camera: Collect stack traces when bad things happen, print with dumpsys

Bug: 11324229
Change-Id: Ic920e170a8f5a389fc139bbf5416c0e3186c7fb6

1 files changed, 66 insertions, 0 deletions

diff --git a/services/camera/libcameraservice/utils/CameraTraces.h b/services/camera/libcameraservice/utils/CameraTraces.h
new file mode 100644
index 0000000..d10dbc9
--- /dev/null
+++ b/services/camera/libcameraservice/utils/CameraTraces.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ANDROID_SERVERS_CAMERA_TRACES_H_
+#define ANDROID_SERVERS_CAMERA_TRACES_H_
+
+#include <utils/Errors.h>
+#include <utils/String16.h>
+#include <utils/Vector.h>
+
+namespace android {
+namespace camera3 {
+
+class CameraTracesImpl;
+
+// Collect a list of the process's stack traces
+class CameraTraces {
+public:
+    /**
+     * Save the current stack trace for each thread in the process. At most
+     * MAX_TRACES will be saved, after which the oldest traces will be discarded.
+     *
+     * <p>Use CameraTraces::dump to print out the traces.</p>
+     */
+    static void     saveTrace();
+
+    /**
+     * Prints all saved traces to the specified file descriptor.
+     *
+     * <p>Each line is indented by DUMP_INDENT spaces.</p>
+     */
+    static status_t dump(int fd, const Vector<String16>& args);
+
+private:
+    enum {
+        // Don't collect more than 100 traces. Discard oldest.
+        MAX_TRACES = 100,
+
+        // Insert 2 spaces when dumping the traces
+        DUMP_INDENT = 2,
+    };
+
+    CameraTraces();
+    ~CameraTraces();
+    CameraTraces(CameraTraces& rhs);
+
+    static CameraTracesImpl& sImpl;
+}; // class CameraTraces
+
+}; // namespace camera3
+}; // namespace android
+
+#endif // ANDROID_SERVERS_CAMERA_TRACES_H_