69 lines
1.8 KiB
Plaintext
69 lines
1.8 KiB
Plaintext
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== Description
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Concurrency primitives that may be used in a cross-process way to
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coordinate share memory between processes.
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A small C library (libpsem) is compiled to support portable access to
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semaphores. This library is then accessed using FFI to implement Ruby
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classes ProcessShared::Semaphore, ProcessShared::BoundedSemaphore,
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ProcessShared::Mutex, and ProcessShared::SharedMemory.
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This is an incomplete work in progress.
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== License
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MIT
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== Install
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Install the gem with:
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gem install process_shared
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== Usage
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require 'process_shared'
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mutex = ProcessShared::Mutex.new
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mem = ProcessShared::SharedMemory.new(:int) # extends FFI::Pointer
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mem.put_int(0, 0)
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pid1 = fork do
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puts "in process 1 (#{Process.pid})"
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10.times do
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sleep 0.01
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mutex.synchronize do
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value = mem.get_int(0)
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sleep 0.01
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puts "process 1 (#{Process.pid}) incrementing"
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mem.put_int(0, value + 1)
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end
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end
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end
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pid2 = fork do
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puts "in process 2 (#{Process.pid})"
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10.times do
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sleep 0.01
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mutex.synchronize do
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value = mem.get_int(0)
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sleep 0.01
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puts "process 2 (#{Process.pid}) decrementing"
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mem.put_int(0, value - 1)
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end
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end
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end
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Process.wait(pid1)
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Process.wait(pid2)
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puts "value should be zero: #{mem.get_int(0)}"
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== Todo
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* Implement ConditionVariable
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* Implement optional override of core Thread/Mutex classes
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* Extend libpsem to win32? (See Python's processing library)
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* Break out tests that use PSem.getvalue() (which isn't supported on Mac OS X)
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so that the test suite will pass
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* Add finalizer to Mutex? (finalizer on Semaphore objects may be enough) or a method to
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explicitly close and release resources?
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