[VOL-4291] OfAgent changes for gRPC migration
Change-Id: I8da1db6df49d478ef24ec8f9bd719e9692f48a7f
diff --git a/vendor/golang.org/x/sys/unix/epoll_zos.go b/vendor/golang.org/x/sys/unix/epoll_zos.go
new file mode 100644
index 0000000..cedaf7e
--- /dev/null
+++ b/vendor/golang.org/x/sys/unix/epoll_zos.go
@@ -0,0 +1,221 @@
+// 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)
+}