d6e8f6b3f5080dea5f1cfbedf19b187ef048da3d
[strongswan.git] / Source / charon / queues / job_queue.c
1 /**
2 * @file job_queue.c
3 *
4 * @brief Implementation of job_queue_t
5 *
6 */
7
8 /*
9 * Copyright (C) 2005 Jan Hutter, Martin Willi
10 * Hochschule fuer Technik Rapperswil
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
19 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
20 * for more details.
21 */
22
23 #include <stdlib.h>
24 #include <pthread.h>
25
26 #include "job_queue.h"
27
28 #include <utils/allocator.h>
29 #include <utils/linked_list.h>
30
31
32 typedef struct private_job_queue_t private_job_queue_t;
33
34 /**
35 * @brief Private Variables and Functions of job_queue class
36 *
37 */
38 struct private_job_queue_t {
39 job_queue_t public;
40
41 /**
42 * The jobs are stored in a linked list
43 */
44 linked_list_t *list;
45 /**
46 * access to linked_list is locked through this mutex
47 */
48 pthread_mutex_t mutex;
49
50 /**
51 * If the queue is empty a thread has to wait
52 * This condvar is used to wake up such a thread
53 */
54 pthread_cond_t condvar;
55 };
56
57
58 /**
59 * implements job_queue_t.get_count
60 */
61 static int get_count(private_job_queue_t *this)
62 {
63 int count;
64 pthread_mutex_lock(&(this->mutex));
65 count = this->list->get_count(this->list);
66 pthread_mutex_unlock(&(this->mutex));
67 return count;
68 }
69
70 /**
71 * implements job_queue_t.get
72 */
73 static job_t *get(private_job_queue_t *this)
74 {
75 int oldstate;
76 job_t *job;
77 pthread_mutex_lock(&(this->mutex));
78 /* go to wait while no jobs available */
79 while(this->list->get_count(this->list) == 0)
80 {
81 /* add mutex unlock handler for cancellation, enable cancellation */
82 pthread_cleanup_push((void(*)(void*))pthread_mutex_unlock, (void*)&(this->mutex));
83 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate);
84
85 pthread_cond_wait( &(this->condvar), &(this->mutex));
86
87 /* reset cancellation, remove mutex-unlock handler (without executing) */
88 pthread_setcancelstate(oldstate, NULL);
89 pthread_cleanup_pop(0);
90 }
91 this->list->remove_first(this->list,(void **) &job);
92 pthread_mutex_unlock(&(this->mutex));
93 return job;
94 }
95
96 /**
97 * implements function job_queue_t.add
98 */
99 static void add(private_job_queue_t *this, job_t *job)
100 {
101 pthread_mutex_lock(&(this->mutex));
102 this->list->insert_last(this->list,job);
103 pthread_cond_signal( &(this->condvar));
104 pthread_mutex_unlock(&(this->mutex));
105 }
106
107 /**
108 * implements job_queue_t.destroy
109 */
110 static void job_queue_destroy (private_job_queue_t *this)
111 {
112 while (this->list->get_count(this->list) > 0)
113 {
114 job_t *job;
115 if (this->list->remove_first(this->list,(void *) &job) != SUCCESS)
116 {
117 this->list->destroy(this->list);
118 break;
119 }
120 job->destroy_all(job);
121 }
122 this->list->destroy(this->list);
123
124 pthread_mutex_destroy(&(this->mutex));
125
126 pthread_cond_destroy(&(this->condvar));
127
128 allocator_free(this);
129 }
130
131 /*
132 *
133 * Documented in header
134 */
135 job_queue_t *job_queue_create()
136 {
137 private_job_queue_t *this = allocator_alloc_thing(private_job_queue_t);
138
139 this->public.get_count = (int(*)(job_queue_t*))get_count;
140 this->public.get = (job_t*(*)(job_queue_t*))get;
141 this->public.add = (void(*)(job_queue_t*, job_t*))add;
142 this->public.destroy = (void(*)(job_queue_t*))job_queue_destroy;
143
144 this->list = linked_list_create();
145 pthread_mutex_init(&(this->mutex), NULL);
146 pthread_cond_init(&(this->condvar), NULL);
147
148 return (&this->public);
149 }