Camera2: Allow devices to opt-out of threaded camera startup

On at least the current Exynos based devices, the vendor's HAL
appears to be unable to handle the threaded startup.  Since we
cannot easily fix their HAL, allow these devices to opt out
of the faster camera startup.

Change-Id: I8d1935eb69bb8ba1396b59d92993062637654258

2 files changed, 33 insertions, 12 deletions

diff --git a/res/values/config.xml b/res/values/config.xml
index 9bb3b8b73..fde705275 100644
--- a/res/values/config.xml
+++ b/res/values/config.xml
@@ -43,4 +43,8 @@
     <bool name="enableHDRWithZSL">false</bool>
     <!-- Enable histogram support -->
     <bool name="enableHistogram">false</bool>
+
+    <!-- Controls whether or not the HAL allows a multi-threaded
+         camera startup -->
+    <bool name="enableThreadedCameraStartup">true</bool>
 </resources>
diff --git a/src/com/android/camera/PhotoModule.java b/src/com/android/camera/PhotoModule.java
index 5a1013b63..ababaf291 100644
--- a/src/com/android/camera/PhotoModule.java
+++ b/src/com/android/camera/PhotoModule.java
@@ -237,6 +237,28 @@ public class PhotoModule
     }
 
     private OpenCameraThread mOpenCameraThread = null;
+    private boolean mEnableThreadedCameraStartup = true;
+
+    private void startOpenCameraThread() {
+        mOpenCameraThread = new OpenCameraThread();
+        if (mEnableThreadedCameraStartup) {
+             mOpenCameraThread.start();
+        } else {
+             mOpenCameraThread.run();
+        }
+    }
+
+    private void stopOpenCameraThread() {
+        if (mOpenCameraThread != null && mEnableThreadedCameraStartup) {
+            try {
+                mOpenCameraThread.join();
+            } catch (InterruptedException ex) {
+                // ignore
+            }
+        }
+        mOpenCameraThread = null;
+    }
+
     /**
      * An unpublished intent flag requesting to return as soon as capturing
      * is completed.
@@ -520,9 +542,11 @@ public class PhotoModule
         // Max brightness
         mActivity.initMaxBrightness(mPreferences);
 
+        mEnableThreadedCameraStartup = mActivity.getResources().getBoolean(
+                R.bool.enableThreadedCameraStartup);
+
         if (mOpenCameraThread == null && !mActivity.mIsModuleSwitchInProgress) {
-            mOpenCameraThread = new OpenCameraThread();
-            mOpenCameraThread.start();
+            startOpenCameraThread();
         }
         initializeControlByIntent();
         mQuickCapture = mActivity.getIntent().getBooleanExtra(EXTRA_QUICK_CAPTURE, false);
@@ -1886,8 +1910,7 @@ public class PhotoModule
         if (mOpenCameraFail || mCameraDisabled) return;
 
         if (mOpenCameraThread == null) {
-            mOpenCameraThread = new OpenCameraThread();
-            mOpenCameraThread.start();
+            startOpenCameraThread();
         }
 
         mJpegPictureCallbackTime = 0;
@@ -1950,14 +1973,8 @@ public class PhotoModule
         Log.v(TAG, "On pause.");
         mUI.showPreviewCover();
 
-        try {
-            if (mOpenCameraThread != null) {
-                mOpenCameraThread.join();
-            }
-        } catch (InterruptedException ex) {
-            // ignore
-        }
-        mOpenCameraThread = null;
+        stopOpenCameraThread();
+
         // Reset the focus first. Camera CTS does not guarantee that
         // cancelAutoFocus is allowed after preview stops.
         if (mCameraDevice != null && mCameraState != PREVIEW_STOPPED) {