DockerCLI/vendor/github.com/Microsoft/hcsshim/internal/hcs/process.go

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package hcs
import (
"encoding/json"
"io"
"sync"
"syscall"
"time"
"github.com/Microsoft/hcsshim/internal/interop"
"github.com/Microsoft/hcsshim/internal/logfields"
"github.com/sirupsen/logrus"
)
// ContainerError is an error encountered in HCS
type Process struct {
handleLock sync.RWMutex
handle hcsProcess
processID int
system *System
cachedPipes *cachedPipes
callbackNumber uintptr
logctx logrus.Fields
closedWaitOnce sync.Once
waitBlock chan struct{}
waitError error
}
func newProcess(process hcsProcess, processID int, computeSystem *System) *Process {
return &Process{
handle: process,
processID: processID,
system: computeSystem,
logctx: logrus.Fields{
logfields.ContainerID: computeSystem.ID(),
logfields.ProcessID: processID,
},
waitBlock: make(chan struct{}),
}
}
type cachedPipes struct {
stdIn syscall.Handle
stdOut syscall.Handle
stdErr syscall.Handle
}
type processModifyRequest struct {
Operation string
ConsoleSize *consoleSize `json:",omitempty"`
CloseHandle *closeHandle `json:",omitempty"`
}
type consoleSize struct {
Height uint16
Width uint16
}
type closeHandle struct {
Handle string
}
type ProcessStatus struct {
ProcessID uint32
Exited bool
ExitCode uint32
LastWaitResult int32
}
const (
stdIn string = "StdIn"
stdOut string = "StdOut"
stdErr string = "StdErr"
)
const (
modifyConsoleSize string = "ConsoleSize"
modifyCloseHandle string = "CloseHandle"
)
// Pid returns the process ID of the process within the container.
func (process *Process) Pid() int {
return process.processID
}
// SystemID returns the ID of the process's compute system.
func (process *Process) SystemID() string {
return process.system.ID()
}
func (process *Process) logOperationBegin(operation string) {
logOperationBegin(
process.logctx,
operation+" - Begin Operation")
}
func (process *Process) logOperationEnd(operation string, err error) {
var result string
if err == nil {
result = "Success"
} else {
result = "Error"
}
logOperationEnd(
process.logctx,
operation+" - End Operation - "+result,
err)
}
// Signal signals the process with `options`.
//
// For LCOW `guestrequest.SignalProcessOptionsLCOW`.
//
// For WCOW `guestrequest.SignalProcessOptionsWCOW`.
func (process *Process) Signal(options interface{}) (err error) {
process.handleLock.RLock()
defer process.handleLock.RUnlock()
operation := "hcsshim::Process::Signal"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
if process.handle == 0 {
return makeProcessError(process, operation, ErrAlreadyClosed, nil)
}
optionsb, err := json.Marshal(options)
if err != nil {
return err
}
optionsStr := string(optionsb)
var resultp *uint16
syscallWatcher(process.logctx, func() {
err = hcsSignalProcess(process.handle, optionsStr, &resultp)
})
events := processHcsResult(resultp)
if err != nil {
return makeProcessError(process, operation, err, events)
}
return nil
}
// Kill signals the process to terminate but does not wait for it to finish terminating.
func (process *Process) Kill() (err error) {
process.handleLock.RLock()
defer process.handleLock.RUnlock()
operation := "hcsshim::Process::Kill"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
if process.handle == 0 {
return makeProcessError(process, operation, ErrAlreadyClosed, nil)
}
var resultp *uint16
syscallWatcher(process.logctx, func() {
err = hcsTerminateProcess(process.handle, &resultp)
})
events := processHcsResult(resultp)
if err != nil {
return makeProcessError(process, operation, err, events)
}
return nil
}
// waitBackground waits for the process exit notification. Once received sets
// `process.waitError` (if any) and unblocks all `Wait` and `WaitTimeout` calls.
//
// This MUST be called exactly once per `process.handle` but `Wait` and
// `WaitTimeout` are safe to call multiple times.
func (process *Process) waitBackground() {
process.waitError = waitForNotification(process.callbackNumber, hcsNotificationProcessExited, nil)
process.closedWaitOnce.Do(func() {
close(process.waitBlock)
})
}
// Wait waits for the process to exit. If the process has already exited returns
// the pervious error (if any).
func (process *Process) Wait() (err error) {
operation := "hcsshim::Process::Wait"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
<-process.waitBlock
if process.waitError != nil {
return makeProcessError(process, operation, process.waitError, nil)
}
return nil
}
// WaitTimeout waits for the process to exit or the duration to elapse. If the
// process has already exited returns the pervious error (if any). If a timeout
// occurs returns `ErrTimeout`.
func (process *Process) WaitTimeout(timeout time.Duration) (err error) {
operation := "hcssshim::Process::WaitTimeout"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
select {
case <-process.waitBlock:
if process.waitError != nil {
return makeProcessError(process, operation, process.waitError, nil)
}
return nil
case <-time.After(timeout):
return makeProcessError(process, operation, ErrTimeout, nil)
}
}
// ResizeConsole resizes the console of the process.
func (process *Process) ResizeConsole(width, height uint16) (err error) {
process.handleLock.RLock()
defer process.handleLock.RUnlock()
operation := "hcsshim::Process::ResizeConsole"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
if process.handle == 0 {
return makeProcessError(process, operation, ErrAlreadyClosed, nil)
}
modifyRequest := processModifyRequest{
Operation: modifyConsoleSize,
ConsoleSize: &consoleSize{
Height: height,
Width: width,
},
}
modifyRequestb, err := json.Marshal(modifyRequest)
if err != nil {
return err
}
modifyRequestStr := string(modifyRequestb)
var resultp *uint16
err = hcsModifyProcess(process.handle, modifyRequestStr, &resultp)
events := processHcsResult(resultp)
if err != nil {
return makeProcessError(process, operation, err, events)
}
return nil
}
func (process *Process) Properties() (_ *ProcessStatus, err error) {
process.handleLock.RLock()
defer process.handleLock.RUnlock()
operation := "hcsshim::Process::Properties"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
if process.handle == 0 {
return nil, makeProcessError(process, operation, ErrAlreadyClosed, nil)
}
var (
resultp *uint16
propertiesp *uint16
)
syscallWatcher(process.logctx, func() {
err = hcsGetProcessProperties(process.handle, &propertiesp, &resultp)
})
events := processHcsResult(resultp)
if err != nil {
return nil, makeProcessError(process, operation, err, events)
}
if propertiesp == nil {
return nil, ErrUnexpectedValue
}
propertiesRaw := interop.ConvertAndFreeCoTaskMemBytes(propertiesp)
properties := &ProcessStatus{}
if err := json.Unmarshal(propertiesRaw, properties); err != nil {
return nil, makeProcessError(process, operation, err, nil)
}
return properties, nil
}
// ExitCode returns the exit code of the process. The process must have
// already terminated.
func (process *Process) ExitCode() (_ int, err error) {
operation := "hcsshim::Process::ExitCode"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
properties, err := process.Properties()
if err != nil {
return -1, makeProcessError(process, operation, err, nil)
}
if properties.Exited == false {
return -1, makeProcessError(process, operation, ErrInvalidProcessState, nil)
}
if properties.LastWaitResult != 0 {
logrus.WithFields(logrus.Fields{
logfields.ContainerID: process.SystemID(),
logfields.ProcessID: process.processID,
"wait-result": properties.LastWaitResult,
}).Warn("hcsshim::Process::ExitCode - Non-zero last wait result")
return -1, nil
}
return int(properties.ExitCode), nil
}
// Stdio returns the stdin, stdout, and stderr pipes, respectively. Closing
// these pipes does not close the underlying pipes; it should be possible to
// call this multiple times to get multiple interfaces.
func (process *Process) Stdio() (_ io.WriteCloser, _ io.ReadCloser, _ io.ReadCloser, err error) {
process.handleLock.RLock()
defer process.handleLock.RUnlock()
operation := "hcsshim::Process::Stdio"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
if process.handle == 0 {
return nil, nil, nil, makeProcessError(process, operation, ErrAlreadyClosed, nil)
}
var stdIn, stdOut, stdErr syscall.Handle
if process.cachedPipes == nil {
var (
processInfo hcsProcessInformation
resultp *uint16
)
err = hcsGetProcessInfo(process.handle, &processInfo, &resultp)
events := processHcsResult(resultp)
if err != nil {
return nil, nil, nil, makeProcessError(process, operation, err, events)
}
stdIn, stdOut, stdErr = processInfo.StdInput, processInfo.StdOutput, processInfo.StdError
} else {
// Use cached pipes
stdIn, stdOut, stdErr = process.cachedPipes.stdIn, process.cachedPipes.stdOut, process.cachedPipes.stdErr
// Invalidate the cache
process.cachedPipes = nil
}
pipes, err := makeOpenFiles([]syscall.Handle{stdIn, stdOut, stdErr})
if err != nil {
return nil, nil, nil, makeProcessError(process, operation, err, nil)
}
return pipes[0], pipes[1], pipes[2], nil
}
// CloseStdin closes the write side of the stdin pipe so that the process is
// notified on the read side that there is no more data in stdin.
func (process *Process) CloseStdin() (err error) {
process.handleLock.RLock()
defer process.handleLock.RUnlock()
operation := "hcsshim::Process::CloseStdin"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
if process.handle == 0 {
return makeProcessError(process, operation, ErrAlreadyClosed, nil)
}
modifyRequest := processModifyRequest{
Operation: modifyCloseHandle,
CloseHandle: &closeHandle{
Handle: stdIn,
},
}
modifyRequestb, err := json.Marshal(modifyRequest)
if err != nil {
return err
}
modifyRequestStr := string(modifyRequestb)
var resultp *uint16
err = hcsModifyProcess(process.handle, modifyRequestStr, &resultp)
events := processHcsResult(resultp)
if err != nil {
return makeProcessError(process, operation, err, events)
}
return nil
}
// Close cleans up any state associated with the process but does not kill
// or wait on it.
func (process *Process) Close() (err error) {
process.handleLock.Lock()
defer process.handleLock.Unlock()
operation := "hcsshim::Process::Close"
process.logOperationBegin(operation)
defer func() { process.logOperationEnd(operation, err) }()
// Don't double free this
if process.handle == 0 {
return nil
}
if err = process.unregisterCallback(); err != nil {
return makeProcessError(process, operation, err, nil)
}
if err = hcsCloseProcess(process.handle); err != nil {
return makeProcessError(process, operation, err, nil)
}
process.handle = 0
process.closedWaitOnce.Do(func() {
close(process.waitBlock)
})
return nil
}
func (process *Process) registerCallback() error {
context := &notifcationWatcherContext{
channels: newProcessChannels(),
systemID: process.SystemID(),
processID: process.processID,
}
callbackMapLock.Lock()
callbackNumber := nextCallback
nextCallback++
callbackMap[callbackNumber] = context
callbackMapLock.Unlock()
var callbackHandle hcsCallback
err := hcsRegisterProcessCallback(process.handle, notificationWatcherCallback, callbackNumber, &callbackHandle)
if err != nil {
return err
}
context.handle = callbackHandle
process.callbackNumber = callbackNumber
return nil
}
func (process *Process) unregisterCallback() error {
callbackNumber := process.callbackNumber
callbackMapLock.RLock()
context := callbackMap[callbackNumber]
callbackMapLock.RUnlock()
if context == nil {
return nil
}
handle := context.handle
if handle == 0 {
return nil
}
// hcsUnregisterProcessCallback has its own syncronization
// to wait for all callbacks to complete. We must NOT hold the callbackMapLock.
err := hcsUnregisterProcessCallback(handle)
if err != nil {
return err
}
closeChannels(context.channels)
callbackMapLock.Lock()
delete(callbackMap, callbackNumber)
callbackMapLock.Unlock()
handle = 0
return nil
}