@@ -1,13 +1,29 @@
|
|
|
|
1 |
// How many threads have arrived to the barrier
|
2 |
shared count := 0
|
3 |
// Protects the increment of the count
|
4 |
shared mutex := semaphore(1)
|
5 |
// Locked (0) until all threads arrive, then it is unlocked (1)
|
6 |
shared barrier := semaphore(0)
|
7 |
|
8 |
-
|
9 |
-
thread_count := read_integer()
|
10 |
create_thread(secondary, thread_count)
|
11 |
|
12 |
secondary:
|
13 |
-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
+
main:
|
2 |
// How many threads have arrived to the barrier
|
3 |
shared count := 0
|
4 |
// Protects the increment of the count
|
5 |
shared mutex := semaphore(1)
|
6 |
// Locked (0) until all threads arrive, then it is unlocked (1)
|
7 |
shared barrier := semaphore(0)
|
8 |
|
9 |
+
// Create arbitrary amount of threads
|
10 |
+
shared thread_count := read_integer()
|
11 |
create_thread(secondary, thread_count)
|
12 |
|
13 |
secondary:
|
14 |
+
Statement A
|
15 |
+
|
16 |
+
// Barrier
|
17 |
+
wait(mutex)
|
18 |
+
// If this is the last thread that reaches the barrier
|
19 |
+
if ++count = thread_count:
|
20 |
+
while count > 0:
|
21 |
+
--count
|
22 |
+
signal(barrier)
|
23 |
+
signal(mutex)
|
24 |
+
|
25 |
+
wait(barrier)
|
26 |
+
|
27 |
+
// Statement B must be executed until
|
28 |
+
// all threads have executed Statement A
|
29 |
+
Statement B
|