Timer resolution.

Author: ncruces

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/psanford/httpreadat v0.1.0
 	github.com/tetratelabs/wazero v1.4.0
 	golang.org/x/sync v0.3.0
-	golang.org/x/sys v0.11.0
+	golang.org/x/sys v0.11.1-0.20230807062127-60ecf133770b
 	golang.org/x/text v0.12.0
 )
 

go.sum

@@ -6,7 +6,7 @@ github.com/tetratelabs/wazero v1.4.0 h1:9/MirYvmkJ/zSUOygKY/ia3t+e+RqIZXKbylIby1
 github.com/tetratelabs/wazero v1.4.0/go.mod h1:0U0G41+ochRKoPKCJlh0jMg1CHkyfK8kDqiirMmKY8A=
 golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
 golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
-golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
-golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.11.1-0.20230807062127-60ecf133770b h1:SVkT2ohjl5jbz5YNEn1KslYMggyeWG0FbUBDnQOZ3s8=
+golang.org/x/sys v0.11.1-0.20230807062127-60ecf133770b/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
 golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=

vfs/memdb/memdb.go

@@ -176,6 +176,8 @@ func (m *memFile) Size() (int64, error) {
 	return m.size, nil
 }
 
+const spinWait = 25 * time.Microsecond
+
 func (m *memFile) Lock(lock vfs.LockLevel) error {
 	if m.lock >= lock {
 		return nil
@@ -210,8 +212,8 @@ func (m *memFile) Lock(lock vfs.LockLevel) error {
 			m.pending = m
 		}
 
-		for start := time.Now(); m.shared > 1; {
-			if time.Since(start) > time.Millisecond {
+		for before := time.Now(); m.shared > 1; {
+			if time.Since(before) > spinWait {
 				return sqlite3.BUSY
 			}
 			m.lockMtx.Unlock()

vfs/os_bsd.go

@@ -20,16 +20,16 @@ func osUnlock(file *os.File, start, len int64) _ErrorCode {
 }
 
 func osLock(file *os.File, how int, timeout time.Duration, def _ErrorCode) _ErrorCode {
+	before := time.Now()
 	var err error
 	for {
 		err = unix.Flock(int(file.Fd()), how)
 		if errno, _ := err.(unix.Errno); errno != unix.EAGAIN {
 			break
 		}
-		if timeout < time.Millisecond {
+		if timeout <= 0 || timeout < time.Since(before) {
 			break
 		}
-		timeout -= time.Millisecond
 		time.Sleep(time.Millisecond)
 	}
 	return osLockErrorCode(err, def)

vfs/os_ofd.go

@@ -27,16 +27,16 @@ func osLock(file *os.File, typ int16, start, len int64, timeout time.Duration, d
 		Start: start,
 		Len:   len,
 	}
+	before := time.Now()
 	var err error
 	for {
 		err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &lock)
 		if errno, _ := err.(unix.Errno); errno != unix.EAGAIN {
 			break
 		}
-		if timeout < time.Millisecond {
+		if timeout <= 0 || timeout < time.Since(before) {
 			break
 		}
-		timeout -= time.Millisecond
 		time.Sleep(time.Millisecond)
 	}
 	return osLockErrorCode(err, def)

vfs/os_windows.go

@@ -138,18 +138,24 @@ func osUnlock(file *os.File, start, len uint32) _ErrorCode {
 }
 
 func osLock(file *os.File, flags, start, len uint32, timeout time.Duration, def _ErrorCode) _ErrorCode {
+	before := time.Now()
 	var err error
 	for {
 		err = windows.LockFileEx(windows.Handle(file.Fd()), flags,
 			0, len, 0, &windows.Overlapped{Offset: start})
 		if errno, _ := err.(windows.Errno); errno != windows.ERROR_LOCK_VIOLATION {
 			break
 		}
-		if timeout < time.Millisecond {
+		if timeout <= 0 || timeout < time.Since(before) {
+			break
+		}
+		if err := windows.TimeBeginPeriod(1); err != nil {
 			break
 		}
-		timeout -= time.Millisecond
 		time.Sleep(time.Millisecond)
+		if err := windows.TimeEndPeriod(1); err != nil {
+			break
+		}
 	}
 	return osLockErrorCode(err, def)
 }