veyron/lib/stats: Fix race due to non-pointer receiver
The previous code had a race condition because the Integer object was
access with both pointer and non-pointer receivers without higher lever
synchronization. The mutex inside Integer doesn't matter: the access to 'i'
itself caused the race, not the access to i.value.
51 func (i Integer) Value() interface{} {
52 i.mu.RLock()
53 defer i.mu.RUnlock()
54 return i.value
55 }
The solution is to always use a pointer receiver.
Change-Id: Ieb13032afdaa63e2418f1468d6d5b7a803f00c76
Context: https://code.google.com/p/envyor/issues/detail?id=316
diff --git a/lib/stats/float.go b/lib/stats/float.go
index d124cbb..d74f957 100644
--- a/lib/stats/float.go
+++ b/lib/stats/float.go
@@ -41,14 +41,14 @@
}
// LastUpdate returns the time at which the object was last updated.
-func (f Float) LastUpdate() time.Time {
+func (f *Float) LastUpdate() time.Time {
f.mu.RLock()
defer f.mu.RUnlock()
return f.lastUpdate
}
// Value returns the current value of the object.
-func (f Float) Value() interface{} {
+func (f *Float) Value() interface{} {
f.mu.RLock()
defer f.mu.RUnlock()
return f.value
