put get_microseconds() into PBD namsepace

This implementation is a blend of the two previously in libs/ardour/globals.cc
and libs/pbd/window_timer_utils.cc

libs/pbd/pbd.cc

@@ -36,6 +36,7 @@
 #include "pbd/id.h"
 #include "pbd/enumwriter.h"
 #include "pbd/fpu.h"
+#include "pbd/microseconds.h"
 #include "pbd/xml++.h"
 
 #ifdef PLATFORM_WINDOWS
@@ -80,6 +81,8 @@ PBD::init ()
 		return true;
 	}
 
+	microsecond_timer_init ();
+
 #ifdef PLATFORM_WINDOWS
 	// Essential!!  Make sure that any files used by Ardour
 	//              will be created or opened in BINARY mode!

libs/pbd/pbd/windows_timer_utils.h

@@ -59,46 +59,6 @@ bool LIBPBD_API reset_resolution();
 
 } // namespace MMTIMERS
 
-namespace QPC {
-
-/**
- * Initialize the QPC timer, must be called before QPC::get_microseconds will
- * return a valid value.
- * @return true if QPC timer is usable, use check_timer_valid to try to check
- * if it is monotonic.
- */
-bool LIBPBD_API initialize ();
-
-/**
- * @return true if QueryPerformanceCounter is usable as a timer source
- * This should always return true for systems > XP as those versions of windows
- * have there own tests to check timer validity and will select an appropriate
- * timer source. This check is not conclusive and there are probably conditions
- * under which this check will return true but the timer is not monotonic.
- */
-bool LIBPBD_API check_timer_valid ();
-
-/**
- * @return the value of the performance counter converted to microseconds
- *
- * If initialize returns true then get_microseconds will always return a
- * positive value. If QPC is not supported(OS < XP) then -1 is returned but the
- * MS docs say that this won't occur for systems >= XP.
- */
-int64_t LIBPBD_API get_microseconds ();
-
-} // namespace QPC
-
-/**
- * The highest resolution timer source provided by the system. On Vista and
- * above this is the value returned by QueryPerformanceCounter(QPC). On XP,
- * this will QPC if supported or otherwise g_get_monotonic_time will be used.
- *
- * @return A timer value in microseconds or -1 in the event that the reading
- * the timer source fails.
- */
-int64_t LIBPBD_API get_microseconds ();
-
 } // namespace PBD
 
 #endif // PBD_WINDOWS_TIMER_UTILS_H

libs/pbd/windows_timer_utils.cc

@@ -111,81 +111,3 @@ reset_resolution ()
 
 } // namespace MMTIMERS
 
-namespace {
-
-static double timer_rate_us = 0.0;
-
-static
-bool
-test_qpc_validity ()
-{
-	int64_t last_timer_val = PBD::QPC::get_microseconds ();
-	if (last_timer_val < 0) return false;
-
-	for (int i = 0; i < 100000; ++i) {
-		int64_t timer_val = PBD::QPC::get_microseconds ();
-		if (timer_val < 0) return false;
-		// try and test for non-syncronized TSC(AMD K8/etc)
-		if (timer_val < last_timer_val) return false;
-		last_timer_val = timer_val;
-	}
-	return true;
-}
-
-} // anon namespace
-
-namespace QPC {
-
-bool
-check_timer_valid ()
-{
-	if (!timer_rate_us) {
-		return false;
-	}
-	return test_qpc_validity ();
-}
-
-bool
-initialize ()
-{
-	LARGE_INTEGER freq;
-	if (!QueryPerformanceFrequency(&freq) || freq.QuadPart < 1) {
-		info << X_("Failed to determine frequency of QPC\n") << endmsg;
-		timer_rate_us = 0;
-	} else {
-		timer_rate_us = 1000000.0 / freq.QuadPart;
-	}
-	info << string_compose(X_("QPC timer microseconds per tick: %1\n"),
-	                       timer_rate_us) << endmsg;
-	return !timer_rate_us;
-}
-
-int64_t
-get_microseconds ()
-{
-	LARGE_INTEGER current_val;
-
-	if (timer_rate_us) {
-		// MS docs say this will always succeed for systems >= XP but it may
-		// not return a monotonic value with non-invariant TSC's etc
-		if (QueryPerformanceCounter(&current_val) != 0) {
-			return (int64_t)(current_val.QuadPart * timer_rate_us);
-		}
-	}
-	DEBUG_TIMING ("Could not get QPC timer\n");
-	return -1;
-}
-
-} // namespace QPC
-
-int64_t
-get_microseconds ()
-{
-	if (timer_rate_us) {
-		return QPC::get_microseconds ();
-	}
-	// For XP systems that don't support a high-res performance counter
-	return g_get_monotonic_time ();
-}
-
-} // namespace PBD

libs/pbd/wscript

@@ -56,6 +56,7 @@ libpbd_sources = [
     'localtime_r.cc',
     'malign.cc',
     'md5.cc',
+    'microseconds.cc',
     'mountpoint.cc',
     'openuri.cc',
     'pathexpand.cc',