diff options
Diffstat (limited to 'src/lib/shm_rbuff.c')
| -rw-r--r-- | src/lib/shm_rbuff.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/src/lib/shm_rbuff.c b/src/lib/shm_rbuff.c index 93108332..00f0b92b 100644 --- a/src/lib/shm_rbuff.c +++ b/src/lib/shm_rbuff.c @@ -24,6 +24,181 @@ #include "config.h" +#include <ouroboros/shm_rbuff.h> +#include <ouroboros/lockfile.h> +#include <ouroboros/time_utils.h> +#include <ouroboros/errno.h> +#include <ouroboros/fccntl.h> + +#include <pthread.h> +#include <sys/mman.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.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_RB_FILE_SIZE ((SHM_BUFFER_SIZE) * sizeof(ssize_t) \ + + 3 * sizeof(size_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 */ + size_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 */ +}; + +void shm_rbuff_close(struct shm_rbuff * rb) +{ + assert(rb); + + munmap(rb->shm_base, SHM_RB_FILE_SIZE); + + free(rb); +} + +#define MM_FLAGS (PROT_READ | PROT_WRITE) + +struct shm_rbuff * rbuff_create(pid_t api, int port_id, int flags) +{ + struct shm_rbuff * rb; + int 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) + goto fail_malloc; + + fd = shm_open(fn, flags, 0666); + if (fd == -1) + goto fail_open; + + if ((flags & O_CREAT) && ftruncate(fd, SHM_RB_FILE_SIZE - 1) < 0) + goto fail_truncate; + + shm_base = mmap(NULL, SHM_RB_FILE_SIZE, MM_FLAGS, MAP_SHARED, fd, 0); + if (shm_base == MAP_FAILED) + goto fail_truncate; + + close(fd); + + rb->shm_base = shm_base; + rb->head = (size_t *) (rb->shm_base + (SHM_BUFFER_SIZE)); + rb->tail = rb->head + 1; + rb->acl = 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; + + fail_truncate: + close(fd); + if (flags & O_CREAT) + shm_unlink(fn); + fail_open: + free(rb); + fail_malloc: + return NULL; +} + +struct shm_rbuff * shm_rbuff_create(pid_t api, int port_id) +{ + struct shm_rbuff * rb; + pthread_mutexattr_t mattr; + pthread_condattr_t cattr; + mode_t mask; + + mask = umask(0); + + rb = rbuff_create(api, port_id, O_CREAT | O_EXCL | O_RDWR); + + umask(mask); + + if (rb == NULL) + goto fail_rb; + + if (pthread_mutexattr_init(&mattr)) + goto fail_mattr; + + pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED); +#ifdef HAVE_ROBUST_MUTEX + pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST); +#endif + if (pthread_mutex_init(rb->lock, &mattr)) + goto fail_mutex; + + if (pthread_condattr_init(&cattr)) + goto fail_cattr; + + pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED); +#ifndef __APPLE__ + pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK); +#endif + if (pthread_cond_init(rb->add, &cattr)) + goto fail_add; + + if (pthread_cond_init(rb->del, &cattr)) + goto fail_del; + + *rb->acl = ACL_RDWR; + *rb->head = 0; + *rb->tail = 0; + + rb->api = api; + rb->port_id = port_id; + + pthread_mutexattr_destroy(&mattr); + pthread_condattr_destroy(&cattr); + + return rb; + + fail_del: + pthread_cond_destroy(rb->add); + fail_add: + pthread_condattr_destroy(&cattr); + fail_cattr: + pthread_mutex_destroy(rb->lock); + fail_mutex: + pthread_mutexattr_destroy(&mattr); + fail_mattr: + shm_rbuff_destroy(rb); + fail_rb: + return NULL; +} + +struct shm_rbuff * shm_rbuff_open(pid_t api, int port_id) +{ + return rbuff_create(api, port_id, O_RDWR); +} + #if (defined(SHM_RBUFF_LOCKLESS) && \ (defined(__GNUC__) || defined (__clang__))) #include "shm_rbuff_ll.c" |