1 files changed, 273 insertions, 0 deletions
diff --git a/src/libstrongswan/processing/processor.c b/src/libstrongswan/processing/processor.c
new file mode 100644
index 000000000..2a44f61e8
--- /dev/null
+++ b/src/libstrongswan/processing/processor.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2005-2007 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "processor.h"
+
+#include <debug.h>
+#include <threading/thread.h>
+#include <threading/condvar.h>
+#include <threading/mutex.h>
+#include <utils/linked_list.h>
+
+
+typedef struct private_processor_t private_processor_t;
+
+/**
+ * Private data of processor_t class.
+ */
+struct private_processor_t {
+	/**
+	 * Public processor_t interface.
+	 */
+	processor_t public;
+
+	/**
+	 * Number of running threads
+	 */
+	u_int total_threads;
+
+	/**
+	 * Desired number of threads
+	 */
+	u_int desired_threads;
+
+	/**
+	 * Number of threads waiting for work
+	 */
+	u_int idle_threads;
+
+	/**
+	 * All threads managed in the pool (including threads that have been
+	 * cancelled, this allows to join them during destruction)
+	 */
+	linked_list_t *threads;
+
+	/**
+	 * The jobs are stored in a linked list
+	 */
+	linked_list_t *list;
+
+	/**
+	 * access to linked_list is locked through this mutex
+	 */
+	mutex_t *mutex;
+
+	/**
+	 * Condvar to wait for new jobs
+	 */
+	condvar_t *job_added;
+
+	/**
+	 * Condvar to wait for terminated threads
+	 */
+	condvar_t *thread_terminated;
+};
+
+static void process_jobs(private_processor_t *this);
+
+/**
+ * restart a terminated thread
+ */
+static void restart(private_processor_t *this)
+{
+	thread_t *thread;
+
+	DBG2(DBG_JOB, "terminated worker thread, ID: %u", thread_current_id());
+
+	/* respawn thread if required */
+	this->mutex->lock(this->mutex);
+	if (this->desired_threads < this->total_threads ||
+		(thread = thread_create((thread_main_t)process_jobs, this)) == NULL)
+	{
+		this->total_threads--;
+		this->thread_terminated->signal(this->thread_terminated);
+	}
+	else
+	{
+		this->threads->insert_last(this->threads, thread);
+	}
+	this->mutex->unlock(this->mutex);
+}
+
+/**
+ * Process queued jobs, called by the worker threads
+ */
+static void process_jobs(private_processor_t *this)
+{
+	/* worker threads are not cancellable by default */
+	thread_cancelability(FALSE);
+
+	DBG2(DBG_JOB, "started worker thread, ID: %u", thread_current_id());
+
+	this->mutex->lock(this->mutex);
+	while (this->desired_threads >= this->total_threads)
+	{
+		job_t *job;
+
+		if (this->list->get_count(this->list) == 0)
+		{
+			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);
+		job->execute(job);
+		thread_cleanup_pop(FALSE);
+		this->mutex->lock(this->mutex);
+	}
+	this->mutex->unlock(this->mutex);
+	restart(this);
+}
+
+/**
+ * Implementation of processor_t.get_total_threads.
+ */
+static u_int get_total_threads(private_processor_t *this)
+{
+	u_int count;
+	this->mutex->lock(this->mutex);
+	count = this->total_threads;
+	this->mutex->unlock(this->mutex);
+	return count;
+}
+
+/**
+ * Implementation of processor_t.get_idle_threads.
+ */
+static u_int get_idle_threads(private_processor_t *this)
+{
+	u_int count;
+	this->mutex->lock(this->mutex);
+	count = this->idle_threads;
+	this->mutex->unlock(this->mutex);
+	return count;
+}
+
+/**
+ * implements processor_t.get_job_load
+ */
+static u_int get_job_load(private_processor_t *this)
+{
+	u_int load;
+	this->mutex->lock(this->mutex);
+	load = this->list->get_count(this->list);
+	this->mutex->unlock(this->mutex);
+	return load;
+}
+
+/**
+ * implements function processor_t.queue_job
+ */
+static void queue_job(private_processor_t *this, job_t *job)
+{
+	this->mutex->lock(this->mutex);
+	this->list->insert_last(this->list, job);
+	this->job_added->signal(this->job_added);
+	this->mutex->unlock(this->mutex);
+}
+
+/**
+ * Implementation of processor_t.set_threads.
+ */
+static void set_threads(private_processor_t *this, u_int count)
+{
+	this->mutex->lock(this->mutex);
+	if (count > this->total_threads)
+	{	/* increase thread count */
+		int i;
+		thread_t *current;
+
+		this->desired_threads = count;
+		DBG1(DBG_JOB, "spawning %d worker threads", count - this->total_threads);
+		for (i = this->total_threads; i < count; i++)
+		{
+			current = thread_create((thread_main_t)process_jobs, this);
+			if (current)
+			{
+				this->threads->insert_last(this->threads, current);
+				this->total_threads++;
+			}
+		}
+	}
+	else if (count < this->total_threads)
+	{	/* decrease thread count */
+		this->desired_threads = count;
+	}
+	this->job_added->broadcast(this->job_added);
+	this->mutex->unlock(this->mutex);
+}
+
+/**
+ * Implementation of processor_t.destroy.
+ */
+static void destroy(private_processor_t *this)
+{
+	thread_t *current;
+	set_threads(this, 0);
+	this->mutex->lock(this->mutex);
+	while (this->total_threads > 0)
+	{
+		this->job_added->broadcast(this->job_added);
+		this->thread_terminated->wait(this->thread_terminated, this->mutex);
+	}
+	while (this->threads->remove_first(this->threads,
+									   (void**)&current) == SUCCESS)
+	{
+		current->join(current);
+	}
+	this->mutex->unlock(this->mutex);
+	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));
+	this->threads->destroy(this->threads);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+processor_t *processor_create(size_t pool_size)
+{
+	private_processor_t *this = malloc_thing(private_processor_t);
+
+	this->public.get_total_threads = (u_int(*)(processor_t*))get_total_threads;
+	this->public.get_idle_threads = (u_int(*)(processor_t*))get_idle_threads;
+	this->public.get_job_load = (u_int(*)(processor_t*))get_job_load;
+	this->public.queue_job = (void(*)(processor_t*, job_t*))queue_job;
+	this->public.set_threads = (void(*)(processor_t*, u_int))set_threads;
+	this->public.destroy = (void(*)(processor_t*))destroy;
+
+	this->list = linked_list_create();
+	this->threads = linked_list_create();
+	this->mutex = mutex_create(MUTEX_TYPE_DEFAULT);
+	this->job_added = condvar_create(CONDVAR_TYPE_DEFAULT);
+	this->thread_terminated = condvar_create(CONDVAR_TYPE_DEFAULT);
+	this->total_threads = 0;
+	this->desired_threads = 0;
+	this->idle_threads = 0;
+
+	return &this->public;
+}
+