Freezing USB communication with libusb

I have an application that connects to USB using libusb. The app has worked so far. In Android 5.0 (Lollipop) SELinux blocked my USB device. I managed to do a workaround and SELinux no longer blocks USB, but now the data transfer between the device and the phone freezes after a while (it could be 10 seconds, 30 seconds, 1 minute, etc.)

I am working with NDK r10d.

LogCat :

 I/USBHelp(21136): entering iniUSB
 I/USBHelp(21136): successfully initialized libusb
 D/OpenGLRenderer(21136): Render dirty regions requested: true
 D/Atlas(21136): Validating map...
 I/Adreno-EGL(21136): <qeglDrvAPI_eglInitialize:410>: QUALCOMM Build: 10/24/14, 167c270, I68fa98814b
 I/OpenGLRenderer(21136): Initialized EGL, version 1.4
 D/OpenGLRenderer(21136): Enabling debug mode 0
JNI DETECTED ERROR IN APPLICATION: thread Thread[15,tid=21176,Native,Thread*=0xac85d800,peer=0x12c00200,"Thread-1044"] using JNIEnv* from thread Thread[16,tid=21177,Runnable,Thread*=0xac85dc00,peer=0x12c00260,"Thread-1045"]
    in call to CallVoidMethod
     from int nok.pack.Device.SendData(byte[], int)
 "Thread-1044" prio=1 tid=15 Runnable
   | group="main" sCount=0 dsCount=0 obj=0x12c00200 self=0xac85d800
   | sysTid=21176 nice=0 cgrp=apps sched=0/0 handle=0xa3e2b700
   | state=R schedstat=( 190490211 139839161 1498 ) utm=17 stm=2 core=0 HZ=100
   | stack=0xa1189000-0xa118b000 stackSize=1036KB
   | held mutexes= "mutator lock"(shared held)
  #00 pc 00004c58  /system/lib/libbacktrace_libc++.so (UnwindCurrent::Unwind(unsigned int, ucontext*)+23)
  #01 pc 000034c1  /system/lib/libbacktrace_libc++.so (Backtrace::Unwind(unsigned int, ucontext*)+8)
  #02 pc 002526ad  /system/lib/libart.so (art::DumpNativeStack(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, int, char const*, art::mirror::ArtMethod*)+84)
  #03 pc 0023618b  /system/lib/libart.so (art::Thread::Dump(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) const+162)
  #04 pc 000b1215  /system/lib/libart.so (art::JniAbort(char const*, char const*)+620)
  #05 pc 000b1945  /system/lib/libart.so (art::JniAbortF(char const*, char const*, ...)+68)
  #06 pc 000b4b35  /system/lib/libart.so (art::ScopedCheck::ScopedCheck(_JNIEnv*, int, char const*)+1172)
  #07 pc 000bcf05  /system/lib/libart.so (art::CheckJNI::CallVoidMethod(_JNIEnv*, _jobject*, _jmethodID*, ...)+48)
  #08 pc 0000fee8  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (cb_in+88)
  #09 pc 000074b4  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (usbi_handle_transfer_completion+276)
  #10 pc 0000ef20  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (???)
  #11 pc 0000f888  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (???)
  #12 pc 0000fa34  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (???)
  #13 pc 0000800c  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (???)
  #14 pc 00008234  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (libusb_handle_events_timeout_completed+172)
  #15 pc 000083a4  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (libusb_handle_events_completed+52)
  #16 pc 00009258  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (???)
  #17 pc 00009408  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (libusb_bulk_transfer+76)
  #18 pc 00010304  /data/app/nok.pack.sample-1/lib/arm/libusbnok.so (Java_nok_pack_Device_SendData+120)
  #19 pc 00001613  /data/dalvik-cache/arm/data@app@nok.pack.sample-1@base.apk@classes.dex (Java_nok_pack_Device_SendData___3BI+106)
   at nok.pack.Device.SendData(Native method)
   at nok.pack.Device.access$3(Device.java:30)
   at nok.pack.Device$1.run(Device.java:96)
   - locked <0x066c1f6a> (a nok.pack.Device$1)
   at java.lang.Thread.run(Thread.java:818)

  W/art(21136): Thread suspension timed out: 16

      

        
        
        
      

    

code:

#define TIMEOUT_VIN     -1
#define TIMEOUT_COUT    -1
#define ENDPOINT_BULK_IN 0x61
#define ENDPOINT_BULK_OUT 0x12
#define USB_CHUNC_SIZE 512

libusb_context * ctx = NULL;
libusb_device_handle *dev_handle = NULL;

JNIEnv * callback_env;
jobject callback_obj;
jmethodID mid;
jclass cls;
struct libusb_transfer *transfer_in;

int do_exit = 1;
int grab_en = 1;

jint length;

void cb_in()
{
     (*callback_env)->CallVoidMethod(callback_env, callback_obj, mid, 0);
    do_exit = 1;
}

jint
Java_nok_pack_Device_DataRequest(JNIEnv * env, jobject this,
        jbyteArray buffer_1, jbyteArray buffer_2, jint length_loc)
{
    unsigned char* bufferPtr_1 = (unsigned char* )((*env)->GetByteArrayElements(env, buffer_1,    NULL));
    unsigned char* bufferPtr_2 = (unsigned char* )((*env)->GetByteArrayElements(env, buffer_2,    NULL));
    unsigned char* tmp;


    length = length_loc;
    transfer_in =  libusb_alloc_transfer(0);

    callback_env = env;
    callback_obj = this;

    cls = (*callback_env)->GetObjectClass(callback_env, callback_obj);
    mid = (*callback_env)->GetMethodID(callback_env, cls, "RecCallback", "(I)V");

    grab_en = 1;
    do_exit = 0;

    while(grab_en)
    {

        libusb_fill_bulk_transfer( transfer_in, dev_handle, ENDPOINT_BULK_IN,
                bufferPtr_1,  length,  // Note: in_buffer is where input data written.
                cb_in, NULL, // no user data
                TIMEOUT_VIN); // wait untill data available

        libusb_submit_transfer(transfer_in);

        while ( !do_exit )
        {
            libusb_handle_events_completed(ctx, NULL);
        }

        tmp = bufferPtr_1;
        bufferPtr_1 = bufferPtr_2;
        bufferPtr_2 = tmp;

        do_exit = 0;
    }

    if(NULL != dev_handle) libusb_close(dev_handle);
    if(NULL != ctx) libusb_exit(ctx);

    (*env)->ReleaseByteArrayElements(env,buffer_1,  bufferPtr_1,  JNI_ABORT);
    (*env)->ReleaseByteArrayElements(env,buffer_2,  bufferPtr_2,  JNI_ABORT);
}

jint
Java_nok_pack_Device_SendData(JNIEnv * env, jobject this,
        jbyteArray cnfg, jint length)
{
    int actual_length = 0;

    jbyte* cnfgPtr = (*env)->GetByteArrayElements(env, cnfg, NULL);

    int ret = libusb_bulk_transfer(dev_handle, ENDPOINT_BULK_OUT, cnfgPtr, length, &actual_length, TIMEOUT_COUT);

    (*env)->ReleaseByteArrayElements(env,cnfg,cnfgPtr,JNI_ABORT);

    return actual_length;
}