FlushFSTest.Mmap_MunmapBeforeClose
parent
7020914422
commit
5908a93101
|
@ -570,7 +570,57 @@ func (t *FlushFSTest) Dup2_FlushError() {
|
|||
}
|
||||
|
||||
func (t *FlushFSTest) Mmap_MunmapBeforeClose() {
|
||||
AssertTrue(false, "TODO")
|
||||
var n int
|
||||
var err error
|
||||
|
||||
// If we run this test with GOMAXPROCS=1 (the default), the program will
|
||||
// deadlock for the reason described here:
|
||||
//
|
||||
// https://groups.google.com/d/msg/golang-nuts/11rdExWP6ac/TzwT6HBOb3wJ
|
||||
//
|
||||
// In summary, the goroutine reading from the mmap'd file is camping on a
|
||||
// scheduler slot while it blocks on a page fault, and the goroutine handling
|
||||
// fuse requests is waiting for the scheduler slot.
|
||||
//
|
||||
// So run with GOMAXPROCS=2.
|
||||
old := runtime.GOMAXPROCS(2)
|
||||
defer runtime.GOMAXPROCS(old)
|
||||
|
||||
// Open the file.
|
||||
t.f1, err = os.OpenFile(path.Join(t.Dir, "foo"), os.O_RDWR, 0)
|
||||
AssertEq(nil, err)
|
||||
|
||||
// Write some contents to the file.
|
||||
n, err = t.f1.Write([]byte("taco"))
|
||||
AssertEq(nil, err)
|
||||
AssertEq(4, n)
|
||||
|
||||
// mmap the file.
|
||||
data, err := syscall.Mmap(
|
||||
int(t.f1.Fd()), 0, 4,
|
||||
syscall.PROT_READ|syscall.PROT_WRITE,
|
||||
syscall.MAP_SHARED)
|
||||
|
||||
AssertEq(nil, err)
|
||||
AssertEq("taco", string(data))
|
||||
|
||||
// Modify then unmap.
|
||||
data[0] = 'p'
|
||||
|
||||
err = syscall.Munmap(data)
|
||||
AssertEq(nil, err)
|
||||
|
||||
// munmap does not cause a flush.
|
||||
ExpectThat(t.getFlushes(), ElementsAre())
|
||||
ExpectThat(t.getFsyncs(), ElementsAre())
|
||||
|
||||
// Close the file. We should see a flush.
|
||||
err = t.f1.Close()
|
||||
t.f1 = nil
|
||||
AssertEq(nil, err)
|
||||
|
||||
AssertThat(t.getFlushes(), ElementsAre("paco"))
|
||||
AssertThat(t.getFsyncs(), ElementsAre())
|
||||
}
|
||||
|
||||
func (t *FlushFSTest) Mmap_CloseBeforeMunmap() {
|
||||
|
|
Loading…
Reference in New Issue