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  	"syscall"
    12  	"time"
    13  )
    14  
    15  // Note that Process.mode is always modeHandle because Windows always requires
    16  // a handle. A manually-created Process literal is not valid.
    17  
    18  func (p *Process) wait() (ps *ProcessState, err error) {
    19  	handle, status := p.handleTransientAcquire()
    20  	switch status {
    21  	case statusDone:
    22  		return nil, ErrProcessDone
    23  	case statusReleased:
    24  		return nil, syscall.EINVAL
    25  	}
    26  	defer p.handleTransientRelease()
    27  
    28  	s, e := syscall.WaitForSingleObject(syscall.Handle(handle), syscall.INFINITE)
    29  	switch s {
    30  	case syscall.WAIT_OBJECT_0:
    31  		break
    32  	case syscall.WAIT_FAILED:
    33  		return nil, NewSyscallError("WaitForSingleObject", e)
    34  	default:
    35  		return nil, errors.New("os: unexpected result from WaitForSingleObject")
    36  	}
    37  	var ec uint32
    38  	e = syscall.GetExitCodeProcess(syscall.Handle(handle), &ec)
    39  	if e != nil {
    40  		return nil, NewSyscallError("GetExitCodeProcess", e)
    41  	}
    42  	var u syscall.Rusage
    43  	e = syscall.GetProcessTimes(syscall.Handle(handle), &u.CreationTime, &u.ExitTime, &u.KernelTime, &u.UserTime)
    44  	if e != nil {
    45  		return nil, NewSyscallError("GetProcessTimes", e)
    46  	}
    47  	defer p.Release()
    48  	return &ProcessState{p.Pid, syscall.WaitStatus{ExitCode: ec}, &u}, nil
    49  }
    50  
    51  func (p *Process) signal(sig Signal) error {
    52  	handle, status := p.handleTransientAcquire()
    53  	switch status {
    54  	case statusDone:
    55  		return ErrProcessDone
    56  	case statusReleased:
    57  		return syscall.EINVAL
    58  	}
    59  	defer p.handleTransientRelease()
    60  
    61  	if sig == Kill {
    62  		var terminationHandle syscall.Handle
    63  		e := syscall.DuplicateHandle(^syscall.Handle(0), syscall.Handle(handle), ^syscall.Handle(0), &terminationHandle, syscall.PROCESS_TERMINATE, false, 0)
    64  		if e != nil {
    65  			return NewSyscallError("DuplicateHandle", e)
    66  		}
    67  		runtime.KeepAlive(p)
    68  		defer syscall.CloseHandle(terminationHandle)
    69  		e = syscall.TerminateProcess(syscall.Handle(terminationHandle), 1)
    70  		return NewSyscallError("TerminateProcess", e)
    71  	}
    72  	// TODO(rsc): Handle Interrupt too?
    73  	return syscall.Errno(syscall.EWINDOWS)
    74  }
    75  
    76  func (p *Process) release() error {
    77  	// Drop the Process' reference and mark handle unusable for
    78  	// future calls.
    79  	//
    80  	// The API on Windows expects EINVAL if Release is called multiple
    81  	// times.
    82  	if old := p.handlePersistentRelease(statusReleased); old == statusReleased {
    83  		return syscall.EINVAL
    84  	}
    85  
    86  	// no need for a finalizer anymore
    87  	runtime.SetFinalizer(p, nil)
    88  	return nil
    89  }
    90  
    91  func (p *Process) closeHandle() {
    92  	syscall.CloseHandle(syscall.Handle(p.handle))
    93  }
    94  
    95  func findProcess(pid int) (p *Process, err error) {
    96  	const da = syscall.STANDARD_RIGHTS_READ |
    97  		syscall.PROCESS_QUERY_INFORMATION | syscall.SYNCHRONIZE
    98  	h, e := syscall.OpenProcess(da, false, uint32(pid))
    99  	if e != nil {
   100  		return nil, NewSyscallError("OpenProcess", e)
   101  	}
   102  	return newHandleProcess(pid, uintptr(h)), nil
   103  }
   104  
   105  func init() {
   106  	cmd := windows.UTF16PtrToString(syscall.GetCommandLine())
   107  	if len(cmd) == 0 {
   108  		arg0, _ := Executable()
   109  		Args = []string{arg0}
   110  	} else {
   111  		Args = commandLineToArgv(cmd)
   112  	}
   113  }
   114  
   115  // appendBSBytes appends n '\\' bytes to b and returns the resulting slice.
   116  func appendBSBytes(b []byte, n int) []byte {
   117  	for ; n > 0; n-- {
   118  		b = append(b, '\\')
   119  	}
   120  	return b
   121  }
   122  
   123  // readNextArg splits command line string cmd into next
   124  // argument and command line remainder.
   125  func readNextArg(cmd string) (arg []byte, rest string) {
   126  	var b []byte
   127  	var inquote bool
   128  	var nslash int
   129  	for ; len(cmd) > 0; cmd = cmd[1:] {
   130  		c := cmd[0]
   131  		switch c {
   132  		case ' ', '\t':
   133  			if !inquote {
   134  				return appendBSBytes(b, nslash), cmd[1:]
   135  			}
   136  		case '"':
   137  			b = appendBSBytes(b, nslash/2)
   138  			if nslash%2 == 0 {
   139  				// use "Prior to 2008" rule from
   140  				// http://daviddeley.com/autohotkey/parameters/parameters.htm
   141  				// section 5.2 to deal with double double quotes
   142  				if inquote && len(cmd) > 1 && cmd[1] == '"' {
   143  					b = append(b, c)
   144  					cmd = cmd[1:]
   145  				}
   146  				inquote = !inquote
   147  			} else {
   148  				b = append(b, c)
   149  			}
   150  			nslash = 0
   151  			continue
   152  		case '\\':
   153  			nslash++
   154  			continue
   155  		}
   156  		b = appendBSBytes(b, nslash)
   157  		nslash = 0
   158  		b = append(b, c)
   159  	}
   160  	return appendBSBytes(b, nslash), ""
   161  }
   162  
   163  // commandLineToArgv splits a command line into individual argument
   164  // strings, following the Windows conventions documented
   165  // at http://daviddeley.com/autohotkey/parameters/parameters.htm#WINARGV
   166  func commandLineToArgv(cmd string) []string {
   167  	var args []string
   168  	for len(cmd) > 0 {
   169  		if cmd[0] == ' ' || cmd[0] == '\t' {
   170  			cmd = cmd[1:]
   171  			continue
   172  		}
   173  		var arg []byte
   174  		arg, cmd = readNextArg(cmd)
   175  		args = append(args, string(arg))
   176  	}
   177  	return args
   178  }
   179  
   180  func ftToDuration(ft *syscall.Filetime) time.Duration {
   181  	n := int64(ft.HighDateTime)<<32 + int64(ft.LowDateTime) // in 100-nanosecond intervals
   182  	return time.Duration(n*100) * time.Nanosecond
   183  }
   184  
   185  func (p *ProcessState) userTime() time.Duration {
   186  	return ftToDuration(&p.rusage.UserTime)
   187  }
   188  
   189  func (p *ProcessState) systemTime() time.Duration {
   190  	return ftToDuration(&p.rusage.KernelTime)
   191  }
   192
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