commit 8a7ffae09a019de7109b30c505561c453910bde1
author Daichi Hirono <hirono@google.com> Thu Aug 20 15:13:40 2015 +0900
committer Daichi Hirono <hirono@google.com> Tue Sep 15 18:50:37 2015 +0900
tree 85222bdac601b44a798890a651a08ac36d71a591
parent 7bafd606eb2390574f0a2b0043074d9cdfde1120

Add functions to read MTP events from MTP devices.

BUG=23368533

Change-Id: I2003dda961339677caf56e57ae90cf6df7bd7430

media/mtp/MtpDevice.h

diff --git a/media/mtp/MtpDevice.h b/media/mtp/MtpDevice.h
index d2c6d67..87b3b90 100644
--- a/media/mtp/MtpDevice.h
+++ b/media/mtp/MtpDevice.h
@@ -17,8 +17,9 @@
 #ifndef _MTP_DEVICE_H
 #define _MTP_DEVICE_H
 
-#include "MtpRequestPacket.h"
+#include "MtpEventPacket.h"
 #include "MtpDataPacket.h"
+#include "MtpRequestPacket.h"
 #include "MtpResponsePacket.h"
 #include "MtpTypes.h"
 
@@ -31,6 +32,7 @@
 namespace android {
 
 class MtpDeviceInfo;
+class MtpEventPacket;
 class MtpObjectInfo;
 class MtpStorageInfo;
 
@@ -53,11 +55,17 @@
     MtpRequestPacket        mRequest;
     MtpDataPacket           mData;
     MtpResponsePacket       mResponse;
+    MtpEventPacket          mEventPacket;
+
     // set to true if we received a response packet instead of a data packet
     bool                    mReceivedResponse;
+    bool                    mProcessingEvent;
+    int                     mCurrentEventHandle;
 
     // to ensure only one MTP transaction at a time
     Mutex                   mMutex;
+    Mutex                   mEventMutex;
+    Mutex                   mEventMutexForInterrupt;
 
 public:
     typedef bool (*ReadObjectCallback)(void* data, int offset, int length, void* clientData);
@@ -101,6 +109,18 @@
     bool                    readObject(MtpObjectHandle handle, const char* destPath, int group,
                                     int perm);
     bool                    readObject(MtpObjectHandle handle, int fd);
+    // Starts a request to read MTP event from MTP device. It returns a request handle that
+    // can be used for blocking read or cancel. If other thread has already been processing an
+    // event returns -1.
+    int                     submitEventRequest();
+    // Waits for MTP event from the device and returns MTP event code. It blocks the current thread
+    // until it receives an event from the device. |handle| should be a request handle returned
+    // by |submitEventRequest|. Returns 0 for cancellations. Returns -1 for errors.
+    int                     reapEventRequest(int handle);
+    // Cancels an event request. |handle| should be request handle returned by
+    // |submitEventRequest|. If there is a thread blocked by |reapEventRequest| with the same
+    // |handle|, the thread will resume.
+    void                    discardEventRequest(int handle);
 
 private:
     // If |objectSize| is not NULL, it checks object size before reading data bytes.
@@ -111,7 +131,6 @@
     bool                    readData();
     bool                    writeDataHeader(MtpOperationCode operation, int dataLength);
     MtpResponseCode         readResponse();
-
 };
 
 }; // namespace android