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-rw-r--r--src/lib/tpm.c266
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);
+}