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Diffstat (limited to 'lib/pure/ioselects/ioselectors_epoll.nim')
| -rw-r--r-- | lib/pure/ioselects/ioselectors_epoll.nim | 534 |
1 files changed, 534 insertions, 0 deletions
diff --git a/lib/pure/ioselects/ioselectors_epoll.nim b/lib/pure/ioselects/ioselectors_epoll.nim new file mode 100644 index 000000000..10658b78e --- /dev/null +++ b/lib/pure/ioselects/ioselectors_epoll.nim @@ -0,0 +1,534 @@ +# +# +# Nim's Runtime Library +# (c) Copyright 2016 Eugene Kabanov +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +# This module implements Linux epoll(). + +import std/[posix, times, epoll] + +# Maximum number of events that can be returned +const MAX_EPOLL_EVENTS = 64 + +when not defined(android): + type + SignalFdInfo* {.importc: "struct signalfd_siginfo", + header: "<sys/signalfd.h>", pure, final.} = object + ssi_signo*: uint32 + ssi_errno*: int32 + ssi_code*: int32 + ssi_pid*: uint32 + ssi_uid*: uint32 + ssi_fd*: int32 + ssi_tid*: uint32 + ssi_band*: uint32 + ssi_overrun*: uint32 + ssi_trapno*: uint32 + ssi_status*: int32 + ssi_int*: int32 + ssi_ptr*: uint64 + ssi_utime*: uint64 + ssi_stime*: uint64 + ssi_addr*: uint64 + pad* {.importc: "__pad".}: array[0..47, uint8] + +proc timerfd_create(clock_id: ClockId, flags: cint): cint + {.cdecl, importc: "timerfd_create", header: "<sys/timerfd.h>".} +proc timerfd_settime(ufd: cint, flags: cint, + utmr: var Itimerspec, otmr: var Itimerspec): cint + {.cdecl, importc: "timerfd_settime", header: "<sys/timerfd.h>".} +proc eventfd(count: cuint, flags: cint): cint + {.cdecl, importc: "eventfd", header: "<sys/eventfd.h>".} + +when not defined(android): + proc signalfd(fd: cint, mask: var Sigset, flags: cint): cint + {.cdecl, importc: "signalfd", header: "<sys/signalfd.h>".} + +when hasThreadSupport: + type + SelectorImpl[T] = object + epollFD: cint + maxFD: int + numFD: int + fds: ptr SharedArray[SelectorKey[T]] + count*: int + Selector*[T] = ptr SelectorImpl[T] +else: + type + SelectorImpl[T] = object + epollFD: cint + maxFD: int + numFD: int + fds: seq[SelectorKey[T]] + count*: int + Selector*[T] = ref SelectorImpl[T] +type + SelectEventImpl = object + efd: cint + SelectEvent* = ptr SelectEventImpl + +proc newSelector*[T](): Selector[T] = + proc initialNumFD(): int {.inline.} = + when defined(nuttx): + result = NEPOLL_MAX + else: + result = 1024 + # Retrieve the maximum fd count (for current OS) via getrlimit() + var maxFD = maxDescriptors() + doAssert(maxFD > 0) + # Start with a reasonable size, checkFd() will grow this on demand + let numFD = initialNumFD() + + var epollFD = epoll_create1(O_CLOEXEC) + if epollFD < 0: + raiseOSError(osLastError()) + + when hasThreadSupport: + result = cast[Selector[T]](allocShared0(sizeof(SelectorImpl[T]))) + result.epollFD = epollFD + result.maxFD = maxFD + result.numFD = numFD + result.fds = allocSharedArray[SelectorKey[T]](numFD) + else: + result = Selector[T]() + result.epollFD = epollFD + result.maxFD = maxFD + result.numFD = numFD + result.fds = newSeq[SelectorKey[T]](numFD) + + for i in 0 ..< numFD: + result.fds[i].ident = InvalidIdent + +proc close*[T](s: Selector[T]) = + let res = posix.close(s.epollFD) + when hasThreadSupport: + deallocSharedArray(s.fds) + deallocShared(cast[pointer](s)) + if res != 0: + raiseIOSelectorsError(osLastError()) + +proc newSelectEvent*(): SelectEvent = + let fdci = eventfd(0, O_CLOEXEC or O_NONBLOCK) + if fdci == -1: + raiseIOSelectorsError(osLastError()) + result = cast[SelectEvent](allocShared0(sizeof(SelectEventImpl))) + result.efd = fdci + +proc trigger*(ev: SelectEvent) = + var data: uint64 = 1 + if posix.write(ev.efd, addr data, sizeof(uint64)) == -1: + raiseIOSelectorsError(osLastError()) + +proc close*(ev: SelectEvent) = + let res = posix.close(ev.efd) + deallocShared(cast[pointer](ev)) + if res != 0: + raiseIOSelectorsError(osLastError()) + +template checkFd(s, f) = + # TODO: I don't see how this can ever happen. You won't be able to create an + # FD if there is too many. -- DP + if f >= s.maxFD: + raiseIOSelectorsError("Maximum number of descriptors is exhausted!") + if f >= s.numFD: + var numFD = s.numFD + while numFD <= f: numFD *= 2 + when hasThreadSupport: + s.fds = reallocSharedArray(s.fds, s.numFD, numFD) + else: + s.fds.setLen(numFD) + for i in s.numFD ..< numFD: + s.fds[i].ident = InvalidIdent + s.numFD = numFD + +proc registerHandle*[T](s: Selector[T], fd: int | SocketHandle, + events: set[Event], data: T) = + let fdi = int(fd) + s.checkFd(fdi) + doAssert(s.fds[fdi].ident == InvalidIdent, "Descriptor $# already registered" % $fdi) + s.setKey(fdi, events, 0, data) + if events != {}: + var epv = EpollEvent(events: EPOLLRDHUP) + epv.data.u64 = fdi.uint + if Event.Read in events: epv.events = epv.events or EPOLLIN + if Event.Write in events: epv.events = epv.events or EPOLLOUT + if epoll_ctl(s.epollFD, EPOLL_CTL_ADD, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + inc(s.count) + +proc updateHandle*[T](s: Selector[T], fd: int | SocketHandle, events: set[Event]) = + let maskEvents = {Event.Timer, Event.Signal, Event.Process, Event.Vnode, + Event.User, Event.Oneshot, Event.Error} + let fdi = int(fd) + s.checkFd(fdi) + var pkey = addr(s.fds[fdi]) + doAssert(pkey.ident != InvalidIdent, + "Descriptor $# is not registered in the selector!" % $fdi) + doAssert(pkey.events * maskEvents == {}) + if pkey.events != events: + var epv = EpollEvent(events: EPOLLRDHUP) + epv.data.u64 = fdi.uint + + if Event.Read in events: epv.events = epv.events or EPOLLIN + if Event.Write in events: epv.events = epv.events or EPOLLOUT + + if pkey.events == {}: + if epoll_ctl(s.epollFD, EPOLL_CTL_ADD, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + inc(s.count) + else: + if events != {}: + if epoll_ctl(s.epollFD, EPOLL_CTL_MOD, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + else: + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + dec(s.count) + pkey.events = events + +proc unregister*[T](s: Selector[T], fd: int|SocketHandle) = + let fdi = int(fd) + s.checkFd(fdi) + var pkey = addr(s.fds[fdi]) + doAssert(pkey.ident != InvalidIdent, + "Descriptor $# is not registered in the selector!" % $fdi) + if pkey.events != {}: + when not defined(android): + if Event.Read in pkey.events or Event.Write in pkey.events or Event.User in pkey.events: + var epv = EpollEvent() + # TODO: Refactor all these EPOLL_CTL_DEL + dec(s.count) into a proc. + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + dec(s.count) + elif Event.Timer in pkey.events: + if Event.Finished notin pkey.events: + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + dec(s.count) + if posix.close(cint(fdi)) != 0: + raiseIOSelectorsError(osLastError()) + elif Event.Signal in pkey.events: + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + var nmask, omask: Sigset + discard sigemptyset(nmask) + discard sigemptyset(omask) + discard sigaddset(nmask, cint(s.fds[fdi].param)) + unblockSignals(nmask, omask) + dec(s.count) + if posix.close(cint(fdi)) != 0: + raiseIOSelectorsError(osLastError()) + elif Event.Process in pkey.events: + if Event.Finished notin pkey.events: + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + var nmask, omask: Sigset + discard sigemptyset(nmask) + discard sigemptyset(omask) + discard sigaddset(nmask, SIGCHLD) + unblockSignals(nmask, omask) + dec(s.count) + if posix.close(cint(fdi)) != 0: + raiseIOSelectorsError(osLastError()) + else: + if Event.Read in pkey.events or Event.Write in pkey.events or Event.User in pkey.events: + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + dec(s.count) + elif Event.Timer in pkey.events: + if Event.Finished notin pkey.events: + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + dec(s.count) + if posix.close(cint(fdi)) != 0: + raiseIOSelectorsError(osLastError()) + clearKey(pkey) + +proc unregister*[T](s: Selector[T], ev: SelectEvent) = + let fdi = int(ev.efd) + s.checkFd(fdi) + var pkey = addr(s.fds[fdi]) + doAssert(pkey.ident != InvalidIdent, "Event is not registered in the queue!") + doAssert(Event.User in pkey.events) + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + dec(s.count) + clearKey(pkey) + +proc registerTimer*[T](s: Selector[T], timeout: int, oneshot: bool, + data: T): int {.discardable.} = + var + newTs: Itimerspec + oldTs: Itimerspec + let fdi = timerfd_create(CLOCK_MONOTONIC, O_CLOEXEC or O_NONBLOCK).int + if fdi == -1: + raiseIOSelectorsError(osLastError()) + + s.checkFd(fdi) + doAssert(s.fds[fdi].ident == InvalidIdent) + + var events = {Event.Timer} + var epv = EpollEvent(events: EPOLLIN or EPOLLRDHUP) + epv.data.u64 = fdi.uint + + if oneshot: + newTs.it_interval.tv_sec = posix.Time(0) + newTs.it_interval.tv_nsec = 0 + newTs.it_value.tv_sec = posix.Time(timeout div 1_000) + newTs.it_value.tv_nsec = (timeout %% 1_000) * 1_000_000 + incl(events, Event.Oneshot) + epv.events = epv.events or EPOLLONESHOT + else: + newTs.it_interval.tv_sec = posix.Time(timeout div 1000) + newTs.it_interval.tv_nsec = (timeout %% 1_000) * 1_000_000 + newTs.it_value.tv_sec = newTs.it_interval.tv_sec + newTs.it_value.tv_nsec = newTs.it_interval.tv_nsec + + if timerfd_settime(fdi.cint, cint(0), newTs, oldTs) != 0: + raiseIOSelectorsError(osLastError()) + if epoll_ctl(s.epollFD, EPOLL_CTL_ADD, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + s.setKey(fdi, events, 0, data) + inc(s.count) + result = fdi + +when not defined(android): + proc registerSignal*[T](s: Selector[T], signal: int, + data: T): int {.discardable.} = + var + nmask: Sigset + omask: Sigset + + discard sigemptyset(nmask) + discard sigemptyset(omask) + discard sigaddset(nmask, cint(signal)) + blockSignals(nmask, omask) + + let fdi = signalfd(-1, nmask, O_CLOEXEC or O_NONBLOCK).int + if fdi == -1: + raiseIOSelectorsError(osLastError()) + + s.checkFd(fdi) + doAssert(s.fds[fdi].ident == InvalidIdent) + + var epv = EpollEvent(events: EPOLLIN or EPOLLRDHUP) + epv.data.u64 = fdi.uint + if epoll_ctl(s.epollFD, EPOLL_CTL_ADD, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + s.setKey(fdi, {Event.Signal}, signal, data) + inc(s.count) + result = fdi + + proc registerProcess*[T](s: Selector, pid: int, + data: T): int {.discardable.} = + var + nmask: Sigset + omask: Sigset + + discard sigemptyset(nmask) + discard sigemptyset(omask) + discard sigaddset(nmask, posix.SIGCHLD) + blockSignals(nmask, omask) + + let fdi = signalfd(-1, nmask, O_CLOEXEC or O_NONBLOCK).int + if fdi == -1: + raiseIOSelectorsError(osLastError()) + + s.checkFd(fdi) + doAssert(s.fds[fdi].ident == InvalidIdent) + + var epv = EpollEvent(events: EPOLLIN or EPOLLRDHUP) + epv.data.u64 = fdi.uint + epv.events = EPOLLIN or EPOLLRDHUP + if epoll_ctl(s.epollFD, EPOLL_CTL_ADD, fdi.cint, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + s.setKey(fdi, {Event.Process, Event.Oneshot}, pid, data) + inc(s.count) + result = fdi + +proc registerEvent*[T](s: Selector[T], ev: SelectEvent, data: T) = + let fdi = int(ev.efd) + doAssert(s.fds[fdi].ident == InvalidIdent, "Event is already registered in the queue!") + s.setKey(fdi, {Event.User}, 0, data) + var epv = EpollEvent(events: EPOLLIN or EPOLLRDHUP) + epv.data.u64 = ev.efd.uint + if epoll_ctl(s.epollFD, EPOLL_CTL_ADD, ev.efd, addr epv) != 0: + raiseIOSelectorsError(osLastError()) + inc(s.count) + +proc selectInto*[T](s: Selector[T], timeout: int, + results: var openArray[ReadyKey]): int = + var + resTable: array[MAX_EPOLL_EVENTS, EpollEvent] + maxres = MAX_EPOLL_EVENTS + i, k: int + + if maxres > len(results): + maxres = len(results) + + verifySelectParams(timeout) + + let count = epoll_wait(s.epollFD, addr(resTable[0]), maxres.cint, + timeout.cint) + if count < 0: + result = 0 + let err = osLastError() + if cint(err) != EINTR: + raiseIOSelectorsError(err) + elif count == 0: + result = 0 + else: + i = 0 + k = 0 + while i < count: + let fdi = int(resTable[i].data.u64) + let pevents = resTable[i].events + var pkey = addr(s.fds[fdi]) + doAssert(pkey.ident != InvalidIdent) + var rkey = ReadyKey(fd: fdi, events: {}) + + if (pevents and EPOLLERR) != 0 or (pevents and EPOLLHUP) != 0: + if (pevents and EPOLLHUP) != 0: + rkey.errorCode = OSErrorCode ECONNRESET + else: + # Try reading SO_ERROR from fd. + var error: cint + var size = SockLen sizeof(error) + if getsockopt(SocketHandle fdi, SOL_SOCKET, SO_ERROR, addr(error), + addr(size)) == 0'i32: + rkey.errorCode = OSErrorCode error + + rkey.events.incl(Event.Error) + if (pevents and EPOLLOUT) != 0: + rkey.events.incl(Event.Write) + when not defined(android): + if (pevents and EPOLLIN) != 0: + if Event.Read in pkey.events: + rkey.events.incl(Event.Read) + elif Event.Timer in pkey.events: + var data: uint64 = 0 + if posix.read(cint(fdi), addr data, + sizeof(uint64)) != sizeof(uint64): + raiseIOSelectorsError(osLastError()) + rkey.events.incl(Event.Timer) + elif Event.Signal in pkey.events: + var data = SignalFdInfo() + if posix.read(cint(fdi), addr data, + sizeof(SignalFdInfo)) != sizeof(SignalFdInfo): + raiseIOSelectorsError(osLastError()) + rkey.events.incl(Event.Signal) + elif Event.Process in pkey.events: + var data = SignalFdInfo() + if posix.read(cint(fdi), addr data, + sizeof(SignalFdInfo)) != sizeof(SignalFdInfo): + raiseIOSelectorsError(osLastError()) + if cast[int](data.ssi_pid) == pkey.param: + rkey.events.incl(Event.Process) + else: + inc(i) + continue + elif Event.User in pkey.events: + var data: uint64 = 0 + if posix.read(cint(fdi), addr data, + sizeof(uint64)) != sizeof(uint64): + let err = osLastError() + if err == OSErrorCode(EAGAIN): + inc(i) + continue + else: + raiseIOSelectorsError(err) + rkey.events.incl(Event.User) + else: + if (pevents and EPOLLIN) != 0: + if Event.Read in pkey.events: + rkey.events.incl(Event.Read) + elif Event.Timer in pkey.events: + var data: uint64 = 0 + if posix.read(cint(fdi), addr data, + sizeof(uint64)) != sizeof(uint64): + raiseIOSelectorsError(osLastError()) + rkey.events.incl(Event.Timer) + elif Event.User in pkey.events: + var data: uint64 = 0 + if posix.read(cint(fdi), addr data, + sizeof(uint64)) != sizeof(uint64): + let err = osLastError() + if err == OSErrorCode(EAGAIN): + inc(i) + continue + else: + raiseIOSelectorsError(err) + rkey.events.incl(Event.User) + + if Event.Oneshot in pkey.events: + var epv = EpollEvent() + if epoll_ctl(s.epollFD, EPOLL_CTL_DEL, cint(fdi), addr epv) != 0: + raiseIOSelectorsError(osLastError()) + # we will not clear key until it will be unregistered, so + # application can obtain data, but we will decrease counter, + # because epoll is empty. + dec(s.count) + # we are marking key with `Finished` event, to avoid double decrease. + pkey.events.incl(Event.Finished) + + results[k] = rkey + inc(k) + inc(i) + result = k + +proc select*[T](s: Selector[T], timeout: int): seq[ReadyKey] = + result = newSeq[ReadyKey](MAX_EPOLL_EVENTS) + let count = selectInto(s, timeout, result) + result.setLen(count) + +template isEmpty*[T](s: Selector[T]): bool = + (s.count == 0) + +proc contains*[T](s: Selector[T], fd: SocketHandle|int): bool {.inline.} = + return s.fds[fd.int].ident != InvalidIdent + +proc getData*[T](s: Selector[T], fd: SocketHandle|int): var T = + let fdi = int(fd) + s.checkFd(fdi) + if fdi in s: + result = s.fds[fdi].data + +proc setData*[T](s: Selector[T], fd: SocketHandle|int, data: T): bool = + let fdi = int(fd) + s.checkFd(fdi) + if fdi in s: + s.fds[fdi].data = data + result = true + +template withData*[T](s: Selector[T], fd: SocketHandle|int, value, + body: untyped) = + mixin checkFd + let fdi = int(fd) + s.checkFd(fdi) + if fdi in s: + var value = addr(s.fds[fdi].data) + body + +template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1, + body2: untyped) = + mixin checkFd + let fdi = int(fd) + s.checkFd(fdi) + if fdi in s: + var value = addr(s.fds[fdi].data) + body1 + else: + body2 + +proc getFd*[T](s: Selector[T]): int = + return s.epollFD.int |