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Strongswan

    1: /*
    2:  * Copyright (C) 2012 Tobias Brunner
    3:  * Copyright (C) 2012 Giuliano Grassi
    4:  * Copyright (C) 2012 Ralf Sager
    5:  * HSR Hochschule fuer Technik Rapperswil
    6:  *
    7:  * This program is free software; you can redistribute it and/or modify it
    8:  * under the terms of the GNU General Public License as published by the
    9:  * Free Software Foundation; either version 2 of the License, or (at your
   10:  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   11:  *
   12:  * This program is distributed in the hope that it will be useful, but
   13:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   14:  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   15:  * for more details.
   16:  */
   17: 
   18: #include "blocking_queue.h"
   19: 
   20: #include <threading/mutex.h>
   21: #include <threading/thread.h>
   22: #include <threading/condvar.h>
   23: #include <collections/linked_list.h>
   24: 
   25: typedef struct private_blocking_queue_t private_blocking_queue_t;
   26: 
   27: /**
   28:  * Private data of a blocking_queue_t object.
   29:  */
   30: struct private_blocking_queue_t {
   31: 
   32: 	/**
   33: 	 * Public part
   34: 	 */
   35: 	blocking_queue_t public;
   36: 
   37: 	/**
   38: 	 * Linked list containing all items in the queue
   39: 	 */
   40: 	linked_list_t *list;
   41: 
   42: 	/**
   43: 	 * Mutex used to synchronize access to the queue
   44: 	 */
   45: 	mutex_t *mutex;
   46: 
   47: 	/**
   48: 	 * Condvar used to wait for items
   49: 	 */
   50: 	condvar_t *condvar;
   51: 
   52: };
   53: 
   54: METHOD(blocking_queue_t, enqueue, void,
   55: 	private_blocking_queue_t *this, void *item)
   56: {
   57: 	this->mutex->lock(this->mutex);
   58: 	this->list->insert_first(this->list, item);
   59: 	this->condvar->signal(this->condvar);
   60: 	this->mutex->unlock(this->mutex);
   61: }
   62: 
   63: METHOD(blocking_queue_t, dequeue, void*,
   64: 	private_blocking_queue_t *this)
   65: {
   66: 	bool oldstate;
   67: 	void *item;
   68: 
   69: 
   70: 	this->mutex->lock(this->mutex);
   71: 	thread_cleanup_push((thread_cleanup_t)this->mutex->unlock, this->mutex);
   72: 	/* ensure that a canceled thread does not dequeue any items */
   73: 	thread_cancellation_point();
   74: 	while (this->list->remove_last(this->list, &item) != SUCCESS)
   75: 	{
   76: 		oldstate = thread_cancelability(TRUE);
   77: 		this->condvar->wait(this->condvar, this->mutex);
   78: 		thread_cancelability(oldstate);
   79: 	}
   80: 	thread_cleanup_pop(TRUE);
   81: 	return item;
   82: }
   83: 
   84: METHOD(blocking_queue_t, destroy, void,
   85: 	private_blocking_queue_t *this)
   86: {
   87: 	this->list->destroy(this->list);
   88: 	this->condvar->destroy(this->condvar);
   89: 	this->mutex->destroy(this->mutex);
   90: 	free(this);
   91: }
   92: 
   93: METHOD(blocking_queue_t, destroy_offset, void,
   94: 	private_blocking_queue_t *this, size_t offset)
   95: {
   96: 	this->list->invoke_offset(this->list, offset);
   97: 	destroy(this);
   98: }
   99: 
  100: METHOD(blocking_queue_t, destroy_function, void,
  101: 	private_blocking_queue_t *this, void (*fn)(void*))
  102: {
  103: 	this->list->invoke_function(this->list, (linked_list_invoke_t)fn);
  104: 	destroy(this);
  105: }
  106: 
  107: /*
  108:  * Described in header.
  109:  */
  110: blocking_queue_t *blocking_queue_create()
  111: {
  112: 	private_blocking_queue_t *this;
  113: 
  114: 	INIT(this,
  115: 		.public = {
  116: 			.enqueue = _enqueue,
  117: 			.dequeue = _dequeue,
  118: 			.destroy = _destroy,
  119: 			.destroy_offset = _destroy_offset,
  120: 			.destroy_function = _destroy_function,
  121: 		},
  122: 		.list = linked_list_create(),
  123: 		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
  124: 		.condvar = condvar_create(CONDVAR_TYPE_DEFAULT),
  125: 	);
  126: 
  127: 	return &this->public;
  128: }
  129: