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| typedef struct job_t {
void (*function)(void*);
void* argument;
} job_t;
typedef struct thread_data {
...
} thread_data;
class ThreadPool {
public:
int max_thread;
queue<job_t> job_queue;
sem_t queue_mutex;
sem_t job_count;
sem_t clean;
bool shutdown = false;
ThreadPool(int thread_count) {
if (thread_count < 0) exit(1);
this->max_thread = thread_count;
// initial job queue mutex
sem_init(&this->queue_mutex, 0, 1);
sem_init(&this->job_count, 0, 0);
sem_init(&this->clean, 0, 0);
// start worker thread
for (int i = 0; i < thread_count; i++) {
pthread_t thread;
pthread_create(&thread, NULL, worker_thread, (void*)this);
}
}
void push_job(job_t job) {
sem_wait(&this->queue_mutex);
job_queue.push(job);
sem_post(&this->queue_mutex);
sem_post(&this->job_count);
}
~ThreadPool() {
this->shutdown = true;
int destroy_thread_count = 0;
while (destroy_thread_count != this->max_thread) {
sem_post(&this->job_count);
sem_getvalue(&this->clean, &destroy_thread_count);
}
}
};
static void* worker_thread(void* data) {
ThreadPool* pool = (ThreadPool*)data;
job_t job;
while (1) {
// keep waiting until new job comming
sem_wait(&pool->job_count);
if (pool->shutdown) break;
// mutex to protect job queue
sem_wait(&pool->queue_mutex);
job = pool->job_queue.front();
pool->job_queue.pop();
sem_post(&pool->queue_mutex);
// do task
(*(job.function))(job.argument);
}
sem_post(&pool->clean);
pthread_exit(NULL);
return 0;
}
void job_func(void* arg) {
...
}
int main() {
ThreadPool pool(thread_num);
for (...) {
job_t job;
thread_data job_func_args;
job.function = job_func;
job.argument = job_func_args;
pool.push_job(job);
}
}
|
