206c851146
- Only have a single copy of all of the tasks_*.cpp sample implementations, stored in examples/. - Reduce dynamic storage allocation and locking in task launch code paths. - Don't have a hard limit of the number of tasks that can be launched on Windows (fix issue #85).
295 lines
9.1 KiB
C++
295 lines
9.1 KiB
C++
/*
|
|
Copyright (c) 2011, Intel Corporation
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are
|
|
met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
* Neither the name of Intel Corporation nor the names of its
|
|
contributors may be used to endorse or promote products derived from
|
|
this software without specific prior written permission.
|
|
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
|
|
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
|
|
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
|
|
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include "taskinfo.h"
|
|
#include <pthread.h>
|
|
#include <semaphore.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <assert.h>
|
|
#include <stdio.h>
|
|
#include <fcntl.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/param.h>
|
|
#include <sys/sysctl.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
|
|
static int initialized = 0;
|
|
static volatile int32_t lock = 0;
|
|
|
|
static int nThreads;
|
|
static pthread_t *threads;
|
|
static pthread_mutex_t taskQueueMutex;
|
|
static int nextTaskToRun;
|
|
static sem_t *workerSemaphore;
|
|
static uint32_t numUnfinishedTasks;
|
|
static pthread_mutex_t tasksRunningConditionMutex;
|
|
static pthread_cond_t tasksRunningCondition;
|
|
|
|
// ispc expects these functions to have C linkage / not be mangled
|
|
extern "C" {
|
|
void ISPCLaunch(void *f, void *data);
|
|
void ISPCSync();
|
|
}
|
|
|
|
static void *lTaskEntry(void *arg);
|
|
|
|
/** Figure out how many CPU cores there are in the system
|
|
*/
|
|
static int
|
|
lNumCPUCores() {
|
|
return sysconf(_SC_NPROCESSORS_ONLN);
|
|
}
|
|
|
|
|
|
static void
|
|
lTasksInit() {
|
|
nThreads = lNumCPUCores();
|
|
|
|
threads = (pthread_t *)malloc(nThreads * sizeof(pthread_t));
|
|
|
|
int err;
|
|
if ((err = pthread_mutex_init(&taskQueueMutex, NULL)) != 0) {
|
|
fprintf(stderr, "Error creating mutex: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
char name[32];
|
|
sprintf(name, "ispc_task.%d", (int)getpid());
|
|
workerSemaphore = sem_open(name, O_CREAT, S_IRUSR|S_IWUSR, 0);
|
|
if (!workerSemaphore) {
|
|
fprintf(stderr, "Error creating semaphore: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
if ((err = pthread_cond_init(&tasksRunningCondition, NULL)) != 0) {
|
|
fprintf(stderr, "Error creating condition variable: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
if ((err = pthread_mutex_init(&tasksRunningConditionMutex, NULL)) != 0) {
|
|
fprintf(stderr, "Error creating mutex: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
for (int i = 0; i < nThreads; ++i) {
|
|
err = pthread_create(&threads[i], NULL, &lTaskEntry, (void *)(i));
|
|
if (err != 0) {
|
|
fprintf(stderr, "Error creating pthread %d: %s\n", i, strerror(err));
|
|
exit(1);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void
|
|
ISPCLaunch(void *f, void *d) {
|
|
int err;
|
|
|
|
if (!initialized) {
|
|
while (1) {
|
|
if (lAtomicCompareAndSwap32(&lock, 1, 0) == 0) {
|
|
if (!initialized) {
|
|
lTasksInit();
|
|
__asm__ __volatile__("mfence":::"memory");
|
|
initialized = 1;
|
|
}
|
|
lock = 0;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
//
|
|
// Acquire mutex, add task
|
|
//
|
|
if ((err = pthread_mutex_lock(&taskQueueMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
// Need a mutex here to ensure we get this filled in before a worker
|
|
// grabs it and starts running...
|
|
TaskInfo *ti = lGetTaskInfo();
|
|
ti->func = f;
|
|
ti->data = d;
|
|
|
|
if ((err = pthread_mutex_unlock(&taskQueueMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_unlock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
//
|
|
// Update count of number of tasks left to run
|
|
//
|
|
if ((err = pthread_mutex_lock(&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
// FIXME: is this redundant with nextTaskInfoCoordinate?
|
|
++numUnfinishedTasks;
|
|
|
|
if ((err = pthread_mutex_unlock(&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
//
|
|
// Post to the worker semaphore to wake up worker threads that are
|
|
// sleeping waiting for tasks to show up
|
|
//
|
|
if ((err = sem_post(workerSemaphore)) != 0) {
|
|
fprintf(stderr, "Error from sem_post: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
|
|
static void *
|
|
lTaskEntry(void *arg) {
|
|
int threadIndex = (int)arg;
|
|
int threadCount = nThreads;
|
|
TaskFuncType func;
|
|
|
|
while (1) {
|
|
int err;
|
|
if ((err = sem_wait(workerSemaphore)) != 0) {
|
|
fprintf(stderr, "Error from sem_wait: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
//
|
|
// Acquire mutex, get task
|
|
//
|
|
if ((err = pthread_mutex_lock(&taskQueueMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
if (nextTaskToRun == nextTaskInfoCoordinate) {
|
|
//
|
|
// Task queue is empty, go back and wait on the semaphore
|
|
//
|
|
if ((err = pthread_mutex_unlock(&taskQueueMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_unlock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
int runCoord = nextTaskToRun++;
|
|
int index = (runCoord >> LOG_TASK_QUEUE_CHUNK_SIZE);
|
|
int offset = runCoord & (TASK_QUEUE_CHUNK_SIZE-1);
|
|
TaskInfo *myTask = &taskInfo[index][offset];
|
|
|
|
if ((err = pthread_mutex_unlock(&taskQueueMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_unlock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
//
|
|
// Do work for _myTask_
|
|
//
|
|
func = (TaskFuncType)myTask->func;
|
|
func(myTask->data, threadIndex, threadCount);
|
|
|
|
//
|
|
// Decrement the number of unfinished tasks counter
|
|
//
|
|
if ((err = pthread_mutex_lock(&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
// FIXME: can this be a comparison of (nextTaskToRun == nextTaskInfoCoordinate)?
|
|
// (I don't think so--think there is a race...)
|
|
int unfinished = --numUnfinishedTasks;
|
|
if (unfinished == 0) {
|
|
//
|
|
// Signal the "no more tasks are running" condition if all of
|
|
// them are done.
|
|
//
|
|
int err;
|
|
if ((err = pthread_cond_signal(&tasksRunningCondition)) != 0) {
|
|
fprintf(stderr, "Error from pthread_cond_signal: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
if ((err = pthread_mutex_unlock(&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
pthread_exit(NULL);
|
|
return 0;
|
|
}
|
|
|
|
|
|
void ISPCSync() {
|
|
int err;
|
|
if ((err = pthread_mutex_lock(&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
|
|
// As long as there are tasks running, wait on the condition variable;
|
|
// doing so causes this thread to go to sleep until someone signals on
|
|
// the tasksRunningCondition condition variable.
|
|
while (numUnfinishedTasks > 0) {
|
|
if ((err = pthread_cond_wait(&tasksRunningCondition,
|
|
&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_cond_wait: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
lResetTaskInfo();
|
|
nextTaskToRun = 0;
|
|
|
|
// We acquire ownership of the condition variable mutex when the above
|
|
// pthread_cond_wait returns.
|
|
// FIXME: is there a lurking issue here if numUnfinishedTasks gets back
|
|
// to zero by the time we get to ISPCSync() and thence we're trying to
|
|
// unlock a mutex we don't have a lock on?
|
|
if ((err = pthread_mutex_unlock(&tasksRunningConditionMutex)) != 0) {
|
|
fprintf(stderr, "Error from pthread_mutex_lock: %s\n", strerror(err));
|
|
exit(1);
|
|
}
|
|
}
|