Function background_thread_create_locked

deps/jemalloc/src/background_thread.c:537–589

}

static bool
background_thread_create_locked(tsd_t *tsd, unsigned arena_ind) {
	assert(have_background_thread);
	malloc_mutex_assert_owner(tsd_tsdn(tsd), &background_thread_lock);

	/* We create at most NCPUs threads. */
	size_t thread_ind = arena_ind % max_background_threads;
	background_thread_info_t *info = &background_thread_info[thread_ind];

	bool need_new_thread;
	malloc_mutex_lock(tsd_tsdn(tsd), &info->mtx);
	need_new_thread = background_thread_enabled() &&
	    (info->state == background_thread_stopped);
	if (need_new_thread) {
		background_thread_init(tsd, info);
	}
	malloc_mutex_unlock(tsd_tsdn(tsd), &info->mtx);
	if (!need_new_thread) {
		return false;
	}
	if (arena_ind != 0) {
		/* Threads are created asynchronously by Thread 0. */
		background_thread_info_t *t0 = &background_thread_info[0];
		malloc_mutex_lock(tsd_tsdn(tsd), &t0->mtx);
		assert(t0->state == background_thread_started);
		pthread_cond_signal(&t0->cond);
		malloc_mutex_unlock(tsd_tsdn(tsd), &t0->mtx);

		return false;
	}

	pre_reentrancy(tsd, NULL);
	/*
	 * To avoid complications (besides reentrancy), create internal
	 * background threads with the underlying pthread_create.
	 */
	int err = background_thread_create_signals_masked(&info->thread, NULL,
	    background_thread_entry, (void *)thread_ind);
	post_reentrancy(tsd);

	if (err != 0) {
		malloc_printf("<jemalloc>: arena 0 background thread creation "
		    "failed (%d)\n", err);
		malloc_mutex_lock(tsd_tsdn(tsd), &info->mtx);
		info->state = background_thread_stopped;
		n_background_threads--;
		malloc_mutex_unlock(tsd_tsdn(tsd), &info->mtx);

		return true;
	}

	return false;
}

/* Create a new background thread if needed. */
bool