github.com/code-reading/golang@v0.0.0-20220303082512-ba5bc0e589a3/go/src/runtime/race/race_windows_test.go (about)

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build windows && race
     6  // +build windows,race
     7  
     8  package race_test
     9  
    10  import (
    11  	"sync/atomic"
    12  	"syscall"
    13  	"testing"
    14  	"unsafe"
    15  )
    16  
    17  func TestAtomicMmap(t *testing.T) {
    18  	// Test that atomic operations work on "external" memory. Previously they crashed (#16206).
    19  	// Also do a sanity correctness check: under race detector atomic operations
    20  	// are implemented inside of race runtime.
    21  	kernel32 := syscall.NewLazyDLL("kernel32.dll")
    22  	VirtualAlloc := kernel32.NewProc("VirtualAlloc")
    23  	VirtualFree := kernel32.NewProc("VirtualFree")
    24  	const (
    25  		MEM_COMMIT     = 0x00001000
    26  		MEM_RESERVE    = 0x00002000
    27  		MEM_RELEASE    = 0x8000
    28  		PAGE_READWRITE = 0x04
    29  	)
    30  	mem, _, err := syscall.Syscall6(VirtualAlloc.Addr(), 4, 0, 1<<20, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE, 0, 0)
    31  	if err != 0 {
    32  		t.Fatalf("VirtualAlloc failed: %v", err)
    33  	}
    34  	defer syscall.Syscall(VirtualFree.Addr(), 3, mem, 1<<20, MEM_RELEASE)
    35  	a := (*uint64)(unsafe.Pointer(mem))
    36  	if *a != 0 {
    37  		t.Fatalf("bad atomic value: %v, want 0", *a)
    38  	}
    39  	atomic.AddUint64(a, 1)
    40  	if *a != 1 {
    41  		t.Fatalf("bad atomic value: %v, want 1", *a)
    42  	}
    43  	atomic.AddUint64(a, 1)
    44  	if *a != 2 {
    45  		t.Fatalf("bad atomic value: %v, want 2", *a)
    46  	}
    47  }