tinygo/src/runtime/gc_globals_precise.go

35 строки
979 Б
Go

// +build gc.conservative gc.extalloc
// +build !baremetal
package runtime
import (
"unsafe"
)
//go:extern runtime.trackedGlobalsStart
var trackedGlobalsStart uintptr
//go:extern runtime.trackedGlobalsLength
var trackedGlobalsLength uintptr
//go:extern runtime.trackedGlobalsBitmap
var trackedGlobalsBitmap [0]uint8
// markGlobals marks all globals, which are reachable by definition.
//
// This implementation relies on a compiler pass that stores all globals in a
// single global (adjusting all uses of them accordingly) and creates a bit
// vector with the locations of each pointer. This implementation then walks the
// bit vector and for each pointer it indicates, it marks the root.
//
//go:nobounds
func markGlobals() {
for i := uintptr(0); i < trackedGlobalsLength; i++ {
if trackedGlobalsBitmap[i/8]&(1<<(i%8)) != 0 {
addr := trackedGlobalsStart + i*unsafe.Alignof(uintptr(0))
root := *(*uintptr)(unsafe.Pointer(addr))
markRoot(addr, root)
}
}
}