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//
// Copyright (c) 2017 The Khronos Group Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "ThreadPool.h"
#include "errorHelpers.h"
#include "fpcontrol.h"
#include <stdio.h>
#include <stdlib.h>
#if defined(__APPLE__) || defined(__linux__) || defined(_WIN32)
// or any other POSIX system
#if defined(_WIN32)
#include <windows.h>
#if defined(_MSC_VER)
#include <intrin.h>
#endif
#include "mingw_compat.h"
#include <process.h>
#else // !_WIN32
#include <pthread.h>
#include <unistd.h>
#include <sys/errno.h>
#ifdef __linux__
#include <sched.h>
#endif
#endif // !_WIN32
// declarations
#ifdef _WIN32
void ThreadPool_WorkerFunc(void *p);
#else
void *ThreadPool_WorkerFunc(void *p);
#endif
void ThreadPool_Init(void);
void ThreadPool_Exit(void);
#if defined(__MINGW32__)
// Mutex for implementing super heavy atomic operations if you don't have GCC or
// MSVC
CRITICAL_SECTION gAtomicLock;
#elif defined(__GNUC__) || defined(_MSC_VER)
#else
pthread_mutex_t gAtomicLock;
#endif
// Atomic add operator with mem barrier. Mem barrier needed to protect state
// modified by the worker functions.
cl_int ThreadPool_AtomicAdd(volatile cl_int *a, cl_int b)
{
#if defined(__MINGW32__)
// No atomics on Mingw32
EnterCriticalSection(&gAtomicLock);
cl_int old = *a;
*a = old + b;
LeaveCriticalSection(&gAtomicLock);
return old;
#elif defined(__GNUC__)
// GCC extension:
// http://gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html#Atomic-Builtins
return __sync_fetch_and_add(a, b);
// do we need __sync_synchronize() here, too? GCC docs are unclear whether
// __sync_fetch_and_add does a synchronize
#elif defined(_MSC_VER)
return (cl_int)_InterlockedExchangeAdd((volatile LONG *)a, (LONG)b);
#else
#warning Please add a atomic add implementation here, with memory barrier. Fallback code is slow.
if (pthread_mutex_lock(&gAtomicLock))
log_error("Atomic operation failed. pthread_mutex_lock(&gAtomicLock) "
"returned an error\n");
cl_int old = *a;
*a = old + b;
if (pthread_mutex_unlock(&gAtomicLock))
log_error("Failed to release gAtomicLock. Further atomic operations "
"may deadlock!\n");
return old;
#endif
}
#if defined(_WIN32)
// Uncomment the following line if Windows XP support is not required.
// #define HAS_INIT_ONCE_EXECUTE_ONCE 1
#if defined(HAS_INIT_ONCE_EXECUTE_ONCE)
#define _INIT_ONCE INIT_ONCE
#define _PINIT_ONCE PINIT_ONCE
#define _InitOnceExecuteOnce InitOnceExecuteOnce
#else // !HAS_INIT_ONCE_EXECUTE_ONCE
typedef volatile LONG _INIT_ONCE;
typedef _INIT_ONCE *_PINIT_ONCE;
typedef BOOL(CALLBACK *_PINIT_ONCE_FN)(_PINIT_ONCE, PVOID, PVOID *);
#define _INIT_ONCE_UNINITIALIZED 0
#define _INIT_ONCE_IN_PROGRESS 1
#define _INIT_ONCE_DONE 2
static BOOL _InitOnceExecuteOnce(_PINIT_ONCE InitOnce, _PINIT_ONCE_FN InitFn,
PVOID Parameter, LPVOID *Context)
{
while (*InitOnce != _INIT_ONCE_DONE)
{
if (*InitOnce != _INIT_ONCE_IN_PROGRESS
&& _InterlockedCompareExchange(InitOnce, _INIT_ONCE_IN_PROGRESS,
_INIT_ONCE_UNINITIALIZED)
== _INIT_ONCE_UNINITIALIZED)
{
InitFn(InitOnce, Parameter, Context);
*InitOnce = _INIT_ONCE_DONE;
return TRUE;
}
Sleep(1);
}
return TRUE;
}
#endif // !HAS_INIT_ONCE_EXECUTE_ONCE
// Uncomment the following line if Windows XP support is not required.
// #define HAS_CONDITION_VARIABLE 1
#if defined(HAS_CONDITION_VARIABLE)
#define _CONDITION_VARIABLE CONDITION_VARIABLE
#define _InitializeConditionVariable InitializeConditionVariable
#define _SleepConditionVariableCS SleepConditionVariableCS
#define _WakeAllConditionVariable WakeAllConditionVariable
#else // !HAS_CONDITION_VARIABLE
typedef struct
{
HANDLE mEvent; // Used to park the thread.
// Used to protect mWaiters, mGeneration and mReleaseCount:
CRITICAL_SECTION mLock[1];
volatile cl_int mWaiters; // Number of threads waiting on this cond var.
volatile cl_int mGeneration; // Wait generation count.
volatile cl_int mReleaseCount; // Number of releases to execute before
// reseting the event.
} _CONDITION_VARIABLE;
typedef _CONDITION_VARIABLE *_PCONDITION_VARIABLE;
static void _InitializeConditionVariable(_PCONDITION_VARIABLE cond_var)
{
cond_var->mEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
InitializeCriticalSection(cond_var->mLock);
cond_var->mWaiters = 0;
cond_var->mGeneration = 0;
#if !defined(NDEBUG)
cond_var->mReleaseCount = 0;
#endif // !NDEBUG
}
static void _SleepConditionVariableCS(_PCONDITION_VARIABLE cond_var,
PCRITICAL_SECTION cond_lock,
DWORD ignored)
{
EnterCriticalSection(cond_var->mLock);
cl_int generation = cond_var->mGeneration;
++cond_var->mWaiters;
LeaveCriticalSection(cond_var->mLock);
LeaveCriticalSection(cond_lock);
while (TRUE)
{
WaitForSingleObject(cond_var->mEvent, INFINITE);
EnterCriticalSection(cond_var->mLock);
BOOL done =
cond_var->mReleaseCount > 0 && cond_var->mGeneration != generation;
LeaveCriticalSection(cond_var->mLock);
if (done)
{
break;
}
}
EnterCriticalSection(cond_lock);
EnterCriticalSection(cond_var->mLock);
if (--cond_var->mReleaseCount == 0)
{
ResetEvent(cond_var->mEvent);
}
--cond_var->mWaiters;
LeaveCriticalSection(cond_var->mLock);
}
static void _WakeAllConditionVariable(_PCONDITION_VARIABLE cond_var)
{
EnterCriticalSection(cond_var->mLock);
if (cond_var->mWaiters > 0)
{
++cond_var->mGeneration;
cond_var->mReleaseCount = cond_var->mWaiters;
SetEvent(cond_var->mEvent);
}
LeaveCriticalSection(cond_var->mLock);
}
#endif // !HAS_CONDITION_VARIABLE
#endif // _WIN32
#define MAX_COUNT (1 << 29)
// Global state to coordinate whether the threads have been launched
// successfully or not
#if defined(_MSC_VER) && (_WIN32_WINNT >= 0x600)
static _INIT_ONCE threadpool_init_control;
#elif defined(_WIN32) // MingW of XP
static int threadpool_init_control;
#else // Posix platforms
pthread_once_t threadpool_init_control = PTHREAD_ONCE_INIT;
#endif
cl_int threadPoolInitErr = -1; // set to CL_SUCCESS on successful thread launch
// critical region lock around ThreadPool_Do. We can only run one ThreadPool_Do
// at a time, because we are too lazy to set up a queue here, and don't expect
// to need one.
#if defined(_WIN32)
CRITICAL_SECTION gThreadPoolLock[1];
#else // !_WIN32
pthread_mutex_t gThreadPoolLock;
#endif // !_WIN32
// Condition variable to park ThreadPool threads when not working
#if defined(_WIN32)
CRITICAL_SECTION cond_lock[1];
_CONDITION_VARIABLE cond_var[1];
#else // !_WIN32
pthread_mutex_t cond_lock;
pthread_cond_t cond_var;
#endif // !_WIN32
// Condition variable state. How many iterations on the function left to run,
// set to CL_INT_MAX to cause worker threads to exit. Note: this value might
// go negative.
volatile cl_int gRunCount = 0;
// State that only changes when the threadpool is not working.
volatile TPFuncPtr gFunc_ptr = NULL;
volatile void *gUserInfo = NULL;
volatile cl_int gJobCount = 0;
// State that may change while the thread pool is working
volatile cl_int jobError = CL_SUCCESS; // err code return for the job as a whole
// Condition variable to park caller while waiting
#if defined(_WIN32)
HANDLE caller_event;
#else // !_WIN32
pthread_mutex_t caller_cond_lock;
pthread_cond_t caller_cond_var;
#endif // !_WIN32
// # of threads intended to be running. Running threads will decrement this
// as they discover they've run out of work to do.
volatile cl_int gRunning = 0;
// The total number of threads launched.
volatile cl_int gThreadCount = 0;
#ifdef _WIN32
void ThreadPool_WorkerFunc(void *p)
#else
void *ThreadPool_WorkerFunc(void *p)
#endif
{
cl_uint threadID = ThreadPool_AtomicAdd((volatile cl_int *)p, 1);
cl_int item = ThreadPool_AtomicAdd(&gRunCount, -1);
// log_info( "ThreadPool_WorkerFunc start: gRunning = %d\n", gRunning );
while (MAX_COUNT > item)
{
cl_int err;
// check for more work to do
if (0 >= item)
{
// log_info("Thread %d has run out of work.\n", threadID);
// No work to do. Attempt to block waiting for work
#if defined(_WIN32)
EnterCriticalSection(cond_lock);
#else // !_WIN32
if ((err = pthread_mutex_lock(&cond_lock)))
{
log_error(
"Error %d from pthread_mutex_lock. Worker %d unable to "
"block waiting for work. ThreadPool_WorkerFunc failed.\n",
err, threadID);
goto exit;
}
#endif // !_WIN32
cl_int remaining = ThreadPool_AtomicAdd(&gRunning, -1);
// log_info("ThreadPool_WorkerFunc: gRunning = %d\n",
// remaining - 1);
if (1 == remaining)
{ // last thread out signal the main thread to wake up
#if defined(_WIN32)
SetEvent(caller_event);
#else // !_WIN32
if ((err = pthread_mutex_lock(&caller_cond_lock)))
{
log_error("Error %d from pthread_mutex_lock. Unable to "
"wake caller.\n",
err);
goto exit;
}
if ((err = pthread_cond_broadcast(&caller_cond_var)))
{
log_error(
"Error %d from pthread_cond_broadcast. Unable to wake "
"up main thread. ThreadPool_WorkerFunc failed.\n",
err);
goto exit;
}
if ((err = pthread_mutex_unlock(&caller_cond_lock)))
{
log_error("Error %d from pthread_mutex_lock. Unable to "
"wake caller.\n",
err);
goto exit;
}
#endif // !_WIN32
}
// loop in case we are woken only to discover that some other thread
// already did all the work
while (0 >= item)
{
#if defined(_WIN32)
_SleepConditionVariableCS(cond_var, cond_lock, INFINITE);
#else // !_WIN32
if ((err = pthread_cond_wait(&cond_var, &cond_lock)))
{
log_error(
"Error %d from pthread_cond_wait. Unable to block for "
"waiting for work. ThreadPool_WorkerFunc failed.\n",
err);
pthread_mutex_unlock(&cond_lock);
goto exit;
}
#endif // !_WIN32
// try again to get a valid item id
item = ThreadPool_AtomicAdd(&gRunCount, -1);
if (MAX_COUNT <= item) // exit if we are done
{
#if defined(_WIN32)
LeaveCriticalSection(cond_lock);
#else // !_WIN32
pthread_mutex_unlock(&cond_lock);
#endif // !_WIN32
goto exit;
}
}
ThreadPool_AtomicAdd(&gRunning, 1);
// log_info("Thread %d has found work.\n", threadID);
#if defined(_WIN32)
LeaveCriticalSection(cond_lock);
#else // !_WIN32
if ((err = pthread_mutex_unlock(&cond_lock)))
{
log_error(
"Error %d from pthread_mutex_unlock. Unable to block for "
"waiting for work. ThreadPool_WorkerFunc failed.\n",
err);
goto exit;
}
#endif // !_WIN32
}
// we have a valid item, so do the work
// but only if we haven't already encountered an error
if (CL_SUCCESS == jobError)
{
// log_info("Thread %d doing job %d\n", threadID, item - 1);
#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
// Call the user's function with this item ID
err = gFunc_ptr(item - 1, threadID, (void *)gUserInfo);
#if defined(__APPLE__) && defined(__arm__)
// Restore FP state
RestoreFPState(&oldMode);
#endif
if (err)
{
#if (__MINGW32__)
EnterCriticalSection(&gAtomicLock);
if (jobError == CL_SUCCESS) jobError = err;
gRunCount = 0;
LeaveCriticalSection(&gAtomicLock);
#elif defined(__GNUC__)
// GCC extension:
// http://gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html#Atomic-Builtins
// set the new error if we are the first one there.
__sync_val_compare_and_swap(&jobError, CL_SUCCESS, err);
// drop run count to 0
gRunCount = 0;
__sync_synchronize();
#elif defined(_MSC_VER)
// set the new error if we are the first one there.
_InterlockedCompareExchange((volatile LONG *)&jobError, err,
CL_SUCCESS);
// drop run count to 0
gRunCount = 0;
_mm_mfence();
#else
if (pthread_mutex_lock(&gAtomicLock))
log_error(
"Atomic operation failed. "
"pthread_mutex_lock(&gAtomicLock) returned an error\n");
if (jobError == CL_SUCCESS) jobError = err;
gRunCount = 0;
if (pthread_mutex_unlock(&gAtomicLock))
log_error("Failed to release gAtomicLock. Further atomic "
"operations may deadlock\n");
#endif
}
}
// get the next item
item = ThreadPool_AtomicAdd(&gRunCount, -1);
}
exit:
log_info("ThreadPool: thread %d exiting.\n", threadID);
ThreadPool_AtomicAdd(&gThreadCount, -1);
#if !defined(_WIN32)
return NULL;
#endif
}
// SetThreadCount() may be used to artifically set the number of worker threads
// If the value is 0 (the default) the number of threads will be determined
// based on the number of CPU cores. If it is a unicore machine, then 2 will be
// used, so that we still get some testing for thread safety.
//
// If count < 2 or the CL_TEST_SINGLE_THREADED environment variable is set then
// the code will run single threaded, but will report an error to indicate that
// the test is invalid. This option is intended for debugging purposes only. It
// is suggested as a convention that test apps set the thread count to 1 in
// response to the -m flag.
//
// SetThreadCount() must be called before the first call to GetThreadCount() or
// ThreadPool_Do(), otherwise the behavior is indefined.
void SetThreadCount(int count)
{
if (threadPoolInitErr == CL_SUCCESS)
{
log_error("Error: It is illegal to set the thread count after the "
"first call to ThreadPool_Do or GetThreadCount\n");
abort();
}
gThreadCount = count;
}
void ThreadPool_Init(void)
{
cl_int i;
int err;
volatile cl_uint threadID = 0;
// Check for manual override of multithreading code. We add this for better
// debuggability.
if (getenv("CL_TEST_SINGLE_THREADED"))
{
log_error("ERROR: CL_TEST_SINGLE_THREADED is set in the environment. "
"Running single threaded.\n*** TEST IS INVALID! ***\n");
gThreadCount = 1;
return;
}
// Figure out how many threads to run -- check first for non-zero to give
// the implementation the chance
if (0 == gThreadCount)
{
#if defined(_MSC_VER) || defined(__MINGW64__)
PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL;
DWORD length = 0;
GetLogicalProcessorInformation(NULL, &length);
buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)malloc(length);
if (buffer != NULL)
{
if (GetLogicalProcessorInformation(buffer, &length) == TRUE)
{
PSYSTEM_LOGICAL_PROCESSOR_INFORMATION ptr = buffer;
while (
ptr
< &buffer[length
/ sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION)])
{
if (ptr->Relationship == RelationProcessorCore)
{
// Count the number of bits in ProcessorMask (number of
// logical cores)
ULONG mask = ptr->ProcessorMask;
while (mask)
{
++gThreadCount;
mask &= mask - 1; // Remove 1 bit at a time
}
}
++ptr;
}
}
free(buffer);
}
#elif defined(__MINGW32__)
{
#warning How about this, instead of hard coding it to 2?
SYSTEM_INFO sysinfo;
GetSystemInfo(&sysinfo);
gThreadCount = sysinfo.dwNumberOfProcessors;
}
#elif defined(__linux__) && !defined(__ANDROID__)
cpu_set_t affinity;
if (0 == sched_getaffinity(0, sizeof(cpu_set_t), &affinity))
{
#if !(defined(CPU_COUNT))
gThreadCount = 1;
#else
gThreadCount = CPU_COUNT(&affinity);
#endif
}
else
{
// Hopefully your system returns logical cpus here, as does MacOS X
gThreadCount = (cl_int)sysconf(_SC_NPROCESSORS_CONF);
}
#else /* !_WIN32 */
// Hopefully your system returns logical cpus here, as does MacOS X
gThreadCount = (cl_int)sysconf(_SC_NPROCESSORS_CONF);
#endif // !_WIN32
// Multithreaded tests are required to run multithreaded even on unicore
// systems so as to test thread safety
if (1 == gThreadCount) gThreadCount = 2;
}
// When working in 32 bit limit the thread number to 12
// This fix was made due to memory issues in integer_ops test
// When running integer_ops, the test opens as many threads as the
// machine has and each thread allocates a fixed amount of memory
// When running this test on dual socket machine in 32-bit, the
// process memory is not sufficient and the test fails
#if defined(_WIN32) && !defined(_M_X64)
if (gThreadCount > 12)
{
gThreadCount = 12;
}
#endif
// Allow the app to set thread count to <0 for debugging purposes.
// This will cause the test to run single threaded.
if (gThreadCount < 2)
{
log_error("ERROR: Running single threaded because thread count < 2. "
"\n*** TEST IS INVALID! ***\n");
gThreadCount = 1;
return;
}
#if defined(_WIN32)
InitializeCriticalSection(gThreadPoolLock);
InitializeCriticalSection(cond_lock);
_InitializeConditionVariable(cond_var);
caller_event = CreateEvent(NULL, FALSE, FALSE, NULL);
#elif defined(__GNUC__)
// Dont rely on PTHREAD_MUTEX_INITIALIZER for intialization of a mutex since
// it might cause problem with some flavors of gcc compilers.
pthread_cond_init(&cond_var, NULL);
pthread_mutex_init(&cond_lock, NULL);
pthread_cond_init(&caller_cond_var, NULL);
pthread_mutex_init(&caller_cond_lock, NULL);
pthread_mutex_init(&gThreadPoolLock, NULL);
#endif
#if !(defined(__GNUC__) || defined(_MSC_VER) || defined(__MINGW32__))
pthread_mutex_initialize(gAtomicLock);
#elif defined(__MINGW32__)
InitializeCriticalSection(&gAtomicLock);
#endif
// Make sure the last thread done in the work pool doesn't signal us to wake
// before we get to the point where we are supposed to wait
// That would cause a deadlock.
#if !defined(_WIN32)
if ((err = pthread_mutex_lock(&caller_cond_lock)))
{
log_error("Error %d from pthread_mutex_lock. Unable to block for work "
"to finish. ThreadPool_Init failed.\n",
err);
gThreadCount = 1;
return;
}
#endif // !_WIN32
gRunning = gThreadCount;
// init threads
for (i = 0; i < gThreadCount; i++)
{
#if defined(_WIN32)
uintptr_t handle =
_beginthread(ThreadPool_WorkerFunc, 0, (void *)&threadID);
err = (handle == 0);
#else // !_WIN32
pthread_t tid = 0;
err = pthread_create(&tid, NULL, ThreadPool_WorkerFunc,
(void *)&threadID);
#endif // !_WIN32
if (err)
{
log_error("Error %d launching thread %d\n", err, i);
threadPoolInitErr = err;
gThreadCount = i;
break;
}
}
atexit(ThreadPool_Exit);
// block until they are done launching.
do
{
#if defined(_WIN32)
WaitForSingleObject(caller_event, INFINITE);
#else // !_WIN32
if ((err = pthread_cond_wait(&caller_cond_var, &caller_cond_lock)))
{
log_error("Error %d from pthread_cond_wait. Unable to block for "
"work to finish. ThreadPool_Init failed.\n",
err);
pthread_mutex_unlock(&caller_cond_lock);
return;
}
#endif // !_WIN32
} while (gRunCount != -gThreadCount);
#if !defined(_WIN32)
if ((err = pthread_mutex_unlock(&caller_cond_lock)))
{
log_error("Error %d from pthread_mutex_unlock. Unable to block for "
"work to finish. ThreadPool_Init failed.\n",
err);
return;
}
#endif // !_WIN32
threadPoolInitErr = CL_SUCCESS;
}
#if defined(_MSC_VER)
static BOOL CALLBACK _ThreadPool_Init(_PINIT_ONCE InitOnce, PVOID Parameter,
PVOID *lpContex)
{
ThreadPool_Init();
return TRUE;
}
#endif
void ThreadPool_Exit(void)
{
int err, count;
gRunCount = CL_INT_MAX;
#if defined(__GNUC__)
// GCC extension:
// http://gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html#Atomic-Builtins
__sync_synchronize();
#elif defined(_MSC_VER)
_mm_mfence();
#else
#warning If this is a weakly ordered memory system, please add a memory barrier here to force this and everything else to memory before we proceed
#endif
// spin waiting for threads to die
for (count = 0; 0 != gThreadCount && count < 1000; count++)
{
#if defined(_WIN32)
_WakeAllConditionVariable(cond_var);
Sleep(1);
#else // !_WIN32
if ((err = pthread_cond_broadcast(&cond_var)))
{
log_error("Error %d from pthread_cond_broadcast. Unable to wake up "
"work threads. ThreadPool_Exit failed.\n",
err);
break;
}
usleep(1000);
#endif // !_WIN32
}
if (gThreadCount)
log_error("Error: Thread pool timed out after 1 second with %d threads "
"still active.\n",
gThreadCount);
else
log_info("Thread pool exited in a orderly fashion.\n");
}
// 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 sense to use those features.
cl_int ThreadPool_Do(TPFuncPtr func_ptr, cl_uint count, void *userInfo)
{
cl_int newErr;
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;
}
#if defined(__APPLE__) && defined(__arm__)
// Restore FP state before leaving
RestoreFPState(&oldMode);
#endif
return CL_SUCCESS;
}
if (count >= MAX_COUNT)
{
log_error(
"Error: ThreadPool_Do count %d >= max threadpool count of %d\n",
count, MAX_COUNT);
return -1;
}
// Enter critical region
#if defined(_WIN32)
EnterCriticalSection(gThreadPoolLock);
#else // !_WIN32
if ((err = pthread_mutex_lock(&gThreadPoolLock)))
{
switch (err)
{
case EDEADLK:
log_error(
"Error EDEADLK returned in ThreadPool_Do(). ThreadPool_Do "
"is not designed to work recursively!\n");
break;
case EINVAL:
log_error("Error EINVAL returned in ThreadPool_Do(). How did "
"we end up with an invalid gThreadPoolLock?\n");
break;
default: break;
}
return err;
}
#endif // !_WIN32
// Start modifying the job state observable by worker threads
#if defined(_WIN32)
EnterCriticalSection(cond_lock);
#else // !_WIN32
if ((err = pthread_mutex_lock(&cond_lock)))
{
log_error("Error %d from pthread_mutex_lock. Unable to wake up work "
"threads. ThreadPool_Do failed.\n",
err);
goto exit;
}
#endif // !_WIN32
// Make sure the last thread done in the work pool doesn't signal us to wake
// before we get to the point where we are supposed to wait
// That would cause a deadlock.
#if !defined(_WIN32)
if ((err = pthread_mutex_lock(&caller_cond_lock)))
{
log_error("Error %d from pthread_mutex_lock. Unable to block for work "
"to finish. ThreadPool_Do failed.\n",
err);
goto exit;
}
#endif // !_WIN32
// Prime the worker threads to get going
jobError = CL_SUCCESS;
gRunCount = gJobCount = count;
gFunc_ptr = func_ptr;
gUserInfo = userInfo;
#if defined(_WIN32)
ResetEvent(caller_event);
_WakeAllConditionVariable(cond_var);
LeaveCriticalSection(cond_lock);
#else // !_WIN32
if ((err = pthread_cond_broadcast(&cond_var)))
{
log_error("Error %d from pthread_cond_broadcast. Unable to wake up "
"work threads. ThreadPool_Do failed.\n",
err);
goto exit;
}
if ((err = pthread_mutex_unlock(&cond_lock)))
{
log_error("Error %d from pthread_mutex_unlock. Unable to wake up work "
"threads. ThreadPool_Do failed.\n",
err);
goto exit;
}
#endif // !_WIN32
// block until they are done. It would be slightly more efficient to do
// some of the work here though.
do
{
#if defined(_WIN32)
WaitForSingleObject(caller_event, INFINITE);
#else // !_WIN32
if ((err = pthread_cond_wait(&caller_cond_var, &caller_cond_lock)))
{
log_error("Error %d from pthread_cond_wait. Unable to block for "
"work to finish. ThreadPool_Do failed.\n",
err);
pthread_mutex_unlock(&caller_cond_lock);
goto exit;
}
#endif // !_WIN32
} while (gRunning);
#if !defined(_WIN32)
if ((err = pthread_mutex_unlock(&caller_cond_lock)))
{
log_error("Error %d from pthread_mutex_unlock. Unable to block for "
"work to finish. ThreadPool_Do failed.\n",
err);
goto exit;
}
#endif // !_WIN32
err = jobError;
exit:
// exit critical region
#if defined(_WIN32)
LeaveCriticalSection(gThreadPoolLock);
#else // !_WIN32
newErr = pthread_mutex_unlock(&gThreadPoolLock);
if (newErr)
{
log_error("Error %d from pthread_mutex_unlock. Unable to exit critical "
"region. ThreadPool_Do failed.\n",
newErr);
return err;
}
#endif // !_WIN32
return err;
}
cl_uint GetThreadCount(void)
{
// Lazily set up our threads
#if defined(_MSC_VER) && (_WIN32_WINNT >= 0x600)
cl_int 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
cl_int 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 // !_WIN32
if (gThreadCount < 1) return 1;
return gThreadCount;
}
#else
#ifndef MY_OS_REALLY_REALLY_DOESNT_SUPPORT_THREADS
#error ThreadPool implementation has not been multithreaded for this operating system. You must multithread this section.
#endif
//
// We require multithreading in parts of the test as a means of simultaneously
// testing reentrancy requirements of OpenCL API, while also checking
//
// A sample single threaded implementation follows, for documentation /
// bootstrapping purposes. It is not okay to use this for conformance testing!!!
//
// Exception: If your operating system does not support multithreaded execution
// of any kind, then you may use this code.
//
cl_int ThreadPool_AtomicAdd(volatile cl_int *a, cl_int b)
{
cl_uint r = *a;
// since this fallback code path is not multithreaded, we just do a regular
// add here. If your operating system supports memory-barrier-atomics, use
// those here.
*a = r + b;
return r;
}
// 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.
cl_int ThreadPool_Do(TPFuncPtr func_ptr, cl_uint count, void *userInfo)
{
cl_uint currentJob = 0;
cl_int result = CL_SUCCESS;
#ifndef MY_OS_REALLY_REALLY_DOESNT_SUPPORT_THREADS
// THIS FUNCTION IS NOT INTENDED FOR USE!!
log_error("ERROR: Test must be multithreaded!\n");
exit(-1);
#else
static int spewCount = 0;
if (0 == spewCount)
{
log_info("\nWARNING: The operating system is claimed not to support "
"threads of any sort. Running single threaded.\n");
spewCount = 1;
}
#endif
// The multithreaded code should mimic this behavior:
for (currentJob = 0; currentJob < count; currentJob++)
if ((result = func_ptr(currentJob, 0, userInfo))) return result;
return CL_SUCCESS;
}
cl_uint GetThreadCount(void) { return 1; }
void SetThreadCount(int count)
{
if (count > 1) log_info("WARNING: SetThreadCount(%d) ignored\n", count);
}
#endif