/* * Ouroboros - Copyright (C) 2016 * * Ring buffer for application processes * * 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> #define OUROBOROS_PREFIX "shm_ap_rbuff" #include <ouroboros/logs.h> #include <ouroboros/shm_ap_rbuff.h> #include <ouroboros/shm_du_map.h> #include <pthread.h> #include <sys/mman.h> #include <fcntl.h> #include <stdlib.h> #include <string.h> #include <stdint.h> #include <unistd.h> #include <errno.h> #include <sys/stat.h> #define SHM_RBUFF_FILE_SIZE (SHM_RBUFF_SIZE * sizeof(struct rb_entry) \ + 2 * sizeof(size_t) + sizeof(pthread_mutex_t) \ + sizeof (pthread_cond_t)) #define shm_rbuff_used(rb)((*rb->ptr_head + SHM_RBUFF_SIZE - *rb->ptr_tail) \ & (SHM_RBUFF_SIZE - 1)) #define shm_rbuff_free(rb)(shm_rbuff_used(rb) + 1 < SHM_RBUFF_SIZE) #define shm_rbuff_empty(rb) (*rb->ptr_head == *rb->ptr_tail) #define head_el_ptr (rb->shm_base + *rb->ptr_head) #define tail_el_ptr (rb->shm_base + *rb->ptr_tail) struct shm_ap_rbuff { struct rb_entry * shm_base; /* start of entry */ size_t * ptr_head; /* start of ringbuffer head */ size_t * ptr_tail; /* start of ringbuffer tail */ pthread_mutex_t * shm_mutex; /* lock all free space in shm */ pthread_cond_t * work; /* threads will wait for a signal */ pid_t api; /* api to which this rb belongs */ int fd; }; struct shm_ap_rbuff * shm_ap_rbuff_create() { struct shm_ap_rbuff * rb; int shm_fd; struct rb_entry * shm_base; pthread_mutexattr_t mattr; pthread_condattr_t cattr; char fn[25]; sprintf(fn, SHM_AP_RBUFF_PREFIX "%d", getpid()); rb = malloc(sizeof(*rb)); if (rb == NULL) { LOG_DBGF("Could not allocate struct."); return NULL; } shm_fd = shm_open(fn, O_CREAT | O_EXCL | O_RDWR, 0666); if (shm_fd == -1) { LOG_DBGF("Failed creating ring buffer."); free(rb); return NULL; } if (fchmod(shm_fd, 0666)) { LOG_DBGF("Failed to chmod shared memory."); free(rb); return NULL; } if (lseek(shm_fd, SHM_RBUFF_FILE_SIZE - 1, SEEK_SET) < 0) { LOG_DBGF("Failed to extend ringbuffer."); free(rb); return NULL; } if (write(shm_fd, "", 1) != 1) { LOG_DBGF("Failed to finalise extension of ringbuffer."); free(rb); return NULL; } shm_base = mmap(NULL, SHM_RBUFF_FILE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); if (shm_base == MAP_FAILED) { LOG_DBGF("Failed to map shared memory."); if (close(shm_fd) == -1) LOG_DBGF("Failed to close invalid shm."); if (shm_unlink(fn) == -1) LOG_DBGF("Failed to remove invalid shm."); free(rb); return NULL; } rb->shm_base = shm_base; rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE); rb->ptr_tail = rb->ptr_head + 1; rb->shm_mutex = (pthread_mutex_t *) (rb->ptr_tail + 1); rb->work = (pthread_cond_t *) (rb->shm_mutex + 1); pthread_mutexattr_init(&mattr); pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST); pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED); pthread_mutex_init(rb->shm_mutex, &mattr); pthread_condattr_init(&cattr); pthread_condattr_setpshared(&cattr, PTHREAD_PROCESS_SHARED); pthread_cond_init(rb->work, &cattr); *rb->ptr_head = 0; *rb->ptr_tail = 0; rb->fd = shm_fd; rb->api = getpid(); return rb; } struct shm_ap_rbuff * shm_ap_rbuff_open(pid_t api) { struct shm_ap_rbuff * rb; int shm_fd; struct rb_entry * shm_base; char fn[25]; sprintf(fn, SHM_AP_RBUFF_PREFIX "%d", api); rb = malloc(sizeof(*rb)); if (rb == NULL) { LOG_DBGF("Could not allocate struct."); return NULL; } shm_fd = shm_open(fn, O_RDWR, 0666); if (shm_fd == -1) { LOG_DBGF("Failed opening shared memory %s.", fn); return NULL; } shm_base = mmap(NULL, SHM_RBUFF_FILE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0); if (shm_base == MAP_FAILED) { LOG_DBGF("Failed to map shared memory."); if (close(shm_fd) == -1) LOG_DBGF("Failed to close invalid shm."); if (shm_unlink(fn) == -1) LOG_DBGF("Failed to remove invalid shm."); free(rb); return NULL; } rb->shm_base = shm_base; rb->ptr_head = (size_t *) (rb->shm_base + SHM_RBUFF_SIZE); rb->ptr_tail = rb->ptr_head + 1; rb->shm_mutex = (pthread_mutex_t *) (rb->ptr_tail + 1); rb->work = (pthread_cond_t *) (rb->shm_mutex + 1); rb->fd = shm_fd; rb->api = api; return rb; } void shm_ap_rbuff_close(struct shm_ap_rbuff * rb) { if (rb == NULL) { LOG_DBGF("Bogus input. Bugging out."); return; } if (close(rb->fd) < 0) LOG_DBGF("Couldn't close shared memory."); if (munmap(rb->shm_base, SHM_RBUFF_FILE_SIZE) == -1) LOG_DBGF("Couldn't unmap shared memory."); free(rb); } void shm_ap_rbuff_destroy(struct shm_ap_rbuff * rb) { char fn[25]; struct shm_du_map * dum = NULL; if (rb == NULL) { LOG_DBGF("Bogus input. Bugging out."); return; } if (rb->api != getpid()) { dum = shm_du_map_open(); if (shm_du_map_owner(dum) == getpid()) { LOG_DBGF("Ringbuffer %d destroyed by IRMd %d.", rb->api, getpid()); shm_du_map_close(dum); } else { LOG_ERR("AP-I %d tried to destroy rbuff owned by %d.", getpid(), rb->api); shm_du_map_close(dum); return; } } if (close(rb->fd) < 0) LOG_DBGF("Couldn't close shared memory."); sprintf(fn, SHM_AP_RBUFF_PREFIX "%d", rb->api); if (munmap(rb->shm_base, SHM_RBUFF_FILE_SIZE) == -1) LOG_DBGF("Couldn't unmap shared memory."); if (shm_unlink(fn) == -1) LOG_DBGF("Failed to unlink shm."); free(rb); } int shm_ap_rbuff_write(struct shm_ap_rbuff * rb, struct rb_entry * e) { if (rb == NULL || e == NULL) return -1; if (pthread_mutex_lock(rb->shm_mutex) == EOWNERDEAD) { LOG_DBGF("Recovering dead mutex."); pthread_mutex_consistent(rb->shm_mutex); } if (!shm_rbuff_free(rb)) { pthread_mutex_unlock(rb->shm_mutex); return -1; } if (shm_rbuff_empty(rb)) pthread_cond_broadcast(rb->work); *head_el_ptr = *e; *rb->ptr_head = (*rb->ptr_head + 1) & (SHM_RBUFF_SIZE -1); pthread_mutex_unlock(rb->shm_mutex); return 0; } struct rb_entry * shm_ap_rbuff_read(struct shm_ap_rbuff * rb) { struct rb_entry * e = NULL; if (rb == NULL) return NULL; pthread_cleanup_push((void(*)(void *))pthread_mutex_unlock, (void *) rb->shm_mutex); if (pthread_mutex_lock(rb->shm_mutex) == EOWNERDEAD) { LOG_DBGF("Recovering dead mutex."); pthread_mutex_consistent(rb->shm_mutex); } while (tail_el_ptr->port_id < 0) *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1); while(shm_rbuff_empty(rb)) if (pthread_cond_wait(rb->work, rb->shm_mutex) == EOWNERDEAD) { LOG_DBGF("Recovering dead mutex."); pthread_mutex_consistent(rb->shm_mutex); } e = malloc(sizeof(*e)); if (e == NULL) { pthread_mutex_unlock(rb->shm_mutex); return NULL; } *e = *(rb->shm_base + *rb->ptr_tail); *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1); pthread_cleanup_pop(1); return e; } ssize_t shm_ap_rbuff_read_port(struct shm_ap_rbuff * rb, int port_id) { ssize_t idx = -1; if (pthread_mutex_lock(rb->shm_mutex) == EOWNERDEAD) { LOG_DBGF("Recovering dead mutex."); pthread_mutex_consistent(rb->shm_mutex); } if (shm_rbuff_empty(rb)) { pthread_mutex_unlock(rb->shm_mutex); return -1; } while (tail_el_ptr->port_id < 0) *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1); if (tail_el_ptr->port_id != port_id) { pthread_mutex_unlock(rb->shm_mutex); return -1; } idx = tail_el_ptr->index; *rb->ptr_tail = (*rb->ptr_tail + 1) & (SHM_RBUFF_SIZE -1); pthread_mutex_unlock(rb->shm_mutex); return idx; } pid_t shm_ap_rbuff_get_api(struct shm_ap_rbuff *rb) { pid_t api = 0; if (rb == NULL) return 0; pthread_mutex_lock(rb->shm_mutex); api = rb->api; pthread_mutex_unlock(rb->shm_mutex); return api; } void shm_ap_rbuff_reset(struct shm_ap_rbuff * rb) { if (rb == NULL) return; pthread_mutex_lock(rb->shm_mutex); *rb->ptr_tail = 0; *rb->ptr_head = 0; pthread_mutex_unlock(rb->shm_mutex); }