diff options
Diffstat (limited to 'libgo/go/sync/once.go')
| -rw-r--r-- | libgo/go/sync/once.go | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libgo/go/sync/once.go b/libgo/go/sync/once.go index 161ae3b3e9..10b42fddc2 100644 --- a/libgo/go/sync/once.go +++ b/libgo/go/sync/once.go @@ -15,7 +15,7 @@ type Once struct { } // Do calls the function f if and only if Do is being called for the -// first time for this instance of Once. In other words, given +// first time for this instance of Once. In other words, given // var once Once // if once.Do(f) is called multiple times, only the first call will invoke f, // even if f has a different value in each invocation. A new instance of @@ -29,6 +29,9 @@ type Once struct { // Because no call to Do returns until the one call to f returns, if f causes // Do to be called, it will deadlock. // +// If f panics, Do considers it to have returned; future calls of Do return +// without calling f. +// func (o *Once) Do(f func()) { if atomic.LoadUint32(&o.done) == 1 { return @@ -37,7 +40,7 @@ func (o *Once) Do(f func()) { o.m.Lock() defer o.m.Unlock() if o.done == 0 { + defer atomic.StoreUint32(&o.done, 1) f() - atomic.StoreUint32(&o.done, 1) } } |