diff --git a/internal/runtime/type.go b/internal/runtime/type.go index 0167cd2c..4b693cb0 100644 --- a/internal/runtime/type.go +++ b/internal/runtime/type.go @@ -2,6 +2,7 @@ package runtime import ( "reflect" + "sync" "unsafe" ) @@ -23,8 +24,8 @@ type TypeAddr struct { } var ( - typeAddr *TypeAddr - alreadyAnalyzed bool + typeAddr *TypeAddr + once sync.Once ) //go:linkname typelinks reflect.typelinks @@ -34,67 +35,64 @@ func typelinks() ([]unsafe.Pointer, [][]int32) func rtypeOff(unsafe.Pointer, int32) unsafe.Pointer func AnalyzeTypeAddr() *TypeAddr { - defer func() { - alreadyAnalyzed = true - }() - if alreadyAnalyzed { - return typeAddr - } - sections, offsets := typelinks() - if len(sections) != 1 { - return nil - } - if len(offsets) != 1 { - return nil - } - section := sections[0] - offset := offsets[0] - var ( - min uintptr = uintptr(^uint(0)) - max uintptr = 0 - isAligned64 = true - isAligned32 = true - ) - for i := 0; i < len(offset); i++ { - typ := (*Type)(rtypeOff(section, offset[i])) - addr := uintptr(unsafe.Pointer(typ)) - if min > addr { - min = addr + once.Do(func() { + sections, offsets := typelinks() + if len(sections) != 1 { + return } - if max < addr { - max = addr + if len(offsets) != 1 { + return } - if typ.Kind() == reflect.Ptr { - addr = uintptr(unsafe.Pointer(typ.Elem())) + section := sections[0] + offset := offsets[0] + var ( + min uintptr = uintptr(^uint(0)) + max uintptr = 0 + isAligned64 = true + isAligned32 = true + ) + for i := 0; i < len(offset); i++ { + typ := (*Type)(rtypeOff(section, offset[i])) + addr := uintptr(unsafe.Pointer(typ)) if min > addr { min = addr } if max < addr { max = addr } + if typ.Kind() == reflect.Ptr { + addr = uintptr(unsafe.Pointer(typ.Elem())) + if min > addr { + min = addr + } + if max < addr { + max = addr + } + } + isAligned64 = isAligned64 && (addr-min)&63 == 0 + isAligned32 = isAligned32 && (addr-min)&31 == 0 + } + addrRange := max - min + if addrRange == 0 { + return + } + var addrShift uintptr + if isAligned64 { + addrShift = 6 + } else if isAligned32 { + addrShift = 5 } - isAligned64 = isAligned64 && (addr-min)&63 == 0 - isAligned32 = isAligned32 && (addr-min)&31 == 0 - } - addrRange := max - min - if addrRange == 0 { - return nil - } - var addrShift uintptr - if isAligned64 { - addrShift = 6 - } else if isAligned32 { - addrShift = 5 - } - cacheSize := addrRange >> addrShift - if cacheSize > maxAcceptableTypeAddrRange { - return nil - } - typeAddr = &TypeAddr{ - BaseTypeAddr: min, - MaxTypeAddr: max, - AddrRange: addrRange, - AddrShift: addrShift, - } + cacheSize := addrRange >> addrShift + if cacheSize > maxAcceptableTypeAddrRange { + return + } + typeAddr = &TypeAddr{ + BaseTypeAddr: min, + MaxTypeAddr: max, + AddrRange: addrRange, + AddrShift: addrShift, + } + }) + return typeAddr }