diff options
| author | Ian Lance Taylor <iant@golang.org> | 2020-07-27 22:27:54 -0700 |
|---|---|---|
| committer | Ian Lance Taylor <iant@golang.org> | 2020-08-01 11:21:40 -0700 |
| commit | f75af8c1464e948b5e166cf5ab09ebf0d82fc253 (patch) | |
| tree | 3ba3299859b504bdeb477727471216bd094a0191 /libgo/go/runtime/testdata/testprog/gc.go | |
| parent | 75a23e59031fe673fc3b2e60fd1fe5f4c70ecb85 (diff) | |
| download | gcc-f75af8c1464e948b5e166cf5ab09ebf0d82fc253.tar.gz | |
libgo: update to go1.15rc1
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/245157
Diffstat (limited to 'libgo/go/runtime/testdata/testprog/gc.go')
| -rw-r--r-- | libgo/go/runtime/testdata/testprog/gc.go | 52 |
1 files changed, 46 insertions, 6 deletions
diff --git a/libgo/go/runtime/testdata/testprog/gc.go b/libgo/go/runtime/testdata/testprog/gc.go index cc16413ef5c..74732cd9f4b 100644 --- a/libgo/go/runtime/testdata/testprog/gc.go +++ b/libgo/go/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() { @@ -150,16 +152,20 @@ func GCPhys() { // The page cache could hide 64 8-KiB pages from the scavenger today. maxPageCache = (8 << 10) * 64 + + // Reduce GOMAXPROCS down to 4 if it's greater. We need to bound the amount + // of memory held in the page cache because the scavenger can't reach it. + // The page cache will hold at most maxPageCache of memory per-P, so this + // bounds the amount of memory hidden from the scavenger to 4*maxPageCache + // at most. + maxProcs = 4 ) // Set GOGC so that this test operates under consistent assumptions. debug.SetGCPercent(100) - // Reduce GOMAXPROCS down to 4 if it's greater. We need to bound the amount - // of memory held in the page cache because the scavenger can't reach it. - // The page cache will hold at most maxPageCache of memory per-P, so this - // bounds the amount of memory hidden from the scavenger to 4*maxPageCache. procs := runtime.GOMAXPROCS(-1) - if procs > 4 { - defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(4)) + if procs > maxProcs { + defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(maxProcs)) + procs = runtime.GOMAXPROCS(-1) } // Save objects which we want to survive, and condemn objects which we don't. // Note that we condemn objects in this way and release them all at once in @@ -260,3 +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) +} |