Move Windows timer utility functions from PA backend into libpbd

1 files changed, 86 insertions, 0 deletions

diff --git a/libs/pbd/pbd/windows_timer_utils.h b/libs/pbd/pbd/windows_timer_utils.h
new file mode 100644
index 0000000000..2e4f800bd5
--- /dev/null
+++ b/libs/pbd/pbd/windows_timer_utils.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2015 Tim Mayberry <mojofunk@gmail.com>
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef PBD_WINDOWS_TIMER_UTILS_H
+#define PBD_WINDOWS_TIMER_UTILS_H
+
+#include <stdint.h>
+
+namespace PBD {
+
+namespace MMTIMERS {
+
+/**
+ * Set the minimum Multimedia Timer resolution as supported by the system
+ * @return true if min timer resolution was successfully set
+ *
+ * Call reset_resolution to restore old timer resolution
+ */
+bool set_min_resolution ();
+
+/**
+ * Get current Multimedia Timer resolution
+ * @return true if getting the timer value was successful
+ */
+bool get_resolution(uint32_t& timer_resolution_us);
+
+/**
+ * Set current Multimedia Timer resolution
+ * @return true if setting the timer value was successful
+ */
+bool set_resolution(uint32_t timer_resolution_us);
+
+/**
+ * Reset the Multimedia Timer back to what it was originally before
+ * setting the timer resolution.
+ */
+bool reset_resolution ();
+
+} // namespace MMTIMERS
+
+namespace QPC {
+
+/**
+ * @return true if QueryPerformanceCounter is usable as a timer source
+ */
+bool get_timer_valid ();
+
+/**
+ * @return the value of the performance counter converted to microseconds
+ *
+ * If get_counter_valid 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 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 get_microseconds ();
+
+} // namespace PBD
+
+#endif // PBD_WINDOWS_TIMER_UTILS_H