/* * Ouroboros - Copyright (C) 2016 - 2017 * * Ring buffer implementations for incoming SDUs * * 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., http://www.fsf.org/about/contact/. */ #define _POSIX_C_SOURCE 200809L #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 pid; /* pid 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 pid, 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", pid, 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->pid = pid; 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 pid, int port_id) { struct shm_rbuff * rb; pthread_mutexattr_t mattr; pthread_condattr_t cattr; mode_t mask; mask = umask(0); rb = rbuff_create(pid, 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->pid = pid; 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 pid, int port_id) { return rbuff_create(pid, port_id, O_RDWR); } #if (defined(SHM_RBUFF_LOCKLESS) && \ (defined(__GNUC__) || defined (__clang__))) #include "shm_rbuff_ll.c" #else #include "shm_rbuff_pthr.c" #endif