SERVER-31181: ServiceExecutorAdaptive maxLatencyMicros should be greater than the minimum timer resolution of the OS

1 files changed, 17 insertions, 6 deletions

diff --git a/src/mongo/util/platform_init.cpp b/src/mongo/util/platform_init.cpp
index 3ececf3eb0f..4aec1380523 100644
--- a/src/mongo/util/platform_init.cpp
+++ b/src/mongo/util/platform_init.cpp
@@ -56,12 +56,23 @@ MONGO_INITIALIZER(Behaviors_Win32)(InitializerContext*) {
         warning() << "Failed to increase max open files limit from default of 512 to 2048";
     }
 
-    // Let's set minimum Windows Kernel quantum length to 1ms in order to allow sleepmillis()
-    // to support waiting periods below Windows default quantum length (which can vary per
-    // Windows version)
-    // see http://msdn.microsoft.com/en-us/library/windows/desktop/dd757624(v=vs.85).aspx
-    if (timeBeginPeriod(1) != TIMERR_NOERROR) {
-        warning() << "Failed to set minimum timer resolution to 1 millisecond";
+    // Let's try to set minimum Windows Kernel quantum length to smallest viable timer resolution in
+    // order to allow sleepmillis() to support waiting periods below Windows default quantum length
+    // (which can vary per Windows version)
+    // See https://msdn.microsoft.com/en-us/library/windows/desktop/dd743626(v=vs.85).aspx
+    TIMECAPS tc;
+    int targetResolution = 1;
+    int timerResolution;
+
+    if (timeGetDevCaps(&tc, sizeof(TIMECAPS)) != TIMERR_NOERROR) {
+        warning() << "Failed to read timer resolution range.";
+        if (timeBeginPeriod(1) != TIMERR_NOERROR) {
+            warning() << "Failed to set minimum timer resolution to 1 millisecond.";
+        }
+    } else {
+        timerResolution =
+            std::min(std::max(int(tc.wPeriodMin), targetResolution), int(tc.wPeriodMax));
+        invariant(timeBeginPeriod(timerResolution) == TIMERR_NOERROR);
     }
 
     return Status::OK();