func (t *FsyncErrorTest) Msync() {
var err error
// On OS X, msync does not cause SyncFile.
if isDarwin {
return
}
// Open the file.
t.f1, err = os.OpenFile(path.Join(t.Dir, "foo"), os.O_RDWR, 0)
AssertEq(nil, err)
// 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)
defer syscall.Munmap(data)
// msync the mapping.
err = msync(data)
ExpectThat(err, Error(HasSubstr("no such file")))
// Unmap.
err = syscall.Munmap(data)
AssertEq(nil, err)
}
func (p pack) Close() {
if p.p != nil {
_ = syscall.Munmap(p.p.data)
_ = p.pFile.Close()
}
_ = syscall.Munmap(p.idx.data)
_ = p.idxFile.Close()
}
func (t *NoErrorsTest) Mmap_WithMsync_MunmapBeforeClose() {
var n int
var err error
var expectedFsyncs []interface{}
// 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)
defer syscall.Munmap(data)
AssertEq("taco", string(data))
// Modify the contents.
data[0] = 'p'
// msync. This causes an fsync, except on OS X (cf.
// https://github.com/osxfuse/osxfuse/issues/202).
err = msync(data)
ExpectEq(nil, err)
if !isDarwin {
expectedFsyncs = append(expectedFsyncs, "paco")
}
ExpectThat(t.getFlushes(), ElementsAre())
ExpectThat(t.getFsyncs(), ElementsAre(expectedFsyncs...))
// Unmap. This does not cause anything.
err = syscall.Munmap(data)
AssertEq(nil, err)
ExpectThat(t.getFlushes(), ElementsAre())
ExpectThat(t.getFsyncs(), ElementsAre(expectedFsyncs...))
// Close the file. We should now see a flush with the modified contents, even
// on OS X.
err = t.f1.Close()
t.f1 = nil
AssertEq(nil, err)
ExpectThat(t.getFlushes(), ElementsAre("paco"))
ExpectThat(t.getFsyncs(), ElementsAre(expectedFsyncs...))
}
func (t *NoErrorsTest) Mmap_NoMsync_MunmapBeforeClose() {
var n int
var err error
// 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)
defer syscall.Munmap(data)
AssertEq("taco", string(data))
// Modify the contents.
data[0] = 'p'
// Unmap.
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. On Darwin, this will contain out of
// date contents (cf. https://github.com/osxfuse/osxfuse/issues/202).
err = t.f1.Close()
t.f1 = nil
AssertEq(nil, err)
if isDarwin {
ExpectThat(t.getFlushes(), ElementsAre("taco"))
ExpectThat(t.getFsyncs(), ElementsAre())
} else {
ExpectThat(t.getFlushes(), ElementsAre("paco"))
ExpectThat(t.getFsyncs(), ElementsAre())
}
}
func (r *Runner) Close() (first error) {
if r.stack != nil {
if err := syscall.Munmap(r.stack); err != nil && first == nil {
first = err
}
}
if r.globalsMemory != nil {
if err := syscall.Munmap(r.globalsMemory); err != nil && first == nil {
first = err
}
}
return
}
func (p *Program) Close() (first error) {
if p.Text != nil {
if err := syscall.Munmap(p.Text); err != nil && first == nil {
first = err
}
}
if p.ROData != nil {
if err := syscall.Munmap(p.ROData); err != nil && first == nil {
first = err
}
}
return
}
// Close closes the pisearch object. Note: This code is not thread-safe.
// The caller must guarantee that no other threads are accessing the object.
func (p *Pisearch) Close() {
// I'm writing the code this way
// as a reminder to my future-self that, if you really want
// to have threads playing willy-nilly, you'll need to guard
// piMap and idxMap.
p.numDigits = 0
tmp := p.piMap
p.piMap = nil
_ = syscall.Munmap(tmp)
p.piFile.Close()
tmp = p.idxMap
p.idxMap = nil
_ = syscall.Munmap(tmp)
p.idxFile.Close()
}
// Close closes the pisearch object. Note: This code is not thread-safe.
// The caller must guarantee that no other threads are accessing the object.
func (pisearch *Pisearch) Close() {
// I'm writing the code this way
// as a reminder to my future-self that, if you really want
// to have threads playing willy-nilly, you'll need to guard
// filemap_ and idxmap_.
pisearch.numDigits = 0
tmp := pisearch.filemap_
pisearch.filemap_ = nil
_ = syscall.Munmap(tmp)
pisearch.pifile_.Close()
tmp = pisearch.idxmap_
pisearch.idxmap_ = nil
_ = syscall.Munmap(tmp)
pisearch.idxfile_.Close()
}
func unmmapFile(m *mmapData) error {
if err := syscall.Munmap(m.o); err != nil {
return err
}
return m.f.Close()
}
func main() {
const n = 4096 * 50 // size of shared memory
t := int(1) * n
fmt.Println("Total size of shared memory : ", t)
// open device file
mmap_file, err := os.OpenFile(device_file, os.O_RDWR, 0666)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer mmap_file.Close()
// mmap memory
mmap, err := syscall.Mmap(int(mmap_file.Fd()), 0, int(t),
syscall.PROT_READ|syscall.PROT_WRITE,
syscall.MAP_SHARED)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer syscall.Munmap(mmap)
mmap_array := (*[n]byte)(unsafe.Pointer(&mmap[0]))
fmt.Println(*mmap_array)
// using memcpy to copy mmap memory buffer into program buffer
mmap_buf := make([]byte, t)
copy(mmap_buf, mmap_array[:])
fmt.Println(mmap_buf)
}
// Unmaps the shared memory, closes the region and - if the region owns the
// underlying shm object - signals that the shm object can be unlinked
// when its unmapped by all processes.
func (r *region) Close() error {
err := syscall.Munmap(r.bytes)
if err != nil {
rpcLog.Error("Failed to unmap memory: %s", err.Error())
return err
}
err = r.fd.Close()
if err != nil {
rpcLog.Error("Failed to close shared memory handle: %s", err.Error())
return err
}
if r.unlink {
cname := C.CString(r.name)
defer C.free(unsafe.Pointer(cname))
_, err = C.shm_unlink(cname)
if err != nil {
rpcLog.Error("Failed to mark shm block for deletion: %s", err.Error())
return err
}
}
return nil
}
// Open takes a string path to a MaxMind DB file and returns a Reader
// structure or an error. The database file is opened using a memory map. Use
// the Close method on the Reader object to return the resources to the
// system.
func Open(file string) (*Reader, error) {
mapFile, err := os.Open(file)
if err != nil {
return nil, err
}
stats, err := mapFile.Stat()
if err != nil {
return nil, err
}
fileSize := int(stats.Size())
mmap, err := syscall.Mmap(int(mapFile.Fd()), 0, fileSize, syscall.PROT_READ, syscall.MAP_SHARED)
if err != nil {
return nil, err
}
reader, err := FromBytes(mmap)
if err != nil {
syscall.Munmap(mmap)
mapFile.Close()
return nil, err
}
reader.file = mapFile
return reader, nil
}
func findModifiedAndUntracked() (err error) {
_, entries, _, data, err := ggit.MapIndexFile(".git/index")
if err != nil {
return err
}
defer syscall.Munmap(data)
parseIgnored(".git/info/exclude")
modified = make([]string, 0)
untracked = make([]string, 0)
ignorePatterns = make([]string, 0)
err = walkDir(".", entries)
/*
err = filepath.Walk(".", func(path string, info os.FileInfo, err error) error {
return statusWalk(path, info, err, entries)
})
*/
if err != nil {
return err
}
return nil
}
func (this *Bitmap) Close() error {
this.Sync()
syscall.Munmap(this.Data)
return nil
}
// seqMmapRead does n sequential reads of records of size rsize using mmap and copy.
func seqMmapRead(fname string, rsize int, n int) (int, error) {
f, err := os.Open(fname)
if err != nil {
return 0, err
}
defer f.Close()
fi, err := f.Stat()
if err != nil {
return 0, err
}
fsize := int(fi.Size())
data, err := syscall.Mmap(int(f.Fd()), 0, fsize, syscall.PROT_READ, syscall.MAP_FILE|syscall.MAP_SHARED)
// syscall.Madvise(data, syscall.MADV_SEQUENTIAL)
defer syscall.Munmap(data)
buf := make([]byte, rsize)
if n <= 0 || n > fsize/rsize {
n = fsize / rsize
}
var i int
for i = 0; i < n; i++ {
offset := i * rsize
copy(buf, data[offset:offset+len(buf)])
}
return i, nil
}
func helperMmap() {
f, err := os.Create("child")
if err != nil {
log.Fatalf("Create: %v", err)
}
defer f.Close()
data, err := syscall.Mmap(int(f.Fd()), 0, mmapSize, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
if err != nil {
log.Fatalf("Mmap: %v", err)
}
for i, b := range mmapWrites {
data[i] = b
}
if err := syscallx.Msync(data, syscall.MS_SYNC); err != nil {
log.Fatalf("Msync: %v", err)
}
if err := syscall.Munmap(data); err != nil {
log.Fatalf("Munmap: %v", err)
}
if err := f.Sync(); err != nil {
log.Fatalf("Fsync = %v", err)
}
err = f.Close()
if err != nil {
log.Fatalf("Close: %v", err)
}
}
// Ensure the file ahs room for more data.
func (file *File) Ensure(more uint64) (err error) {
if file.Append+more <= file.Size {
return
}
if file.Buf != nil {
if err = syscall.Munmap(file.Buf); err != nil {
return
}
}
if _, err = file.Fh.Seek(0, os.SEEK_END); err != nil {
return
}
if _, err = file.Fh.Write(make([]byte, file.Growth)); err != nil {
return
}
if err = file.Fh.Sync(); err != nil {
return
}
if newSize := int(file.Size + file.Growth); newSize < 0 {
log.Panicf("File %s is getting too large", file.Name)
} else if file.Buf, err = syscall.Mmap(int(file.Fh.Fd()), 0, newSize, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED); err != nil {
return
}
file.Size += file.Growth
log.Printf("File %s has grown %d bytes\n", file.Name, file.Growth)
return file.Ensure(more)
}
// Close closes framebuffer device and restores its contents.
func (fb *Framebuffer) Close() {
for i := range fb.restData {
fb.data[i] = fb.restData[i]
}
syscall.Munmap(fb.data)
fb.dev.Close()
}
func ReadLastNLines(f *os.File, lines int) (string, error) {
if lines <= 0 {
return "", fmt.Errorf("invalid line count")
}
stat, err := f.Stat()
if err != nil {
return "", err
}
data, err := syscall.Mmap(int(f.Fd()), 0, int(stat.Size()), syscall.PROT_READ, syscall.MAP_SHARED)
if err != nil {
return "", err
}
defer syscall.Munmap(data)
for i := len(data) - 1; i >= 0; i-- {
if data[i] == '\n' {
lines--
}
if lines < 0 {
return string(data[i+1 : len(data)]), nil
}
}
return string(data), nil
}
func MMapPal(filename string) (*Pal, error) {
p := &Pal{}
fi, err := os.Stat(filename)
if err != nil {
return nil, err
}
if fi.IsDir() {
return nil, errors.New(fmt.Sprintf("%s is a directory, file needed", filename))
}
file, err := os.OpenFile(filename, os.O_RDWR, 0777)
if err != nil {
return nil, err
}
defer file.Close()
mmap, err := syscall.Mmap(int(file.Fd()), 0, int(fi.Size()), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
if err != nil {
return nil, err
}
err = p.From(mmap)
if err != nil {
syscall.Munmap(mmap)
return nil, err
}
p.mmaped = true
runtime.SetFinalizer(p, func(p *Pal) {
p.Free()
})
return p, nil
}
func unmmapFile(mm *mmapData) {
len_equal_cap := mm.d[0:cap(mm.d)] // else get EINVAL
err := syscall.Munmap(len_equal_cap)
if err != nil {
log.Println("unmmapFile:", err)
}
}
func NewCGroup(pid int) (*Cgroup, error) {
fn := filepath.Join(Dir(pid), "cgroup")
f, err := os.Open(fn)
if err != nil {
return nil, errors.New(fmt.Sprintf("Failed to read %s [%s]", fn, err))
}
defer f.Close()
stat, err := f.Stat()
if err != nil {
return nil, errors.New(fmt.Sprintf("Failed to stat %s [%s]", fn, err))
}
b, err := syscall.Mmap(int(f.Fd()), 0, int(stat.Size()), syscall.PROT_READ, syscall.MAP_PRIVATE)
if err != nil {
return nil, errors.New(fmt.Sprintf("Failed to mmap %s [%s]", fn, err))
}
defer syscall.Munmap(b)
return NewCgroupFromReader(bytes.NewReader(b)), nil
}
func (mc *mmapCache) CloseFile(filename string) error {
mc.Lock()
defer mc.Unlock()
// Make sure the file is open first
md, ok := mc.files[filename]
if !ok {
mc.Unlock()
return fmt.Errorf("File '%s' is not open", filename)
}
// Make sure it has a 0 count
if md.count > 0 {
return fmt.Errorf("File '%s' does not have a 0 reference count", filename)
}
// Unmap the file
err := syscall.Munmap(md.data)
if err != nil {
return err
}
// Close the file
err = md.file.Close()
if err != nil {
return err
}
// Remove the file from the map
delete(mc.files, filename)
return nil
}
func (this *ByteProfile) FindValue(doc_id int64) ([]byte, error) {
if doc_id >= this.Len || doc_id < 1 {
return nil, errors.New("docid is wrong")
}
if this.ProfileList[doc_id].InMomory == true {
return this.ProfileList[doc_id].Data, nil
}
f, _ := os.Open(fmt.Sprintf("./index/%v_pfl.dat", this.Name))
defer f.Close()
fi, err := f.Stat()
if err != nil {
fmt.Printf("ERR:%v", err)
}
MmapBytes, err := syscall.Mmap(int(f.Fd()), 0, int(fi.Size()), syscall.PROT_READ, syscall.MAP_PRIVATE)
if err != nil {
fmt.Printf("MAPPING ERROR %v \n", err)
return nil, err
}
defer syscall.Munmap(MmapBytes)
StartPos := int(this.ProfileList[doc_id].Start)
EndPos := this.ProfileList[doc_id].DataLen + StartPos
this.ProfileList[doc_id].Data = make([]byte, this.ProfileList[doc_id].DataLen)
copy(this.ProfileList[doc_id].Data, MmapBytes[StartPos:EndPos])
//fmt.Printf("Cost Time : %v \n",functime("MmapBytes"))
this.ProfileList[doc_id].InMomory = true
//fmt.Printf("list : %v\n", string(this.ProfileList[doc_id].Data))
return this.ProfileList[doc_id].Data, nil
}
func (fb *Framebuffer) Close() {
// restore text mode
ioctl(fb.tty.Fd(), KDSETMODE, unsafe.Pointer(uintptr(KD_TEXT)))
fb.tty.Close()
syscall.Munmap(fb.Mem)
fb.dev.Close()
}
func (p *Pal) Free() {
if p == nil || !p.mmaped || p.data == nil {
return
}
syscall.Munmap(p.data)
p.data = nil
p.mmaped = false
}
// Close releases resources associated with this CDB.
func (db *CDB) Close() error {
var err error
if db.data != nil {
err = syscall.Munmap(db.data)
}
db.data = nil
return err
}
func (m *MappedFile) Close() error {
err1 := syscall.Munmap(m.data)
err2 := m.file.Close()
if err1 != nil {
return err1
}
return err2
}
func (b *sharedMemory) Close() error {
if err := syscall.Munmap(b.raw); err != nil {
return err
}
b.blocks = nil
b.raw = nil
return nil
}
// Unmap unmaps the buffer file from memory.
func (b *Buffer) Unmap() {
if err := syscall.Munmap(b.data); err != nil {
// Munmap should only fail if we pass it a bad pointer
// which should not happen. If it does something has
// gone terribly wrong and should not proceed further.
panic(err)
}
}