diff options
Diffstat (limited to 'lib/unicorn/util.rb')
| -rw-r--r-- | lib/unicorn/util.rb | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/lib/unicorn/util.rb b/lib/unicorn/util.rb index f84241c..94c4e37 100644 --- a/lib/unicorn/util.rb +++ b/lib/unicorn/util.rb @@ -39,7 +39,7 @@ module Unicorn::Util to_reopen.each do |fp| orig_st = begin fp.stat - rescue IOError, Errno::EBADF + rescue IOError, Errno::EBADF # race next end @@ -50,8 +50,28 @@ module Unicorn::Util end begin - File.open(fp.path, 'a') { |tmpfp| fp.reopen(tmpfp) } + # stdin, stdout, stderr are special. The following dance should + # guarantee there is no window where `fp' is unwritable in MRI + # (or any correct Ruby implementation). + # + # Fwiw, GVL has zero bearing here. This is tricky because of + # the unavoidable existence of stdio FILE * pointers for + # std{in,out,err} in all programs which may use the standard C library + if fp.fileno <= 2 + # We do not want to hit fclose(3)->dup(2) window for std{in,out,err} + # MRI will use freopen(3) here internally on std{in,out,err} + fp.reopen(fp.path, "a") + else + # We should not need this workaround, Ruby can be fixed: + # http://bugs.ruby-lang.org/issues/9036 + # MRI will not call call fclose(3) or freopen(3) here + # since there's no associated std{in,out,err} FILE * pointer + # This should atomically use dup3(2) (or dup2(2)) syscall + File.open(fp.path, "a") { |tmpfp| fp.reopen(tmpfp) } + end + fp.sync = true + fp.flush # IO#sync=true may not implicitly flush new_st = fp.stat # this should only happen in the master: |