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authorAdam Jackson <ajax@redhat.com>2009-02-23 16:01:14 -0500
committerAdam Jackson <ajax@redhat.com>2009-02-23 16:01:14 -0500
commit75af278861dcd96124544d3c2889028578708317 (patch)
tree0d4640c5ad80f0edec60e418fe498fa91cf1ceb6
parentRevert "Remove useless include directive." (diff)
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Open with O_NONBLOCK, and simplify EvdevReadInput to match.
xf86WaitForInput() would call select() with zero timeout to discover if more input was ready. But we know that's always true at least once, since we're only ever called from the sigio handler (if silken is active) or from the main loop (if it's not and we selected readable). With nonblocking IO we can just spin around until we hit EAGAIN, which gets us down to n+1 syscalls per event instead of 2n.
-rw-r--r--src/evdev.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/src/evdev.c b/src/evdev.c
index 73291d7..887175b 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -295,7 +295,7 @@ EvdevReopenTimer(OsTimerPtr timer, CARD32 time, pointer arg)
EvdevPtr pEvdev = pInfo->private;
do {
- pInfo->fd = open(pEvdev->device, O_RDWR, 0);
+ pInfo->fd = open(pEvdev->device, O_RDWR | O_NONBLOCK, 0);
} while (pInfo->fd < 0 && errno == EINTR);
if (pInfo->fd != -1)
@@ -347,9 +347,12 @@ EvdevReadInput(InputInfoPtr pInfo)
tmp = 0;
abs = 0;
- while (xf86WaitForInput (pInfo->fd, 0) > 0) {
+ while (1) {
len = read(pInfo->fd, &ev, sizeof ev);
if (len != sizeof ev) {
+ if (errno == EAGAIN)
+ break;
+
/* The kernel promises that we always only read a complete
* event, so len != sizeof ev is an error. */
xf86Msg(X_ERROR, "%s: Read error: %s\n", pInfo->name, strerror(errno));
@@ -1531,7 +1534,7 @@ EvdevPreInit(InputDriverPtr drv, IDevPtr dev, int flags)
xf86Msg(X_CONFIG, "%s: Device: \"%s\"\n", pInfo->name, device);
do {
- pInfo->fd = open(device, O_RDWR, 0);
+ pInfo->fd = open(device, O_RDWR | O_NONBLOCK, 0);
} while (pInfo->fd < 0 && errno == EINTR);
if (pInfo->fd < 0) {