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Apply read and write deadlines to pending IO

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In order to upgrade to go1.8 all IO operations
including previous pending IO must have the deadline
set when SetReadDeadline or SetWriteDeadline is called

Signed-off-by: Darren Stahl <darst@microsoft.com>
This commit is contained in:
Darren Stahl
2017-05-05 14:53:42 -07:00
parent 2a0317319a
commit 899dbf3ba5
2 changed files with 107 additions and 46 deletions
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file.go
+106 -45
View File
@@ -7,6 +7,7 @@ import (
"io"
"runtime"
"sync"
"sync/atomic"
"syscall"
"time"
)
@@ -17,6 +18,12 @@ import (
//sys setFileCompletionNotificationModes(h syscall.Handle, flags uint8) (err error) = SetFileCompletionNotificationModes
//sys timeBeginPeriod(period uint32) (n int32) = winmm.timeBeginPeriod
type atomicBool int32
func (b *atomicBool) isSet() bool { return atomic.LoadInt32((*int32)(b)) != 0 }
func (b *atomicBool) setFalse() { atomic.StoreInt32((*int32)(b), 0) }
func (b *atomicBool) setTrue() { atomic.StoreInt32((*int32)(b), 1) }
const (
cFILE_SKIP_COMPLETION_PORT_ON_SUCCESS = 1
cFILE_SKIP_SET_EVENT_ON_HANDLE = 2
@@ -33,6 +40,8 @@ func (e *timeoutError) Error() string { return "i/o timeout" }
func (e *timeoutError) Timeout() bool { return true }
func (e *timeoutError) Temporary() bool { return true }
type timeoutChan chan struct{}
var ioInitOnce sync.Once
var ioCompletionPort syscall.Handle
@@ -63,8 +72,16 @@ type win32File struct {
handle syscall.Handle
wg sync.WaitGroup
closing bool
readDeadline time.Time
writeDeadline time.Time
readDeadline deadlineHandler
writeDeadline deadlineHandler
}
type deadlineHandler struct {
setLock sync.Mutex
channel timeoutChan
channelLock sync.RWMutex
timer *time.Timer
timedout atomicBool
}
// makeWin32File makes a new win32File from an existing file handle
@@ -79,6 +96,8 @@ func makeWin32File(h syscall.Handle) (*win32File, error) {
if err != nil {
return nil, err
}
f.readDeadline.channel = make(timeoutChan)
f.writeDeadline.channel = make(timeoutChan)
return f, nil
}
@@ -134,53 +153,47 @@ func ioCompletionProcessor(h syscall.Handle) {
// asyncIo processes the return value from ReadFile or WriteFile, blocking until
// the operation has actually completed.
func (f *win32File) asyncIo(c *ioOperation, deadline time.Time, bytes uint32, err error) (int, error) {
func (f *win32File) asyncIo(c *ioOperation, d *deadlineHandler, bytes uint32, err error) (int, error) {
if err != syscall.ERROR_IO_PENDING {
f.wg.Done()
return int(bytes), err
} else {
var r ioResult
wait := true
timedout := false
if f.closing {
cancelIoEx(f.handle, &c.o)
} else if !deadline.IsZero() {
now := time.Now()
if !deadline.After(now) {
timedout = true
} else {
timeout := time.After(deadline.Sub(now))
select {
case r = <-c.ch:
wait = false
case <-timeout:
timedout = true
}
}
}
if timedout {
cancelIoEx(f.handle, &c.o)
}
if wait {
r = <-c.ch
}
}
// runtime.KeepAlive is needed, as c is passed via native
// code to ioCompletionProcessor, c must remain alive
// until the channel read is complete.
runtime.KeepAlive(c)
if f.closing {
cancelIoEx(f.handle, &c.o)
}
var timeout timeoutChan
if d != nil {
d.channelLock.Lock()
timeout = d.channel
d.channelLock.Unlock()
}
var r ioResult
select {
case r = <-c.ch:
err = r.err
if err == syscall.ERROR_OPERATION_ABORTED {
if f.closing {
err = ErrFileClosed
} else if timedout {
err = ErrTimeout
}
}
f.wg.Done()
return int(r.bytes), err
case <-timeout:
cancelIoEx(f.handle, &c.o)
r = <-c.ch
err = r.err
if err == syscall.ERROR_OPERATION_ABORTED {
err = ErrTimeout
}
}
// runtime.KeepAlive is needed, as c is passed via native
// code to ioCompletionProcessor, c must remain alive
// until the channel read is complete.
runtime.KeepAlive(c)
f.wg.Done()
return int(r.bytes), err
}
// Read reads from a file handle.
@@ -189,9 +202,14 @@ func (f *win32File) Read(b []byte) (int, error) {
if err != nil {
return 0, err
}
if f.readDeadline.timedout.isSet() {
return 0, ErrTimeout
}
var bytes uint32
err = syscall.ReadFile(f.handle, b, &bytes, &c.o)
n, err := f.asyncIo(c, f.readDeadline, bytes, err)
n, err := f.asyncIo(c, &f.readDeadline, bytes, err)
runtime.KeepAlive(b)
// Handle EOF conditions.
@@ -210,23 +228,66 @@ func (f *win32File) Write(b []byte) (int, error) {
if err != nil {
return 0, err
}
if f.writeDeadline.timedout.isSet() {
return 0, ErrTimeout
}
var bytes uint32
err = syscall.WriteFile(f.handle, b, &bytes, &c.o)
n, err := f.asyncIo(c, f.writeDeadline, bytes, err)
n, err := f.asyncIo(c, &f.writeDeadline, bytes, err)
runtime.KeepAlive(b)
return n, err
}
func (f *win32File) SetReadDeadline(t time.Time) error {
f.readDeadline = t
return nil
func (f *win32File) SetReadDeadline(deadline time.Time) error {
return f.readDeadline.set(deadline)
}
func (f *win32File) SetWriteDeadline(t time.Time) error {
f.writeDeadline = t
return nil
func (f *win32File) SetWriteDeadline(deadline time.Time) error {
return f.writeDeadline.set(deadline)
}
func (f *win32File) Flush() error {
return syscall.FlushFileBuffers(f.handle)
}
func (d *deadlineHandler) set(deadline time.Time) error {
d.setLock.Lock()
defer d.setLock.Unlock()
if d.timer != nil {
if !d.timer.Stop() {
<-d.channel
}
d.timer = nil
}
d.timedout.setFalse()
select {
case <-d.channel:
d.channelLock.Lock()
d.channel = make(chan struct{})
d.channelLock.Unlock()
default:
}
if deadline.IsZero() {
return nil
}
timeoutIO := func() {
d.timedout.setTrue()
close(d.channel)
}
now := time.Now()
duration := deadline.Sub(now)
if deadline.After(now) {
// Deadline is in the future, set a timer to wait
d.timer = time.AfterFunc(duration, timeoutIO)
} else {
// Deadline is in the past. Cancel all pending IO now.
timeoutIO()
}
return nil
}
pipe.go
+1 -1
View File
@@ -367,7 +367,7 @@ func connectPipe(p *win32File) error {
return err
}
err = connectNamedPipe(p.handle, &c.o)
_, err = p.asyncIo(c, time.Time{}, 0, err)
_, err = p.asyncIo(c, nil, 0, err)
if err != nil && err != cERROR_PIPE_CONNECTED {
return err
}