}
if (writing)
{
- /* If there is anything available in the pipe buffer then signal
- that. This means that a pipe could still block since you could
- be trying to write more to the pipe than is available in the
- buffer but that is the hazard of select(). */
+ /* WriteQuotaAvailable is decremented by the number of bytes requested
+ by a blocking reader on the other side of the pipe. Cygwin readers
+ are serialized and never request a number of bytes equivalent to the
+ full buffer size. So WriteQuotaAvailable is 0 only if either the
+ read buffer on the other side is really full, or if we have non-Cygwin
+ readers. */
if (fpli.WriteQuotaAvailable > 0)
{
paranoid_printf ("fd %d, %s, write: size %u, avail %u", fd,
fpli.WriteQuotaAvailable);
return 1;
}
- /* 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. */
- if (fpli.OutboundQuota < PIPE_BUF
- && fpli.WriteQuotaAvailable == fpli.OutboundQuota)
- {
- select_printf ("fd, %s, write tiny pipe: size %u, avail %u",
- fd, fh->get_name (), fpli.OutboundQuota,
- fpli.WriteQuotaAvailable);
- return 1;
- }
+ /* TODO: Buffer really full or non-Cygwin reader? */
}
else if (fpli.ReadDataAvailable)
{