diff options
Diffstat (limited to 'vendor/golang.org/x/sys/unix/epoll_zos.go')
| -rw-r--r-- | vendor/golang.org/x/sys/unix/epoll_zos.go | 221 |
1 files changed, 0 insertions, 221 deletions
diff --git a/vendor/golang.org/x/sys/unix/epoll_zos.go b/vendor/golang.org/x/sys/unix/epoll_zos.go deleted file mode 100644 index cedaf7e..0000000 --- a/vendor/golang.org/x/sys/unix/epoll_zos.go +++ /dev/null @@ -1,221 +0,0 @@ -// Copyright 2020 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. - -//go:build zos && s390x -// +build zos,s390x - -package unix - -import ( - "sync" -) - -// This file simulates epoll on z/OS using poll. - -// Analogous to epoll_event on Linux. -// TODO(neeilan): Pad is because the Linux kernel expects a 96-bit struct. We never pass this to the kernel; remove? -type EpollEvent struct { - Events uint32 - Fd int32 - Pad int32 -} - -const ( - EPOLLERR = 0x8 - EPOLLHUP = 0x10 - EPOLLIN = 0x1 - EPOLLMSG = 0x400 - EPOLLOUT = 0x4 - EPOLLPRI = 0x2 - EPOLLRDBAND = 0x80 - EPOLLRDNORM = 0x40 - EPOLLWRBAND = 0x200 - EPOLLWRNORM = 0x100 - EPOLL_CTL_ADD = 0x1 - EPOLL_CTL_DEL = 0x2 - EPOLL_CTL_MOD = 0x3 - // The following constants are part of the epoll API, but represent - // currently unsupported functionality on z/OS. - // EPOLL_CLOEXEC = 0x80000 - // EPOLLET = 0x80000000 - // EPOLLONESHOT = 0x40000000 - // EPOLLRDHUP = 0x2000 // Typically used with edge-triggered notis - // EPOLLEXCLUSIVE = 0x10000000 // Exclusive wake-up mode - // EPOLLWAKEUP = 0x20000000 // Relies on Linux's BLOCK_SUSPEND capability -) - -// TODO(neeilan): We can eliminate these epToPoll / pToEpoll calls by using identical mask values for POLL/EPOLL -// constants where possible The lower 16 bits of epoll events (uint32) can fit any system poll event (int16). - -// epToPollEvt converts epoll event field to poll equivalent. -// In epoll, Events is a 32-bit field, while poll uses 16 bits. -func epToPollEvt(events uint32) int16 { - var ep2p = map[uint32]int16{ - EPOLLIN: POLLIN, - EPOLLOUT: POLLOUT, - EPOLLHUP: POLLHUP, - EPOLLPRI: POLLPRI, - EPOLLERR: POLLERR, - } - - var pollEvts int16 = 0 - for epEvt, pEvt := range ep2p { - if (events & epEvt) != 0 { - pollEvts |= pEvt - } - } - - return pollEvts -} - -// pToEpollEvt converts 16 bit poll event bitfields to 32-bit epoll event fields. -func pToEpollEvt(revents int16) uint32 { - var p2ep = map[int16]uint32{ - POLLIN: EPOLLIN, - POLLOUT: EPOLLOUT, - POLLHUP: EPOLLHUP, - POLLPRI: EPOLLPRI, - POLLERR: EPOLLERR, - } - - var epollEvts uint32 = 0 - for pEvt, epEvt := range p2ep { - if (revents & pEvt) != 0 { - epollEvts |= epEvt - } - } - - return epollEvts -} - -// Per-process epoll implementation. -type epollImpl struct { - mu sync.Mutex - epfd2ep map[int]*eventPoll - nextEpfd int -} - -// eventPoll holds a set of file descriptors being watched by the process. A process can have multiple epoll instances. -// On Linux, this is an in-kernel data structure accessed through a fd. -type eventPoll struct { - mu sync.Mutex - fds map[int]*EpollEvent -} - -// epoll impl for this process. -var impl epollImpl = epollImpl{ - epfd2ep: make(map[int]*eventPoll), - nextEpfd: 0, -} - -func (e *epollImpl) epollcreate(size int) (epfd int, err error) { - e.mu.Lock() - defer e.mu.Unlock() - epfd = e.nextEpfd - e.nextEpfd++ - - e.epfd2ep[epfd] = &eventPoll{ - fds: make(map[int]*EpollEvent), - } - return epfd, nil -} - -func (e *epollImpl) epollcreate1(flag int) (fd int, err error) { - return e.epollcreate(4) -} - -func (e *epollImpl) epollctl(epfd int, op int, fd int, event *EpollEvent) (err error) { - e.mu.Lock() - defer e.mu.Unlock() - - ep, ok := e.epfd2ep[epfd] - if !ok { - - return EBADF - } - - switch op { - case EPOLL_CTL_ADD: - // TODO(neeilan): When we make epfds and fds disjoint, detect epoll - // loops here (instances watching each other) and return ELOOP. - if _, ok := ep.fds[fd]; ok { - return EEXIST - } - ep.fds[fd] = event - case EPOLL_CTL_MOD: - if _, ok := ep.fds[fd]; !ok { - return ENOENT - } - ep.fds[fd] = event - case EPOLL_CTL_DEL: - if _, ok := ep.fds[fd]; !ok { - return ENOENT - } - delete(ep.fds, fd) - - } - return nil -} - -// Must be called while holding ep.mu -func (ep *eventPoll) getFds() []int { - fds := make([]int, len(ep.fds)) - for fd := range ep.fds { - fds = append(fds, fd) - } - return fds -} - -func (e *epollImpl) epollwait(epfd int, events []EpollEvent, msec int) (n int, err error) { - e.mu.Lock() // in [rare] case of concurrent epollcreate + epollwait - ep, ok := e.epfd2ep[epfd] - - if !ok { - e.mu.Unlock() - return 0, EBADF - } - - pollfds := make([]PollFd, 4) - for fd, epollevt := range ep.fds { - pollfds = append(pollfds, PollFd{Fd: int32(fd), Events: epToPollEvt(epollevt.Events)}) - } - e.mu.Unlock() - - n, err = Poll(pollfds, msec) - if err != nil { - return n, err - } - - i := 0 - for _, pFd := range pollfds { - if pFd.Revents != 0 { - events[i] = EpollEvent{Fd: pFd.Fd, Events: pToEpollEvt(pFd.Revents)} - i++ - } - - if i == n { - break - } - } - - return n, nil -} - -func EpollCreate(size int) (fd int, err error) { - return impl.epollcreate(size) -} - -func EpollCreate1(flag int) (fd int, err error) { - return impl.epollcreate1(flag) -} - -func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) { - return impl.epollctl(epfd, op, fd, event) -} - -// Because EpollWait mutates events, the caller is expected to coordinate -// concurrent access if calling with the same epfd from multiple goroutines. -func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) { - return impl.epollwait(epfd, events, msec) -} |