diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libmdsclient/inbound.c | 8 | ||||
| -rw-r--r-- | src/libmdsclient/inbound.h | 140 |
2 files changed, 128 insertions, 20 deletions
diff --git a/src/libmdsclient/inbound.c b/src/libmdsclient/inbound.c index 6fcd8ec..62ea172 100644 --- a/src/libmdsclient/inbound.c +++ b/src/libmdsclient/inbound.c @@ -36,8 +36,8 @@ * be used by `mds_message_read` * * @param this Memory slot in which to store the new message - * @return Non-zero on error, `errno` will be set accordingly. - * Destroy the message on error. + * @return Zero on success, -1 error, `errno` will be set + * accordingly. Destroy the message on error. * * @throws ENOMEM Out of memory. Possibly, the process hit the RLIMIT_AS or * RLIMIT_DATA limit described in getrlimit(2). @@ -431,8 +431,8 @@ static int continue_read(libmds_message_t* restrict this, int fd) * * @param this Memory slot in which to store the new message * @param fd The file descriptor - * @return Non-zero on error or interruption, `errno` will be - * set accordingly. Destroy the message on error, + * @return Zero on success, -1 on error or interruption, `errno` + * will be set accordingly. Destroy the message on error, * be aware that the reading could have been * interrupted by a signal rather than canonical error. * If -2 is returned `errno` will not have been set, diff --git a/src/libmdsclient/inbound.h b/src/libmdsclient/inbound.h index 1bd1c74..7682b54 100644 --- a/src/libmdsclient/inbound.h +++ b/src/libmdsclient/inbound.h @@ -78,7 +78,7 @@ typedef struct libmds_message /** * Zero unless the structure is flattend, otherwise - * the size of the object (semiinternal data) + * the size of the object (internal data) * * Flattened means that all pointers are subpointers * of the object itself @@ -99,23 +99,23 @@ typedef struct libmds_message typedef struct libmds_mspool { /** - * Array of messages + * Array of messages (internal data) */ libmds_message_t** messages; /** * The number of elements the current - * allocation of `messages` can hold + * allocation of `messages` can hold (internal data) */ size_t size; /** - * Push end + * Push end (internal data) */ size_t head; /** - * Poll end + * Poll end (internal data) */ size_t tail; @@ -137,23 +137,39 @@ typedef struct libmds_mspool */ size_t spool_limit_messages; + /** + * If non-zero, `wait_semaphore` shall + * be incremented when a message is + * polled (internal data) + */ + int please_post; + /* POSIX semaphores are lighter weight than XSI semaphores, so we use POSIX here. */ /** * Binary semaphore used to lock the spool whilst - * manipulating it + * manipulating it (internal data) */ sem_t lock; /** - * Seamphore used to signal addition of messages, + * Semaphore used to signal addition of messages, * each time a message is spooled, this semaphore * in increased, the polling thread decreases the * the semaphore before despooling a message, * causing it to block when the spool is empty + * (internal data) */ sem_t semaphore; + /** + * If the spool is full, the semaphore is acquired + * so that the spool function blocks, it is then + * posted when a message is polled so that the + * spool function may try again (internal data) + */ + sem_t wait_semaphore; + } libmds_mspool_t; @@ -163,24 +179,24 @@ typedef struct libmds_mspool typedef struct libmds_mpool { /** - * Array of messages + * Array of messages (internal data) */ libmds_message_t** messages; /** * The number of elements the current - * allocation of 'messages` can hold + * allocation of 'messages` can hold (internal data) */ size_t size; /** - * The tip of the stack + * The tip of the stack (internal data) */ - size_t tip; + volatile size_t tip; /** * Binary semaphore used to lock the pool - * whilst manipulating it + * whilst manipulating it (internal data) */ sem_t lock; @@ -193,8 +209,8 @@ typedef struct libmds_mpool * be used by `libmds_message_read` * * @param this Memory slot in which to store the new message - * @return Non-zero on error, `errno` will be set accordingly. - * Destroy the message on error. + * @return Zero on success, -1 error, `errno` will be set + * accordingly. Destroy the message on error. * * @throws ENOMEM Out of memory. Possibly, the process hit the RLIMIT_AS or * RLIMIT_DATA limit described in getrlimit(2). @@ -229,8 +245,8 @@ libmds_message_t* libmds_message_duplicate(libmds_message_t* restrict this); * * @param this Memory slot in which to store the new message * @param fd The file descriptor - * @return Non-zero on error or interruption, `errno` will be - * set accordingly. Destroy the message on error, + * @return Zero on success, -1 on error or interruption, `errno` + * will be set accordingly. Destroy the message on error, * be aware that the reading could have been * interrupted by a signal rather than canonical error. * If -2 is returned `errno` will not have been set, @@ -246,5 +262,97 @@ int libmds_message_read(libmds_message_t* restrict this, int fd); +/** + * Initialise a message spool + * + * @param this The message spool + * @return Zero on success, -1 on error, `errno` will be set accordingly + */ +__attribute__((nonnull, warn_unused_result)) +int libmds_mspool_initialise(libmds_mspool_t* restrict this); + +/** + * Destroy a message spool, deallocate its resources + * + * @param this The message spool + */ +__attribute__((nonnull)) +void libmds_mspool_destroy(libmds_mspool_t* restrict this); + +/** + * Spool a message + * + * @param this The message spool + * @param message The message to spool + * @return Zero on success, -1 on error, `errno` will be set accordingly + */ +__attribute__((nonnull, warn_unused_result)) +int libmds_mspool_spool(libmds_mspool_t* restrict this, libmds_message_t* restrict message); + +/** + * Poll a message from a spool, wait if empty + * + * @param this The message spool + * @return A spooled message, `NULL`on error, `errno` will be set accordingly + */ +__attribute__((nonnull, warn_unused_result, malloc)) +libmds_message_t* libmds_mspool_poll(libmds_mspool_t* restrict this); + +/** + * Poll a message from a spool, wait for a limited time + * or return unsuccessfully if empty + * + * @param this The message spool + * @param deadline The CLOCK_REALTIME time the function must return, + * `NULL` to return immediately if it would block + * @return A spooled message, `NULL`on error, `errno` will be set accordingly + */ +__attribute__((nonnull(1), warn_unused_result, malloc)) +libmds_message_t* libmds_mspool_poll_try(libmds_mspool_t* restrict this, const struct timespec* deadline); + + + +/** + * Initialise a pool of reusable message allocations + * + * @param this The message allocation pool + * @param size The number of allocations that may be pooled + * @return Zero on success, -1 on error, `errno` will be set accordingly + */ +__attribute__((nonnull, warn_unused_result)) +int libmds_mpool_initialise(libmds_mpool_t* restrict this, size_t size); + +/** + * Destroy a pool of reusable message allocations, + * deallocate its resources and pooled allocations + * + * @param this The message allocation pool + */ +__attribute__((nonnull)) +void libmds_mpool_destroy(libmds_mpool_t* restrict this); + +/** + * Add a message allocation to a pool + * + * @param this The message allocation pool + * @param message Message allocation to pool + * @return Zero on success, -1 on error, `errno` will be set accordingly + */ +__attribute__((nonnull, warn_unused_result)) +int libmds_mpool_offer(libmds_mpool_t* restrict this, libmds_message_t* restrict message); + +/** + * Fetch a message allocation from a pool + * + * @param this The message allocation pool + * @return An offered message allocation, `NULL` on error or if none + * are available. If `NULL` is returned, `errno` is set to zero, + * if the pool was empty, otherwise `errno` will describe the error. + */ +__attribute__((nonnull, warn_unused_result, malloc)) +libmds_message_t* libmds_mpool_poll(libmds_mpool_t* restrict this); + + + #endif |