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Diffstat (limited to 'src/os/exec.go')
-rw-r--r-- | src/os/exec.go | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/os/exec.go b/src/os/exec.go new file mode 100644 index 0000000..edb773a --- /dev/null +++ b/src/os/exec.go @@ -0,0 +1,173 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package os + +import ( + "errors" + "internal/testlog" + "runtime" + "sync" + "sync/atomic" + "syscall" + "time" +) + +// ErrProcessDone indicates a Process has finished. +var ErrProcessDone = errors.New("os: process already finished") + +// Process stores the information about a process created by StartProcess. +type Process struct { + Pid int + handle uintptr // handle is accessed atomically on Windows + isdone uint32 // process has been successfully waited on, non zero if true + sigMu sync.RWMutex // avoid race between wait and signal +} + +func newProcess(pid int, handle uintptr) *Process { + p := &Process{Pid: pid, handle: handle} + runtime.SetFinalizer(p, (*Process).Release) + return p +} + +func (p *Process) setDone() { + atomic.StoreUint32(&p.isdone, 1) +} + +func (p *Process) done() bool { + return atomic.LoadUint32(&p.isdone) > 0 +} + +// ProcAttr holds the attributes that will be applied to a new process +// started by StartProcess. +type ProcAttr struct { + // If Dir is non-empty, the child changes into the directory before + // creating the process. + Dir string + // If Env is non-nil, it gives the environment variables for the + // new process in the form returned by Environ. + // If it is nil, the result of Environ will be used. + Env []string + // Files specifies the open files inherited by the new process. The + // first three entries correspond to standard input, standard output, and + // standard error. An implementation may support additional entries, + // depending on the underlying operating system. A nil entry corresponds + // to that file being closed when the process starts. + Files []*File + + // Operating system-specific process creation attributes. + // Note that setting this field means that your program + // may not execute properly or even compile on some + // operating systems. + Sys *syscall.SysProcAttr +} + +// A Signal represents an operating system signal. +// The usual underlying implementation is operating system-dependent: +// on Unix it is syscall.Signal. +type Signal interface { + String() string + Signal() // to distinguish from other Stringers +} + +// Getpid returns the process id of the caller. +func Getpid() int { return syscall.Getpid() } + +// Getppid returns the process id of the caller's parent. +func Getppid() int { return syscall.Getppid() } + +// FindProcess looks for a running process by its pid. +// +// The Process it returns can be used to obtain information +// about the underlying operating system process. +// +// On Unix systems, FindProcess always succeeds and returns a Process +// for the given pid, regardless of whether the process exists. +func FindProcess(pid int) (*Process, error) { + return findProcess(pid) +} + +// StartProcess starts a new process with the program, arguments and attributes +// specified by name, argv and attr. The argv slice will become os.Args in the +// new process, so it normally starts with the program name. +// +// If the calling goroutine has locked the operating system thread +// with runtime.LockOSThread and modified any inheritable OS-level +// thread state (for example, Linux or Plan 9 name spaces), the new +// process will inherit the caller's thread state. +// +// StartProcess is a low-level interface. The os/exec package provides +// higher-level interfaces. +// +// If there is an error, it will be of type *PathError. +func StartProcess(name string, argv []string, attr *ProcAttr) (*Process, error) { + testlog.Open(name) + return startProcess(name, argv, attr) +} + +// Release releases any resources associated with the Process p, +// rendering it unusable in the future. +// Release only needs to be called if Wait is not. +func (p *Process) Release() error { + return p.release() +} + +// Kill causes the Process to exit immediately. Kill does not wait until +// the Process has actually exited. This only kills the Process itself, +// not any other processes it may have started. +func (p *Process) Kill() error { + return p.kill() +} + +// Wait waits for the Process to exit, and then returns a +// ProcessState describing its status and an error, if any. +// Wait releases any resources associated with the Process. +// On most operating systems, the Process must be a child +// of the current process or an error will be returned. +func (p *Process) Wait() (*ProcessState, error) { + return p.wait() +} + +// Signal sends a signal to the Process. +// Sending Interrupt on Windows is not implemented. +func (p *Process) Signal(sig Signal) error { + return p.signal(sig) +} + +// UserTime returns the user CPU time of the exited process and its children. +func (p *ProcessState) UserTime() time.Duration { + return p.userTime() +} + +// SystemTime returns the system CPU time of the exited process and its children. +func (p *ProcessState) SystemTime() time.Duration { + return p.systemTime() +} + +// Exited reports whether the program has exited. +func (p *ProcessState) Exited() bool { + return p.exited() +} + +// Success reports whether the program exited successfully, +// such as with exit status 0 on Unix. +func (p *ProcessState) Success() bool { + return p.success() +} + +// Sys returns system-dependent exit information about +// the process. Convert it to the appropriate underlying +// type, such as syscall.WaitStatus on Unix, to access its contents. +func (p *ProcessState) Sys() interface{} { + return p.sys() +} + +// SysUsage returns system-dependent resource usage information about +// the exited process. Convert it to the appropriate underlying +// type, such as *syscall.Rusage on Unix, to access its contents. +// (On Unix, *syscall.Rusage matches struct rusage as defined in the +// getrusage(2) manual page.) +func (p *ProcessState) SysUsage() interface{} { + return p.sysUsage() +} |