/* 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, 2004-2014 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 native Windows 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
- can't sleep more than 49.7 days (2**32 milliseconds). Solve this
- by breaking the sleep up into smaller chunks. Verify that time_t
- is large enough. */
- verify (TYPE_MAXIMUM (time_t) / 49 / 24 / 60 / 60);
- const time_t limit = 49 * 24 * 60 * 60;
- time_t seconds = requested_delay->tv_sec;
- struct timespec intermediate;
- intermediate.tv_nsec = 0;
-
- while (limit < seconds)
+ /* nanosleep mishandles large sleeps due to internal overflow problems.
+ The worst known case of this is Linux 2.6.9 with glibc 2.3.4, which
+ can't sleep more than 24.85 days (2^31 milliseconds). Similarly,
+ cygwin 1.5.x, which can't sleep more than 49.7 days (2^32 milliseconds).
+ Solve this by breaking the sleep up into smaller chunks. */
+
+ if (requested_delay->tv_nsec < 0 || BILLION <= requested_delay->tv_nsec)
{
- int result;
- intermediate.tv_sec = limit;
- result = nanosleep (&intermediate, remaining_delay);
- seconds -= limit;
- if (result)
+ errno = EINVAL;
+ return -1;
+ }
+
+ {
+ /* Verify that time_t is large enough. */
+ verify (TYPE_MAXIMUM (time_t) / 24 / 24 / 60 / 60);
+ const time_t limit = 24 * 24 * 60 * 60;
+ time_t seconds = requested_delay->tv_sec;
+ struct timespec intermediate;
+ intermediate.tv_nsec = requested_delay->tv_nsec;
+
+ while (limit < seconds)
+ {
+ int result;
+ intermediate.tv_sec = limit;
+ result = nanosleep (&intermediate, remaining_delay);
+ seconds -= limit;
+ if (result)
+ {
+ if (remaining_delay)
+ remaining_delay->tv_sec += seconds;
+ return result;
+ }
+ intermediate.tv_nsec = 0;
+ }
+ intermediate.tv_sec = seconds;
+ return nanosleep (&intermediate, remaining_delay);
+ }
+}
+
+#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Windows platforms. */
+
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+
+/* The Windows API 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)
{
- if (remaining_delay)
+ /* 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))
{
- remaining_delay->tv_sec += seconds;
- remaining_delay->tv_nsec += requested_delay->tv_nsec;
- if (BILLION <= requested_delay->tv_nsec)
+ /* 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 (;;)
{
- remaining_delay->tv_sec++;
- remaining_delay->tv_nsec -= BILLION;
+ 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;
}
- return result;
}
}
- intermediate.tv_sec = seconds;
- intermediate.tv_nsec = requested_delay->tv_nsec;
- return nanosleep (&intermediate, remaining_delay);
+ /* 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
tv_delay.tv_usec = (ts_delay->tv_nsec + 999) / 1000;
if (tv_delay.tv_usec == 1000000)
{
- time_t t1 = tv_delay.tv_sec + 1;
- if (t1 < tv_delay.tv_sec)
+ if (tv_delay.tv_sec == TYPE_MAXIMUM (time_t))
tv_delay.tv_usec = 1000000 - 1; /* close enough */
else
{
- tv_delay.tv_sec = t1;
+ tv_delay.tv_sec++;
tv_delay.tv_usec = 0;
}
}
*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;
projects / gnulib.git / blobdiff