Changes between Version 8 and Version 9 of user_synchro

Timestamp:

Oct 9, 2018, 7:27:21 PM (6 years ago)

Author:

alain

Comment:

--

user_synchro

@@ -47 +47 @@
 The three  functions wait(), signal() and broadcast() must be called by a thread holding the mutex associated to the condvar.
 
-== D) Semaphore ==
+== D) Barrier ==
+
+The user level, POSIX compliant, barrier is defined in the '''pthread''' library, implemented by the [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/libs/libpthread/pthread.h pthread.h] and [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/libs/libpthread/pthread.c pthread.c] files.
+
+It can be used by a muti-threaded user application to implement a "rendez-vous" for a given number of  threads running in different clusters.
+
+The kernel implementation of a barrier is defined in the [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/kernel/libk/remote_barrier.h remote_barrier.h] and [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/kernel/libk/remote_barrier.c remote_barrier.c] files.
+
+For each user barrier, ALMOS-MKH creates a kernel ''remote_barrier_t'' structure, dynamically allocated in the reference cluster (i.e. in the cluster containing the reference process descriptor).
+ * The '''remote_barrier_create()''' function allocates and initializes a barrier, using an RPC if if the calling thread is not running in the reference cluster.
+ * The '''remote_barrier_destroy()''' function destroys a given barrier, using RPC if the calling thread is not running in the reference cluster. 
+ * The blocking '''remote_barrier_wait()''' function returns only when all expected threads (defined by the remote_barrier_create() function) reach the barrier. As the implementation uses a toggle variable, this barrier can be safely called several times, as long as the number of expected threads does not change. 
+
+== E) Semaphore ==
 
 The user level, POSIX compliant, semaphore is defined in the '''semaphore''' library, implemented by the [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/libs/libsemaphore/semaphore.h semaphore.h] and [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/libs/libsemaphore/semaphore.c semaphore.c] files.
@@ -61 +74 @@
  * The '''remote_sem_post()''' function  atomically increments the semaphore. If the waiting queue is not empty, it unblock all waiting threads.
  * The '''remote_sem_get_value()''' function returns the semaphore current value, without modifying the semaphore state. 
-
-== E) Barrier ==
-
-The user level, POSIX compliant, barrier is defined in the '''pthread''' library, implemented by the [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/libs/libpthread/pthread.h] and [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/libs/libpthread/pthread.c pthread.c] files.
-
-It can be used by a muti-threaded user application to implement a "rendez-vous" for a given number of  threads running in different clusters. This toggle barrier can be used 
-
-The kernel implementation of a barrier is defined in the [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/kernel/libk/remote_barrier.h remote_barrier.h] and [https://www-soc.lip6.fr/trac/almos-mkh/browser/trunk/kernel/libk/remote_barrier.c remote_barrier.c] files.
-
-For each user barrier, ALMOS-MKH creates a kernel ''remote_barrier_t'' structure, dynamically allocated in the reference cluster (i.e. in the cluster containing the reference process descriptor).
- * The '''remote_barrier_create()''' function allocates and initializes a barrier, using an RPC if if the calling thread is not running in the reference cluster.
- * The '''remote_barrier_destroy()''' function destroys a given barrier, using RPC if the calling thread is not running in the reference cluster. 
- * The blocking '''remote_barrier_wait()''' function returns only when the all expected threads (defined by the remote_barrier_create() function) reach the barrier. As the implementation uses a toggle variable, this barrier can be safely called several times, as long as the number of expected threads does not change.