MSG:
* Dramatically change the way files are handled. API and internals changed, but
- this part of MSG was not considered as production grade either.
+ this part of MSG was not considered as production grade either.
+ * Add explicit synchronization facilities through semaphores
SMPI:
* SMPI is now included directly in the libsimgrid as the windows
- \ref msg_file_management
- \ref msg_task_usage
- \ref msg_VMs
+ - \ref msg_synchro
- \ref msg_trace_driven
- \ref MSG_examples
- \ref msg_deprecated_functions
* by a process to execute, communicate or otherwise handle some task.
*/
+/** @defgroup msg_synchro Explicit Synchronization Functions
+ * @ingroup MSG_API
+ * @brief This section describes several explicit synchronization
+ * mechanisms existing in MSG: semaphores (#msg_sem_t) and friends.
+ *
+ * In some situations, these things are very helpful to synchronize processes without message exchanges.
+ */
+
/** @defgroup msg_VMs VMs
* @ingroup MSG_API
* @brief This section describes the interface created to mimic IaaS clouds.
XBT_PUBLIC(int) MSG_get_channel_number(void);
#endif
+/** @brief Opaque type representing a semaphore
+ * @ingroup msg_synchro
+ * @hideinitializer
+ */
+typedef struct s_smx_sem *msg_sem_t; // Yeah that's a rename of the smx_sem_t which doesnt require smx_sem_t to be declared here
+XBT_PUBLIC(msg_sem_t) MSG_sem_init(int initial_value);
+XBT_PUBLIC(void) MSG_sem_acquire(msg_sem_t sem);
+XBT_PUBLIC(msg_error_t) MSG_sem_acquire_timeout(msg_sem_t sem, double timeout);
+XBT_PUBLIC(void) MSG_sem_release(msg_sem_t sem);
+XBT_PUBLIC(void) MSG_sem_get_capacity(msg_sem_t sem);
+XBT_PUBLIC(void) MSG_sem_destroy(msg_sem_t sem);
+XBT_PUBLIC(int) MSG_sem_would_block(msg_sem_t sem);
+
/** @brief Opaque type describing a Virtual Machine.
* @ingroup msg_VMs
*
--- /dev/null
+/* Copyright (c) 2013 Da SimGrid Team. All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#include "msg_private.h"
+#include "xbt/sysdep.h"
+#include "xbt/log.h"
+
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_synchro, msg,
+ "Logging specific to MSG (synchro)");
+
+
+/** @addtogroup msg_synchro
+ *
+ * @{
+ */
+
+/********************************* Host **************************************/
+
+/** @brief creates a semaphore object of the given initial capacity */
+msg_sem_t MSG_sem_init(int initial_value) {
+ return simcall_sem_init(initial_value);
+}
+
+/** @brief locks on a semaphore object */
+void MSG_sem_acquire(msg_sem_t sem) {
+ simcall_sem_acquire(sem);
+}
+/** @brief locks on a semaphore object up until the provided timeout expires */
+msg_error_t MSG_sem_acquire_timeout(msg_sem_t sem, double timeout) {
+ xbt_ex_t e;
+ msg_error_t res = MSG_OK;
+ TRY {
+ simcall_sem_acquire_timeout(sem,timeout);
+ } CATCH(e) {
+ if (e.category == timeout_error) {
+ res = MSG_TIMEOUT;
+ xbt_ex_free(e);
+ } else {
+ RETHROW;
+ }
+ }
+ return res;
+}
+/** @brief releases the semaphore object */
+void MSG_sem_release(msg_sem_t sem) {
+ simcall_sem_release(sem);
+}
+void MSG_sem_get_capacity(msg_sem_t sem) {
+ simcall_sem_get_capacity(sem);
+}
+
+void MSG_sem_destroy(msg_sem_t sem) {
+ simcall_sem_destroy(sem);
+}
+/** @brief returns a boolean indicating it this semaphore would block at this very specific time
+ *
+ * Note that the returned value may be wrong right after the function call, when you try to use it...
+ * But that's a classical semaphore issue, and SimGrid's semaphore are not different to usual ones here.
+ */
+int MSG_sem_would_block(msg_sem_t sem) {
+ return simcall_sem_would_block(sem);
+}
+
+/**@}*/
