diff options
Diffstat (limited to 'src/runtime/testdata')
| -rw-r--r-- | src/runtime/testdata/testprog/gc.go | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/src/runtime/testdata/testprog/gc.go b/src/runtime/testdata/testprog/gc.go index f691a1d127..74732cd9f4 100644 --- a/src/runtime/testdata/testprog/gc.go +++ b/src/runtime/testdata/testprog/gc.go @@ -11,6 +11,7 @@ import ( "runtime/debug" "sync/atomic" "time" + "unsafe" ) func init() { @@ -19,6 +20,7 @@ func init() { register("GCSys", GCSys) register("GCPhys", GCPhys) register("DeferLiveness", DeferLiveness) + register("GCZombie", GCZombie) } func GCSys() { @@ -264,3 +266,37 @@ func DeferLiveness() { func escape(x interface{}) { sink2 = x; sink2 = nil } var sink2 interface{} + +// Test zombie object detection and reporting. +func GCZombie() { + // Allocate several objects of unusual size (so free slots are + // unlikely to all be re-allocated by the runtime). + const size = 190 + const count = 8192 / size + keep := make([]*byte, 0, (count+1)/2) + free := make([]uintptr, 0, (count+1)/2) + zombies := make([]*byte, 0, len(free)) + for i := 0; i < count; i++ { + obj := make([]byte, size) + p := &obj[0] + if i%2 == 0 { + keep = append(keep, p) + } else { + free = append(free, uintptr(unsafe.Pointer(p))) + } + } + + // Free the unreferenced objects. + runtime.GC() + + // Bring the free objects back to life. + for _, p := range free { + zombies = append(zombies, (*byte)(unsafe.Pointer(p))) + } + + // GC should detect the zombie objects. + runtime.GC() + println("failed") + runtime.KeepAlive(keep) + runtime.KeepAlive(zombies) +} |