This is the O3D source tree's initial commit to the Chromium tree. It

is not built or referenced at all by the chrome build yet, and doesn't 
yet build in it's new home.  We'll change that shortly.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@17035 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 106 insertions, 0 deletions

diff --git a/o3d/statsreport/common/highres_timer-linux.h b/o3d/statsreport/common/highres_timer-linux.h
new file mode 100644
index 0000000..7574a8f
--- /dev/null
+++ b/o3d/statsreport/common/highres_timer-linux.h
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+/*
+ * Copyright 2009, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#ifndef O3D_STATSREPORT_COMMON_HIGHRES_TIMER_LINUX_H_
+#define O3D_STATSREPORT_COMMON_HIGHRES_TIMER_LINUX_H_
+
+#include "base/basictypes.h"
+
+#include <sys/time.h>
+
+const uint64 MICROS_IN_SECOND = 1000000L;
+
+// A handy class for reliably measuring wall-clock time with decent resolution.
+//
+// We want to measure time with high resolution on Linux. What to do?
+//
+// RDTSC? Sure, but how do you convert it to wall clock time?
+// clock_gettime? It's not in all Linuxes.
+//
+// Let's just use gettimeofday; it's good to the microsecond.
+class HighresTimer {
+ public:
+  // Captures the current start time
+  HighresTimer();
+
+  // Captures the current tick, can be used to reset a timer for reuse.
+  void Start();
+
+  // Returns the elapsed ticks with full resolution
+  uint64 GetElapsedTicks() const;
+
+  // Returns the elapsed time in milliseconds, rounded to the nearest
+  // millisecond.
+  uint64 GetElapsedMs() const;
+
+  // Returns the elapsed time in seconds, rounded to the nearest second.
+  uint64 GetElapsedSec() const;
+
+  uint64 start_ticks() const { return start_ticks_; }
+
+  // Returns timer frequency from cache, should be less
+  // overhead than ::QueryPerformanceFrequency
+  static uint64 GetTimerFrequency();
+  // Returns current ticks
+  static uint64 GetCurrentTicks();
+
+ private:
+  // Captured start time
+  uint64 start_ticks_;
+};
+
+inline HighresTimer::HighresTimer() {
+  Start();
+}
+
+inline void HighresTimer::Start() {
+  start_ticks_ = GetCurrentTicks();
+}
+
+inline uint64 HighresTimer::GetTimerFrequency() {
+  // fixed; one "tick" is one microsecond
+
+  return MICROS_IN_SECOND;
+}
+
+inline uint64 HighresTimer::GetCurrentTicks() {
+  timeval tv;
+  (void)gettimeofday(&tv, 0);
+
+  return tv.tv_sec * MICROS_IN_SECOND + tv.tv_usec;
+}
+
+inline uint64 HighresTimer::GetElapsedTicks() const {
+  return start_ticks_ - GetCurrentTicks();
+}
+
+#endif  // O3D_STATSREPORT_COMMON_HIGHRES_TIMER_LINUX_H_