33 lines
1.8 KiB
Plaintext
33 lines
1.8 KiB
Plaintext
This module collection manages continuations in general, most often in
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the form of cooperative threads (also called coros, or simply "coro" in
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the documentation). They are similar to kernel threads but don't (in
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general) run in parallel at the same time even on SMP machines. The
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specific flavor of thread offered by this module also guarantees you
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that it will not switch between threads unless necessary, at
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easily-identified points in your program, so locking and parallel access
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are rarely an issue, making thread programming much safer and easier
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than using other thread models.
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Unlike the so-called "Perl threads" (which are not actually real threads
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but only the windows process emulation (see section of same name for
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more details) ported to UNIX, and as such act as processes), Coro
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provides a full shared address space, which makes communication between
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threads very easy. And coro threads are fast, too: disabling the Windows
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process emulation code in your perl and using Coro can easily result in
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a two to four times speed increase for your programs. A parallel matrix
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multiplication benchmark (very communication-intensive) runs over 300
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times faster on a single core than perls pseudo-threads on a quad core
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using all four cores.
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Coro achieves that by supporting multiple running interpreters that
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share data, which is especially useful to code pseudo-parallel processes
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and for event-based programming, such as multiple HTTP-GET requests
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running concurrently. See Coro::AnyEvent to learn more on how to
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integrate Coro into an event-based environment.
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In this module, a thread is defined as "callchain + lexical variables +
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some package variables + C stack), that is, a thread has its own
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callchain, its own set of lexicals and its own set of perls most
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important global variables (see Coro::State for more configuration and
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background info).
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