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31 lines
1.5 KiB
Markdown
31 lines
1.5 KiB
Markdown
Motivation
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> “Why an event loop, why not use threads?”
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With the advent of light-weight processes (threads) programmers these
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days have a [golden hammer](http://c2.com/cgi/wiki?GoldenHammer) they
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often swing without consideration. Event loops and non-blocking I/O is
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often a far easier approach, as well as less error prone.
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The purpose of many applications is, with a little logic sprinkled on
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top, to act on network packets entering an interface, timeouts expiring,
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mouse clicks, or other types of events. Such applications are often
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very well suited to use an event loop.
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Applications that need to churn massively parallel algorithms are more
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suitable for running multiple (independent) threads on several CPU
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cores. However, threaded applications must deal with the side effects
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of concurrency, like race conditions, deadlocks, live locks, etc.
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Writing error free threaded applications is hard, debugging them can be
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even harder.
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Sometimes the combination of multiple threads *and* an event loop per
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thread can be the best approach, but each application of course needs to
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be broken down individually to find the most optimal approach. Do keep
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in mind, however, that not all systems your application will run on have
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multiple CPU cores -- some small embedded systems still use a single CPU
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core, even though they run Linux, with multiple threads a program may
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actually run slower! Always profile your program, and if possible, test
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it on different architectures.
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