/* Provide a replacement for the POSIX nanosleep function.
- Copyright (C) 1999, 2000, 2002, 2004, 2005, 2006, 2007, 2008, 2009
- Free Software Foundation, Inc.
+ Copyright (C) 1999-2000, 2002, 2004-2010 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-/* written by Jim Meyering */
+/* written by Jim Meyering
+ and Bruno Haible for the Woe32 part */
#include <config.h>
#include <unistd.h>
-#undef nanosleep
enum { BILLION = 1000 * 1000 * 1000 };
#if HAVE_BUG_BIG_NANOSLEEP
int
-rpl_nanosleep (const struct timespec *requested_delay,
- struct timespec *remaining_delay)
+nanosleep (const struct timespec *requested_delay,
+ struct timespec *remaining_delay)
+#undef nanosleep
{
/* nanosleep mishandles large sleeps due to internal overflow
problems. The worst known case of this is cygwin 1.5.x, which
return nanosleep (&intermediate, remaining_delay);
}
+#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Windows platforms. */
+
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+
+/* The Win32 function Sleep() has a resolution of about 15 ms and takes
+ at least 5 ms to execute. We use this function for longer time periods.
+ Additionally, we use busy-looping over short time periods, to get a
+ resolution of about 0.01 ms. In order to measure such short timespans,
+ we use the QueryPerformanceCounter() function. */
+
+int
+nanosleep (const struct timespec *requested_delay,
+ struct timespec *remaining_delay)
+{
+ static bool initialized;
+ /* Number of performance counter increments per nanosecond,
+ or zero if it could not be determined. */
+ static double ticks_per_nanosecond;
+
+ if (requested_delay->tv_nsec < 0 || BILLION <= requested_delay->tv_nsec)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* For requested delays of one second or more, 15ms resolution is
+ sufficient. */
+ if (requested_delay->tv_sec == 0)
+ {
+ if (!initialized)
+ {
+ /* Initialize ticks_per_nanosecond. */
+ LARGE_INTEGER ticks_per_second;
+
+ if (QueryPerformanceFrequency (&ticks_per_second))
+ ticks_per_nanosecond =
+ (double) ticks_per_second.QuadPart / 1000000000.0;
+
+ initialized = true;
+ }
+ if (ticks_per_nanosecond)
+ {
+ /* QueryPerformanceFrequency worked. We can use
+ QueryPerformanceCounter. Use a combination of Sleep and
+ busy-looping. */
+ /* Number of milliseconds to pass to the Sleep function.
+ Since Sleep can take up to 8 ms less or 8 ms more than requested
+ (or maybe more if the system is loaded), we subtract 10 ms. */
+ int sleep_millis = (int) requested_delay->tv_nsec / 1000000 - 10;
+ /* Determine how many ticks to delay. */
+ LONGLONG wait_ticks = requested_delay->tv_nsec * ticks_per_nanosecond;
+ /* Start. */
+ LARGE_INTEGER counter_before;
+ if (QueryPerformanceCounter (&counter_before))
+ {
+ /* Wait until the performance counter has reached this value.
+ We don't need to worry about overflow, because the performance
+ counter is reset at reboot, and with a frequency of 3.6E6
+ ticks per second 63 bits suffice for over 80000 years. */
+ LONGLONG wait_until = counter_before.QuadPart + wait_ticks;
+ /* Use Sleep for the longest part. */
+ if (sleep_millis > 0)
+ Sleep (sleep_millis);
+ /* Busy-loop for the rest. */
+ for (;;)
+ {
+ LARGE_INTEGER counter_after;
+ if (!QueryPerformanceCounter (&counter_after))
+ /* QueryPerformanceCounter failed, but succeeded earlier.
+ Should not happen. */
+ break;
+ if (counter_after.QuadPart >= wait_until)
+ /* The requested time has elapsed. */
+ break;
+ }
+ goto done;
+ }
+ }
+ }
+ /* Implementation for long delays and as fallback. */
+ Sleep (requested_delay->tv_sec * 1000 + requested_delay->tv_nsec / 1000000);
+
+ done:
+ /* Sleep is not interruptible. So there is no remaining delay. */
+ if (remaining_delay != NULL)
+ {
+ remaining_delay->tv_sec = 0;
+ remaining_delay->tv_nsec = 0;
+ }
+ return 0;
+}
+
#else
+/* Unix platforms lacking nanosleep. */
/* Some systems (MSDOS) don't have SIGCONT.
Using SIGTERM here turns the signal-handling code below
{
time_t t1 = tv_delay.tv_sec + 1;
if (t1 < tv_delay.tv_sec)
- tv_delay.tv_usec = 1000000 - 1; /* close enough */
+ tv_delay.tv_usec = 1000000 - 1; /* close enough */
else
- {
- tv_delay.tv_sec = t1;
- tv_delay.tv_usec = 0;
- }
+ {
+ tv_delay.tv_sec = t1;
+ tv_delay.tv_usec = 0;
+ }
}
select (0, NULL, NULL, NULL, &tv_delay);
}
*REMAINING_DELAY part isn't implemented yet. */
int
-rpl_nanosleep (const struct timespec *requested_delay,
- struct timespec *remaining_delay)
+nanosleep (const struct timespec *requested_delay,
+ struct timespec *remaining_delay)
{
static bool initialized;
sigaction (SIGCONT, NULL, &oldact);
if (get_handler (&oldact) != SIG_IGN)
- {
- struct sigaction newact;
-
- newact.sa_handler = sighandler;
- sigemptyset (&newact.sa_mask);
- newact.sa_flags = 0;
- sigaction (SIGCONT, &newact, NULL);
- }
+ {
+ struct sigaction newact;
+
+ newact.sa_handler = sighandler;
+ sigemptyset (&newact.sa_mask);
+ newact.sa_flags = 0;
+ sigaction (SIGCONT, &newact, NULL);
+ }
initialized = true;
}
{
/* Calculate time remaining. */
/* FIXME: the code in sleep doesn't use this, so there's no
- rush to implement it. */
+ rush to implement it. */
errno = EINTR;
}
projects / gnulib.git / blobdiff