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authorLorry Tar Creator <lorry-tar-importer@baserock.org>2014-02-21 04:46:49 +0000
committer <>2014-08-04 21:38:17 +0000
commitf3765db04b903b3671733e07cf1541a51966dd14 (patch)
treedefcc3c47d9b8bd78b97dcc04ee779a758d37b1c /demo4/child.py
downloadposix-ipc-tarball-master.tar.gz
Imported from /home/lorry/working-area/delta_python-packages_posix-ipc-tarball/posix_ipc-0.9.8.tar.gz.HEADposix_ipc-0.9.8master
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+import posix_ipc
+import time
+import sys
+import random
+
+# The parent passes the semaphore's name to me.
+name = sys.argv[1]
+
+print('Child: waiting to aquire semaphore ' + name)
+
+with posix_ipc.Semaphore(name) as sem:
+ print('Child: semaphore ' + sem.name + ' aquired; holding for 3 seconds.')
+
+ # Flip a coin to determine whether or not to bail out of the context.
+ if random.randint(0, 1):
+ print("Child: raising ValueError to demonstrate unplanned context exit")
+ raise ValueError
+
+ time.sleep(3)
+
+ print('Child: gracefully exiting context (releasing the semaphore).')