...
Run Format

Source file src/net/fd_poll_runtime.go

  // Copyright 2013 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.
  
  // +build darwin dragonfly freebsd linux netbsd openbsd windows solaris
  
  package net
  
  import (
  	"runtime"
  	"sync"
  	"syscall"
  	"time"
  )
  
  // runtimeNano returns the current value of the runtime clock in nanoseconds.
  func runtimeNano() int64
  
  func runtime_pollServerInit()
  func runtime_pollOpen(fd uintptr) (uintptr, int)
  func runtime_pollClose(ctx uintptr)
  func runtime_pollWait(ctx uintptr, mode int) int
  func runtime_pollWaitCanceled(ctx uintptr, mode int) int
  func runtime_pollReset(ctx uintptr, mode int) int
  func runtime_pollSetDeadline(ctx uintptr, d int64, mode int)
  func runtime_pollUnblock(ctx uintptr)
  
  type pollDesc struct {
  	runtimeCtx uintptr
  }
  
  var serverInit sync.Once
  
  func (pd *pollDesc) init(fd *netFD) error {
  	serverInit.Do(runtime_pollServerInit)
  	ctx, errno := runtime_pollOpen(uintptr(fd.sysfd))
  	runtime.KeepAlive(fd)
  	if errno != 0 {
  		return syscall.Errno(errno)
  	}
  	pd.runtimeCtx = ctx
  	return nil
  }
  
  func (pd *pollDesc) close() {
  	if pd.runtimeCtx == 0 {
  		return
  	}
  	runtime_pollClose(pd.runtimeCtx)
  	pd.runtimeCtx = 0
  }
  
  // Evict evicts fd from the pending list, unblocking any I/O running on fd.
  func (pd *pollDesc) evict() {
  	if pd.runtimeCtx == 0 {
  		return
  	}
  	runtime_pollUnblock(pd.runtimeCtx)
  }
  
  func (pd *pollDesc) prepare(mode int) error {
  	res := runtime_pollReset(pd.runtimeCtx, mode)
  	return convertErr(res)
  }
  
  func (pd *pollDesc) prepareRead() error {
  	return pd.prepare('r')
  }
  
  func (pd *pollDesc) prepareWrite() error {
  	return pd.prepare('w')
  }
  
  func (pd *pollDesc) wait(mode int) error {
  	res := runtime_pollWait(pd.runtimeCtx, mode)
  	return convertErr(res)
  }
  
  func (pd *pollDesc) waitRead() error {
  	return pd.wait('r')
  }
  
  func (pd *pollDesc) waitWrite() error {
  	return pd.wait('w')
  }
  
  func (pd *pollDesc) waitCanceled(mode int) {
  	runtime_pollWaitCanceled(pd.runtimeCtx, mode)
  }
  
  func (pd *pollDesc) waitCanceledRead() {
  	pd.waitCanceled('r')
  }
  
  func (pd *pollDesc) waitCanceledWrite() {
  	pd.waitCanceled('w')
  }
  
  func convertErr(res int) error {
  	switch res {
  	case 0:
  		return nil
  	case 1:
  		return errClosing
  	case 2:
  		return errTimeout
  	}
  	println("unreachable: ", res)
  	panic("unreachable")
  }
  
  func (fd *netFD) setDeadline(t time.Time) error {
  	return setDeadlineImpl(fd, t, 'r'+'w')
  }
  
  func (fd *netFD) setReadDeadline(t time.Time) error {
  	return setDeadlineImpl(fd, t, 'r')
  }
  
  func (fd *netFD) setWriteDeadline(t time.Time) error {
  	return setDeadlineImpl(fd, t, 'w')
  }
  
  func setDeadlineImpl(fd *netFD, t time.Time, mode int) error {
  	diff := int64(time.Until(t))
  	d := runtimeNano() + diff
  	if d <= 0 && diff > 0 {
  		// If the user has a deadline in the future, but the delay calculation
  		// overflows, then set the deadline to the maximum possible value.
  		d = 1<<63 - 1
  	}
  	if t.IsZero() {
  		d = 0
  	}
  	if err := fd.incref(); err != nil {
  		return err
  	}
  	runtime_pollSetDeadline(fd.pd.runtimeCtx, d, mode)
  	fd.decref()
  	return nil
  }
  

View as plain text