diff options
Diffstat (limited to 'src/sync/waitgroup.go')
| -rw-r--r-- | src/sync/waitgroup.go | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/sync/waitgroup.go b/src/sync/waitgroup.go index 029e6077cd..b386e1fec2 100644 --- a/src/sync/waitgroup.go +++ b/src/sync/waitgroup.go @@ -15,7 +15,11 @@ import ( // goroutines to wait for. Then each of the goroutines // runs and calls Done when finished. At the same time, // Wait can be used to block until all goroutines have finished. +// +// A WaitGroup must not be copied after first use. type WaitGroup struct { + noCopy noCopy + // 64-bit value: high 32 bits are counter, low 32 bits are waiter count. // 64-bit atomic operations require 64-bit alignment, but 32-bit // compilers do not ensure it. So we allocate 12 bytes and then use |