/* $NetBSD: ev_streams.c,v 1.1.1.2 2012/09/09 16:08:03 christos Exp $ */ /* * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") * Copyright (c) 1996-1999 by Internet Software Consortium * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* ev_streams.c - implement asynch stream file IO for the eventlib * vix 04mar96 [initial] */ #if !defined(LINT) && !defined(CODECENTER) static const char rcsid[] = "Id: ev_streams.c,v 1.5 2005/04/27 04:56:36 sra Exp "; #endif #include "port_before.h" #include "fd_setsize.h" #include <sys/types.h> #include <sys/uio.h> #include <errno.h> #include <isc/eventlib.h> #include <isc/assertions.h> #include "eventlib_p.h" #include "port_after.h" static int copyvec(evStream *str, const struct iovec *iov, int iocnt); static void consume(evStream *str, size_t bytes); static void done(evContext opaqueCtx, evStream *str); static void writable(evContext opaqueCtx, void *uap, int fd, int evmask); static void readable(evContext opaqueCtx, void *uap, int fd, int evmask); struct iovec evConsIovec(void *buf, size_t cnt) { struct iovec ret; memset(&ret, 0xf5, sizeof ret); ret.iov_base = buf; ret.iov_len = cnt; return (ret); } int evWrite(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, evStreamFunc func, void *uap, evStreamID *id) { evContext_p *ctx = opaqueCtx.opaque; evStream *new; int save; OKNEW(new); new->func = func; new->uap = uap; new->fd = fd; new->flags = 0; if (evSelectFD(opaqueCtx, fd, EV_WRITE, writable, new, &new->file) < 0) goto free; if (copyvec(new, iov, iocnt) < 0) goto free; new->prevDone = NULL; new->nextDone = NULL; if (ctx->streams != NULL) ctx->streams->prev = new; new->prev = NULL; new->next = ctx->streams; ctx->streams = new; if (id != NULL) id->opaque = new; return (0); free: save = errno; FREE(new); errno = save; return (-1); } int evRead(evContext opaqueCtx, int fd, const struct iovec *iov, int iocnt, evStreamFunc func, void *uap, evStreamID *id) { evContext_p *ctx = opaqueCtx.opaque; evStream *new; int save; OKNEW(new); new->func = func; new->uap = uap; new->fd = fd; new->flags = 0; if (evSelectFD(opaqueCtx, fd, EV_READ, readable, new, &new->file) < 0) goto free; if (copyvec(new, iov, iocnt) < 0) goto free; new->prevDone = NULL; new->nextDone = NULL; if (ctx->streams != NULL) ctx->streams->prev = new; new->prev = NULL; new->next = ctx->streams; ctx->streams = new; if (id) id->opaque = new; return (0); free: save = errno; FREE(new); errno = save; return (-1); } int evTimeRW(evContext opaqueCtx, evStreamID id, evTimerID timer) /*ARGSUSED*/ { evStream *str = id.opaque; UNUSED(opaqueCtx); str->timer = timer; str->flags |= EV_STR_TIMEROK; return (0); } int evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ { evStream *str = id.opaque; UNUSED(opaqueCtx); str->flags &= ~EV_STR_TIMEROK; return (0); } int evCancelRW(evContext opaqueCtx, evStreamID id) { evContext_p *ctx = opaqueCtx.opaque; evStream *old = id.opaque; /* * The streams list is doubly threaded. First, there's ctx->streams * that's used by evDestroy() to find and cancel all streams. Second, * there's ctx->strDone (head) and ctx->strLast (tail) which thread * through the potentially smaller number of "IO completed" streams, * used in evGetNext() to avoid scanning the entire list. */ /* Unlink from ctx->streams. */ if (old->prev != NULL) old->prev->next = old->next; else ctx->streams = old->next; if (old->next != NULL) old->next->prev = old->prev; /* * If 'old' is on the ctx->strDone list, remove it. Update * ctx->strLast if necessary. */ if (old->prevDone == NULL && old->nextDone == NULL) { /* * Either 'old' is the only item on the done list, or it's * not on the done list. If the former, then we unlink it * from the list. If the latter, we leave the list alone. */ if (ctx->strDone == old) { ctx->strDone = NULL; ctx->strLast = NULL; } } else { if (old->prevDone != NULL) old->prevDone->nextDone = old->nextDone; else ctx->strDone = old->nextDone; if (old->nextDone != NULL) old->nextDone->prevDone = old->prevDone; else ctx->strLast = old->prevDone; } /* Deallocate the stream. */ if (old->file.opaque) evDeselectFD(opaqueCtx, old->file); memput(old->iovOrig, sizeof (struct iovec) * old->iovOrigCount); FREE(old); return (0); } /* Copy a scatter/gather vector and initialize a stream handler's IO. */ static int copyvec(evStream *str, const struct iovec *iov, int iocnt) { int i; str->iovOrig = (struct iovec *)memget(sizeof(struct iovec) * iocnt); if (str->iovOrig == NULL) { errno = ENOMEM; return (-1); } str->ioTotal = 0; for (i = 0; i < iocnt; i++) { str->iovOrig[i] = iov[i]; str->ioTotal += iov[i].iov_len; } str->iovOrigCount = iocnt; str->iovCur = str->iovOrig; str->iovCurCount = str->iovOrigCount; str->ioDone = 0; return (0); } /* Pull off or truncate lead iovec(s). */ static void consume(evStream *str, size_t bytes) { while (bytes > 0U) { if (bytes < (size_t)str->iovCur->iov_len) { str->iovCur->iov_len -= bytes; str->iovCur->iov_base = (void *) ((u_char *)str->iovCur->iov_base + bytes); str->ioDone += bytes; bytes = 0; } else { bytes -= str->iovCur->iov_len; str->ioDone += str->iovCur->iov_len; str->iovCur++; str->iovCurCount--; } } } /* Add a stream to Done list and deselect the FD. */ static void done(evContext opaqueCtx, evStream *str) { evContext_p *ctx = opaqueCtx.opaque; if (ctx->strLast != NULL) { str->prevDone = ctx->strLast; ctx->strLast->nextDone = str; ctx->strLast = str; } else { INSIST(ctx->strDone == NULL); ctx->strDone = ctx->strLast = str; } evDeselectFD(opaqueCtx, str->file); str->file.opaque = NULL; /* evDrop() will call evCancelRW() on us. */ } /* Dribble out some bytes on the stream. (Called by evDispatch().) */ static void writable(evContext opaqueCtx, void *uap, int fd, int evmask) { evStream *str = uap; int bytes; UNUSED(evmask); bytes = writev(fd, str->iovCur, str->iovCurCount); if (bytes > 0) { if ((str->flags & EV_STR_TIMEROK) != 0) evTouchIdleTimer(opaqueCtx, str->timer); consume(str, bytes); } else { if (bytes < 0 && errno != EINTR) { str->ioDone = -1; str->ioErrno = errno; } } if (str->ioDone == -1 || str->ioDone == str->ioTotal) done(opaqueCtx, str); } /* Scoop up some bytes from the stream. (Called by evDispatch().) */ static void readable(evContext opaqueCtx, void *uap, int fd, int evmask) { evStream *str = uap; int bytes; UNUSED(evmask); bytes = readv(fd, str->iovCur, str->iovCurCount); if (bytes > 0) { if ((str->flags & EV_STR_TIMEROK) != 0) evTouchIdleTimer(opaqueCtx, str->timer); consume(str, bytes); } else { if (bytes == 0) str->ioDone = 0; else { if (errno != EINTR) { str->ioDone = -1; str->ioErrno = errno; } } } if (str->ioDone <= 0 || str->ioDone == str->ioTotal) done(opaqueCtx, str); } /*! \file */