diff options
Diffstat (limited to 'gnu/usr.bin/perl/eg/sysvipc/ipcsem')
-rw-r--r-- | gnu/usr.bin/perl/eg/sysvipc/ipcsem | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/gnu/usr.bin/perl/eg/sysvipc/ipcsem b/gnu/usr.bin/perl/eg/sysvipc/ipcsem new file mode 100644 index 0000000..d72a2dd --- /dev/null +++ b/gnu/usr.bin/perl/eg/sysvipc/ipcsem @@ -0,0 +1,46 @@ +#!/usr/bin/perl +eval 'exec /usr/bin/perl -S $0 ${1+"$@"}' + if 0; + +require 'sys/ipc.ph'; +require 'sys/msg.ph'; + +$| = 1; + +$mode = shift; +die "usage: ipcmsg {r|s}\n" unless $mode =~ /^[rs]$/; +$signal = ($mode eq "s"); + +$id = semget(0x1234, 1, ($signal ? 0 : &IPC_CREAT) | 0644); +die "Can't get semaphore: $!\n" unless defined($id); +print "semaphore id: $id\n"; + +if ($signal) { + while (<STDIN>) { + print "Signalling\n"; + unless (semop($id, 0, pack("sss", 0, 1, 0))) { + die "Can't signal semaphore: $!\n"; + } + } +} +else { + $SIG{'INT'} = $SIG{'QUIT'} = "leave"; + for (;;) { + unless (semop($id, 0, pack("sss", 0, -1, 0))) { + die "Can't wait for semaphore: $!\n"; + } + print "Unblocked\n"; + } +} + +&leave; + +sub leave { + if (!$signal) { + $x = semctl($id, 0, &IPC_RMID, 0); + if (!defined($x) || $x < 0) { + die "Can't remove semaphore: $!\n"; + } + } + exit; +} |