LOGV("%s", __FUNCTION__);
-
     int res;
     Mutex::Autolock locker(&mObjectLock);
 

tools/emulator/system/camera/QemuClient.cpp

@@ -25,6 +25,13 @@
 #include "EmulatedCamera.h"
 #include "QemuClient.h"
 
+#define LOG_QUERIES 0
+#if LOG_QUERIES
+#define LOGQ(...)   LOGD(__VA_ARGS__)
+#else
+#define LOGQ(...)   (void(0))
+
+#endif  // LOG_QUERIES
 namespace android {
 
 /****************************************************************************
@@ -329,13 +336,18 @@ status_t QemuClient::doQuery(QemuQuery* query)
         return query->mQueryStatus;
     }
 
+    LOGQ("Send query '%s'", query->mQuery);
+
     /* Send the query. */
     status_t res = sendMessage(query->mQuery, strlen(query->mQuery) + 1);
     if (res == NO_ERROR) {
         /* Read the response. */
         res = receiveMessage(reinterpret_cast<void**>(&query->mReplyBuffer),
                       &query->mReplySize);
-        if (res != NO_ERROR) {
+        if (res == NO_ERROR) {
+            LOGQ("Response to query '%s': Status = '%.2s', %d bytes in response",
+                 query->mQuery, query->mReplyBuffer, query->mReplySize);
+        } else {
             LOGE("%s Response to query '%s' has failed: %s",
                  __FUNCTION__, query->mQuery, strerror(res));
         }
@@ -488,8 +500,6 @@ status_t CameraQemuClient::queryFrame(void* vframe,
                                       size_t vframe_size,
                                       size_t pframe_size)
 {
-    LOGV("%s", __FUNCTION__);
-
     char query_str[256];
     snprintf(query_str, sizeof(query_str), "%s video=%d preview=%d",
              mQueryFrame, (vframe && vframe_size) ? vframe_size : 0,