blob: 79dafb0279656afa63f2721e7d5506e9fa60211a [file] [log] [blame]
// 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.
package runtime
import (
"unsafe"
)
const _DWORD_MAX = 0xffffffff
const _INVALID_HANDLE_VALUE = ^uintptr(0)
// net_op must be the same as beginning of internal/poll.operation.
// Keep these in sync.
type net_op struct {
// used by windows
o overlapped
// used by netpoll
pd *pollDesc
mode int32
errno int32
qty uint32
}
type overlappedEntry struct {
key uintptr
op *net_op // In reality it's *overlapped, but we cast it to *net_op anyway.
internal uintptr
qty uint32
}
var iocphandle uintptr = _INVALID_HANDLE_VALUE // completion port io handle
func netpollinit() {
iocphandle = stdcall4(_CreateIoCompletionPort, _INVALID_HANDLE_VALUE, 0, 0, _DWORD_MAX)
if iocphandle == 0 {
println("runtime: CreateIoCompletionPort failed (errno=", getlasterror(), ")")
throw("runtime: netpollinit failed")
}
}
func netpolldescriptor() uintptr {
return iocphandle
}
func netpollopen(fd uintptr, pd *pollDesc) int32 {
if stdcall4(_CreateIoCompletionPort, fd, iocphandle, 0, 0) == 0 {
return -int32(getlasterror())
}
return 0
}
func netpollclose(fd uintptr) int32 {
// nothing to do
return 0
}
func netpollarm(pd *pollDesc, mode int) {
throw("runtime: unused")
}
// Polls for completed network IO.
// Returns list of goroutines that become runnable.
func netpoll(block bool) *g {
var entries [64]overlappedEntry
var wait, qty, key, flags, n, i uint32
var errno int32
var op *net_op
var gp guintptr
mp := getg().m
if iocphandle == _INVALID_HANDLE_VALUE {
return nil
}
wait = 0
if block {
wait = _INFINITE
}
retry:
if _GetQueuedCompletionStatusEx != nil {
n = uint32(len(entries) / int(gomaxprocs))
if n < 8 {
n = 8
}
if block {
mp.blocked = true
}
if stdcall6(_GetQueuedCompletionStatusEx, iocphandle, uintptr(unsafe.Pointer(&entries[0])), uintptr(n), uintptr(unsafe.Pointer(&n)), uintptr(wait), 0) == 0 {
mp.blocked = false
errno = int32(getlasterror())
if !block && errno == _WAIT_TIMEOUT {
return nil
}
println("runtime: GetQueuedCompletionStatusEx failed (errno=", errno, ")")
throw("runtime: netpoll failed")
}
mp.blocked = false
for i = 0; i < n; i++ {
op = entries[i].op
errno = 0
qty = 0
if stdcall5(_WSAGetOverlappedResult, op.pd.fd, uintptr(unsafe.Pointer(op)), uintptr(unsafe.Pointer(&qty)), 0, uintptr(unsafe.Pointer(&flags))) == 0 {
errno = int32(getlasterror())
}
handlecompletion(&gp, op, errno, qty)
}
} else {
op = nil
errno = 0
qty = 0
if block {
mp.blocked = true
}
if stdcall5(_GetQueuedCompletionStatus, iocphandle, uintptr(unsafe.Pointer(&qty)), uintptr(unsafe.Pointer(&key)), uintptr(unsafe.Pointer(&op)), uintptr(wait)) == 0 {
mp.blocked = false
errno = int32(getlasterror())
if !block && errno == _WAIT_TIMEOUT {
return nil
}
if op == nil {
println("runtime: GetQueuedCompletionStatus failed (errno=", errno, ")")
throw("runtime: netpoll failed")
}
// dequeued failed IO packet, so report that
}
mp.blocked = false
handlecompletion(&gp, op, errno, qty)
}
if block && gp == 0 {
goto retry
}
return gp.ptr()
}
func handlecompletion(gpp *guintptr, op *net_op, errno int32, qty uint32) {
if op == nil {
println("runtime: GetQueuedCompletionStatus returned op == nil")
throw("runtime: netpoll failed")
}
mode := op.mode
if mode != 'r' && mode != 'w' {
println("runtime: GetQueuedCompletionStatus returned invalid mode=", mode)
throw("runtime: netpoll failed")
}
op.errno = errno
op.qty = qty
netpollready(gpp, op.pd, mode)
}