Golang runtime.Alloc函数代码示例

// Prime the data structures by allocating one of
// each block in order.  After this, there should be
// little reason to ask for more memory from the OS.
func prime() {
	for i := 0; i < 16; i++ {
		b := runtime.Alloc(1 << uint(i))
		runtime.Free(b)
	}
	for i := uintptr(0); i < 256; i++ {
		b := runtime.Alloc(i << 12)
		runtime.Free(b)
	}
}

func main() {
	flag.Parse()
	//	prime();
	var blocks [1]struct {
		base *byte
		siz  uintptr
	}
	for i := 0; i < 1<<10; i++ {
		if i%(1<<10) == 0 && *chatty {
			println(i)
		}
		b := rand.Int() % len(blocks)
		if blocks[b].base != nil {
			//	println("Free", blocks[b].siz, blocks[b].base);
			runtime.Free(blocks[b].base)
			blocks[b].base = nil
			allocated -= uint64(blocks[b].siz)
			continue
		}
		siz := uintptr(rand.Int() >> (11 + rand.Uint32()%20))
		base := runtime.Alloc(siz)
		//	ptr := uintptr(syscall.BytePtr(base))+uintptr(siz/2);
		//	obj, size, ref, ok := allocator.find(ptr);
		//	if obj != base || *ref != 0 || !ok {
		//		panicln("find", siz, obj, ref, ok);
		//	}
		blocks[b].base = base
		blocks[b].siz = siz
		allocated += uint64(siz)
		//	println("Alloc", siz, base);
		memset(base, 0xbb, siz)
		bigger()
	}
}

func main() {
	runtime.Free(runtime.Alloc(1))
	runtime.UpdateMemStats()
	if *chatty {
		fmt.Printf("%+v %v\n", runtime.MemStats, uint64(0))
	}
}

func main() {
	flag.Parse()
	runtime.MemStats.Alloc = 0 // ignore stacks
	for i := 0; i < 1<<7; i++ {
		for j := 1; j <= 1<<22; j <<= 1 {
			if i == 0 && *chatty {
				println("First alloc:", j)
			}
			if a := runtime.MemStats.Alloc; a != 0 {
				panicln("no allocations but stats report", a, "bytes allocated")
			}
			b := runtime.Alloc(uintptr(j))
			during := runtime.MemStats.Alloc
			runtime.Free(b)
			if a := runtime.MemStats.Alloc; a != 0 {
				panic("allocated ", j, ": wrong stats: during=", during, " after=", a, " (want 0)")
			}
			bigger()
		}
		if i%(1<<10) == 0 && *chatty {
			println(i)
		}
		if i == 0 {
			if *chatty {
				println("Primed", i)
			}
			//	runtime.frozen = true;
		}
	}
}

func main() {
	runtime.GC()               // clean up garbage from init
	runtime.MemProfileRate = 0 // disable profiler
	runtime.MemStats.Alloc = 0 // ignore stacks
	flag.Parse()
	for i := 0; i < 1<<7; i++ {
		for j := 1; j <= 1<<22; j <<= 1 {
			if i == 0 && *chatty {
				println("First alloc:", j)
			}
			if a := runtime.MemStats.Alloc; a != 0 {
				println("no allocations but stats report", a, "bytes allocated")
				panic("fail")
			}
			b := runtime.Alloc(uintptr(j))
			during := runtime.MemStats.Alloc
			runtime.Free(b)
			if a := runtime.MemStats.Alloc; a != 0 {
				println("allocated ", j, ": wrong stats: during=", during, " after=", a, " (want 0)")
				panic("fail")
			}
			bigger()
		}
		if i%(1<<10) == 0 && *chatty {
			println(i)
		}
		if i == 0 {
			if *chatty {
				println("Primed", i)
			}
			//	runtime.frozen = true
		}
	}
}

func AllocAndFree(size, count int) {
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
	if *chatty {
		fmt.Printf("size=%d count=%d ...\n", size, count)
	}
	runtime.ReadMemStats(stats)
	n1 := stats.Alloc
	for i := 0; i < count; i++ {
		b[i] = runtime.Alloc(uintptr(size))
		base, n := runtime.Lookup(b[i])
		if base != b[i] || !OkAmount(uintptr(size), n) {
			println("lookup failed: got", base, n, "for", b[i])
			panic("fail")
		}
		runtime.ReadMemStats(stats)
		if stats.Sys > 1e9 {
			println("too much memory allocated")
			panic("fail")
		}
	}
	runtime.ReadMemStats(stats)
	n2 := stats.Alloc
	if *chatty {
		fmt.Printf("size=%d count=%d stats=%+v\n", size, count, *stats)
	}
	n3 := stats.Alloc
	for j := 0; j < count; j++ {
		i := j
		if *reverse {
			i = count - 1 - j
		}
		alloc := uintptr(stats.Alloc)
		base, n := runtime.Lookup(b[i])
		if base != b[i] || !OkAmount(uintptr(size), n) {
			println("lookup failed: got", base, n, "for", b[i])
			panic("fail")
		}
		runtime.Free(b[i])
		runtime.ReadMemStats(stats)
		if stats.Alloc != uint64(alloc-n) {
			println("free alloc got", stats.Alloc, "expected", alloc-n, "after free of", n)
			panic("fail")
		}
		if stats.Sys > 1e9 {
			println("too much memory allocated")
			panic("fail")
		}
	}
	runtime.ReadMemStats(stats)
	n4 := stats.Alloc

	if *chatty {
		fmt.Printf("size=%d count=%d stats=%+v\n", size, count, *stats)
	}
	if n2-n1 != n3-n4 {
		println("wrong alloc count: ", n2-n1, n3-n4)
		panic("fail")
	}
}

func main() {
	memstats := new(runtime.MemStats)
	runtime.Free(runtime.Alloc(1))
	runtime.ReadMemStats(memstats)
	if *chatty {
		fmt.Printf("%+v %v\n", memstats, uint64(0))
	}
}

func newBagKV(size uint8) *bagKV {
	asize := sizeofSub*uintptr(size) + sizeofBagKV
	b := (*bagKV)(unsafe.Pointer(runtime.Alloc(asize)))
	b.occupied_ = size
	return b
}

func newSpanKV(size uint16) *spanKV {
	asize := sizeofSub*uintptr(size) + sizeofSpanKV
	s := (*spanKV)(unsafe.Pointer(runtime.Alloc(asize)))
	s.size = size
	return s
}