exec_windows.go

     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  	"internal/syscall/windows"
    10  	"runtime"
    11  	"sync/atomic"
    12  	"syscall"
    13  	"time"
    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.
    42  	// See https://golang.org/issue/25965 for details.
    43  	defer time.Sleep(5 * time.Millisecond)
    44  	defer p.Release()
    45  	return &ProcessState{p.Pid, syscall.WaitStatus{ExitCode: ec}, &u}, nil
    46  }
    47  
    48  func (p *Process) signal(sig Signal) error {
    49  	handle := atomic.LoadUintptr(&p.handle)
    50  	if handle == uintptr(syscall.InvalidHandle) {
    51  		return syscall.EINVAL
    52  	}
    53  	if p.done() {
    54  		return ErrProcessDone
    55  	}
    56  	if sig == Kill {
    57  		var terminationHandle syscall.Handle
    58  		e := syscall.DuplicateHandle(^syscall.Handle(0), syscall.Handle(handle), ^syscall.Handle(0), &terminationHandle, syscall.PROCESS_TERMINATE, false, 0)
    59  		if e != nil {
    60  			return NewSyscallError("DuplicateHandle", e)
    61  		}
    62  		runtime.KeepAlive(p)
    63  		defer syscall.CloseHandle(terminationHandle)
    64  		e = syscall.TerminateProcess(syscall.Handle(terminationHandle), 1)
    65  		return NewSyscallError("TerminateProcess", e)
    66  	}
    67  	// TODO(rsc): Handle Interrupt too?
    68  	return syscall.Errno(syscall.EWINDOWS)
    69  }
    70  
    71  func (p *Process) release() error {
    72  	handle := atomic.SwapUintptr(&p.handle, uintptr(syscall.InvalidHandle))
    73  	if handle == uintptr(syscall.InvalidHandle) {
    74  		return syscall.EINVAL
    75  	}
    76  	e := syscall.CloseHandle(syscall.Handle(handle))
    77  	if e != nil {
    78  		return NewSyscallError("CloseHandle", e)
    79  	}
    80  	// no need for a finalizer anymore
    81  	runtime.SetFinalizer(p, nil)
    82  	return nil
    83  }
    84  
    85  func findProcess(pid int) (p *Process, err error) {
    86  	const da = syscall.STANDARD_RIGHTS_READ |
    87  		syscall.PROCESS_QUERY_INFORMATION | syscall.SYNCHRONIZE
    88  	h, e := syscall.OpenProcess(da, false, uint32(pid))
    89  	if e != nil {
    90  		return nil, NewSyscallError("OpenProcess", e)
    91  	}
    92  	return newProcess(pid, uintptr(h)), nil
    93  }
    94  
    95  func init() {
    96  	cmd := windows.UTF16PtrToString(syscall.GetCommandLine())
    97  	if len(cmd) == 0 {
    98  		arg0, _ := Executable()
    99  		Args = []string{arg0}
   100  	} else {
   101  		Args = commandLineToArgv(cmd)
   102  	}
   103  }
   104  
   105  // appendBSBytes appends n '\\' bytes to b and returns the resulting slice.
   106  func appendBSBytes(b []byte, n int) []byte {
   107  	for ; n > 0; n-- {
   108  		b = append(b, '\\')
   109  	}
   110  	return b
   111  }
   112  
   113  // readNextArg splits command line string cmd into next
   114  // argument and command line remainder.
   115  func readNextArg(cmd string) (arg []byte, rest string) {
   116  	var b []byte
   117  	var inquote bool
   118  	var nslash int
   119  	for ; len(cmd) > 0; cmd = cmd[1:] {
   120  		c := cmd[0]
   121  		switch c {
   122  		case ' ', '\t':
   123  			if !inquote {
   124  				return appendBSBytes(b, nslash), cmd[1:]
   125  			}
   126  		case '"':
   127  			b = appendBSBytes(b, nslash/2)
   128  			if nslash%2 == 0 {
   129  				// use "Prior to 2008" rule from
   130  				// http://daviddeley.com/autohotkey/parameters/parameters.htm
   131  				// section 5.2 to deal with double double quotes
   132  				if inquote && len(cmd) > 1 && cmd[1] == '"' {
   133  					b = append(b, c)
   134  					cmd = cmd[1:]
   135  				}
   136  				inquote = !inquote
   137  			} else {
   138  				b = append(b, c)
   139  			}
   140  			nslash = 0
   141  			continue
   142  		case '\\':
   143  			nslash++
   144  			continue
   145  		}
   146  		b = appendBSBytes(b, nslash)
   147  		nslash = 0
   148  		b = append(b, c)
   149  	}
   150  	return appendBSBytes(b, nslash), ""
   151  }
   152  
   153  // commandLineToArgv splits a command line into individual argument
   154  // strings, following the Windows conventions documented
   155  // at http://daviddeley.com/autohotkey/parameters/parameters.htm#WINARGV
   156  func commandLineToArgv(cmd string) []string {
   157  	var args []string
   158  	for len(cmd) > 0 {
   159  		if cmd[0] == ' ' || cmd[0] == '\t' {
   160  			cmd = cmd[1:]
   161  			continue
   162  		}
   163  		var arg []byte
   164  		arg, cmd = readNextArg(cmd)
   165  		args = append(args, string(arg))
   166  	}
   167  	return args
   168  }
   169  
   170  func ftToDuration(ft *syscall.Filetime) time.Duration {
   171  	n := int64(ft.HighDateTime)<<32 + int64(ft.LowDateTime) // in 100-nanosecond intervals
   172  	return time.Duration(n*100) * time.Nanosecond
   173  }
   174  
   175  func (p *ProcessState) userTime() time.Duration {
   176  	return ftToDuration(&p.rusage.UserTime)
   177  }
   178  
   179  func (p *ProcessState) systemTime() time.Duration {
   180  	return ftToDuration(&p.rusage.KernelTime)
   181  }
   182
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