[PATCH xserver 23/25] xfree86: Switch from select(2) to poll(2)
Keith Packard
keithp at keithp.com
Wed May 25 05:39:00 UTC 2016
xf86WaitForInput and the xf86 SIGIO handling code.
Signed-off-by: Keith Packard <keithp at keithp.com>
---
hw/xfree86/common/xf86Events.c | 1 -
hw/xfree86/os-support/shared/posix_tty.c | 33 ++++++-----------
hw/xfree86/os-support/shared/sigio.c | 63 +++++++++++++++++++++-----------
3 files changed, 52 insertions(+), 45 deletions(-)
diff --git a/hw/xfree86/common/xf86Events.c b/hw/xfree86/common/xf86Events.c
index b12766f..9a8f432 100644
--- a/hw/xfree86/common/xf86Events.c
+++ b/hw/xfree86/common/xf86Events.c
@@ -54,7 +54,6 @@
#endif
#include <X11/X.h>
-#include <X11/Xpoll.h>
#include <X11/Xproto.h>
#include <X11/Xatom.h>
#include "misc.h"
diff --git a/hw/xfree86/os-support/shared/posix_tty.c b/hw/xfree86/os-support/shared/posix_tty.c
index 6e2af00..d5a70ba 100644
--- a/hw/xfree86/os-support/shared/posix_tty.c
+++ b/hw/xfree86/os-support/shared/posix_tty.c
@@ -57,6 +57,7 @@
#endif
#include <X11/X.h>
+#include <poll.h>
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"
@@ -387,26 +388,19 @@ xf86CloseSerial(int fd)
int
xf86WaitForInput(int fd, int timeout)
{
- fd_set readfds;
- struct timeval to;
int r;
+ struct pollfd poll_fd;
- FD_ZERO(&readfds);
+ poll_fd.fd = fd;
+ poll_fd.events = POLLIN;
if (fd >= 0) {
- FD_SET(fd, &readfds);
- }
-
- to.tv_sec = timeout / 1000000;
- to.tv_usec = timeout % 1000000;
-
- if (fd >= 0) {
- SYSCALL(r = select(FD_SETSIZE, &readfds, NULL, NULL, &to));
+ SYSCALL(r = poll(&poll_fd, 1, timeout));
}
else {
- SYSCALL(r = select(FD_SETSIZE, NULL, NULL, NULL, &to));
+ SYSCALL(r = poll(&poll_fd, 0, timeout));
}
- xf86ErrorFVerb(9, "select returned %d\n", r);
+ xf86ErrorFVerb(9, "poll returned %d\n", r);
return r;
}
@@ -423,8 +417,7 @@ xf86SerialSendBreak(int fd, int duration)
int
xf86FlushInput(int fd)
{
- fd_set fds;
- struct timeval timeout;
+ struct pollfd poll_fd;
/* this needs to be big enough to flush an evdev event. */
char c[256];
@@ -432,15 +425,11 @@ xf86FlushInput(int fd)
if (tcflush(fd, TCIFLUSH) == 0)
return 0;
- timeout.tv_sec = 0;
- timeout.tv_usec = 0;
- FD_ZERO(&fds);
- FD_SET(fd, &fds);
- while (select(FD_SETSIZE, &fds, NULL, NULL, &timeout) > 0) {
+ poll_fd.fd = fd;
+ poll_fd.events = POLLIN;
+ while (poll(&poll_fd, 1, 0) > 0) {
if (read(fd, &c, sizeof(c)) < 1)
return 0;
- FD_ZERO(&fds);
- FD_SET(fd, &fds);
}
return 0;
}
diff --git a/hw/xfree86/os-support/shared/sigio.c b/hw/xfree86/os-support/shared/sigio.c
index e0cd7a8..53ebacf 100644
--- a/hw/xfree86/os-support/shared/sigio.c
+++ b/hw/xfree86/os-support/shared/sigio.c
@@ -57,6 +57,7 @@
#endif
#include <X11/X.h>
+#include <poll.h>
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"
@@ -83,8 +84,35 @@ typedef struct _xf86SigIOFunc {
static Xf86SigIOFunc xf86SigIOFuncs[MAX_FUNCS];
static int xf86SigIOMax;
-static int xf86SigIOMaxFd;
-static fd_set xf86SigIOMask;
+static struct pollfd *xf86SigIOFds;
+static int xf86SigIONum;
+
+static Bool
+xf86SigIOAdd(int fd)
+{
+ struct pollfd *n;
+
+ n = realloc(xf86SigIOFds, (xf86SigIONum + 1) * sizeof (struct pollfd));
+ if (!n)
+ return FALSE;
+
+ n[xf86SigIONum].fd = fd;
+ n[xf86SigIONum].events = POLLIN;
+ xf86SigIOFds = n;
+ return TRUE;
+}
+
+static void
+xf86SigIORemove(int fd)
+{
+ int i;
+ for (i = 0; i < xf86SigIONum; i++)
+ if (xf86SigIOFds[i].fd == fd) {
+ memmove(&xf86SigIOFds[i], &xf86SigIOFds[i+1], (xf86SigIONum - i - 1) * sizeof (struct pollfd));
+ xf86SigIONum--;
+ break;
+ }
+}
/*
* SIGIO gives no way of discovering which fd signalled, select
@@ -93,24 +121,22 @@ static fd_set xf86SigIOMask;
static void
xf86SIGIO(int sig)
{
- int i;
- fd_set ready;
- struct timeval to;
+ int i, f;
int save_errno = errno; /* do not clobber the global errno */
int r;
inSignalContext = TRUE;
- ready = xf86SigIOMask;
- to.tv_sec = 0;
- to.tv_usec = 0;
- SYSCALL(r = select(xf86SigIOMaxFd, &ready, 0, 0, &to));
- for (i = 0; r > 0 && i < xf86SigIOMax; i++)
- if (xf86SigIOFuncs[i].f && FD_ISSET(xf86SigIOFuncs[i].fd, &ready)) {
- (*xf86SigIOFuncs[i].f) (xf86SigIOFuncs[i].fd,
- xf86SigIOFuncs[i].closure);
+ SYSCALL(r = poll(xf86SigIOFds, xf86SigIONum, 0));
+ for (f = 0; r > 0 && f < xf86SigIONum; f++) {
+ if (xf86SigIOFds[f].revents & POLLIN) {
+ for (i = 0; i < xf86SigIOMax; i++)
+ if (xf86SigIOFuncs[i].f && xf86SigIOFuncs[i].fd == xf86SigIOFds[f].fd)
+ (*xf86SigIOFuncs[i].f) (xf86SigIOFuncs[i].fd,
+ xf86SigIOFuncs[i].closure);
r--;
}
+ }
if (r > 0) {
xf86Msg(X_ERROR, "SIGIO %d descriptors not handled\n", r);
}
@@ -206,9 +232,7 @@ xf86InstallSIGIOHandler(int fd, void (*f) (int, void *), void *closure)
xf86SigIOFuncs[i].f = f;
if (i >= xf86SigIOMax)
xf86SigIOMax = i + 1;
- if (fd >= xf86SigIOMaxFd)
- xf86SigIOMaxFd = fd + 1;
- FD_SET(fd, &xf86SigIOMask);
+ xf86SigIOAdd(fd);
xf86ReleaseSIGIO();
return 1;
}
@@ -229,14 +253,12 @@ xf86RemoveSIGIOHandler(int fd)
struct sigaction osa;
int i;
int max;
- int maxfd;
int ret;
if (!xf86Info.useSIGIO)
return 0;
max = 0;
- maxfd = -1;
ret = 0;
for (i = 0; i < MAX_FUNCS; i++) {
if (xf86SigIOFuncs[i].f) {
@@ -244,13 +266,11 @@ xf86RemoveSIGIOHandler(int fd)
xf86SigIOFuncs[i].f = 0;
xf86SigIOFuncs[i].fd = 0;
xf86SigIOFuncs[i].closure = 0;
- FD_CLR(fd, &xf86SigIOMask);
+ xf86SigIORemove(fd);
ret = 1;
}
else {
max = i + 1;
- if (xf86SigIOFuncs[i].fd >= maxfd)
- maxfd = xf86SigIOFuncs[i].fd + 1;
}
}
}
@@ -267,7 +287,6 @@ xf86RemoveSIGIOHandler(int fd)
}
#endif
xf86SigIOMax = max;
- xf86SigIOMaxFd = maxfd;
if (!max) {
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGIO);
--
2.8.0.rc3
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