Function ThreadPool_Do

test_common/harness/ThreadPool.cpp:772–969

Blocking API that farms out count jobs to a thread pool. It may return with some work undone if func_ptr() returns a non-zero result. This function obviously has its shortcommings. Only one call to ThreadPool_Do can be running at a time. It is not intended for general purpose use. If clEnqueueNativeKernelFn, out of order queues and a CL_DEVICE_TYPE_CPU were all available then it would make more s

// If clEnqueueNativeKernelFn, out of order queues and a CL_DEVICE_TYPE_CPU were
// all available then it would make more sense to use those features.
cl_int ThreadPool_Do(TPFuncPtr func_ptr, cl_uint count, void *userInfo)
{
#ifndef _WIN32
    cl_int newErr;
#endif
    cl_int err = 0;
    // Lazily set up our threads
#if defined(_MSC_VER) && (_WIN32_WINNT >= 0x600)
    err = !_InitOnceExecuteOnce(&threadpool_init_control, _ThreadPool_Init,
                                NULL, NULL);
#elif defined(_WIN32)
    if (threadpool_init_control == 0)
    {
#warning This is buggy and race prone.  Find a better way.
        ThreadPool_Init();
        threadpool_init_control = 1;
    }
#else // posix platform
    err = pthread_once(&threadpool_init_control, ThreadPool_Init);
    if (err)
    {
        log_error("Error %d from pthread_once. Unable to init threads. "
                  "ThreadPool_Do failed.\n",
                  err);
        return err;
    }
#endif
    // Single threaded code to handle case where threadpool wasn't allocated or
    // was disabled by environment variable
    if (threadPoolInitErr)
    {
        cl_uint currentJob = 0;
        cl_int result = CL_SUCCESS;

#if defined(__APPLE__) && defined(__arm__)
        // On most platforms which support denorm, default is FTZ off. However,
        // on some hardware where the reference is computed, default might be
        // flush denorms to zero e.g. arm. This creates issues in result
        // verification. Since spec allows the implementation to either flush or
        // not flush denorms to zero, an implementation may choose not be flush
        // i.e. return denorm result whereas reference result may be zero
        // (flushed denorm). Hence we need to disable denorm flushing on host
        // side where reference is being computed to make sure we get
        // non-flushed reference result. If implementation returns flushed
        // result, we correctly take care of that in verification code.
        FPU_mode_type oldMode;
        DisableFTZ(&oldMode);
#endif
        for (currentJob = 0; currentJob < count; currentJob++)
            if ((result = func_ptr(currentJob, 0, userInfo)))
            {
#if defined(__APPLE__) && defined(__arm__)
                // Restore FP state before leaving
                RestoreFPState(&oldMode);
#endif
                return result;
            }