NetBSD/dist/bind/lib/isc/ev_streams.c

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1999-11-20 21:53:57 +03:00
/* $NetBSD: ev_streams.c,v 1.1.1.1 1999/11/20 18:54:11 veego Exp $ */
/*
* 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM 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 8.21 1999/10/07 20:44:04 vixie 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;
str->timer = timer;
str->flags |= EV_STR_TIMEROK;
return (0);
}
int
evUntimeRW(evContext opaqueCtx, evStreamID id) /*ARGSUSED*/ {
evStream *str = id.opaque;
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 > 0) {
if (bytes < 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;
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;
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);
}