net: Use preallocated buffer for kqueue/kevent.

R=rsc
CC=golang-dev
https://golang.org/cl/4293056

diff --git a/src/pkg/net/fd_darwin.go b/src/pkg/net/fd_darwin.go
index f1ddd82351884febc50d5c3cd802b062d4fe084c..6ed196324d6dcf89b51314ebc34dcf451d525713 100644 (file)
--- a/src/pkg/net/fd_darwin.go
+++ b/src/pkg/net/fd_darwin.go
@@ -15,6 +15,10 @@ type pollster struct {
        kq       int
        eventbuf [10]syscall.Kevent_t
        events   []syscall.Kevent_t
+
+       // An event buffer for AddFD/DelFD.
+       // Must hold pollServer lock.
+       kbuf [1]syscall.Kevent_t
 }
 
 func newpollster() (p *pollster, err os.Error) {
@@ -28,14 +32,15 @@ func newpollster() (p *pollster, err os.Error) {
 }
 
 func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
+       // pollServer is locked.
+
        var kmode int
        if mode == 'r' {
                kmode = syscall.EVFILT_READ
        } else {
                kmode = syscall.EVFILT_WRITE
        }
-       var events [1]syscall.Kevent_t
-       ev := &events[0]
+       ev := &p.kbuf[0]
        // EV_ADD - add event to kqueue list
        // EV_RECEIPT - generate fake EV_ERROR as result of add,
        //      rather than waiting for real event
@@ -46,7 +51,7 @@ func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
        }
        syscall.SetKevent(ev, fd, kmode, flags)
 
-       n, e := syscall.Kevent(p.kq, events[0:], events[0:], nil)
+       n, e := syscall.Kevent(p.kq, p.kbuf[0:], p.kbuf[0:], nil)
        if e != 0 {
                return os.NewSyscallError("kevent", e)
        }
@@ -60,19 +65,20 @@ func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
 }
 
 func (p *pollster) DelFD(fd int, mode int) {
+       // pollServer is locked.
+
        var kmode int
        if mode == 'r' {
                kmode = syscall.EVFILT_READ
        } else {
                kmode = syscall.EVFILT_WRITE
        }
-       var events [1]syscall.Kevent_t
-       ev := &events[0]
+       ev := &p.kbuf[0]
        // EV_DELETE - delete event from kqueue list
        // EV_RECEIPT - generate fake EV_ERROR as result of add,
        //      rather than waiting for real event
        syscall.SetKevent(ev, fd, kmode, syscall.EV_DELETE|syscall.EV_RECEIPT)
-       syscall.Kevent(p.kq, events[0:], events[0:], nil)
+       syscall.Kevent(p.kq, p.kbuf[0:], p.kbuf[0:], nil)
 }
 
 func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err os.Error) {

diff --git a/src/pkg/net/fd_freebsd.go b/src/pkg/net/fd_freebsd.go
index 0b847a1e730d0bbaf2f47e13aa30d361086bda21..feea92588ab0eedb951b419e52c63e033feff932 100644 (file)
--- a/src/pkg/net/fd_freebsd.go
+++ b/src/pkg/net/fd_freebsd.go
@@ -15,6 +15,10 @@ type pollster struct {
        kq       int
        eventbuf [10]syscall.Kevent_t
        events   []syscall.Kevent_t
+
+       // An event buffer for AddFD/DelFD.
+       // Must hold pollServer lock.
+       kbuf [1]syscall.Kevent_t
 }
 
 func newpollster() (p *pollster, err os.Error) {
@@ -28,14 +32,15 @@ func newpollster() (p *pollster, err os.Error) {
 }
 
 func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
+       // pollServer is locked.
+
        var kmode int
        if mode == 'r' {
                kmode = syscall.EVFILT_READ
        } else {
                kmode = syscall.EVFILT_WRITE
        }
-       var events [1]syscall.Kevent_t
-       ev := &events[0]
+       ev := &p.kbuf[0]
        // EV_ADD - add event to kqueue list
        // EV_ONESHOT - delete the event the first time it triggers
        flags := syscall.EV_ADD
@@ -44,7 +49,7 @@ func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
        }
        syscall.SetKevent(ev, fd, kmode, flags)
 
-       n, e := syscall.Kevent(p.kq, events[:], nil, nil)
+       n, e := syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
        if e != 0 {
                return os.NewSyscallError("kevent", e)
        }
@@ -58,17 +63,18 @@ func (p *pollster) AddFD(fd int, mode int, repeat bool) os.Error {
 }
 
 func (p *pollster) DelFD(fd int, mode int) {
+       // pollServer is locked.
+
        var kmode int
        if mode == 'r' {
                kmode = syscall.EVFILT_READ
        } else {
                kmode = syscall.EVFILT_WRITE
        }
-       var events [1]syscall.Kevent_t
-       ev := &events[0]
+       ev := &p.kbuf[0]
        // EV_DELETE - delete event from kqueue list
        syscall.SetKevent(ev, fd, kmode, syscall.EV_DELETE)
-       syscall.Kevent(p.kq, events[:], nil, nil)
+       syscall.Kevent(p.kq, p.kbuf[:], nil, nil)
 }
 
 func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err os.Error) {