diff options
| -rw-r--r-- | src/libmdsclient/comm.c | 24 | ||||
| -rw-r--r-- | src/libmdsclient/comm.h | 73 |
2 files changed, 95 insertions, 2 deletions
diff --git a/src/libmdsclient/comm.c b/src/libmdsclient/comm.c index c9cdcde..1084e8b 100644 --- a/src/libmdsclient/comm.c +++ b/src/libmdsclient/comm.c @@ -37,7 +37,8 @@ void libmds_connection_initialise(libmds_connection_t* restrict this) /** * Allocate and initialise a connection descriptor * - * @return The connection descriptor, `NULL` on error + * @return The connection descriptor, `NULL` on error, + * `errno` will have been set accordingly on error * * @throws ENOMEM Out of memory, Possibly, the process hit the RLIMIT_AS or * RLIMIT_DATA limit described in getrlimit(2). @@ -78,3 +79,24 @@ void libmds_connection_free(libmds_connection_t* restrict this) free(this); } + +int libmds_connection_send(libmds_connection_t* restrict this, const char* message, size_t length) +{ + int r, saved_errno; + + if (libmds_connection_lock(this)) + return -1; + + r = libmds_connection_send_unlocked(this, message, length); + + saved_errno = errno; + libmds_connection_unlock(this); + return errno = saved_errno, r; +} + + +int libmds_connection_send_unlocked(libmds_connection_t* restrict this, const char* message, size_t length) +{ + /* TODO */ +} + diff --git a/src/libmdsclient/comm.h b/src/libmdsclient/comm.h index 9cc3b74..8f3f0d9 100644 --- a/src/libmdsclient/comm.h +++ b/src/libmdsclient/comm.h @@ -21,6 +21,9 @@ #include <stdint.h> #include <stddef.h> +#include <pthread.h> +#include <time.h> +#include <errno.h> @@ -46,6 +49,12 @@ typedef struct libmds_connection */ char* client_id; + /** + * Mutex used to hinder concurrent modification + * and concurrent message passing + */ + pthread_mutex_t mutex; + } libmds_connection_t; @@ -60,7 +69,8 @@ void libmds_connection_initialise(libmds_connection_t* restrict this); /** * Allocate and initialise a connection descriptor * - * @return The connection descriptor, `NULL` on error + * @return The connection descriptor, `NULL` on error, + * `errno` will have been set accordingly on error * * @throws ENOMEM Out of memory, Possibly, the process hit the RLIMIT_AS or * RLIMIT_DATA limit described in getrlimit(2). @@ -82,6 +92,67 @@ void libmds_connection_destroy(libmds_connection_t* restrict this); */ void libmds_connection_free(libmds_connection_t* restrict this); +/** + * TODO doc + */ +__attribute__((nonnull)) +int libmds_connection_send(libmds_connection_t* restrict this, const char* message, size_t length); + +/** + * TODO doc + */ +__attribute__((nonnull)) +int libmds_connection_send_unlocked(libmds_connection_t* restrict this, const char* message, size_t length); + +/** + * Lock the connection descriptor for being modified, + * or used to send data to the display, by another thread + * + * @param this:libmds_connection_t* The connection descriptor + * @return :int Zero on success, -1 on error, `errno` + * will have been set accordingly on error + * @throws See pthread_mutex_lock(3) + */ +#define libmds_connection_lock(this) \ + (errno = pthread_mutex_lock(&((this)->mutex)), (errno ? 0 : -1)) + +/** + * Lock the connection descriptor for being modified, + * or used to send data to the display, by another thread + * + * @param this:libmds_connection_t* The connection descriptor + * @return :int Zero on success, -1 on error, `errno` + * will have been set accordingly on error + * @throws See pthread_mutex_trylock(3) + */ +#define libmds_connection_trylock(this) \ + (errno = pthread_mutex_trylock(&((this)->mutex)), (errno ? 0 : -1)) + +/** + * Lock the connection descriptor for being modified, + * or used to send data to the display, by another thread + * + * @param this:libmds_connection_t* The connection descriptor + * @param deadline:const struct timespec *restrict The CLOCK_REALTIME time when the function shall fail + * @return :int Zero on success, -1 on error, `errno` + * will have been set accordingly on error + * @throws See pthread_mutex_timedlock(3) + */ +#define libmds_connection_timedlock(this, deadline) \ + (errno = pthread_mutex_timedlock(&((this)->mutex), deadline), (errno ? 0 : -1)) + +/** + * Undo the action of `libmds_connection_lock`, `libmds_connection_trylock` + * or `libmds_connection_timedlock` + * + * @param this:libmds_connection_t* The connection descriptor + * @return :int Zero on success, -1 on error, `errno` + * will have been set accordingly on error + * @throws See pthread_mutex_unlock(3) + */ +#define libmds_connection_unlock(this) + (errno = pthread_mutex_unlock(&((this)->mutex)), (errno ? 0 : -1)) + #endif |