qb_ringbuffer_t *
qb_rb_open(const char *name, size_t size, uint32_t flags,
size_t shared_user_data_size)
{
struct qb_ringbuffer_s *rb;
size_t real_size;
size_t shared_size;
char path[PATH_MAX];
int32_t fd_hdr;
int32_t fd_data;
uint32_t file_flags = O_RDWR;
char filename[PATH_MAX];
int32_t error = 0;
void *shm_addr;
long page_size = sysconf(_SC_PAGESIZE);
#ifdef QB_FORCE_SHM_ALIGN
page_size = QB_MAX(page_size, 16 * 1024);
#endif /* QB_FORCE_SHM_ALIGN */
real_size = QB_ROUNDUP(size, page_size);
shared_size =
sizeof(struct qb_ringbuffer_shared_s) + shared_user_data_size;
if (flags & QB_RB_FLAG_CREATE) {
file_flags |= O_CREAT | O_TRUNC;
}
rb = calloc(1, sizeof(struct qb_ringbuffer_s));
if (rb == NULL) {
return NULL;
}
/*
* Create a shared_hdr memory segment for the header.
*/
snprintf(filename, PATH_MAX, "qb-%s-header", name);
fd_hdr = qb_sys_mmap_file_open(path, filename,
shared_size, file_flags);
if (fd_hdr < 0) {
error = fd_hdr;
qb_util_log(LOG_ERR, "couldn't create file for mmap");
goto cleanup_hdr;
}
rb->shared_hdr = mmap(0,
shared_size,
PROT_READ | PROT_WRITE, MAP_SHARED, fd_hdr, 0);
if (rb->shared_hdr == MAP_FAILED) {
error = -errno;
qb_util_log(LOG_ERR, "couldn't create mmap for header");
goto cleanup_hdr;
}
rb->flags = flags;
/*
* create the semaphore
*/
if (flags & QB_RB_FLAG_CREATE) {
rb->shared_data = NULL;
/* rb->shared_hdr->word_size tracks data by ints and not bytes/chars. */
rb->shared_hdr->word_size = real_size / sizeof(uint32_t);
rb->shared_hdr->write_pt = 0;
rb->shared_hdr->read_pt = 0;
(void)strlcpy(rb->shared_hdr->hdr_path, path, PATH_MAX);
}
error = qb_rb_sem_create(rb, flags);
if (error < 0) {
qb_util_perror(LOG_ERR, "couldn't get a semaphore");
goto cleanup_hdr;
}
/* Create the shared_data memory segment for the actual ringbuffer.
* They have to be separate.
*/
if (flags & QB_RB_FLAG_CREATE) {
snprintf(filename, PATH_MAX, "qb-%s-data", name);
fd_data = qb_sys_mmap_file_open(path,
filename,
real_size, file_flags);
(void)strlcpy(rb->shared_hdr->data_path, path, PATH_MAX);
} else {
fd_data = qb_sys_mmap_file_open(path,
rb->shared_hdr->data_path,
real_size, file_flags);
}
if (fd_data < 0) {
error = fd_data;
qb_util_log(LOG_ERR, "couldn't create file for mmap");
goto cleanup_hdr;
}
qb_util_log(LOG_DEBUG,
"shm size:%zd; real_size:%zd; rb->word_size:%d", size,
real_size, rb->shared_hdr->word_size);
error = qb_sys_circular_mmap(fd_data, &shm_addr, real_size);
rb->shared_data = shm_addr;
if (error != 0) {
qb_util_log(LOG_ERR, "couldn't create circular mmap on %s",
rb->shared_hdr->data_path);
goto cleanup_data;
}
if (flags & QB_RB_FLAG_CREATE) {
memset(rb->shared_data, 0, real_size);
rb->shared_data[rb->shared_hdr->word_size] = 5;
rb->shared_hdr->ref_count = 1;
} else {
qb_atomic_int_inc(&rb->shared_hdr->ref_count);
}
close(fd_hdr);
close(fd_data);
return rb;
cleanup_data:
close(fd_data);
if (flags & QB_RB_FLAG_CREATE) {
unlink(rb->shared_hdr->data_path);
}
cleanup_hdr:
if (fd_hdr >= 0) {
close(fd_hdr);
}
if (rb && (flags & QB_RB_FLAG_CREATE)) {
unlink(rb->shared_hdr->hdr_path);
(void)rb->sem_destroy_fn(rb);
}
if (rb && (rb->shared_hdr != MAP_FAILED && rb->shared_hdr != NULL)) {
munmap(rb->shared_hdr, sizeof(struct qb_ringbuffer_shared_s));
}
free(rb);
errno = -error;
return NULL;
}
qb_ringbuffer_t *
qb_rb_open_2(const char *name, size_t size, uint32_t flags,
size_t shared_user_data_size,
struct qb_rb_notifier *notifiers)
{
struct qb_ringbuffer_s *rb;
size_t real_size;
size_t shared_size;
char path[PATH_MAX];
int32_t fd_hdr;
int32_t fd_data;
uint32_t file_flags = O_RDWR;
char filename[PATH_MAX];
int32_t error = 0;
void *shm_addr;
long page_size = sysconf(_SC_PAGESIZE);
#ifdef QB_ARCH_HPPA
page_size = QB_MAX(page_size, 0x00400000); /* align to page colour */
#elif defined(QB_FORCE_SHM_ALIGN)
page_size = QB_MAX(page_size, 16 * 1024);
#endif /* QB_FORCE_SHM_ALIGN */
/* The user of this api expects the 'size' parameter passed into this function
* to be reflective of the max size single write we can do to the
* ringbuffer. This means we have to add both the 'margin' space used
* to calculate if there is enough space for a new chunk as well as the '+1' that
* prevents overlap of the read/write pointers */
size += QB_RB_CHUNK_MARGIN + 1;
real_size = QB_ROUNDUP(size, page_size);
shared_size =
sizeof(struct qb_ringbuffer_shared_s) + shared_user_data_size;
if (flags & QB_RB_FLAG_CREATE) {
file_flags |= O_CREAT | O_TRUNC;
}
rb = calloc(1, sizeof(struct qb_ringbuffer_s));
if (rb == NULL) {
return NULL;
}
/*
* Create a shared_hdr memory segment for the header.
*/
snprintf(filename, PATH_MAX, "qb-%s-header", name);
fd_hdr = qb_sys_mmap_file_open(path, filename,
shared_size, file_flags);
if (fd_hdr < 0) {
error = fd_hdr;
qb_util_log(LOG_ERR, "couldn't create file for mmap");
goto cleanup_hdr;
}
rb->shared_hdr = mmap(0,
shared_size,
PROT_READ | PROT_WRITE, MAP_SHARED, fd_hdr, 0);
if (rb->shared_hdr == MAP_FAILED) {
error = -errno;
qb_util_log(LOG_ERR, "couldn't create mmap for header");
goto cleanup_hdr;
}
qb_atomic_init();
rb->flags = flags;
/*
* create the semaphore
*/
if (flags & QB_RB_FLAG_CREATE) {
rb->shared_data = NULL;
/* rb->shared_hdr->word_size tracks data by ints and not bytes/chars. */
rb->shared_hdr->word_size = real_size / sizeof(uint32_t);
rb->shared_hdr->write_pt = 0;
rb->shared_hdr->read_pt = 0;
(void)strlcpy(rb->shared_hdr->hdr_path, path, PATH_MAX);
}
if (notifiers && notifiers->post_fn) {
error = 0;
memcpy(&rb->notifier,
notifiers,
sizeof(struct qb_rb_notifier));
} else {
error = qb_rb_sem_create(rb, flags);
}
if (error < 0) {
errno = -error;
qb_util_perror(LOG_ERR, "couldn't create a semaphore");
goto cleanup_hdr;
}
/* Create the shared_data memory segment for the actual ringbuffer.
* They have to be separate.
*/
if (flags & QB_RB_FLAG_CREATE) {
snprintf(filename, PATH_MAX, "qb-%s-data", name);
fd_data = qb_sys_mmap_file_open(path,
filename,
real_size, file_flags);
(void)strlcpy(rb->shared_hdr->data_path, path, PATH_MAX);
} else {
fd_data = qb_sys_mmap_file_open(path,
rb->shared_hdr->data_path,
real_size, file_flags);
}
if (fd_data < 0) {
error = fd_data;
qb_util_log(LOG_ERR, "couldn't create file for mmap");
goto cleanup_hdr;
}
qb_util_log(LOG_DEBUG,
"shm size:%ld; real_size:%ld; rb->word_size:%d", size,
real_size, rb->shared_hdr->word_size);
/* this function closes fd_data */
error = qb_sys_circular_mmap(fd_data, &shm_addr, real_size);
rb->shared_data = shm_addr;
if (error != 0) {
qb_util_log(LOG_ERR, "couldn't create circular mmap on %s",
rb->shared_hdr->data_path);
goto cleanup_data;
}
if (flags & QB_RB_FLAG_CREATE) {
memset(rb->shared_data, 0, real_size);
rb->shared_data[rb->shared_hdr->word_size] = 5;
rb->shared_hdr->ref_count = 1;
} else {
qb_atomic_int_inc(&rb->shared_hdr->ref_count);
}
close(fd_hdr);
return rb;
cleanup_data:
if (flags & QB_RB_FLAG_CREATE) {
unlink(rb->shared_hdr->data_path);
}
cleanup_hdr:
if (fd_hdr >= 0) {
close(fd_hdr);
}
if (rb && (flags & QB_RB_FLAG_CREATE)) {
unlink(rb->shared_hdr->hdr_path);
if (rb->notifier.destroy_fn) {
(void)rb->notifier.destroy_fn(rb->notifier.instance);
}
}
if (rb && (rb->shared_hdr != MAP_FAILED && rb->shared_hdr != NULL)) {
munmap(rb->shared_hdr, sizeof(struct qb_ringbuffer_shared_s));
}
free(rb);
errno = -error;
return NULL;
}