diff options
Diffstat (limited to 'winsup/cygwin/select.cc')
| -rw-r--r-- | winsup/cygwin/select.cc | 104 |
1 files changed, 52 insertions, 52 deletions
diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc index e2d11a408..95ee14161 100644 --- a/winsup/cygwin/select.cc +++ b/winsup/cygwin/select.cc @@ -507,63 +507,63 @@ out: if (s->write_selected) { if (s->write_ready) - { - select_printf ("%s, already ready for write", fh->get_name ()); - gotone++; - } + { + select_printf ("%s, already ready for write", fh->get_name ()); + gotone++; + } /* Do we need to do anything about SIGTTOU here? */ else if (fh->get_device () == FH_PIPER) select_printf ("%s, select for write on read end of pipe", fh->get_name ()); else - { - /* We don't worry about the guard mutex, because that only applies - when from_select is false, and peek_pipe is never called that - way for writes. */ - - IO_STATUS_BLOCK iosb = {0}; - FILE_PIPE_LOCAL_INFORMATION fpli = {0}; - - if (NtQueryInformationFile (h, - &iosb, - &fpli, - sizeof (fpli), - FilePipeLocalInformation)) - { - /* If NtQueryInformationFile fails, optimistically assume the - pipe is writable. This could happen on Win9x, because - NtQueryInformationFile is not available, or if we somehow - inherit a pipe that doesn't permit FILE_READ_ATTRIBUTES - access on the write end. */ - select_printf ("%s, NtQueryInformationFile failed", - fh->get_name ()); - gotone += s->write_ready = true; - } - /* Ensure that enough space is available for atomic writes, - as required by POSIX. Subsequent writes with size > PIPE_BUF - can still block, but most (all?) UNIX variants seem to work - this way (e.g., BSD, Linux, Solaris). */ - else if (fpli.WriteQuotaAvailable >= PIPE_BUF) - { - select_printf ("%s, ready for write: size %lu, avail %lu", - fh->get_name (), - fpli.OutboundQuota, - fpli.WriteQuotaAvailable); - gotone += s->write_ready = true; - } - /* If we somehow inherit a tiny pipe (size < PIPE_BUF), then consider - the pipe writable only if it is completely empty, to minimize the - probability that a subsequent write will block. */ - else if (fpli.OutboundQuota < PIPE_BUF && - fpli.WriteQuotaAvailable == fpli.OutboundQuota) - { - select_printf ("%s, tiny pipe: size %lu, avail %lu", - fh->get_name (), - fpli.OutboundQuota, - fpli.WriteQuotaAvailable); - gotone += s->write_ready = true; - } - } + { + /* We don't worry about the guard mutex, because that only applies + when from_select is false, and peek_pipe is never called that + way for writes. */ + + IO_STATUS_BLOCK iosb = {0}; + FILE_PIPE_LOCAL_INFORMATION fpli = {0}; + + if (NtQueryInformationFile (h, + &iosb, + &fpli, + sizeof (fpli), + FilePipeLocalInformation)) + { + /* If NtQueryInformationFile fails, optimistically assume the + pipe is writable. This could happen on Win9x, because + NtQueryInformationFile is not available, or if we somehow + inherit a pipe that doesn't permit FILE_READ_ATTRIBUTES + access on the write end. */ + select_printf ("%s, NtQueryInformationFile failed", + fh->get_name ()); + gotone += s->write_ready = true; + } + /* Ensure that enough space is available for atomic writes, + as required by POSIX. Subsequent writes with size > PIPE_BUF + can still block, but most (all?) UNIX variants seem to work + this way (e.g., BSD, Linux, Solaris). */ + else if (fpli.WriteQuotaAvailable >= PIPE_BUF) + { + select_printf ("%s, ready for write: size %lu, avail %lu", + fh->get_name (), + fpli.OutboundQuota, + fpli.WriteQuotaAvailable); + gotone += s->write_ready = true; + } + /* If we somehow inherit a tiny pipe (size < PIPE_BUF), then consider + the pipe writable only if it is completely empty, to minimize the + probability that a subsequent write will block. */ + else if (fpli.OutboundQuota < PIPE_BUF && + fpli.WriteQuotaAvailable == fpli.OutboundQuota) + { + select_printf ("%s, tiny pipe: size %lu, avail %lu", + fh->get_name (), + fpli.OutboundQuota, + fpli.WriteQuotaAvailable); + gotone += s->write_ready = true; + } + } } return gotone; |