Changes between Version 55 and Version 56 of Language

Timestamp:

05/25/23 06:28:03 (3 years ago)

Author:

Alex Wilton

Comment:

--

Language

@@ -329 +329 @@
 
 Semantics: there is a global atomic lock which is initially free.
-A process attempting to execute an atomic statement will wait until the atomic lock becomes free, i.e., no other process is inside an atomic statement.
-The process must also wait until the guard of the atomic statement holds; this means that the first sub-statement of the statement is enabled.
-Once the atomic lock is free and the guard holds, the atomic statement becomes enabled and the process may enter the atomic statement.
+The global atomic lock can be obtained by a process by entering an atomic statement.
+Whenever the lock is held by some process, all other processes must wait until the atomic lock becomes free to continue execution.
+The guard of an atomic statement is simply the guard of the first sub-statement of the atomic statement.
+So, a process may only enter an atomic statement if the lock is free (or if the process already owns the lock) and the guard holds.
 The process may not necessarily enter the atomic statement as soon as these conditions hold, because some other enabled process may be scheduled first.
 In fact, some other process may obtain the atomic lock.