update: using global struct mutex

tiny_pool.c

@@ -26,39 +26,48 @@ pool_t* tiny_pool_create(uint32_t size) {
     pool->task_queue_front = NULL;
 
     /// thread mutex initialization
-    if (pthread_mutex_init(&pool->status_mutex, NULL)) {
-        free(pool->threads);
-        free(pool);
-        return NULL; // status mutex init error -> stop create
-    }
-    if (pthread_mutex_init(&pool->task_queue_busy, NULL)) {
-        pthread_mutex_destroy(&pool->status_mutex);
-        free(pool->threads);
-        free(pool);
-        return NULL; // queue mutex init error -> stop create
-    }
-    if (pthread_mutex_init(&pool->busy_thr_num_mutex, NULL)) {
-        pthread_mutex_destroy(&pool->task_queue_busy);
-        pthread_mutex_destroy(&pool->status_mutex);
-        free(pool->threads);
-        free(pool);
-        return NULL; // busy thread num mutex init error -> stop create
-    }
+
+    pthread_mutex_init(&pool->mutex, NULL);
+
+//    if (pthread_mutex_init(&pool->status_mutex, NULL)) {
+//        free(pool->threads);
+//        free(pool);
+//        return NULL; // status mutex init error -> stop create
+//    }
+//    if (pthread_mutex_init(&pool->task_queue_busy, NULL)) {
+//        pthread_mutex_destroy(&pool->status_mutex);
+//        free(pool->threads);
+//        free(pool);
+//        return NULL; // queue mutex init error -> stop create
+//    }
+//    if (pthread_mutex_init(&pool->busy_thr_num_mutex, NULL)) {
+//        pthread_mutex_destroy(&pool->task_queue_busy);
+//        pthread_mutex_destroy(&pool->status_mutex);
+//        free(pool->threads);
+//        free(pool);
+//        return NULL; // busy thread num mutex init error -> stop create
+//    }
 
     /// thread condition variable initialization
     if (pthread_cond_init(&pool->task_queue_empty, NULL)) {
-        pthread_mutex_destroy(&pool->busy_thr_num_mutex);
-        pthread_mutex_destroy(&pool->task_queue_busy);
-        pthread_mutex_destroy(&pool->status_mutex);
+//        pthread_mutex_destroy(&pool->busy_thr_num_mutex);
+//        pthread_mutex_destroy(&pool->task_queue_busy);
+//        pthread_mutex_destroy(&pool->status_mutex);
+
+        pthread_mutex_destroy(&pool->mutex);
+
         free(pool->threads);
         free(pool);
         return NULL; // pthread cond init error -> stop create
     }
     if (pthread_cond_init(&pool->task_queue_not_empty, NULL)) {
         pthread_cond_destroy(&pool->task_queue_empty);
-        pthread_mutex_destroy(&pool->busy_thr_num_mutex);
-        pthread_mutex_destroy(&pool->task_queue_busy);
-        pthread_mutex_destroy(&pool->status_mutex);
+//        pthread_mutex_destroy(&pool->busy_thr_num_mutex);
+//        pthread_mutex_destroy(&pool->task_queue_busy);
+//        pthread_mutex_destroy(&pool->status_mutex);
+
+        pthread_mutex_destroy(&pool->mutex);
+
         free(pool->threads);
         free(pool);
         return NULL;
@@ -70,7 +79,10 @@ void task_queue_push(pool_t *pool, task_t *task) {
 
     printf("push one task\n");
 
-    pthread_mutex_lock(&pool->task_queue_busy); // lock task queue
+//    pthread_mutex_lock(&pool->task_queue_busy); // lock task queue
+
+    printf("start push process\n");
+
     if (pool->task_queue_rear == NULL) { // task queue is empty
         pool->task_queue_front = task;
         pool->task_queue_rear = task; // init task queue with one element
@@ -82,27 +94,40 @@ void task_queue_push(pool_t *pool, task_t *task) {
 
     printf("push success -> size = %d\n", pool->task_queue_size);
 
-    pthread_mutex_unlock(&pool->task_queue_busy); // unlock task queue
-    if (pool->status > PREPARING) { // avoid send signal in PREPARING stage
+//    bool signal_flag = false;
+//    if (pool->status > PREPARING) {
+//        signal_flag = true;
+//    }
 
-        printf("signal -> queue not empty\n");
+//    pthread_mutex_unlock(&pool->task_queue_busy); // unlock task queue
+    pthread_mutex_unlock(&pool->mutex); // unlock task queue
 
-        pthread_cond_signal(&pool->task_queue_not_empty); // active one blocking thread
-    }
+//    if (pool->status > PREPARING) { // avoid send signal in PREPARING stage
+
+//    if (signal_flag) {
+//
+//        printf("signal -> queue not empty\n");
+//
+//        pthread_cond_signal(&pool->task_queue_not_empty); // active one blocking thread
+//    }
 }
 
 task_t* task_queue_pop(pool_t *pool) { // pop one task with blocking wait
 
     printf("%lu -> try pop one task\n", pthread_self());
 
-    pthread_mutex_lock(&pool->task_queue_busy); // lock task queue
+//    pthread_mutex_lock(&pool->task_queue_busy); // lock task queue
+    pthread_mutex_lock(&pool->mutex); // lock task queue
+
     while (pool->task_queue_front == NULL) { // loop until task queue not empty
 
         printf("%lu -> pop start wait\n", pthread_self());
 
         // TODO: at EXITING process may receive active broadcast -> we should stop pop task here
         //       should we cancel thread here directly, or return NULL for sub thread loop?
-        pthread_cond_wait(&pool->task_queue_not_empty, &pool->task_queue_busy); // wait new task added
+//        pthread_cond_wait(&pool->task_queue_not_empty, &pool->task_queue_busy); // wait new task added
+        pthread_cond_wait(&pool->task_queue_not_empty, &pool->mutex); // wait new task added
+        // TODO: for now, it seems that first one is more suitable
 
         printf("%lu -> pop exit wait\n", pthread_self());
 
@@ -121,9 +146,12 @@ task_t* task_queue_pop(pool_t *pool) { // pop one task with blocking wait
     }
     --pool->task_queue_size;
 
+    ++pool->busy_thr_num; // task must pop by one ready thread
+
     printf("%lu -> pop success -> size = %d\n", pthread_self(), pool->task_queue_size);
 
-    pthread_mutex_unlock(&pool->task_queue_busy); // unlock task queue
+//    pthread_mutex_unlock(&pool->task_queue_busy); // unlock task queue
+    pthread_mutex_unlock(&pool->mutex); // unlock task queue
 
     if (queue_empty) { // send signal after mutex unlocked
         pthread_cond_signal(&pool->task_queue_empty); // active blocking pool join thread
@@ -132,23 +160,50 @@ task_t* task_queue_pop(pool_t *pool) { // pop one task with blocking wait
 }
 
 bool tiny_pool_submit(pool_t *pool, void (*func)(void*), void *arg) {
+
+    // TODO: pre-check status here: if > RUNNING --> return false
+
     task_t *new_task = (task_t*)malloc(sizeof(task_t));
     if (new_task == NULL) {
         return false; // malloc new task error -> stop submit
     }
-    new_task->func = func; // load custom task
+    new_task->entry = func; // load custom task
     new_task->arg = arg;
     new_task->next = NULL;
 
     // TODO: warning -> check dead lock here
-    pthread_mutex_lock(&pool->status_mutex);
+
+//    pthread_mutex_lock(&pool->status_mutex);
+    pthread_mutex_lock(&pool->mutex);
+
+    //    pthread_mutex_lock(&pool->mutex); // lock task queue
+
     if (pool->status > RUNNING) {
+
+        pthread_mutex_unlock(&pool->mutex);
+
         free(new_task);
+
         return false; // adding task is prohibited after STOPPING
     } else {
         task_queue_push(pool, new_task); // push into task queue
     }
-    pthread_mutex_unlock(&pool->status_mutex);
+
+    bool signal_flag = false;
+    if (pool->status > PREPARING) {
+        signal_flag = true;
+    }
+
+//    pthread_mutex_unlock(&pool->status_mutex);
+    pthread_mutex_unlock(&pool->mutex);
+
+    if (signal_flag) {
+
+        printf("signal -> queue not empty\n");
+
+        pthread_cond_signal(&pool->task_queue_not_empty); // active one blocking thread
+    }
+
     return true; // task push success
 }
 
@@ -163,21 +218,27 @@ void* thread_entry(void *pool_ptr) { // main loop for sub thread
 
         task_t *task = task_queue_pop(pool); // pop one task -> blocking function
 
-        pthread_mutex_lock(&pool->busy_thr_num_mutex);
-        ++pool->busy_thr_num; // change busy thread number
-        pthread_mutex_unlock(&pool->busy_thr_num_mutex);
 
-        task->func(task->arg); // start running task function
+//        pthread_mutex_lock(&pool->busy_thr_num_mutex);
+//        ++pool->busy_thr_num; // change busy thread number
+//        pthread_mutex_unlock(&pool->busy_thr_num_mutex);
 
-        pthread_mutex_lock(&pool->busy_thr_num_mutex);
-        --pool->busy_thr_num; // change busy thread number
-        pthread_mutex_unlock(&pool->busy_thr_num_mutex);
+        task->entry(task->arg); // start running task function
 
         free(task); // free allocated memory
+
+//        pthread_mutex_lock(&pool->busy_thr_num_mutex);
+        pthread_mutex_lock(&pool->mutex);
+        --pool->busy_thr_num; // change busy thread number
+        pthread_mutex_unlock(&pool->mutex);
+//        pthread_mutex_unlock(&pool->busy_thr_num_mutex);
+
     }
 
     printf("%lu -> sub thread exit\n", pthread_self());
 
+    pthread_exit(NULL);
+
     return NULL; // sub thread exit
 }
 
@@ -186,14 +247,20 @@ void tiny_pool_boot(pool_t *pool) {
 
     // TODO: avoid booting multi-times
 
-    pthread_mutex_lock(&pool->status_mutex);
+    // TODO: pre-check pool status: if != PREPARING --> return
+
+//    pthread_mutex_lock(&pool->status_mutex);
+    pthread_mutex_lock(&pool->mutex);
 
     if (pool->status != PREPARING) {
-        pthread_mutex_unlock(&pool->status_mutex);
+//        pthread_mutex_unlock(&pool->status_mutex);
+        pthread_mutex_unlock(&pool->mutex);
         return;
     }
 
-    pthread_mutex_lock(&pool->task_queue_busy);
+    pool->status = RUNNING;
+
+//    pthread_mutex_lock(&pool->task_queue_busy);
 
     for (uint32_t i = 0; i < pool->thread_num; ++i) {
         pthread_create(&(pool->threads[i]), NULL, thread_entry, (void*)pool);
@@ -201,10 +268,10 @@ void tiny_pool_boot(pool_t *pool) {
 
     printf("thread boot complete\n");
 
-    pool->status = RUNNING;
+//    pthread_mutex_unlock(&pool->task_queue_busy);
+//    pthread_mutex_unlock(&pool->status_mutex);
 
-    pthread_mutex_unlock(&pool->task_queue_busy);
-    pthread_mutex_unlock(&pool->status_mutex);
+    pthread_mutex_unlock(&pool->mutex);
 
 }
 
@@ -221,11 +288,13 @@ bool tiny_pool_join(pool_t *pool) {
 
     printf("start pool join\n");
 
-    pthread_mutex_lock(&pool->status_mutex);
+//    pthread_mutex_lock(&pool->status_mutex);
+    pthread_mutex_lock(&pool->mutex);
 
     if (pool->status != RUNNING) {
 
-        pthread_mutex_unlock(&pool->status_mutex);
+//        pthread_mutex_unlock(&pool->status_mutex);
+        pthread_mutex_unlock(&pool->mutex);
 
         return false;
 
@@ -233,6 +302,8 @@ bool tiny_pool_join(pool_t *pool) {
     pool->status = STOPPING;
 
 
+    pthread_mutex_unlock(&pool->mutex);
+
     // TODO: join process
 
     return true;

tiny_pool.h

@@ -53,25 +53,28 @@ enum pool_status {
 };
 
 typedef struct task_t {
-    void (*func)(void*); // function pointer of the task
+    void (*entry)(void*); // function pointer of the task
     void *arg; // argument of task function
     struct task_t *next; // the next task in the queue
 } task_t;
 
 typedef struct pool_t {
+
+    pthread_mutex_t mutex; // global pool mutex
+
     pthread_t *threads; // store thread id
     uint32_t thread_num; // number of threads
 
     enum pool_status status; // life cycle state
-    pthread_mutex_t status_mutex; // mutex for `status`
+//    pthread_mutex_t status_mutex; // mutex for `status`
 
     uint32_t busy_thr_num; // number of working threads
-    pthread_mutex_t busy_thr_num_mutex; // mutex for `busy_thr_num`
+//    pthread_mutex_t busy_thr_num_mutex; // mutex for `busy_thr_num`
 
     task_t *task_queue_front; // head of task queue
     task_t *task_queue_rear; // end of task queue
     uint32_t task_queue_size; // size of task queue
-    pthread_mutex_t task_queue_busy; // mutex for `task_queue_xxx`
+//    pthread_mutex_t task_queue_busy; // mutex for `task_queue_xxx`
 
     pthread_cond_t task_queue_empty; // condition for task queue becomes empty
     pthread_cond_t task_queue_not_empty; // condition for task queue becomes not empty