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author | Rob Pike <r@golang.org> | 2010-08-12 12:59:37 +1000 |
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committer | Rob Pike <r@golang.org> | 2010-08-12 12:59:37 +1000 |
commit | 32a81fa8bb61a46eecea5d5956ad8fbc49fee7a3 (patch) | |
tree | ec1e2a12ff08052014478c96ed60180de1c84e4d | |
parent | 8fcdc6a1e2cd91390130f7122be427466db000e9 (diff) | |
download | go-32a81fa8bb61a46eecea5d5956ad8fbc49fee7a3.tar.gz go-32a81fa8bb61a46eecea5d5956ad8fbc49fee7a3.zip |
sync.once: document that Do cannot be invoked recursively.
documentation change only.
R=rsc
CC=golang-dev
https://golang.org/cl/1964043
-rw-r--r-- | src/pkg/sync/once.go | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/pkg/sync/once.go b/src/pkg/sync/once.go index 298d8e85f1..8c877cdec2 100644 --- a/src/pkg/sync/once.go +++ b/src/pkg/sync/once.go @@ -13,7 +13,7 @@ type Once struct { // Do calls the function f if and only if the method is being called for the // first time with this receiver. In other words, given // var once Once -// if once.Do(f) is called multiple times, only the first call will invoke f, +// if 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 // Once is required for each function to execute. // @@ -22,6 +22,9 @@ type Once struct { // arguments to a function to be invoked by Do: // config.once.Do(func() { config.init(filename) }) // +// Because no call to Do returns until the one call to f returns, if f causes +// Do to be called, it will deadlock. +// func (o *Once) Do(f func()) { o.m.Lock() defer o.m.Unlock() |