Colin Cross | 7bb052a | 2015-02-03 12:59:37 -0800 | [diff] [blame^] | 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 dragonfly freebsd linux netbsd openbsd windows solaris |
| 6 | |
| 7 | package net |
| 8 | |
| 9 | import ( |
| 10 | "sync" |
| 11 | "syscall" |
| 12 | "time" |
| 13 | ) |
| 14 | |
| 15 | // runtimeNano returns the current value of the runtime clock in nanoseconds. |
| 16 | func runtimeNano() int64 |
| 17 | |
| 18 | func runtime_pollServerInit() |
| 19 | func runtime_pollOpen(fd uintptr) (uintptr, int) |
| 20 | func runtime_pollClose(ctx uintptr) |
| 21 | func runtime_pollWait(ctx uintptr, mode int) int |
| 22 | func runtime_pollWaitCanceled(ctx uintptr, mode int) int |
| 23 | func runtime_pollReset(ctx uintptr, mode int) int |
| 24 | func runtime_pollSetDeadline(ctx uintptr, d int64, mode int) |
| 25 | func runtime_pollUnblock(ctx uintptr) |
| 26 | |
| 27 | type pollDesc struct { |
| 28 | runtimeCtx uintptr |
| 29 | } |
| 30 | |
| 31 | var serverInit sync.Once |
| 32 | |
| 33 | func (pd *pollDesc) Init(fd *netFD) error { |
| 34 | serverInit.Do(runtime_pollServerInit) |
| 35 | ctx, errno := runtime_pollOpen(uintptr(fd.sysfd)) |
| 36 | if errno != 0 { |
| 37 | return syscall.Errno(errno) |
| 38 | } |
| 39 | pd.runtimeCtx = ctx |
| 40 | return nil |
| 41 | } |
| 42 | |
| 43 | func (pd *pollDesc) Close() { |
| 44 | if pd.runtimeCtx == 0 { |
| 45 | return |
| 46 | } |
| 47 | runtime_pollClose(pd.runtimeCtx) |
| 48 | pd.runtimeCtx = 0 |
| 49 | } |
| 50 | |
| 51 | func (pd *pollDesc) Lock() { |
| 52 | } |
| 53 | |
| 54 | func (pd *pollDesc) Unlock() { |
| 55 | } |
| 56 | |
| 57 | func (pd *pollDesc) Wakeup() { |
| 58 | } |
| 59 | |
| 60 | // Evict evicts fd from the pending list, unblocking any I/O running on fd. |
| 61 | // Return value is whether the pollServer should be woken up. |
| 62 | func (pd *pollDesc) Evict() bool { |
| 63 | if pd.runtimeCtx == 0 { |
| 64 | return false |
| 65 | } |
| 66 | runtime_pollUnblock(pd.runtimeCtx) |
| 67 | return false |
| 68 | } |
| 69 | |
| 70 | func (pd *pollDesc) Prepare(mode int) error { |
| 71 | res := runtime_pollReset(pd.runtimeCtx, mode) |
| 72 | return convertErr(res) |
| 73 | } |
| 74 | |
| 75 | func (pd *pollDesc) PrepareRead() error { |
| 76 | return pd.Prepare('r') |
| 77 | } |
| 78 | |
| 79 | func (pd *pollDesc) PrepareWrite() error { |
| 80 | return pd.Prepare('w') |
| 81 | } |
| 82 | |
| 83 | func (pd *pollDesc) Wait(mode int) error { |
| 84 | res := runtime_pollWait(pd.runtimeCtx, mode) |
| 85 | return convertErr(res) |
| 86 | } |
| 87 | |
| 88 | func (pd *pollDesc) WaitRead() error { |
| 89 | return pd.Wait('r') |
| 90 | } |
| 91 | |
| 92 | func (pd *pollDesc) WaitWrite() error { |
| 93 | return pd.Wait('w') |
| 94 | } |
| 95 | |
| 96 | func (pd *pollDesc) WaitCanceled(mode int) { |
| 97 | runtime_pollWaitCanceled(pd.runtimeCtx, mode) |
| 98 | } |
| 99 | |
| 100 | func (pd *pollDesc) WaitCanceledRead() { |
| 101 | pd.WaitCanceled('r') |
| 102 | } |
| 103 | |
| 104 | func (pd *pollDesc) WaitCanceledWrite() { |
| 105 | pd.WaitCanceled('w') |
| 106 | } |
| 107 | |
| 108 | func convertErr(res int) error { |
| 109 | switch res { |
| 110 | case 0: |
| 111 | return nil |
| 112 | case 1: |
| 113 | return errClosing |
| 114 | case 2: |
| 115 | return errTimeout |
| 116 | } |
| 117 | println("unreachable: ", res) |
| 118 | panic("unreachable") |
| 119 | } |
| 120 | |
| 121 | func (fd *netFD) setDeadline(t time.Time) error { |
| 122 | return setDeadlineImpl(fd, t, 'r'+'w') |
| 123 | } |
| 124 | |
| 125 | func (fd *netFD) setReadDeadline(t time.Time) error { |
| 126 | return setDeadlineImpl(fd, t, 'r') |
| 127 | } |
| 128 | |
| 129 | func (fd *netFD) setWriteDeadline(t time.Time) error { |
| 130 | return setDeadlineImpl(fd, t, 'w') |
| 131 | } |
| 132 | |
| 133 | func setDeadlineImpl(fd *netFD, t time.Time, mode int) error { |
| 134 | d := runtimeNano() + int64(t.Sub(time.Now())) |
| 135 | if t.IsZero() { |
| 136 | d = 0 |
| 137 | } |
| 138 | if err := fd.incref(); err != nil { |
| 139 | return err |
| 140 | } |
| 141 | runtime_pollSetDeadline(fd.pd.runtimeCtx, d, mode) |
| 142 | fd.decref() |
| 143 | return nil |
| 144 | } |