tor-browser

commit db5606dc9f6c06ff908aafdf3055c781667af375
parent 5e8844a9dd264a537994ed9a0105f917b03b4f56
Author: Jens Stutte <jstutte@mozilla.com>
Date:   Fri, 14 Nov 2025 10:29:04 +0000

Bug 1995934 - Remove BaseTimeDuration::Resolution. r=glandium

There is no comsumer left and we can treat the resolution as an internal implementation detail nobody should need to care about.

Differential Revision: https://phabricator.services.mozilla.com/D272452

Diffstat:
M
mozglue/misc/TimeStamp.h
 | 
9
---------
M
mozglue/misc/TimeStamp_darwin.cpp
 | 
12
+-----------
M
mozglue/misc/TimeStamp_posix.cpp
 | 
4
----
M
mozglue/misc/TimeStamp_windows.cpp
 | 
17
+++++------------

4 files changed, 6 insertions(+), 36 deletions(-)
diff --git a/mozglue/misc/TimeStamp.h b/mozglue/misc/TimeStamp.h
@@ -36,7 +36,6 @@ class BaseTimeDurationPlatformUtils {
   static MFBT_API double ToSeconds(int64_t aTicks);
   static MFBT_API double ToSecondsSigDigits(int64_t aTicks);
   static MFBT_API int64_t TicksFromMilliseconds(double aMilliseconds);
-  static MFBT_API int64_t ResolutionInTicks();
 };
 
 /**
@@ -237,14 +236,6 @@ class BaseTimeDuration {
     return aStream << aDuration.ToMilliseconds() << " ms";
   }
 
-  // Return a best guess at the system's current timing resolution,
-  // which might be variable.  BaseTimeDurations below this order of
-  // magnitude are meaningless, and those at the same order of
-  // magnitude or just above are suspect.
-  static BaseTimeDuration Resolution() {
-    return FromTicks(BaseTimeDurationPlatformUtils::ResolutionInTicks());
-  }
-
   // We could define additional operators here:
   // -- convert to/from other time units
   // -- scale duration by a float
diff --git a/mozglue/misc/TimeStamp_darwin.cpp b/mozglue/misc/TimeStamp_darwin.cpp
@@ -26,9 +26,6 @@
 #include "mozilla/TimeStamp.h"
 #include "mozilla/Uptime.h"
 
-// Each tick is significant, so we have a resolution of 1.
-static constexpr uint64_t kResolution = 1;
-
 static const uint64_t kUsPerSec = 1000000;
 static const double kNsPerMsd = 1000000.0;
 static const double kNsPerSecd = 1000000000.0;
@@ -56,9 +53,7 @@ double BaseTimeDurationPlatformUtils::ToSeconds(int64_t aTicks) {
 
 double BaseTimeDurationPlatformUtils::ToSecondsSigDigits(int64_t aTicks) {
   MOZ_ASSERT(gInitialized, "calling TimeDuration too early");
-  // As we fix the resolution to 1, all digits are significant and there are
-  // no extra calculations needed. Ensure we do not change this inadvertedly.
-  static_assert(kResolution == 1);
+  // We trust mach_timebase_info that all digits are significant.
   return ToSeconds(aTicks);
 }
 
@@ -77,11 +72,6 @@ int64_t BaseTimeDurationPlatformUtils::TicksFromMilliseconds(
   return result;
 }
 
-int64_t BaseTimeDurationPlatformUtils::ResolutionInTicks() {
-  MOZ_ASSERT(gInitialized, "calling TimeDuration too early");
-  return static_cast<int64_t>(kResolution);
-}
-
 void TimeStamp::Startup() {
   if (gInitialized) {
     return;
diff --git a/mozglue/misc/TimeStamp_posix.cpp b/mozglue/misc/TimeStamp_posix.cpp
@@ -171,10 +171,6 @@ int64_t BaseTimeDurationPlatformUtils::TicksFromMilliseconds(
   return result;
 }
 
-int64_t BaseTimeDurationPlatformUtils::ResolutionInTicks() {
-  return static_cast<int64_t>(sResolution);
-}
-
 static bool gInitialized = false;
 
 void TimeStamp::Startup() {
diff --git a/mozglue/misc/TimeStamp_windows.cpp b/mozglue/misc/TimeStamp_windows.cpp
@@ -33,11 +33,6 @@ static double sTicksPerMsd;
 // ----------------------------------------------------------------------------
 
 static constexpr double kMsPerSecd = 1000.0;
-// Note: Resolution used to be sampled based on a loop of QPC calls.
-// While it is true that on most systems we cannot expect to subsequently
-// sample QPC values as fast as the QPC frequency, we still will get that
-// as resolution of the sampled values, that is we have 1 tick resolution.
-static constexpr LONGLONG kResolution = 1;
 
 namespace mozilla {
 
@@ -50,6 +45,10 @@ static inline ULONGLONG PerformanceCounter() {
 
 static void InitConstants() {
   // Query the frequency from QPC and rely on it for all values.
+  // Note: The resolution used to be sampled based on a loop of QPC calls.
+  // While it is true that on most systems we cannot expect to subsequently
+  // sample QPC values as fast as the QPC frequency, we still will get that
+  // as resolution of the sampled values, that is we have 1 tick resolution.
   LARGE_INTEGER freq;
   bool hasQPC = ::QueryPerformanceFrequency(&freq);
   MOZ_RELEASE_ASSERT(hasQPC);
@@ -67,9 +66,7 @@ MFBT_API double BaseTimeDurationPlatformUtils::ToSeconds(int64_t aTicks) {
 
 MFBT_API double BaseTimeDurationPlatformUtils::ToSecondsSigDigits(
     int64_t aTicks) {
-  // As we fix the resolution to 1, all digits are significant and there are
-  // no extra calculations needed. Ensure we do not change this inadvertedly.
-  static_assert(kResolution == 1);
+  // We trust QueryPerformanceFrequency that all digits are significant.
   return ToSeconds(aTicks);
 }
 
@@ -88,10 +85,6 @@ BaseTimeDurationPlatformUtils::TicksFromMilliseconds(double aMilliseconds) {
   return (int64_t)result;
 }
 
-MFBT_API int64_t BaseTimeDurationPlatformUtils::ResolutionInTicks() {
-  return static_cast<int64_t>(kResolution);
-}
-
 // Note that we init early enough during startup such that we are supposed to
 // not yet have started other threads which could try to use us.
 static bool gInitialized = false;