diff options
Diffstat (limited to 'pkg/fdchannel')
| -rw-r--r-- | pkg/fdchannel/fdchannel_unsafe.go | 39 |
1 files changed, 18 insertions, 21 deletions
diff --git a/pkg/fdchannel/fdchannel_unsafe.go b/pkg/fdchannel/fdchannel_unsafe.go index 367235be5..b253a8fdd 100644 --- a/pkg/fdchannel/fdchannel_unsafe.go +++ b/pkg/fdchannel/fdchannel_unsafe.go @@ -21,7 +21,6 @@ package fdchannel import ( "fmt" "reflect" - "sync/atomic" "syscall" "unsafe" ) @@ -41,7 +40,7 @@ func NewConnectedSockets() ([2]int, error) { // // Endpoint is not copyable or movable by value. type Endpoint struct { - sockfd int32 // accessed using atomic memory operations + sockfd int32 msghdr syscall.Msghdr cmsg *syscall.Cmsghdr // followed by sizeofInt32 bytes of data } @@ -54,10 +53,10 @@ func (ep *Endpoint) Init(sockfd int) { // sendmsg+recvmsg for a zero-length datagram is slightly faster than // sendmsg+recvmsg for a single byte over a stream socket. cmsgSlice := make([]byte, syscall.CmsgSpace(sizeofInt32)) - cmsgReflect := (*reflect.SliceHeader)((unsafe.Pointer)(&cmsgSlice)) + cmsgReflect := (*reflect.SliceHeader)(unsafe.Pointer(&cmsgSlice)) ep.sockfd = int32(sockfd) - ep.msghdr.Control = (*byte)((unsafe.Pointer)(cmsgReflect.Data)) - ep.cmsg = (*syscall.Cmsghdr)((unsafe.Pointer)(cmsgReflect.Data)) + ep.msghdr.Control = (*byte)(unsafe.Pointer(cmsgReflect.Data)) + ep.cmsg = (*syscall.Cmsghdr)(unsafe.Pointer(cmsgReflect.Data)) // ep.msghdr.Controllen and ep.cmsg.* are mutated by recvmsg(2), so they're // set before calling sendmsg/recvmsg. } @@ -73,12 +72,8 @@ func NewEndpoint(sockfd int) *Endpoint { // Destroy releases resources owned by ep. No other Endpoint methods may be // called after Destroy. func (ep *Endpoint) Destroy() { - // These need not use sync/atomic since there must not be any concurrent - // calls to Endpoint methods. - if ep.sockfd >= 0 { - syscall.Close(int(ep.sockfd)) - ep.sockfd = -1 - } + syscall.Close(int(ep.sockfd)) + ep.sockfd = -1 } // Shutdown causes concurrent and future calls to ep.SendFD(), ep.RecvFD(), and @@ -88,10 +83,7 @@ func (ep *Endpoint) Destroy() { // Shutdown is the only Endpoint method that may be called concurrently with // other methods. func (ep *Endpoint) Shutdown() { - if sockfd := int(atomic.SwapInt32(&ep.sockfd, -1)); sockfd >= 0 { - syscall.Shutdown(sockfd, syscall.SHUT_RDWR) - syscall.Close(sockfd) - } + syscall.Shutdown(int(ep.sockfd), syscall.SHUT_RDWR) } // SendFD sends the open file description represented by the given file @@ -103,7 +95,7 @@ func (ep *Endpoint) SendFD(fd int) error { ep.cmsg.SetLen(cmsgLen) *ep.cmsgData() = int32(fd) ep.msghdr.SetControllen(cmsgLen) - _, _, e := syscall.Syscall(syscall.SYS_SENDMSG, uintptr(atomic.LoadInt32(&ep.sockfd)), uintptr((unsafe.Pointer)(&ep.msghdr)), 0) + _, _, e := syscall.Syscall(syscall.SYS_SENDMSG, uintptr(ep.sockfd), uintptr(unsafe.Pointer(&ep.msghdr)), 0) if e != 0 { return e } @@ -113,7 +105,7 @@ func (ep *Endpoint) SendFD(fd int) error { // RecvFD receives an open file description from the connected Endpoint and // returns a file descriptor representing it, owned by the caller. func (ep *Endpoint) RecvFD() (int, error) { - return ep.recvFD(0) + return ep.recvFD(false) } // RecvFDNonblock receives an open file description from the connected Endpoint @@ -121,13 +113,18 @@ func (ep *Endpoint) RecvFD() (int, error) { // are no pending receivable open file descriptions, RecvFDNonblock returns // (<unspecified>, EAGAIN or EWOULDBLOCK). func (ep *Endpoint) RecvFDNonblock() (int, error) { - return ep.recvFD(syscall.MSG_DONTWAIT) + return ep.recvFD(true) } -func (ep *Endpoint) recvFD(flags uintptr) (int, error) { +func (ep *Endpoint) recvFD(nonblock bool) (int, error) { cmsgLen := syscall.CmsgLen(sizeofInt32) ep.msghdr.SetControllen(cmsgLen) - _, _, e := syscall.Syscall(syscall.SYS_RECVMSG, uintptr(atomic.LoadInt32(&ep.sockfd)), uintptr((unsafe.Pointer)(&ep.msghdr)), flags|syscall.MSG_TRUNC) + var e syscall.Errno + if nonblock { + _, _, e = syscall.RawSyscall(syscall.SYS_RECVMSG, uintptr(ep.sockfd), uintptr(unsafe.Pointer(&ep.msghdr)), syscall.MSG_TRUNC|syscall.MSG_DONTWAIT) + } else { + _, _, e = syscall.Syscall(syscall.SYS_RECVMSG, uintptr(ep.sockfd), uintptr(unsafe.Pointer(&ep.msghdr)), syscall.MSG_TRUNC) + } if e != 0 { return -1, e } @@ -142,5 +139,5 @@ func (ep *Endpoint) recvFD(flags uintptr) (int, error) { func (ep *Endpoint) cmsgData() *int32 { // syscall.CmsgLen(0) == syscall.cmsgAlignOf(syscall.SizeofCmsghdr) - return (*int32)((unsafe.Pointer)(uintptr((unsafe.Pointer)(ep.cmsg)) + uintptr(syscall.CmsgLen(0)))) + return (*int32)(unsafe.Pointer(uintptr(unsafe.Pointer(ep.cmsg)) + uintptr(syscall.CmsgLen(0)))) } |