libgo/go/runtime/os_dragonfly.go

   1 // Copyright 2014 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 package runtime
   6
   7 import "unsafe"
   8
   9 type mOS struct {
  10         unused byte
  11 }
  12
  13 //go:noescape
  14 //extern umtx_sleep
  15 func sys_umtx_sleep(addr *uint32, val, timeout int32) int32
  16
  17 //go:noescape
  18 //extern umtx_wakeup
  19 func sys_umtx_wakeup(addr *uint32, val int32) int32
  20
  21 //go:nosplit
  22 func futexsleep(addr *uint32, val uint32, ns int64) {
  23         systemstack(func() {
  24                 futexsleep1(addr, val, ns)
  25         })
  26 }
  27
  28 func futexsleep1(addr *uint32, val uint32, ns int64) {
  29         var timeout int32
  30         if ns >= 0 {
  31                 // The timeout is specified in microseconds - ensure that we
  32                 // do not end up dividing to zero, which would put us to sleep
  33                 // indefinitely...
  34                 timeout = timediv(ns, 1000, nil)
  35                 if timeout == 0 {
  36                         timeout = 1
  37                 }
  38         }
  39
  40         // sys_umtx_sleep will return EWOULDBLOCK (EAGAIN) when the timeout
  41         // expires or EBUSY if the mutex value does not match.
  42         ret := sys_umtx_sleep(addr, int32(val), timeout)
  43         if ret >= 0 || ret == -_EINTR || ret == -_EAGAIN || ret == -_EBUSY {
  44                 return
  45         }
  46
  47         print("umtx_sleep addr=", addr, " val=", val, " ret=", ret, "\n")
  48         *(*int32)(unsafe.Pointer(uintptr(0x1005))) = 0x1005
  49 }
  50
  51 //go:nosplit
  52 func futexwakeup(addr *uint32, cnt uint32) {
  53         ret := sys_umtx_wakeup(addr, int32(cnt))
  54         if ret >= 0 {
  55                 return
  56         }
  57
  58         systemstack(func() {
  59                 print("umtx_wake_addr=", addr, " ret=", ret, "\n")
  60                 *(*int32)(unsafe.Pointer(uintptr(0x1006))) = 0x1006
  61         })
  62 }