Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 108505b3 authored by Mike Lockwood's avatar Mike Lockwood
Browse files

MTP: Remove race condition in initial device enumeration for host mode. 



Change-Id: Iee01aaae3f8cca4234daa289bef6631da4d6c2b6
Signed-off-by: default avatarMike Lockwood <lockwood@android.com>
parent 9bbc2ea9

media/mtp/MtpClient.cpp

+25 −11
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ 
#include <sys/stat.h>

#include <fcntl.h>

#include <errno.h>

#include <utils/threads.h>



#include <usbhost/usbhost.h>

#include <linux/version.h>
@@ -67,6 +66,8 @@ MtpClient::~MtpClient() { 
}



bool MtpClient::start() {

    Mutex::Autolock autoLock(mMutex);



    if (mThread)

        return true;
@@ -76,6 +77,8 @@ bool MtpClient::start() { 


    mThread = new MtpClientThread(this);

    mThread->run("MtpClientThread");

    // wait for the thread to do initial device discovery before returning

    mThreadStartCondition.wait(mMutex);



    return true;

}
@@ -84,6 +87,15 @@ void MtpClient::stop() { 
    mDone = true;

}



MtpDevice* MtpClient::getDevice(int id) {

    for (int i = 0; i < mDeviceList.size(); i++) {

        MtpDevice* device = mDeviceList[i];

        if (device->getID() == id)

            return device;

    }

    return NULL;

}



bool MtpClient::usbDeviceAdded(const char *devname) {

    struct usb_descriptor_header* desc;

    struct usb_descriptor_iter iter;
@@ -159,15 +171,6 @@ bool MtpClient::usbDeviceAdded(const char *devname) { 
    return mDone;

}



MtpDevice* MtpClient::getDevice(int id) {

    for (int i = 0; i < mDeviceList.size(); i++) {

        MtpDevice* device = mDeviceList[i];

        if (device->getID() == id)

            return device;

    }

    return NULL;

}



bool MtpClient::usbDeviceRemoved(const char *devname) {

    for (int i = 0; i < mDeviceList.size(); i++) {

        MtpDevice* device = mDeviceList[i];
@@ -182,8 +185,14 @@ bool MtpClient::usbDeviceRemoved(const char *devname) { 
    return mDone;

}



bool MtpClient::usbDiscoveryDone() {

    Mutex::Autolock autoLock(mMutex);

    mThreadStartCondition.signal();

    return mDone;

}



bool MtpClient::threadLoop() {

    usb_host_run(mUsbHostContext, usb_device_added, usb_device_removed, this);

    usb_host_run(mUsbHostContext, usb_device_added, usb_device_removed, usb_discovery_done, this);

    return false;

}
@@ -197,4 +206,9 @@ int MtpClient::usb_device_removed(const char *devname, void* client_data) { 
    return ((MtpClient *)client_data)->usbDeviceRemoved(devname);

}



int MtpClient::usb_discovery_done(void* client_data) {

    LOGD("usb_discovery_done\n");

    return ((MtpClient *)client_data)->usbDiscoveryDone();

}



}  // namespace android

media/mtp/MtpClient.h

+6 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 


#include "MtpTypes.h"



#include <utils/threads.h>



struct usb_host_context;



namespace android {
@@ -29,6 +31,8 @@ class MtpClient { 
private:

    MtpDeviceList               mDeviceList;

    MtpClientThread*            mThread;

    Condition                   mThreadStartCondition;

    Mutex                       mMutex;

    struct usb_host_context*    mUsbHostContext;

    bool                        mDone;
@@ -50,11 +54,13 @@ private: 
    // these return true if we should stop monitoring USB and clean up

    bool                    usbDeviceAdded(const char *devname);

    bool                    usbDeviceRemoved(const char *devname);

    bool                    usbDiscoveryDone();



    friend class MtpClientThread;

    bool                    threadLoop();

    static int              usb_device_added(const char *devname, void* client_data);

    static int              usb_device_removed(const char *devname, void* client_data);

    static int              usb_discovery_done(void* client_data);

};



}; // namespace android