Cygwin: implement extensible clock interface

- Drop hires_[nm]s clocks, rename hires.h to clock.h.

- Implement clk_t class as an extensible clock class in new file clock.cc.

- Introduce get_clock(clock_id) returning a pointer to the clk_t instance
  for clock_id.  Provide the following methods along the lines of the former
  hires classes:

	void		clk_t::nsecs (struct timespec *);
	ULONGLONG	clk_t::nsecs ();
	LONGLONG	clk_t::usecs ();
	LONGLONG	clk_t::msecs ();
	void 		clk_t::resolution (struct timespec *);

- Add CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_COARSE
  and CLOCK_BOOTTIME clocks.

- Allow clock_nanosleep, pthread_condattr_setclock and timer_create to use
  all new clocks (both clocks should be usable with a small tweak, though).

- Bump DLL major version to 2.12.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/clock.h

@@ -0,0 +1,149 @@
+/* clock.h: Definitions for clock calculations
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#ifndef __CLOCK_H__
+#define __CLOCK_H__
+
+#include <mmsystem.h>
+
+/* Must be a power of 2. */
+#define MAX_CLOCKS		 (8)
+
+/* Conversions for per-process and per-thread clocks */
+#define CLOCKID(cid) \
+		((cid) % MAX_CLOCKS)
+#define PID_TO_CLOCKID(pid) \
+		((pid) * MAX_CLOCKS + CLOCK_PROCESS_CPUTIME_ID)
+#define CLOCKID_TO_PID(cid) \
+		(((cid) - CLOCK_PROCESS_CPUTIME_ID) / MAX_CLOCKS)
+#define CLOCKID_IS_PROCESS(cid) \
+		(CLOCKID(cid) == CLOCK_PROCESS_CPUTIME_ID)
+#define THREADID_TO_CLOCKID(tid) \
+		((tid) * MAX_CLOCKS + CLOCK_THREAD_CPUTIME_ID)
+#define CLOCKID_TO_THREADID(cid) \
+		(((cid) - CLOCK_THREAD_CPUTIME_ID) / MAX_CLOCKS)
+#define CLOCKID_IS_THREAD(cid) \
+		(CLOCKID(cid) == CLOCK_THREAD_CPUTIME_ID)
+
+/* Largest delay in ms for sleep and alarm calls.
+   Allow actual delay to exceed requested delay by 10 s.
+   Express as multiple of 1000 (i.e. seconds) + max resolution
+   The tv_sec argument in timeval structures cannot exceed
+   CLOCK_DELAY_MAX / 1000 - 1, so that adding fractional part
+   and rounding won't exceed CLOCK_DELAY_MAX */
+#define CLOCK_DELAY_MAX ((((UINT_MAX - 10000) / 1000) * 1000) + 10)
+
+/* 100ns difference between Windows and UNIX timebase. */
+#define FACTOR (0x19db1ded53e8000LL)
+/* # of nanosecs per second. */
+#define NSPERSEC (1000000000LL)
+/* # of 100ns intervals per second. */
+#define NS100PERSEC (10000000LL)
+/* # of microsecs per second. */
+#define USPERSEC (1000000LL)
+/* # of millisecs per second. */
+#define MSPERSEC (1000L)
+
+class clk_t
+{
+ protected:
+  LONG inited;
+  LONGLONG ticks_per_sec;
+  virtual void init ();
+  virtual int now (clockid_t, struct timespec *) = 0;
+
+ public:
+  int nsecs (clockid_t _id, struct timespec *ts)
+  {
+    return now (_id, ts);
+  }
+  void resolution (struct timespec *);
+
+  /* shortcuts for non-process/thread clocks */
+  void nsecs (struct timespec *ts) { nsecs (0, ts); }
+  ULONGLONG nsecs ()
+  {
+    struct timespec ts;
+    nsecs (&ts);
+    return (ULONGLONG) ts.tv_sec * NSPERSEC + ts.tv_nsec;
+  }
+  LONGLONG n100secs ()
+  {
+    struct timespec ts;
+    nsecs (&ts);
+    return ts.tv_sec * NS100PERSEC + ts.tv_nsec / (NSPERSEC/NS100PERSEC);
+  }
+  LONGLONG usecs ()
+  {
+    struct timespec ts;
+    nsecs (&ts);
+    return ts.tv_sec * USPERSEC + ts.tv_nsec / (NSPERSEC/USPERSEC);
+  }
+  LONGLONG msecs ()
+  {
+    struct timespec ts;
+    nsecs (&ts);
+    return ts.tv_sec * MSPERSEC + ts.tv_nsec / (NSPERSEC/MSPERSEC);
+  }
+};
+
+class clk_realtime_coarse_t : public clk_t
+{
+  virtual int now (clockid_t, struct timespec *);
+};
+
+class clk_realtime_t : public clk_t
+{
+  virtual void init ();
+  virtual int now (clockid_t, struct timespec *);
+};
+
+class clk_process_t : public clk_t
+{
+  virtual int now (clockid_t, struct timespec *);
+};
+
+class clk_thread_t : public clk_t
+{
+  virtual int now (clockid_t, struct timespec *);
+};
+
+class clk_monotonic_t : public clk_t
+{
+ protected:
+  virtual void init ();
+ private:
+  virtual int now (clockid_t, struct timespec *);
+};
+
+class clk_monotonic_coarse_t : public clk_t
+{
+  virtual int now (clockid_t, struct timespec *);
+};
+
+class clk_boottime_t : public clk_monotonic_t
+{
+  virtual int now (clockid_t, struct timespec *);
+};
+
+clk_t *get_clock (clockid_t clk_id);
+
+/* Compute interval between two timespec timestamps: ts1  = ts1 - ts0. */
+static inline void
+ts_diff (const struct timespec &ts0, struct timespec &ts1)
+{
+  ts1.tv_nsec -= ts0.tv_nsec;
+  if (ts1.tv_nsec < 0)
+    {
+      ts1.tv_nsec += NSPERSEC;
+      --ts1.tv_sec;
+    }
+  ts1.tv_sec -= ts0.tv_sec;
+}
+
+#endif /*__CLOCK_H__*/