libgo/misc/cgo/testsanitizers/src/msan4.go

   1 // Copyright 2015 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 package main
   6
   7 // The memory profiler can call copy from a slice on the system stack,
   8 // which msan used to think meant a reference to uninitialized memory.
   9
  10 /*
  11 #include <time.h>
  12 #include <unistd.h>
  13
  14 extern void Nop(char*);
  15
  16 // Use weak as a hack to permit defining a function even though we use export.
  17 void poison() __attribute__ ((weak));
  18
  19 // Poison the stack.
  20 void poison() {
  21         char a[1024];
  22         Nop(&a[0]);
  23 }
  24
  25 */
  26 import "C"
  27
  28 import (
  29         "runtime"
  30 )
  31
  32 func main() {
  33         runtime.MemProfileRate = 1
  34         start(100)
  35 }
  36
  37 func start(i int) {
  38         if i == 0 {
  39                 return
  40         }
  41         C.poison()
  42         // Tie up a thread.
  43         // We won't actually wait for this sleep to complete.
  44         go func() { C.sleep(1) }()
  45         start(i - 1)
  46 }
  47
  48 //export Nop
  49 func Nop(*C.char) {
  50 }