split ptr retrieval and incrementation

This commit is contained in:
oliverpool 2017-02-20 16:38:27 +01:00
parent ebd6873cbb
commit 3da4095c08
1 changed files with 17 additions and 16 deletions

View File

@ -31,7 +31,8 @@ func (m *Metrics) incRequestsTotal(method string) {
// incErrorsTotal increases the counter for this error atomically by one.
func (m *Metrics) incErrorsTotal(err HTTPError) {
m.ErrorsTotal.incError(err)
ptr := m.ErrorsTotal.retrievePointerFor(err)
atomic.AddUint64(ptr, 1)
}
// incBytesReceived increases the number of received bytes atomically be the
@ -86,15 +87,17 @@ func newErrorsTotalMap() ErrorsTotalMap {
}
}
// incErrorsTotal increases the counter for this error atomically by one.
func (e *ErrorsTotalMap) incError(err HTTPError) {
// The goal is to have a valid ptr to the counter for this err
// retrievePointerFor returns (after creating it if necessary) the pointer to
// the counter for the error.
func (e *ErrorsTotalMap) retrievePointerFor(err HTTPError) *uint64 {
e.RLock()
ptr, ok := e.m[err]
e.RUnlock()
if !ok {
// The ptr does not seem to exist for this err
// Hence we create it (using a write lock)
if ok {
return ptr
}
// For pointer creation, a WriteLock is required
e.Lock()
// We ensure that the ptr wasn't created in the meantime
if ptr, ok = e.m[err]; !ok {
@ -102,9 +105,7 @@ func (e *ErrorsTotalMap) incError(err HTTPError) {
e.m[err] = ptr
}
e.Unlock()
}
// We can then increase the counter
atomic.AddUint64(ptr, 1)
return ptr
}
// Load retrieves the map of the counter pointers atomically