Commit b4cc1627 authored by Han-Wen Nienhuys's avatar Han-Wen Nienhuys

fuse: add pollhack that compiles on Darwin too

parent 6416abc3
package fuse
// Go 1.9 introduces polling for file I/O. The implementation causes
// the runtime's epoll to take up the last GOMAXPROCS slot, and if
// that happens, we won't have any threads left to service FUSE's
// _OP_POLL request. Prevent this by forcing _OP_POLL to happen, so we
// can say ENOSYS and prevent further _OP_POLL requests.
const pollHackName = ".go-fuse-epoll-hack"
const pollHackInode = ^uint64(0)
package fuse
import (
"path/filepath"
"syscall"
"unsafe"
)
type pollFd struct {
Fd int32
Events int16
Revents int16
}
func sysPoll(fds []pollFd, timeout int) (n int, err error) {
r0, _, e1 := syscall.Syscall(syscall.SYS_POLL, uintptr(unsafe.Pointer(&fds[0])),
uintptr(len(fds)), uintptr(timeout))
n = int(r0)
if e1 != 0 {
err = syscall.Errno(e1)
}
return n, err
}
func pollHack(mountPoint string) error {
const (
POLLIN = 0x1
POLLPRI = 0x2
POLLOUT = 0x4
POLLRDHUP = 0x2000
POLLERR = 0x8
POLLHUP = 0x10
)
fd, err := syscall.Open(filepath.Join(mountPoint, pollHackName), syscall.O_CREAT|syscall.O_TRUNC|syscall.O_RDWR, 0644)
if err != nil {
return err
}
pollData := []pollFd{{
Fd: int32(fd),
Events: POLLIN | POLLPRI | POLLOUT,
}}
// Trigger _OP_POLL, so we can say ENOSYS. We don't care about
// the return value.
sysPoll(pollData, 0)
syscall.Close(fd)
return nil
}
package fuse
import (
"path/filepath"
"syscall"
"golang.org/x/sys/unix"
)
func pollHack(mountPoint string) error {
fd, err := syscall.Creat(filepath.Join(mountPoint, pollHackName), syscall.O_CREAT)
if err != nil {
return err
}
pollData := []unix.PollFd{{
Fd: int32(fd),
Events: unix.POLLIN | unix.POLLPRI | unix.POLLOUT,
}}
// Trigger _OP_POLL, so we can say ENOSYS. We don't care about
// the return value.
unix.Poll(pollData, 0)
syscall.Close(fd)
return nil
}
...@@ -15,8 +15,6 @@ import ( ...@@ -15,8 +15,6 @@ import (
"syscall" "syscall"
"time" "time"
"unsafe" "unsafe"
"golang.org/x/sys/unix"
) )
const ( const (
...@@ -57,9 +55,6 @@ type Server struct { ...@@ -57,9 +55,6 @@ type Server struct {
ready chan error ready chan error
} }
const pollHackName = ".go-fuse-epoll-hack"
const pollHackInode = ^uint64(0)
// SetDebug is deprecated. Use MountOptions.Debug instead. // SetDebug is deprecated. Use MountOptions.Debug instead.
func (ms *Server) SetDebug(dbg bool) { func (ms *Server) SetDebug(dbg bool) {
// This will typically trigger the race detector. // This will typically trigger the race detector.
...@@ -598,25 +593,3 @@ func (ms *Server) WaitMount() error { ...@@ -598,25 +593,3 @@ func (ms *Server) WaitMount() error {
} }
return pollHack(ms.mountPoint) return pollHack(ms.mountPoint)
} }
// Go 1.9 introduces polling for file I/O. The implementation causes
// the runtime's epoll to take up the last GOMAXPROCS slot, and if
// that happens, we won't have any threads left to service FUSE's
// _OP_POLL request. Prevent this by forcing _OP_POLL to happen, so we
// can say ENOSYS and prevent further _OP_POLL requests.
func pollHack(mountPoint string) error {
fd, err := syscall.Creat(filepath.Join(mountPoint, pollHackName), syscall.O_CREAT)
if err != nil {
return err
}
pollData := []unix.PollFd{{
Fd: int32(fd),
Events: unix.POLLIN | unix.POLLPRI | unix.POLLOUT,
}}
// Trigger _OP_POLL, so we can say ENOSYS. We don't care about
// the return value.
unix.Poll(pollData, 0)
syscall.Close(fd)
return nil
}
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