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|
open Netsys_posix
open Printf
let s1 =
let n1 = sprintf "/s1_%d" (Unix.getpid()) in
let s = sem_open n1 [SEM_O_CREAT] 0o666 0 in
sem_unlink n1;
s
let s2 =
let n2 = sprintf "/s2_%d" (Unix.getpid()) in
let s = sem_open n2 [SEM_O_CREAT] 0o666 0 in
sem_unlink n2;
s
let process1 n =
for k = 1 to n do
sem_post s1;
sem_wait s2 SEM_WAIT_BLOCK
done;
exit 0
let process2 n =
for k = 1 to n do
sem_wait s1 SEM_WAIT_BLOCK;
sem_post s2
done;
exit 0
let main() =
let n = int_of_string Sys.argv.(1) in
let pid1 =
match Unix.fork() with
| 0 ->
process1 n
| pid ->
pid in
let pid2 =
match Unix.fork() with
| 0 ->
process2 n
| pid ->
pid in
ignore(Unix.waitpid [] pid1);
ignore(Unix.waitpid [] pid2)
let () =
main()
|
