Processor job scheduling respects job priority classes

src/libstrongswan/processing/processor.c

@@ -34,6 +34,7 @@ typedef struct private_processor_t private_processor_t;
  * Private data of processor_t class.
  */
 struct private_processor_t {
+
 	/**
 	 * Public processor_t interface.
 	 */
@@ -61,12 +62,12 @@ struct private_processor_t {
 	linked_list_t *threads;
 
 	/**
-	 * The jobs are stored in a linked list
+	 * A list of queued jobs for each priority
 	 */
-	linked_list_t *list;
+	linked_list_t *jobs[JOB_PRIO_MAX];
 
 	/**
-	 * access to linked_list is locked through this mutex
+	 * access to job lists is locked through this mutex
 	 */
 	mutex_t *mutex;
 
@@ -120,16 +121,24 @@ static void process_jobs(private_processor_t *this)
 	this->mutex->lock(this->mutex);
 	while (this->desired_threads >= this->total_threads)
 	{
-		job_t *job;
+		job_t *job = NULL;
+		int i;
 
-		if (this->list->get_count(this->list) == 0)
+		for (i = 0; i < JOB_PRIO_MAX; i++)
+		{
+			if (this->jobs[i]->remove_first(this->jobs[i],
+											(void**)&job) == SUCCESS)
+			{
+				break;
+			}
+		}
+		if (!job)
 		{
 			this->idle_threads++;
 			this->job_added->wait(this->job_added, this->mutex);
 			this->idle_threads--;
 			continue;
 		}
-		this->list->remove_first(this->list, (void**)&job);
 		this->mutex->unlock(this->mutex);
 		/* terminated threads are restarted, so we have a constant pool */
 		thread_cleanup_push((thread_cleanup_t)restart, this);
@@ -164,13 +173,26 @@ METHOD(processor_t, get_idle_threads, u_int,
 	return count;
 }
 
+/**
+ * Check priority bounds
+ */
+static job_priority_t sane_prio(job_priority_t prio)
+{
+	if (prio < 0 || prio >= JOB_PRIO_MAX)
+	{
+		return JOB_PRIO_MAX - 1;
+	}
+	return prio;
+}
+
 METHOD(processor_t, get_job_load, u_int,
-	private_processor_t *this)
+	private_processor_t *this, job_priority_t prio)
 {
 	u_int load;
 
+	prio = sane_prio(prio);
 	this->mutex->lock(this->mutex);
-	load = this->list->get_count(this->list);
+	load = this->jobs[prio]->get_count(this->jobs[prio]);
 	this->mutex->unlock(this->mutex);
 	return load;
 }
@@ -178,8 +200,11 @@ METHOD(processor_t, get_job_load, u_int,
 METHOD(processor_t, queue_job, void,
 	private_processor_t *this, job_t *job)
 {
+	job_priority_t prio;
+
+	prio = sane_prio(job->get_priority(job));
 	this->mutex->lock(this->mutex);
-	this->list->insert_last(this->list, job);
+	this->jobs[prio]->insert_last(this->jobs[prio], job);
 	this->job_added->signal(this->job_added);
 	this->mutex->unlock(this->mutex);
 }
@@ -217,6 +242,7 @@ METHOD(processor_t, destroy, void,
 	private_processor_t *this)
 {
 	thread_t *current;
+	int i;
 
 	set_threads(this, 0);
 	this->mutex->lock(this->mutex);
@@ -234,7 +260,10 @@ METHOD(processor_t, destroy, void,
 	this->thread_terminated->destroy(this->thread_terminated);
 	this->job_added->destroy(this->job_added);
 	this->mutex->destroy(this->mutex);
-	this->list->destroy_offset(this->list, offsetof(job_t, destroy));
+	for (i = 0; i < JOB_PRIO_MAX; i++)
+	{
+		this->jobs[i]->destroy_offset(this->jobs[i], offsetof(job_t, destroy));
+	}
 	this->threads->destroy(this->threads);
 	free(this);
 }
@@ -245,6 +274,7 @@ METHOD(processor_t, destroy, void,
 processor_t *processor_create()
 {
 	private_processor_t *this;
+	int i;
 
 	INIT(this,
 		.public = {
@@ -255,12 +285,15 @@ processor_t *processor_create()
 			.set_threads = _set_threads,
 			.destroy = _destroy,
 		},
-		.list = linked_list_create(),
 		.threads = linked_list_create(),
 		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
 		.job_added = condvar_create(CONDVAR_TYPE_DEFAULT),
 		.thread_terminated = condvar_create(CONDVAR_TYPE_DEFAULT),
 	);
+	for (i = 0; i < JOB_PRIO_MAX; i++)
+	{
+		this->jobs[i] = linked_list_create();
+	}
 
 	return &this->public;
 }