libgo/go/net/fd_poll_runtime.go

   1 // Copyright 2013 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 // +build darwin linux
   6
   7 package net
   8
   9 import (
  10         "sync"
  11         "syscall"
  12         "time"
  13 )
  14
  15 func runtime_pollServerInit()
  16 func runtime_pollOpen(fd int) (uintptr, int)
  17 func runtime_pollClose(ctx uintptr)
  18 func runtime_pollWait(ctx uintptr, mode int) int
  19 func runtime_pollReset(ctx uintptr, mode int) int
  20 func runtime_pollSetDeadline(ctx uintptr, d int64, mode int)
  21 func runtime_pollUnblock(ctx uintptr)
  22
  23 var canCancelIO = true // used for testing current package
  24
  25 type pollDesc struct {
  26         runtimeCtx uintptr
  27 }
  28
  29 var serverInit sync.Once
  30
  31 func sysInit() {
  32 }
  33
  34 func (pd *pollDesc) Init(fd *netFD) error {
  35         serverInit.Do(runtime_pollServerInit)
  36         ctx, errno := runtime_pollOpen(fd.sysfd)
  37         if errno != 0 {
  38                 return syscall.Errno(errno)
  39         }
  40         pd.runtimeCtx = ctx
  41         return nil
  42 }
  43
  44 func (pd *pollDesc) Close() {
  45         runtime_pollClose(pd.runtimeCtx)
  46 }
  47
  48 func (pd *pollDesc) Lock() {
  49 }
  50
  51 func (pd *pollDesc) Unlock() {
  52 }
  53
  54 func (pd *pollDesc) Wakeup() {
  55 }
  56
  57 // Evict evicts fd from the pending list, unblocking any I/O running on fd.
  58 // Return value is whether the pollServer should be woken up.
  59 func (pd *pollDesc) Evict() bool {
  60         runtime_pollUnblock(pd.runtimeCtx)
  61         return false
  62 }
  63
  64 func (pd *pollDesc) PrepareRead() error {
  65         res := runtime_pollReset(pd.runtimeCtx, 'r')
  66         return convertErr(res)
  67 }
  68
  69 func (pd *pollDesc) PrepareWrite() error {
  70         res := runtime_pollReset(pd.runtimeCtx, 'w')
  71         return convertErr(res)
  72 }
  73
  74 func (pd *pollDesc) WaitRead() error {
  75         res := runtime_pollWait(pd.runtimeCtx, 'r')
  76         return convertErr(res)
  77 }
  78
  79 func (pd *pollDesc) WaitWrite() error {
  80         res := runtime_pollWait(pd.runtimeCtx, 'w')
  81         return convertErr(res)
  82 }
  83
  84 func convertErr(res int) error {
  85         switch res {
  86         case 0:
  87                 return nil
  88         case 1:
  89                 return errClosing
  90         case 2:
  91                 return errTimeout
  92         }
  93         panic("unreachable")
  94 }
  95
  96 func setReadDeadline(fd *netFD, t time.Time) error {
  97         return setDeadlineImpl(fd, t, 'r')
  98 }
  99
 100 func setWriteDeadline(fd *netFD, t time.Time) error {
 101         return setDeadlineImpl(fd, t, 'w')
 102 }
 103
 104 func setDeadline(fd *netFD, t time.Time) error {
 105         return setDeadlineImpl(fd, t, 'r'+'w')
 106 }
 107
 108 func setDeadlineImpl(fd *netFD, t time.Time, mode int) error {
 109         d := t.UnixNano()
 110         if t.IsZero() {
 111                 d = 0
 112         }
 113         if err := fd.incref(false); err != nil {
 114                 return err
 115         }
 116         runtime_pollSetDeadline(fd.pd.runtimeCtx, d, mode)
 117         fd.decref()
 118         return nil
 119 }