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Source file src/os/exec_windows.go

Documentation: os

     1  // Copyright 2009 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 os
     6  
     7  import (
     8  	"errors"
     9  	"runtime"
    10  	"sync/atomic"
    11  	"syscall"
    12  	"time"
    13  	"unsafe"
    14  )
    15  
    16  func (p *Process) wait() (ps *ProcessState, err error) {
    17  	handle := atomic.LoadUintptr(&p.handle)
    18  	s, e := syscall.WaitForSingleObject(syscall.Handle(handle), syscall.INFINITE)
    19  	switch s {
    20  	case syscall.WAIT_OBJECT_0:
    21  		break
    22  	case syscall.WAIT_FAILED:
    23  		return nil, NewSyscallError("WaitForSingleObject", e)
    24  	default:
    25  		return nil, errors.New("os: unexpected result from WaitForSingleObject")
    26  	}
    27  	var ec uint32
    28  	e = syscall.GetExitCodeProcess(syscall.Handle(handle), &ec)
    29  	if e != nil {
    30  		return nil, NewSyscallError("GetExitCodeProcess", e)
    31  	}
    32  	var u syscall.Rusage
    33  	e = syscall.GetProcessTimes(syscall.Handle(handle), &u.CreationTime, &u.ExitTime, &u.KernelTime, &u.UserTime)
    34  	if e != nil {
    35  		return nil, NewSyscallError("GetProcessTimes", e)
    36  	}
    37  	p.setDone()
    38  	// NOTE(brainman): It seems that sometimes process is not dead
    39  	// when WaitForSingleObject returns. But we do not know any
    40  	// other way to wait for it. Sleeping for a while seems to do
    41  	// the trick sometimes. So we will sleep and smell the roses.
    42  	defer time.Sleep(5 * time.Millisecond)
    43  	defer p.Release()
    44  	return &ProcessState{p.Pid, syscall.WaitStatus{ExitCode: ec}, &u}, nil
    45  }
    46  
    47  func terminateProcess(pid, exitcode int) error {
    48  	h, e := syscall.OpenProcess(syscall.PROCESS_TERMINATE, false, uint32(pid))
    49  	if e != nil {
    50  		return NewSyscallError("OpenProcess", e)
    51  	}
    52  	defer syscall.CloseHandle(h)
    53  	e = syscall.TerminateProcess(h, uint32(exitcode))
    54  	return NewSyscallError("TerminateProcess", e)
    55  }
    56  
    57  func (p *Process) signal(sig Signal) error {
    58  	handle := atomic.LoadUintptr(&p.handle)
    59  	if handle == uintptr(syscall.InvalidHandle) {
    60  		return syscall.EINVAL
    61  	}
    62  	if p.done() {
    63  		return errors.New("os: process already finished")
    64  	}
    65  	if sig == Kill {
    66  		err := terminateProcess(p.Pid, 1)
    67  		runtime.KeepAlive(p)
    68  		return err
    69  	}
    70  	// TODO(rsc): Handle Interrupt too?
    71  	return syscall.Errno(syscall.EWINDOWS)
    72  }
    73  
    74  func (p *Process) release() error {
    75  	handle := atomic.LoadUintptr(&p.handle)
    76  	if handle == uintptr(syscall.InvalidHandle) {
    77  		return syscall.EINVAL
    78  	}
    79  	e := syscall.CloseHandle(syscall.Handle(handle))
    80  	if e != nil {
    81  		return NewSyscallError("CloseHandle", e)
    82  	}
    83  	atomic.StoreUintptr(&p.handle, uintptr(syscall.InvalidHandle))
    84  	// no need for a finalizer anymore
    85  	runtime.SetFinalizer(p, nil)
    86  	return nil
    87  }
    88  
    89  func findProcess(pid int) (p *Process, err error) {
    90  	const da = syscall.STANDARD_RIGHTS_READ |
    91  		syscall.PROCESS_QUERY_INFORMATION | syscall.SYNCHRONIZE
    92  	h, e := syscall.OpenProcess(da, false, uint32(pid))
    93  	if e != nil {
    94  		return nil, NewSyscallError("OpenProcess", e)
    95  	}
    96  	return newProcess(pid, uintptr(h)), nil
    97  }
    98  
    99  func init() {
   100  	p := syscall.GetCommandLine()
   101  	cmd := syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(p))[:])
   102  	if len(cmd) == 0 {
   103  		arg0, _ := Executable()
   104  		Args = []string{arg0}
   105  	} else {
   106  		Args = commandLineToArgv(cmd)
   107  	}
   108  }
   109  
   110  // appendBSBytes appends n '\\' bytes to b and returns the resulting slice.
   111  func appendBSBytes(b []byte, n int) []byte {
   112  	for ; n > 0; n-- {
   113  		b = append(b, '\\')
   114  	}
   115  	return b
   116  }
   117  
   118  // readNextArg splits command line string cmd into next
   119  // argument and command line remainder.
   120  func readNextArg(cmd string) (arg []byte, rest string) {
   121  	var b []byte
   122  	var inquote bool
   123  	var nslash int
   124  	for ; len(cmd) > 0; cmd = cmd[1:] {
   125  		c := cmd[0]
   126  		switch c {
   127  		case ' ', '\t':
   128  			if !inquote {
   129  				return appendBSBytes(b, nslash), cmd[1:]
   130  			}
   131  		case '"':
   132  			b = appendBSBytes(b, nslash/2)
   133  			if nslash%2 == 0 {
   134  				// use "Prior to 2008" rule from
   135  				// http://daviddeley.com/autohotkey/parameters/parameters.htm
   136  				// section 5.2 to deal with double double quotes
   137  				if inquote && len(cmd) > 1 && cmd[1] == '"' {
   138  					b = append(b, c)
   139  					cmd = cmd[1:]
   140  				}
   141  				inquote = !inquote
   142  			} else {
   143  				b = append(b, c)
   144  			}
   145  			nslash = 0
   146  			continue
   147  		case '\\':
   148  			nslash++
   149  			continue
   150  		}
   151  		b = appendBSBytes(b, nslash)
   152  		nslash = 0
   153  		b = append(b, c)
   154  	}
   155  	return appendBSBytes(b, nslash), ""
   156  }
   157  
   158  // commandLineToArgv splits a command line into individual argument
   159  // strings, following the Windows conventions documented
   160  // at http://daviddeley.com/autohotkey/parameters/parameters.htm#WINARGV
   161  func commandLineToArgv(cmd string) []string {
   162  	var args []string
   163  	for len(cmd) > 0 {
   164  		if cmd[0] == ' ' || cmd[0] == '\t' {
   165  			cmd = cmd[1:]
   166  			continue
   167  		}
   168  		var arg []byte
   169  		arg, cmd = readNextArg(cmd)
   170  		args = append(args, string(arg))
   171  	}
   172  	return args
   173  }
   174  
   175  func ftToDuration(ft *syscall.Filetime) time.Duration {
   176  	n := int64(ft.HighDateTime)<<32 + int64(ft.LowDateTime) // in 100-nanosecond intervals
   177  	return time.Duration(n*100) * time.Nanosecond
   178  }
   179  
   180  func (p *ProcessState) userTime() time.Duration {
   181  	return ftToDuration(&p.rusage.UserTime)
   182  }
   183  
   184  func (p *ProcessState) systemTime() time.Duration {
   185  	return ftToDuration(&p.rusage.KernelTime)
   186  }
   187  

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