diff options
Diffstat (limited to 'libgo/go/runtime/mbarrier.go')
| -rw-r--r-- | libgo/go/runtime/mbarrier.go | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/libgo/go/runtime/mbarrier.go b/libgo/go/runtime/mbarrier.go index a4f9b3c0350..836f85a0330 100644 --- a/libgo/go/runtime/mbarrier.go +++ b/libgo/go/runtime/mbarrier.go @@ -163,8 +163,8 @@ func typedmemmove(typ *_type, dst, src unsafe.Pointer) { if dst == src { return } - if typ.ptrdata != 0 { - bulkBarrierPreWrite(uintptr(dst), uintptr(src), typ.size) + if writeBarrier.needed && typ.ptrdata != 0 { + bulkBarrierPreWrite(uintptr(dst), uintptr(src), typ.ptrdata) } // There's a race here: if some other goroutine can write to // src, it may change some pointer in src after we've @@ -199,17 +199,18 @@ func reflectlite_typedmemmove(typ *_type, dst, src unsafe.Pointer) { // typedmemmovepartial is like typedmemmove but assumes that // dst and src point off bytes into the value and only copies size bytes. +// off must be a multiple of sys.PtrSize. //go:linkname reflect_typedmemmovepartial reflect.typedmemmovepartial func reflect_typedmemmovepartial(typ *_type, dst, src unsafe.Pointer, off, size uintptr) { - if writeBarrier.needed && typ.ptrdata != 0 && size >= sys.PtrSize { - // Pointer-align start address for bulk barrier. - adst, asrc, asize := dst, src, size - if frag := -off & (sys.PtrSize - 1); frag != 0 { - adst = add(dst, frag) - asrc = add(src, frag) - asize -= frag + if writeBarrier.needed && typ.ptrdata > off && size >= sys.PtrSize { + if off&(sys.PtrSize-1) != 0 { + panic("reflect: internal error: misaligned offset") } - bulkBarrierPreWrite(uintptr(adst), uintptr(asrc), asize&^(sys.PtrSize-1)) + pwsize := alignDown(size, sys.PtrSize) + if poff := typ.ptrdata - off; pwsize > poff { + pwsize = poff + } + bulkBarrierPreWrite(uintptr(dst), uintptr(src), pwsize) } memmove(dst, src, size) @@ -257,7 +258,8 @@ func typedslicecopy(typ *_type, dstPtr unsafe.Pointer, dstLen int, srcPtr unsafe // before calling typedslicecopy. size := uintptr(n) * typ.size if writeBarrier.needed { - bulkBarrierPreWrite(uintptr(dstPtr), uintptr(srcPtr), size) + pwsize := size - typ.size + typ.ptrdata + bulkBarrierPreWrite(uintptr(dstPtr), uintptr(srcPtr), pwsize) } // See typedmemmove for a discussion of the race between the // barrier and memmove. @@ -304,8 +306,8 @@ func reflect_typedslicecopy(elemType *_type, dst, src slice) int { // //go:nosplit func typedmemclr(typ *_type, ptr unsafe.Pointer) { - if typ.ptrdata != 0 { - bulkBarrierPreWrite(uintptr(ptr), 0, typ.size) + if writeBarrier.needed && typ.ptrdata != 0 { + bulkBarrierPreWrite(uintptr(ptr), 0, typ.ptrdata) } memclrNoHeapPointers(ptr, typ.size) } @@ -317,7 +319,7 @@ func reflect_typedmemclr(typ *_type, ptr unsafe.Pointer) { //go:linkname reflect_typedmemclrpartial reflect.typedmemclrpartial func reflect_typedmemclrpartial(typ *_type, ptr unsafe.Pointer, off, size uintptr) { - if typ.ptrdata != 0 { + if writeBarrier.needed && typ.ptrdata != 0 { bulkBarrierPreWrite(uintptr(ptr), 0, size) } memclrNoHeapPointers(ptr, size) |