Temporary fix to multiple initialisation of eio - pthread-specific #235
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| * race conditions. See Node's test/simple/test-eio-race.js | ||
| */ | ||
| eio_set_max_poll_reqs(10); | ||
| pthread_once(&eio_initialised, eio_init_once); |
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pthread_once() is not fork-safe. If another thread calls fork() right when pthread_once() is doing its magic, eio_initialised will be in an undefined state.
It doesn't matter for Node because we always execve() immediately afterwards but it will be a problem in other applications that depend on libuv.
Then again, there is probably not much we can do about it. We can re-initialize libuv mutexes and guards in pthread_atfork() handlers but libeio uses mutexes internally that are out of our control.
Consider this the ramblings of a (not so) old man.
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Not all platforms have pthread_atfork() either.
The other way to approach it is to pass the buck to the caller, just like eio does, and expose an initialiser that you say must only be called once.
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It's more complex than I thought and that second commit doesn't work. I commented here: The first commit is OK but the second one is not. I will revert that . |
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Closing, a newer version of this PR landed in abf9654. |
Issue summary is here:
paddybyers/node#15