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Diffstat (limited to 'demo4/ReadMe.txt')
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diff --git a/demo4/ReadMe.txt b/demo4/ReadMe.txt new file mode 100644 index 0000000..25f73e9 --- /dev/null +++ b/demo4/ReadMe.txt @@ -0,0 +1,15 @@ +This demonstrates the use of a semaphore with a Python context manager (a +'with' statement). + +To run the demo, simply run `python parent.py`. It launches child.py. + +The programs parent.py and child.py share a semaphore; the latter acquires the +semaphore via a context manager. The child process deliberately kills itself via +an error about half the time (randomly) in order to demonstrate that the +context manager releases the semaphore regardless of whether or not the context +block is exited gracefully. + +Once the child releases the semaphore, the parent destroys it. + +The whole thing happens in less than 10 seconds. + |