diff options
Diffstat (limited to 'src/lib/tpm.c')
| -rw-r--r-- | src/lib/tpm.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/lib/tpm.c b/src/lib/tpm.c new file mode 100644 index 00000000..8298eeb5 --- /dev/null +++ b/src/lib/tpm.c @@ -0,0 +1,266 @@ +/* + * Ouroboros - Copyright (C) 2016 - 2017 + * + * Threadpool management + * + * Dimitri Staessens <dimitri.staessens@ugent.be> + * Sander Vrijders <sander.vrijders@ugent.be> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * version 2.1 as published by the Free Software Foundation. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <ouroboros/config.h> +#include <ouroboros/errno.h> +#include <ouroboros/list.h> +#include <ouroboros/time_utils.h> +#include <ouroboros/tpm.h> + +#include <pthread.h> +#include <stdlib.h> + +#define TPM_TIMEOUT 1000 + +struct pthr_el { + struct list_head next; + + bool join; + + pthread_t thr; +}; + +enum tpm_state { + TPM_NULL = 0, + TPM_INIT, + TPM_RUNNING +}; + +struct { + size_t min; + size_t inc; + size_t max; + size_t cur; + + void * (* func)(void *); + + struct list_head pool; + + enum tpm_state state; + + pthread_cond_t cond; + pthread_mutex_t lock; + + pthread_t mgr; +} tpm; + +static void tpm_join(void) +{ + struct list_head * p; + struct list_head * h; + + list_for_each_safe(p, h, &tpm.pool) { + struct pthr_el * e = list_entry(p, struct pthr_el, next); + if (tpm.state != TPM_RUNNING) + while (!e->join) + pthread_cond_wait(&tpm.cond, &tpm.lock); + + if (e->join) { + pthread_join(e->thr, NULL); + list_del(&e->next); + free(e); + } + } +} + +static void * tpmgr(void * o) +{ + struct timespec dl; + struct timespec to = {(TPM_TIMEOUT / 1000), + (TPM_TIMEOUT % 1000) * MILLION}; + (void) o; + + while (true) { + clock_gettime(PTHREAD_COND_CLOCK, &dl); + ts_add(&dl, &to, &dl); + + pthread_mutex_lock(&tpm.lock); + + tpm_join(); + + if (tpm.state != TPM_RUNNING) { + tpm.max = 0; + tpm_join(); + pthread_mutex_unlock(&tpm.lock); + break; + } + + if (tpm.cur < tpm.min) { + tpm.max = tpm.inc; + + while (tpm.cur < tpm.max) { + struct pthr_el * e = malloc(sizeof(*e)); + if (e == NULL) + break; + + e->join = false; + + if (pthread_create(&e->thr, NULL, + tpm.func, NULL)) { + free(e); + } else { + list_add(&e->next, &tpm.pool); + ++tpm.cur; + } + } + } + + if (pthread_cond_timedwait(&tpm.cond, &tpm.lock, &dl) + == ETIMEDOUT) + if (tpm.cur > tpm.min ) + --tpm.max; + + pthread_mutex_unlock(&tpm.lock); + } + + return (void *) 0; +} + +int tpm_init(size_t min, + size_t inc, + void * (* func)(void *)) +{ + pthread_condattr_t cattr; + + if (pthread_mutex_init(&tpm.lock, NULL)) + goto fail_lock; + + if (pthread_condattr_init(&cattr)) + goto fail_cattr; + +#ifndef __APPLE__ + pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK); +#endif + if (pthread_cond_init(&tpm.cond, &cattr)) + goto fail_cond; + + list_head_init(&tpm.pool); + + pthread_condattr_destroy(&cattr); + + tpm.state = TPM_INIT; + tpm.func = func; + tpm.min = min; + tpm.inc = inc; + tpm.max = 0; + tpm.cur = 0; + + return 0; + + fail_cond: + pthread_condattr_destroy(&cattr); + fail_cattr: + pthread_mutex_destroy(&tpm.lock); + fail_lock: + return -1; +} + +int tpm_start(void) +{ + pthread_mutex_lock(&tpm.lock); + + if (pthread_create(&tpm.mgr, NULL, tpmgr, NULL)) { + pthread_mutex_unlock(&tpm.lock); + return -1; + } + + tpm.state = TPM_RUNNING; + + pthread_mutex_unlock(&tpm.lock); + + return 0; +} + +void tpm_stop(void) +{ + pthread_mutex_lock(&tpm.lock); + + tpm.state = TPM_NULL; + + pthread_mutex_unlock(&tpm.lock); +} + +void tpm_fini(void) +{ + pthread_join(tpm.mgr, NULL); + + pthread_mutex_destroy(&tpm.lock); + pthread_cond_destroy(&tpm.cond); +} + +bool tpm_check(void) +{ + bool ret; + + pthread_mutex_lock(&tpm.lock); + + ret = tpm.cur > tpm.max; + + pthread_mutex_unlock(&tpm.lock); + + return ret; +} + +void tpm_inc(void) +{ + pthread_mutex_lock(&tpm.lock); + + ++tpm.cur; + + pthread_mutex_unlock(&tpm.lock); +} + +void tpm_dec(void) +{ + pthread_mutex_lock(&tpm.lock); + + --tpm.cur; + + pthread_cond_signal(&tpm.cond); + + pthread_mutex_unlock(&tpm.lock); +} + +void tpm_exit(void) +{ + struct list_head * p; + pthread_t id; + + id = pthread_self(); + + pthread_mutex_lock(&tpm.lock); + + --tpm.cur; + + list_for_each(p, &tpm.pool) { + struct pthr_el * e = list_entry(p, struct pthr_el, next); + if (e->thr == id) { + e->join = true; + break; + } + } + + pthread_cond_signal(&tpm.cond); + + pthread_mutex_unlock(&tpm.lock); +} |