Changeset 88199 in webkit

Timestamp:

Jun 6, 2011, 4:04:58 PM (15 years ago)

Author:

simonjam@chromium.org

Message:

2011-06-06 James Simonsen <​simonjam@chromium.org>

Reviewed by James Robinson.

Add monotonicallyIncreasingTime() to get monotonically increasing time
​https://bugs.webkit.org/show_bug.cgi?id=37743

• wtf/CurrentTime.cpp: Add monotonicallyIncreasingTime() for mac and a fallback implementation that just wraps currentTime(). (WTF::monotonicallyIncreasingTime):
• wtf/CurrentTime.h: Add monotonicallyIncreasingTime().

2011-06-06 James Simonsen <​simonjam@chromium.org>

Reviewed by James Robinson.

Add monotonicallyIncreasingTime() to get monotonically increasing time
​https://bugs.webkit.org/show_bug.cgi?id=37743

• platform/chromium/SystemTimeChromium.cpp: (WebCore::monotonicallyIncreasingTime): Add primitive monotonicallyIncreasingTime() which just wraps currentTime().

Location:

trunk/Source

Files:

• JavaScriptCore/ChangeLog (modified) (1 diff)
• JavaScriptCore/wtf/CurrentTime.cpp (modified) (2 diffs)
• JavaScriptCore/wtf/CurrentTime.h (modified) (2 diffs)
• WebCore/ChangeLog (modified) (1 diff)
• WebCore/platform/chromium/SystemTimeChromium.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-06-06  James Simonsen  <simonjam@chromium.org>
+
+        Reviewed by James Robinson.
+
+        Add monotonicallyIncreasingTime() to get monotonically increasing time
+        https://bugs.webkit.org/show_bug.cgi?id=37743
+
+        * wtf/CurrentTime.cpp: Add monotonicallyIncreasingTime() for mac and a fallback implementation that just wraps currentTime().
+        (WTF::monotonicallyIncreasingTime):
+        * wtf/CurrentTime.h: Add monotonicallyIncreasingTime().
+
 2011-06-06  Alexandru Chiculita  <achicu@adobe.com>
 

trunk/Source/JavaScriptCore/wtf/CurrentTime.cpp

@@ -34 +34 @@
 #include "CurrentTime.h"
 
-#if OS(WINDOWS)
+#if PLATFORM(MAC)
+#include <mach/mach_time.h>
+#include <sys/time.h>
+#elif OS(WINDOWS)
 
 // Windows is first since we want to use hires timers, despite USE(CF)
@@ -295 +298 @@
 #endif
 
+#if PLATFORM(MAC)
+
+double monotonicallyIncreasingTime()
+{
+    // Based on listing #2 from Apple QA 1398.
+    static mach_timebase_info_data_t timebaseInfo;
+    if (!timebaseInfo.denom) {
+        kern_return_t kr = mach_timebase_info(&timebaseInfo);
+        ASSERT_UNUSED(kr, kr == KERN_SUCCESS);
+    }
+    return (mach_absolute_time() * timebaseInfo.numer) / (1.0e9 * timebaseInfo.denom);
+}
+
+#else
+
+double monotonicallyIncreasingTime()
+{
+    static double lastTime = 0;
+    double currentTimeNow = currentTime();
+    if (currentTimeNow < lastTime)
+        return lastTime;
+    lastTime = currentTimeNow;
+    return currentTimeNow;
+}
+
+#endif
+
 } // namespace WTF

trunk/Source/JavaScriptCore/wtf/CurrentTime.h

@@ -59 +59 @@
 }
 
+// Provides a monotonically increasing time in seconds since an arbitrary point in the past.
+// On unsupported platforms, this function only guarantees the result will be non-decreasing.
+double monotonicallyIncreasingTime();
+
 } // namespace WTF
 
@@ -64 +68 @@
 using WTF::currentTimeMS;
 using WTF::getLocalTime;
+using WTF::monotonicallyIncreasingTime;
 
 #endif // CurrentTime_h
-

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2011-06-06  James Simonsen  <simonjam@chromium.org>
+
+        Reviewed by James Robinson.
+
+        Add monotonicallyIncreasingTime() to get monotonically increasing time
+        https://bugs.webkit.org/show_bug.cgi?id=37743
+
+        * platform/chromium/SystemTimeChromium.cpp:
+        (WebCore::monotonicallyIncreasingTime): Add primitive monotonicallyIncreasingTime() which just wraps currentTime().
+
 2011-06-06  Emil A Eklund  <eae@chromium.org>
 

trunk/Source/WebCore/platform/chromium/SystemTimeChromium.cpp

@@ -34 +34 @@
 #include "NotImplemented.h"
 #include "PlatformBridge.h"
+#include <wtf/CurrentTime.h>
 
 namespace WebCore {
@@ -41 +42 @@
 {
     return PlatformBridge::currentTime();
+}
+
+double monotonicallyIncreasingTime()
+{
+    static double lastTime = 0;
+    double currentTimeNow = currentTime();
+    if (currentTimeNow < lastTime)
+        return lastTime;
+    lastTime = currentTimeNow;
+    return currentTimeNow;
 }