Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

MTP: Fix some thread safety issues in MTP server start/stop sequence.

Browse Source 
Change-Id: Ied1cddc6220fa7394e8de99df9bc37a1208b04ff
Signed-off-by: Mike Lockwood <lockwood@android.com>
This commit is contained in:
Mike Lockwood
2010-08-03 15:17:55 -04:00
parent d4b5020174
commit 23ee42f904
1 changed files with 55 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

92
media/jni/android_media_MtpServer.cpp
View File

@@ -36,6 +36,7 @@ using namespace android;
// ----------------------------------------------------------------------------
static jfieldID field_context;
static Mutex sMutex;
// in android_media_MtpDatabase.cpp
extern MtpDatabase* getMtpDatabase(JNIEnv *env, jobject database);
@@ -53,63 +54,80 @@ class MtpThread : public Thread {
private:
MtpDatabase* mDatabase;
MtpServer* mServer;
String8 mStoragePath;
bool mDone;
Mutex mMutex;
String8 mStoragePath;
bool mDone;
jobject mJavaServer;
public:
MtpThread(MtpDatabase* database, const char* storagePath)
: mDatabase(database), mServer(NULL), mStoragePath(storagePath), mDone(false)
MtpThread(MtpDatabase* database, const char* storagePath, jobject javaServer)
: mDatabase(database),
mServer(NULL),
mStoragePath(storagePath),
mDone(false),
mJavaServer(javaServer)
{
}
virtual bool threadLoop() {
int fd = open("/dev/mtp_usb", O_RDWR);
printf("open returned %d\n", fd);
if (fd < 0) {
LOGE("could not open MTP driver\n");
return false;
while (1) {
int fd = open("/dev/mtp_usb", O_RDWR);
printf("open returned %d\n", fd);
if (fd < 0) {
LOGE("could not open MTP driver\n");
break;
}
sMutex.lock();
mServer = new MtpServer(fd, mDatabase, AID_SDCARD_RW, 0664, 0775);
mServer->addStorage(mStoragePath);
sMutex.unlock();
LOGD("MtpThread mServer->run");
mServer->run();
close(fd);
sMutex.lock();
delete mServer;
mServer = NULL;
if (mDone)
goto done;
sMutex.unlock();
// wait a bit before retrying
sleep(1);
}
mMutex.lock();
mServer = new MtpServer(fd, mDatabase, AID_SDCARD_RW, 0664, 0775);
mServer->addStorage(mStoragePath);
mMutex.unlock();
sMutex.lock();
done:
JNIEnv* env = AndroidRuntime::getJNIEnv();
env->SetIntField(mJavaServer, field_context, 0);
env->DeleteGlobalRef(mJavaServer);
sMutex.unlock();
LOGD("MtpThread mServer->run");
mServer->run();
close(fd);
mMutex.lock();
delete mServer;
mServer = NULL;
mMutex.unlock();
bool done = mDone;
if (done)
delete this;
LOGD("threadLoop returning %s", (done ? "false" : "true"));
return !done;
LOGD("threadLoop returning");
return false;
}
void setDone() { mDone = true; }
void setDone() {
LOGD("setDone");
mDone = true;
}
void sendObjectAdded(MtpObjectHandle handle) {
mMutex.lock();
sMutex.lock();
if (mServer)
mServer->sendObjectAdded(handle);
else
LOGE("sendObjectAdded called while disconnected\n");
mMutex.unlock();
sMutex.unlock();
}
void sendObjectRemoved(MtpObjectHandle handle) {
mMutex.lock();
sMutex.lock();
if (mServer)
mServer->sendObjectRemoved(handle);
else
LOGE("sendObjectRemoved called while disconnected\n");
mMutex.unlock();
sMutex.unlock();
}
};
@@ -124,7 +142,7 @@ android_media_MtpServer_setup(JNIEnv *env, jobject thiz, jobject javaDatabase, j
MtpDatabase* database = getMtpDatabase(env, javaDatabase);
const char *storagePathStr = env->GetStringUTFChars(storagePath, NULL);
MtpThread* thread = new MtpThread(database, storagePathStr);
MtpThread* thread = new MtpThread(database, storagePathStr, env->NewGlobalRef(thiz));
env->SetIntField(thiz, field_context, (int)thread);
env->ReleaseStringUTFChars(storagePath, storagePathStr);
@@ -153,11 +171,11 @@ android_media_MtpServer_stop(JNIEnv *env, jobject thiz)
{
#ifdef HAVE_ANDROID_OS
LOGD("stop\n");
sMutex.lock();
MtpThread *thread = (MtpThread *)env->GetIntField(thiz, field_context);
if (thread) {
if (thread)
thread->setDone();
env->SetIntField(thiz, field_context, 0);
}
sMutex.unlock();
#endif
}