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-rw-r--r--src/lib/shm_rbuff.c405
1 files changed, 405 insertions, 0 deletions
diff --git a/src/lib/shm_rbuff.c b/src/lib/shm_rbuff.c
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--- /dev/null
+++ b/src/lib/shm_rbuff.c
@@ -0,0 +1,405 @@
+/*
+ * Ouroboros - Copyright (C) 2016
+ *
+ * Ring buffer for incoming SDUs
+ *
+ * Dimitri Staessens <dimitri.staessens@intec.ugent.be>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <ouroboros/config.h>
+#include <ouroboros/shm_rbuff.h>
+#include <ouroboros/lockfile.h>
+#include <ouroboros/time_utils.h>
+#include <ouroboros/errno.h>
+
+#define OUROBOROS_PREFIX "shm_rbuff"
+
+#include <ouroboros/logs.h>
+
+#include <pthread.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <stdbool.h>
+
+#define FN_MAX_CHARS 255
+
+#define SHM_RBUFF_FILE_SIZE (SHM_BUFFER_SIZE * sizeof(ssize_t) \
+ + 2 * sizeof(size_t) + sizeof(int8_t) \
+ + sizeof(pthread_mutex_t) \
+ + 2 * sizeof (pthread_cond_t))
+
+#define shm_rbuff_used(rb) ((*rb->head + SHM_BUFFER_SIZE - *rb->tail) \
+ & (SHM_BUFFER_SIZE - 1))
+#define shm_rbuff_free(rb) (shm_rbuff_used(rb) + 1 < SHM_BUFFER_SIZE)
+#define shm_rbuff_empty(rb) (*rb->head == *rb->tail)
+#define head_el_ptr(rb) (rb->shm_base + *rb->head)
+#define tail_el_ptr(rb) (rb->shm_base + *rb->tail)
+
+struct shm_rbuff {
+ ssize_t * shm_base; /* start of entry */
+ size_t * head; /* start of ringbuffer head */
+ size_t * tail; /* start of ringbuffer tail */
+ int8_t * acl; /* access control */
+ pthread_mutex_t * lock; /* lock all free space in shm */
+ pthread_cond_t * add; /* SDU arrived */
+ pthread_cond_t * del; /* SDU removed */
+ pid_t api; /* api of the owner */
+ int port_id; /* port_id of the flow */
+};
+
+struct shm_rbuff * shm_rbuff_create(pid_t api, int port_id)
+{
+ struct shm_rbuff * rb;
+ int shm_fd;
+ ssize_t * shm_base;
+ pthread_mutexattr_t mattr;
+ pthread_condattr_t cattr;
+ char fn[FN_MAX_CHARS];
+ mode_t mask;
+
+ sprintf(fn, SHM_RBUFF_PREFIX "%d.%d", api, port_id);
+
+ rb = malloc(sizeof(*rb));
+ if (rb == NULL) {
+ LOG_DBG("Could not allocate struct.");
+ return NULL;
+ }
+
+ mask = umask(0);
+
+ shm_fd = shm_open(fn, O_CREAT | O_EXCL | O_RDWR, 0666);
+ if (shm_fd == -1) {
+ LOG_DBG("Failed creating ring buffer.");
+ free(rb);
+ return NULL;
+ }
+
+ umask(mask);
+
+ if (ftruncate(shm_fd, SHM_RBUFF_FILE_SIZE - 1) < 0) {
+ LOG_DBG("Failed to extend ringbuffer.");
+ free(rb);
+ close(shm_fd);
+ return NULL;
+ }
+
+ shm_base = mmap(NULL,
+ SHM_RBUFF_FILE_SIZE,
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED,
+ shm_fd,
+ 0);
+
+ close(shm_fd);
+
+ if (shm_base == MAP_FAILED) {
+ LOG_DBG("Failed to map shared memory.");
+ if (shm_unlink(fn) == -1)
+ LOG_DBG("Failed to remove invalid shm.");
+ free(rb);
+ return NULL;
+ }
+
+ rb->shm_base = shm_base;
+ rb->head = (size_t *) (rb->shm_base + SHM_BUFFER_SIZE);
+ rb->tail = rb->head + 1;
+ rb->acl = (int8_t *) (rb->tail + 1);
+ rb->lock = (pthread_mutex_t *) (rb->acl + 1);
+ rb->add = (pthread_cond_t *) (rb->lock + 1);
+ rb->del = rb->add + 1;
+
+ pthread_mutexattr_init(&mattr);
+#ifndef __APPLE__
+ pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
+#endif
+ pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
+ pthread_mutex_init(rb->lock, &mattr);
+
+ pthread_condattr_init(&cattr);
+ pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED);
+#ifndef __APPLE__
+ pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
+#endif
+ pthread_cond_init(rb->add, &cattr);
+ pthread_cond_init(rb->del, &cattr);
+
+ *rb->acl = 0;
+ *rb->head = 0;
+ *rb->tail = 0;
+
+ rb->api = api;
+ rb->port_id = port_id;
+
+ if (munmap(rb->shm_base, SHM_RBUFF_FILE_SIZE) == -1)
+ LOG_DBG("Couldn't unmap shared memory.");
+
+ return rb;
+}
+
+struct shm_rbuff * shm_rbuff_open(pid_t api, int port_id)
+{
+ struct shm_rbuff * rb;
+ int shm_fd;
+ ssize_t * shm_base;
+ char fn[FN_MAX_CHARS];
+
+ sprintf(fn, SHM_RBUFF_PREFIX "%d.%d", api, port_id);
+
+ rb = malloc(sizeof(*rb));
+ if (rb == NULL) {
+ LOG_DBG("Could not allocate struct.");
+ return NULL;
+ }
+
+ shm_fd = shm_open(fn, O_RDWR, 0666);
+ if (shm_fd == -1) {
+ LOG_DBG("%d failed opening shared memory %s.", getpid(), fn);
+ free(rb);
+ return NULL;
+ }
+
+ shm_base = mmap(NULL,
+ SHM_RBUFF_FILE_SIZE,
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED,
+ shm_fd,
+ 0);
+
+ close(shm_fd);
+
+ if (shm_base == MAP_FAILED) {
+ LOG_DBG("Failed to map shared memory.");
+ if (shm_unlink(fn) == -1)
+ LOG_DBG("Failed to remove invalid shm.");
+
+ free(rb);
+ return NULL;
+ }
+
+ rb->shm_base = shm_base;
+ rb->head = (size_t *) (rb->shm_base + SHM_BUFFER_SIZE);
+ rb->tail = rb->head + 1;
+ rb->acl = (int8_t *) (rb->tail + 1);
+ rb->lock = (pthread_mutex_t *) (rb->acl + 1);
+ rb->add = (pthread_cond_t *) (rb->lock + 1);
+ rb->del = rb->add + 1;
+
+ rb->api = api;
+ rb->port_id = port_id;
+
+ return rb;
+}
+
+void shm_rbuff_close(struct shm_rbuff * rb)
+{
+ assert(rb);
+
+ if (munmap(rb->shm_base, SHM_RBUFF_FILE_SIZE) == -1)
+ LOG_DBG("Couldn't unmap shared memory.");
+
+ free(rb);
+}
+
+void shm_rbuff_destroy(struct shm_rbuff * rb)
+{
+ char fn[25];
+
+ if (rb == NULL)
+ return;
+
+ sprintf(fn, SHM_RBUFF_PREFIX "%d.%d", rb->api, rb->port_id);
+
+ if (shm_unlink(fn) == -1)
+ LOG_DBG("Failed to unlink shm %s.", fn);
+
+ free(rb);
+}
+
+int shm_rbuff_write(struct shm_rbuff * rb, ssize_t idx)
+{
+ assert(rb);
+ assert(idx >= 0);
+
+#ifdef __APPLE__
+ pthread_mutex_lock(rb->lock);
+#else
+ if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+ LOG_DBG("Recovering dead mutex.");
+ pthread_mutex_consistent(rb->lock);
+ }
+#endif
+ if (*rb->acl) {
+ pthread_mutex_unlock(rb->lock);
+ return -ENOTALLOC;
+ }
+
+ if (!shm_rbuff_free(rb)) {
+ pthread_mutex_unlock(rb->lock);
+ return -1;
+ }
+
+ if (shm_rbuff_empty(rb))
+ pthread_cond_broadcast(rb->add);
+
+ *head_el_ptr(rb) = idx;
+ *rb->head = (*rb->head + 1) & (SHM_BUFFER_SIZE -1);
+
+ pthread_mutex_unlock(rb->lock);
+
+ return 0;
+}
+
+ssize_t shm_rbuff_read(struct shm_rbuff * rb)
+{
+ int ret = 0;
+
+ assert(rb);
+
+#ifdef __APPLE__
+ pthread_mutex_lock(rb->lock);
+#else
+ if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+ LOG_DBG("Recovering dead mutex.");
+ pthread_mutex_consistent(rb->lock);
+ }
+#endif
+ if (shm_rbuff_empty(rb)) {
+ pthread_mutex_unlock(rb->lock);
+ return -1;
+ }
+
+ ret = *tail_el_ptr(rb);
+ *rb->tail = (*rb->tail + 1) & (SHM_BUFFER_SIZE -1);
+
+ pthread_mutex_unlock(rb->lock);
+
+ return ret;
+}
+
+ssize_t shm_rbuff_read_b(struct shm_rbuff * rb,
+ const struct timespec * timeout)
+{
+ struct timespec abstime;
+ int ret = 0;
+ ssize_t idx = -1;
+
+ assert(rb);
+
+#ifdef __APPLE__
+ pthread_mutex_lock(rb->lock);
+#else
+ if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+ LOG_DBG("Recovering dead mutex.");
+ pthread_mutex_consistent(rb->lock);
+ }
+#endif
+ if (timeout != NULL) {
+ idx = -ETIMEDOUT;
+ clock_gettime(PTHREAD_COND_CLOCK, &abstime);
+ ts_add(&abstime, timeout, &abstime);
+ }
+
+ pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock,
+ (void *) rb->lock);
+
+ while (shm_rbuff_empty(rb) && (ret != ETIMEDOUT)) {
+ if (timeout != NULL)
+ ret = pthread_cond_timedwait(rb->add,
+ rb->lock,
+ &abstime);
+ else
+ ret = pthread_cond_wait(rb->add, rb->lock);
+#ifndef __APPLE__
+ if (ret == EOWNERDEAD) {
+ LOG_DBG("Recovering dead mutex.");
+ pthread_mutex_consistent(rb->lock);
+ }
+#endif
+ if (ret == ETIMEDOUT) {
+ idx = -ETIMEDOUT;
+ break;
+ }
+ }
+
+ if (idx != -ETIMEDOUT) {
+ idx = *tail_el_ptr(rb);
+ *rb->tail = (*rb->tail + 1) & (SHM_BUFFER_SIZE -1);
+ pthread_cond_broadcast(rb->del);
+ }
+
+ pthread_cleanup_pop(true);
+
+ return idx;
+}
+
+int shm_rbuff_block(struct shm_rbuff * rb)
+{
+ int ret = 0;
+
+ assert(rb);
+
+#ifdef __APPLE__
+ pthread_mutex_lock(rb->lock);
+#else
+ if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+ LOG_DBG("Recovering dead mutex.");
+ pthread_mutex_consistent(rb->lock);
+ }
+#endif
+ *rb->acl = -1;
+
+ if (!shm_rbuff_empty(rb))
+ ret = -EBUSY;
+
+ pthread_mutex_unlock(rb->lock);
+
+ return ret;
+}
+
+void shm_rbuff_unblock(struct shm_rbuff * rb)
+{
+ assert(rb);
+
+#ifdef __APPLE__
+ pthread_mutex_lock(rb->lock);
+#else
+ if (pthread_mutex_lock(rb->lock) == EOWNERDEAD) {
+ LOG_DBG("Recovering dead mutex.");
+ pthread_mutex_consistent(rb->lock);
+ }
+#endif
+ *rb->acl = 0; /* open */
+
+ pthread_mutex_unlock(rb->lock);
+}
+
+void shm_rbuff_reset(struct shm_rbuff * rb)
+{
+ assert(rb);
+
+ pthread_mutex_lock(rb->lock);
+ *rb->tail = 0;
+ *rb->head = 0;
+ pthread_mutex_unlock(rb->lock);
+}
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