| commit | 31ee6b4daa1da9cd02e75b27924b2729345e999d | |
| author | Eric Wong <normalperson@yhbt.net> | |
| Tue, 29 Dec 2009 20:59:01 +0000 (29 12:59 -0800) | ||
| committer | Eric Wong <normalperson@yhbt.net> | |
| Tue, 29 Dec 2009 20:59:01 +0000 (29 12:59 -0800) | ||
| tree | c00cc159a7e330763ae72f307dab3664d0f3d5b9 | treesnapshot (tar.gz zip) |
| parent | d5375f5c24abfae0173007f47bc9e83139d556b5 | commitdiff |
quiet spurious wakeups for accept() in Thread* models
Under all MRI 1.8, a blocking Socket#accept Ruby method (needs
to[1]) translate to a non-blocking accept(2) system call that may
wake up threads/processes unnecessarily. Unfortunately, we
failed to trap and ignore EAGAIN in those cases.
This issue did not affect Ruby 1.9 running under modern Linux
kernels where a _blocking_ accept(2) system call is not (easily,
at least) susceptible to spurious wakeups. Non-Linux systems
running Ruby 1.9 may be affected.
[1] - using a blocking accept(2) on a shared socket with
green threads is dangerous, as noted in
commit ee7fe220ccbc991e1e7cbe982caf48e3303274c7
(and commit 451ca6997b4f298b436605b7f0af75f369320425)
Under all MRI 1.8, a blocking Socket#accept Ruby method (needs
to[1]) translate to a non-blocking accept(2) system call that may
wake up threads/processes unnecessarily. Unfortunately, we
failed to trap and ignore EAGAIN in those cases.
This issue did not affect Ruby 1.9 running under modern Linux
kernels where a _blocking_ accept(2) system call is not (easily,
at least) susceptible to spurious wakeups. Non-Linux systems
running Ruby 1.9 may be affected.
[1] - using a blocking accept(2) on a shared socket with
green threads is dangerous, as noted in
commit ee7fe220ccbc991e1e7cbe982caf48e3303274c7
(and commit 451ca6997b4f298b436605b7f0af75f369320425)