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authorMiles Bader <miles@gnu.org>1996-07-20 17:33:17 +0000
committerMiles Bader <miles@gnu.org>1996-07-20 17:33:17 +0000
commitcbd96c3385df1e0a0c43d094c2d5ae994744c37d (patch)
tree3585ef7d2d8fa03601ec8470e7ec10335735b1bd /sysdeps
parentf0097fa0df4898e1bd1ad06a5b3aadeda19fa173 (diff)
(__select): Don't poll on the last call __io_select unless there's only a single descriptor, as each descriptor now has its own reply port. If there is only a single descriptor, just use its reply port for everything and don't bother creating the port set.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/mach/hurd/select.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/sysdeps/mach/hurd/select.c b/sysdeps/mach/hurd/select.c
index 188f65b3c0..60bb489612 100644
--- a/sysdeps/mach/hurd/select.c
+++ b/sysdeps/mach/hurd/select.c
@@ -126,15 +126,22 @@ DEFUN(__select, (nfds, readfds, writefds, exceptfds, timeout),
int type = d[i].type;
d[i].reply_port = __mach_reply_port ();
err = __io_select (d[i].io_port, d[i].reply_port,
- /* Poll for each but the last. */
- (i == lastfd && got == 0) ? to : 0,
+ /* Poll only when there's a single descriptor. */
+ (firstfd == lastfd) ? to : 0,
&type);
switch (err)
{
case MACH_RCV_TIMED_OUT:
/* No immediate response. This is normal. */
err = 0;
- if (got == 0)
+ if (firstfd == lastfd)
+ /* When there's a single descriptor, we don't need a portset,
+ so just pretend we have one, but really use the single reply
+ port. */
+ portset = d[i].reply_port;
+ else if (got == 0)
+ /* We've got multiple reply ports, so we need a port set to
+ multiplex them. */
{
/* We will wait again for a reply later. */
if (portset == MACH_PORT_NULL)
@@ -276,7 +283,10 @@ DEFUN(__select, (nfds, readfds, writefds, exceptfds, timeout),
for (i = firstfd; i <= lastfd; ++i)
if (d[i].type)
__mach_port_destroy (__mach_task_self (), d[i].reply_port);
- if (portset != MACH_PORT_NULL)
+ if (firstfd != lastfd && portset != MACH_PORT_NULL)
+ /* Destroy PORTSET, but only if it's not actually the reply port for a
+ single descriptor (in which case it's destroyed in the previous loop;
+ not doing it here is just a bit more efficient). */
__mach_port_destroy (__mach_task_self (), portset);
if (err)