diff options
Diffstat (limited to 'lib/frr_pthread.c')
| -rw-r--r-- | lib/frr_pthread.c | 232 |
1 files changed, 161 insertions, 71 deletions
diff --git a/lib/frr_pthread.c b/lib/frr_pthread.c index 19dfbaf54..72b47ae5c 100644 --- a/lib/frr_pthread.c +++ b/lib/frr_pthread.c @@ -1,5 +1,5 @@ /* - * Utilities and interfaces for managing POSIX threads + * Utilities and interfaces for managing POSIX threads within FRR. * Copyright (C) 2017 Cumulus Networks * * This program is free software; you can redistribute it and/or modify @@ -25,78 +25,99 @@ #include "memory.h" #include "hash.h" -DEFINE_MTYPE_STATIC(LIB, FRR_PTHREAD, "FRR POSIX Thread"); +DEFINE_MTYPE(LIB, FRR_PTHREAD, "FRR POSIX Thread"); +DEFINE_MTYPE(LIB, PTHREAD_PRIM, "POSIX synchronization primitives"); +/* id for next created pthread */ static unsigned int next_id = 0; -/* Hash table of all frr_pthreads along with synchronization primitive(s) and - * hash table callbacks. - * ------------------------------------------------------------------------ */ -static struct hash *pthread_table; -static pthread_mutex_t pthread_table_mtx = PTHREAD_MUTEX_INITIALIZER; +/* default frr_pthread start/stop routine prototypes */ +static void *fpt_run(void *arg); +static int fpt_halt(struct frr_pthread *fpt, void **res); -/* pthread_table->hash_cmp */ -static int pthread_table_hash_cmp(const void *value1, const void *value2) +/* default frr_pthread attributes */ +struct frr_pthread_attr frr_pthread_attr_default = { + .id = 0, + .start = fpt_run, + .stop = fpt_halt, + .name = "Anonymous", +}; + +/* hash table to keep track of all frr_pthreads */ +static struct hash *frr_pthread_hash; +static pthread_mutex_t frr_pthread_hash_mtx = PTHREAD_MUTEX_INITIALIZER; + +/* frr_pthread_hash->hash_cmp */ +static int frr_pthread_hash_cmp(const void *value1, const void *value2) { const struct frr_pthread *tq1 = value1; const struct frr_pthread *tq2 = value2; - return (tq1->id == tq2->id); + return (tq1->attr.id == tq2->attr.id); } -/* pthread_table->hash_key */ -static unsigned int pthread_table_hash_key(void *value) +/* frr_pthread_hash->hash_key */ +static unsigned int frr_pthread_hash_key(void *value) { - return ((struct frr_pthread *)value)->id; + return ((struct frr_pthread *)value)->attr.id; } + /* ------------------------------------------------------------------------ */ void frr_pthread_init() { - pthread_mutex_lock(&pthread_table_mtx); + pthread_mutex_lock(&frr_pthread_hash_mtx); { - pthread_table = hash_create(pthread_table_hash_key, - pthread_table_hash_cmp, NULL); + frr_pthread_hash = hash_create(frr_pthread_hash_key, + frr_pthread_hash_cmp, NULL); } - pthread_mutex_unlock(&pthread_table_mtx); + pthread_mutex_unlock(&frr_pthread_hash_mtx); } void frr_pthread_finish() { - pthread_mutex_lock(&pthread_table_mtx); + pthread_mutex_lock(&frr_pthread_hash_mtx); { - hash_clean(pthread_table, + hash_clean(frr_pthread_hash, (void (*)(void *))frr_pthread_destroy); - hash_free(pthread_table); + hash_free(frr_pthread_hash); } - pthread_mutex_unlock(&pthread_table_mtx); + pthread_mutex_unlock(&frr_pthread_hash_mtx); } -struct frr_pthread *frr_pthread_new(const char *name, unsigned int id, - void *(*start_routine)(void *), - int (*stop_routine)(void **, - struct frr_pthread *)) +struct frr_pthread *frr_pthread_new(struct frr_pthread_attr *attr) { static struct frr_pthread holder = {0}; struct frr_pthread *fpt = NULL; - pthread_mutex_lock(&pthread_table_mtx); + attr = attr ? attr : &frr_pthread_attr_default; + + pthread_mutex_lock(&frr_pthread_hash_mtx); { - holder.id = id; - - if (!hash_lookup(pthread_table, &holder)) { - struct frr_pthread *fpt = XCALLOC( - MTYPE_FRR_PTHREAD, sizeof(struct frr_pthread)); - fpt->id = id; - fpt->master = thread_master_create(name); - fpt->start_routine = start_routine; - fpt->stop_routine = stop_routine; - fpt->name = XSTRDUP(MTYPE_FRR_PTHREAD, name); - - hash_get(pthread_table, fpt, hash_alloc_intern); + holder.attr.id = attr->id; + + if (!hash_lookup(frr_pthread_hash, &holder)) { + fpt = XCALLOC(MTYPE_FRR_PTHREAD, + sizeof(struct frr_pthread)); + /* create new thread master */ + fpt->master = thread_master_create(attr->name); + /* set attributes */ + fpt->attr = *attr; + if (attr == &frr_pthread_attr_default) + fpt->attr.id = frr_pthread_get_id(); + /* initialize startup synchronization primitives */ + fpt->running_cond_mtx = XCALLOC( + MTYPE_PTHREAD_PRIM, sizeof(pthread_mutex_t)); + fpt->running_cond = XCALLOC(MTYPE_PTHREAD_PRIM, + sizeof(pthread_cond_t)); + pthread_mutex_init(fpt->running_cond_mtx, NULL); + pthread_cond_init(fpt->running_cond, NULL); + + /* insert into global thread hash */ + hash_get(frr_pthread_hash, fpt, hash_alloc_intern); } } - pthread_mutex_unlock(&pthread_table_mtx); + pthread_mutex_unlock(&frr_pthread_hash_mtx); return fpt; } @@ -104,7 +125,11 @@ struct frr_pthread *frr_pthread_new(const char *name, unsigned int id, void frr_pthread_destroy(struct frr_pthread *fpt) { thread_master_free(fpt->master); - XFREE(MTYPE_FRR_PTHREAD, fpt->name); + + pthread_mutex_destroy(fpt->running_cond_mtx); + pthread_cond_destroy(fpt->running_cond); + XFREE(MTYPE_PTHREAD_PRIM, fpt->running_cond_mtx); + XFREE(MTYPE_PTHREAD_PRIM, fpt->running_cond); XFREE(MTYPE_FRR_PTHREAD, fpt); } @@ -113,74 +138,82 @@ struct frr_pthread *frr_pthread_get(unsigned int id) static struct frr_pthread holder = {0}; struct frr_pthread *fpt; - pthread_mutex_lock(&pthread_table_mtx); + pthread_mutex_lock(&frr_pthread_hash_mtx); { - holder.id = id; - fpt = hash_lookup(pthread_table, &holder); + holder.attr.id = id; + fpt = hash_lookup(frr_pthread_hash, &holder); } - pthread_mutex_unlock(&pthread_table_mtx); + pthread_mutex_unlock(&frr_pthread_hash_mtx); return fpt; } -int frr_pthread_run(unsigned int id, const pthread_attr_t *attr, void *arg) +int frr_pthread_run(struct frr_pthread *fpt, const pthread_attr_t *attr) { - struct frr_pthread *fpt = frr_pthread_get(id); int ret; - if (!fpt) - return -1; - - ret = pthread_create(&fpt->thread, attr, fpt->start_routine, arg); + ret = pthread_create(&fpt->thread, attr, fpt->attr.start, fpt); - /* Per pthread_create(3), the contents of fpt->thread are undefined if - * pthread_create() did not succeed. Reset this value to zero. */ + /* + * Per pthread_create(3), the contents of fpt->thread are undefined if + * pthread_create() did not succeed. Reset this value to zero. + */ if (ret < 0) memset(&fpt->thread, 0x00, sizeof(fpt->thread)); return ret; } -/** - * Calls the stop routine for the frr_pthread and resets any relevant fields. - * - * @param fpt - the frr_pthread to stop - * @param result - pointer to result pointer - * @return the return code from the stop routine - */ -static int frr_pthread_stop_actual(struct frr_pthread *fpt, void **result) +void frr_pthread_wait_running(struct frr_pthread *fpt) { - int ret = (*fpt->stop_routine)(result, fpt); - memset(&fpt->thread, 0x00, sizeof(fpt->thread)); - return ret; + pthread_mutex_lock(fpt->running_cond_mtx); + { + while (!fpt->running) + pthread_cond_wait(fpt->running_cond, + fpt->running_cond_mtx); + } + pthread_mutex_unlock(fpt->running_cond_mtx); } -int frr_pthread_stop(unsigned int id, void **result) +void frr_pthread_notify_running(struct frr_pthread *fpt) { - struct frr_pthread *fpt = frr_pthread_get(id); - return frr_pthread_stop_actual(fpt, result); + pthread_mutex_lock(fpt->running_cond_mtx); + { + fpt->running = true; + pthread_cond_signal(fpt->running_cond); + } + pthread_mutex_unlock(fpt->running_cond_mtx); } -/** +int frr_pthread_stop(struct frr_pthread *fpt, void **result) +{ + int ret = (*fpt->attr.stop)(fpt, result); + memset(&fpt->thread, 0x00, sizeof(fpt->thread)); + return ret; +} + +/* * Callback for hash_iterate to stop all frr_pthread's. */ static void frr_pthread_stop_all_iter(struct hash_backet *hb, void *arg) { struct frr_pthread *fpt = hb->data; - frr_pthread_stop_actual(fpt, NULL); + frr_pthread_stop(fpt, NULL); } void frr_pthread_stop_all() { - pthread_mutex_lock(&pthread_table_mtx); + pthread_mutex_lock(&frr_pthread_hash_mtx); { - hash_iterate(pthread_table, frr_pthread_stop_all_iter, NULL); + hash_iterate(frr_pthread_hash, frr_pthread_stop_all_iter, NULL); } - pthread_mutex_unlock(&pthread_table_mtx); + pthread_mutex_unlock(&frr_pthread_hash_mtx); } unsigned int frr_pthread_get_id() { + /* just a sanity check, this should never happen */ + assert(next_id <= INT_MAX - 1); return next_id++; } @@ -188,3 +221,60 @@ void frr_pthread_yield(void) { (void)sched_yield(); } + +/* + * ---------------------------------------------------------------------------- + * Default Event Loop + * ---------------------------------------------------------------------------- + */ + +/* dummy task for sleeper pipe */ +static int fpt_dummy(struct thread *thread) +{ + return 0; +} + +/* poison pill task to end event loop */ +static int fpt_finish(struct thread *thread) +{ + struct frr_pthread *fpt = THREAD_ARG(thread); + atomic_store_explicit(&fpt->running, false, memory_order_relaxed); + return 0; +} + +/* stop function, called from other threads to halt this one */ +static int fpt_halt(struct frr_pthread *fpt, void **res) +{ + thread_add_event(fpt->master, &fpt_finish, fpt, 0, NULL); + pthread_join(fpt->thread, res); + fpt = NULL; + + return 0; +} + +/* entry pthread function & main event loop */ +static void *fpt_run(void *arg) +{ + struct frr_pthread *fpt = arg; + fpt->master->owner = pthread_self(); + + int sleeper[2]; + pipe(sleeper); + thread_add_read(fpt->master, &fpt_dummy, NULL, sleeper[0], NULL); + + fpt->master->handle_signals = false; + + frr_pthread_notify_running(fpt); + + struct thread task; + while (atomic_load_explicit(&fpt->running, memory_order_relaxed)) { + if (thread_fetch(fpt->master, &task)) { + thread_call(&task); + } + } + + close(sleeper[1]); + close(sleeper[0]); + + return NULL; +} |