2 * Utilities and interfaces for managing POSIX threads within FRR.
3 * Copyright (C) 2017 Cumulus Networks, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; see the file COPYING; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #ifndef _FRR_PTHREAD_H
21 #define _FRR_PTHREAD_H
24 #include "frratomic.h"
33 #define OS_THREAD_NAMELEN 16
36 struct frr_pthread_attr
;
38 struct frr_pthread_attr
{
39 void *(*start
)(void *);
40 int (*stop
)(struct frr_pthread
*, void **);
46 * Mutex protecting this structure. Must be taken for reading some
47 * fields, denoted by a 'Requires: mtx'.
54 struct rcu_thread
*rcu_thread
;
56 /* thread master for this pthread's thread.c event loop */
57 struct thread_master
*master
;
59 /* caller-specified data; start & stop funcs, name, id */
60 struct frr_pthread_attr attr
;
63 * Notification mechanism for allowing pthreads to notify their parents
64 * when they are ready to do work. This mechanism has two associated
67 * - frr_pthread_wait_running()
68 * This function should be called by the spawning thread after
69 * frr_pthread_run(). It safely waits until the spawned thread
70 * indicates that is ready to do work by posting to the condition
73 * - frr_pthread_notify_running()
74 * This function should be called by the spawned thread when it is
75 * ready to do work. It will wake up any threads waiting on the
76 * previously described condition.
78 pthread_cond_t
*running_cond
;
79 pthread_mutex_t
*running_cond_mtx
;
83 * Fake thread-specific storage. No constraints on usage. Helpful when
84 * creating reentrant pthread implementations. Can be used to pass
85 * argument to pthread entry function.
92 * Human-readable thread name.
98 /* Used in pthread_set_name max 16 characters */
99 char os_name
[OS_THREAD_NAMELEN
];
102 extern struct frr_pthread_attr frr_pthread_attr_default
;
105 * Initializes this module.
107 * Must be called before using any of the other functions.
109 void frr_pthread_init(void);
112 * Uninitializes this module.
114 * Destroys all registered frr_pthread's and internal data structures.
116 * It is safe to call frr_pthread_init() after this function to reinitialize
119 void frr_pthread_finish(void);
122 * Creates a new frr_pthread with the given attributes.
124 * The 'attr' argument should be filled out with the desired attributes,
125 * including ID, start and stop functions and the desired name. Alternatively,
126 * if attr is NULL, the default attributes will be used. The pthread will be
127 * set up to run a basic threadmaster loop and the name will be "Anonymous".
128 * Scheduling tasks onto the threadmaster in the 'master' field of the returned
129 * frr_pthread will cause them to run on that pthread.
131 * @param attr - the thread attributes
132 * @param name - Human-readable name
133 * @param os_name - 16 characters (including '\0') thread name to set in os,
134 * @return the created frr_pthread upon success, or NULL upon failure
136 struct frr_pthread
*frr_pthread_new(struct frr_pthread_attr
*attr
,
137 const char *name
, const char *os_name
);
140 * Changes the name of the frr_pthread as reported by the operating
143 * @param fpt - the frr_pthread to operate on
144 * @return - on success returns 0 otherwise nonzero error number.
146 int frr_pthread_set_name(struct frr_pthread
*fpt
);
149 * Destroys an frr_pthread.
151 * Assumes that the associated pthread, if any, has already terminated.
153 * @param fpt - the frr_pthread to destroy
155 void frr_pthread_destroy(struct frr_pthread
*fpt
);
158 * Creates a new pthread and binds it to a frr_pthread.
160 * This function is a wrapper for pthread_create. The first parameter is the
161 * frr_pthread to bind the created pthread to. All subsequent arguments are
162 * passed unmodified to pthread_create(). The frr_pthread * provided will be
163 * used as the argument to the pthread entry function. If it is necessary to
164 * pass additional data, the 'data' field in the frr_pthread may be used.
166 * This function returns the same code as pthread_create(). If the value is
167 * zero, the provided frr_pthread is bound to a running POSIX thread. If the
168 * value is less than zero, the provided frr_pthread is guaranteed to be a
169 * clean instance that may be susbsequently passed to frr_pthread_run().
171 * @param fpt - frr_pthread * to run
172 * @param attr - see pthread_create(3)
174 * @return see pthread_create(3)
176 int frr_pthread_run(struct frr_pthread
*fpt
, const pthread_attr_t
*attr
);
179 * Waits until the specified pthread has finished setting up and is ready to
182 * If the pthread's code makes use of the startup synchronization mechanism,
183 * this function should be called before attempting to use the functionality
184 * exposed by the pthread. It waits until the 'running' condition is satisfied
185 * (see struct definition of frr_pthread).
187 * @param fpt - the frr_pthread * to wait on
189 void frr_pthread_wait_running(struct frr_pthread
*fpt
);
192 * Notifies other pthreads that the calling thread has finished setting up and
193 * is ready to begin work.
195 * This will allow any other pthreads waiting in 'frr_pthread_wait_running' to
198 * @param fpt - the frr_pthread * that has finished setting up
200 void frr_pthread_notify_running(struct frr_pthread
*fpt
);
203 * Stops a frr_pthread with a result.
205 * @param fpt - frr_pthread * to stop
206 * @param result - where to store the thread's result, if any. May be NULL if a
207 * result is not needed.
209 int frr_pthread_stop(struct frr_pthread
*fpt
, void **result
);
211 /* Stops all frr_pthread's. */
212 void frr_pthread_stop_all(void);
214 #ifndef HAVE_PTHREAD_CONDATTR_SETCLOCK
215 #define pthread_condattr_setclock(A, B)
218 /* mutex auto-lock/unlock */
221 * (for short blocks, multiple mutexes supported)
222 * break & return can be used for aborting the block
224 * frr_with_mutex(&mtx, &mtx2) {
230 #define _frr_with_mutex(mutex) \
231 *NAMECTR(_mtx_) __attribute__(( \
232 unused, cleanup(_frr_mtx_unlock))) = _frr_mtx_lock(mutex), \
235 #define frr_with_mutex(...) \
236 for (pthread_mutex_t MACRO_REPEAT(_frr_with_mutex, ##__VA_ARGS__) \
237 *_once = NULL; _once == NULL; _once = (void *)1) \
241 * (more suitable for long blocks, no extra indentation)
243 * frr_mutex_lock_autounlock(&mtx);
246 #define frr_mutex_lock_autounlock(mutex) \
247 pthread_mutex_t *NAMECTR(_mtx_) \
248 __attribute__((unused, cleanup(_frr_mtx_unlock))) = \
249 _frr_mtx_lock(mutex) \
252 static inline pthread_mutex_t
*_frr_mtx_lock(pthread_mutex_t
*mutex
)
254 pthread_mutex_lock(mutex
);
258 static inline void _frr_mtx_unlock(pthread_mutex_t
**mutex
)
262 pthread_mutex_unlock(*mutex
);
270 #endif /* _FRR_PTHREAD_H */