9239c077f4
timer support. This should be enough for the emulation of h/w periodic timers (and no more) e.g. some of the 8254's more esoteric modes that happen to be used by non-FreeBSD o/s's. Approved by: re@ (blanket)
452 lines
8.7 KiB
C
452 lines
8.7 KiB
C
/*-
|
|
* Copyright (c) 2011 NetApp, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* Micro event library for FreeBSD, designed for a single i/o thread
|
|
* using kqueue, and having events be persistent by default.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/event.h>
|
|
#include <sys/time.h>
|
|
|
|
#include <pthread.h>
|
|
#include <pthread_np.h>
|
|
|
|
#include "mevent.h"
|
|
|
|
#define MEVENT_MAX 64
|
|
|
|
#define MEV_ENABLE 1
|
|
#define MEV_DISABLE 2
|
|
#define MEV_DEL_PENDING 3
|
|
|
|
extern char *vmname;
|
|
|
|
static pthread_t mevent_tid;
|
|
static int mevent_timid = 43;
|
|
static int mevent_pipefd[2];
|
|
static pthread_mutex_t mevent_lmutex = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
struct mevent {
|
|
void (*me_func)(int, enum ev_type, void *);
|
|
#define me_msecs me_fd
|
|
int me_fd;
|
|
int me_timid;
|
|
enum ev_type me_type;
|
|
void *me_param;
|
|
int me_cq;
|
|
int me_state;
|
|
int me_closefd;
|
|
LIST_ENTRY(mevent) me_list;
|
|
};
|
|
|
|
static LIST_HEAD(listhead, mevent) global_head, change_head;
|
|
|
|
static void
|
|
mevent_qlock(void)
|
|
{
|
|
pthread_mutex_lock(&mevent_lmutex);
|
|
}
|
|
|
|
static void
|
|
mevent_qunlock(void)
|
|
{
|
|
pthread_mutex_unlock(&mevent_lmutex);
|
|
}
|
|
|
|
static void
|
|
mevent_pipe_read(int fd, enum ev_type type, void *param)
|
|
{
|
|
char buf[MEVENT_MAX];
|
|
int status;
|
|
|
|
/*
|
|
* Drain the pipe read side. The fd is non-blocking so this is
|
|
* safe to do.
|
|
*/
|
|
do {
|
|
status = read(fd, buf, sizeof(buf));
|
|
} while (status == MEVENT_MAX);
|
|
}
|
|
|
|
static void
|
|
mevent_notify(void)
|
|
{
|
|
char c;
|
|
|
|
/*
|
|
* If calling from outside the i/o thread, write a byte on the
|
|
* pipe to force the i/o thread to exit the blocking kevent call.
|
|
*/
|
|
if (mevent_pipefd[1] != 0 && pthread_self() != mevent_tid) {
|
|
write(mevent_pipefd[1], &c, 1);
|
|
}
|
|
}
|
|
|
|
static int
|
|
mevent_kq_filter(struct mevent *mevp)
|
|
{
|
|
int retval;
|
|
|
|
retval = 0;
|
|
|
|
if (mevp->me_type == EVF_READ)
|
|
retval = EVFILT_READ;
|
|
|
|
if (mevp->me_type == EVF_WRITE)
|
|
retval = EVFILT_WRITE;
|
|
|
|
if (mevp->me_type == EVF_TIMER)
|
|
retval = EVFILT_TIMER;
|
|
|
|
return (retval);
|
|
}
|
|
|
|
static int
|
|
mevent_kq_flags(struct mevent *mevp)
|
|
{
|
|
int ret;
|
|
|
|
switch (mevp->me_state) {
|
|
case MEV_ENABLE:
|
|
ret = EV_ADD;
|
|
if (mevp->me_type == EVF_TIMER)
|
|
ret |= EV_ENABLE;
|
|
break;
|
|
case MEV_DISABLE:
|
|
ret = EV_DISABLE;
|
|
break;
|
|
case MEV_DEL_PENDING:
|
|
ret = EV_DELETE;
|
|
break;
|
|
}
|
|
|
|
return (ret);
|
|
}
|
|
|
|
static int
|
|
mevent_kq_fflags(struct mevent *mevp)
|
|
{
|
|
/* XXX nothing yet, perhaps EV_EOF for reads ? */
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
mevent_build(int mfd, struct kevent *kev)
|
|
{
|
|
struct mevent *mevp, *tmpp;
|
|
int i;
|
|
|
|
i = 0;
|
|
|
|
mevent_qlock();
|
|
|
|
LIST_FOREACH_SAFE(mevp, &change_head, me_list, tmpp) {
|
|
if (mevp->me_closefd) {
|
|
/*
|
|
* A close of the file descriptor will remove the
|
|
* event
|
|
*/
|
|
close(mevp->me_fd);
|
|
} else {
|
|
if (mevp->me_type == EVF_TIMER) {
|
|
kev[i].ident = mevp->me_timid;
|
|
kev[i].data = mevp->me_msecs;
|
|
} else {
|
|
kev[i].ident = mevp->me_fd;
|
|
kev[i].data = 0;
|
|
}
|
|
kev[i].filter = mevent_kq_filter(mevp);
|
|
kev[i].flags = mevent_kq_flags(mevp);
|
|
kev[i].fflags = mevent_kq_fflags(mevp);
|
|
kev[i].udata = mevp;
|
|
i++;
|
|
}
|
|
|
|
mevp->me_cq = 0;
|
|
LIST_REMOVE(mevp, me_list);
|
|
|
|
if (mevp->me_state == MEV_DEL_PENDING) {
|
|
free(mevp);
|
|
} else {
|
|
LIST_INSERT_HEAD(&global_head, mevp, me_list);
|
|
}
|
|
|
|
assert(i < MEVENT_MAX);
|
|
}
|
|
|
|
mevent_qunlock();
|
|
|
|
return (i);
|
|
}
|
|
|
|
static void
|
|
mevent_handle(struct kevent *kev, int numev)
|
|
{
|
|
struct mevent *mevp;
|
|
int i;
|
|
|
|
for (i = 0; i < numev; i++) {
|
|
mevp = kev[i].udata;
|
|
|
|
/* XXX check for EV_ERROR ? */
|
|
|
|
(*mevp->me_func)(mevp->me_fd, mevp->me_type, mevp->me_param);
|
|
}
|
|
}
|
|
|
|
struct mevent *
|
|
mevent_add(int tfd, enum ev_type type,
|
|
void (*func)(int, enum ev_type, void *), void *param)
|
|
{
|
|
struct mevent *lp, *mevp;
|
|
|
|
if (tfd < 0 || func == NULL) {
|
|
return (NULL);
|
|
}
|
|
|
|
mevp = NULL;
|
|
|
|
mevent_qlock();
|
|
|
|
/*
|
|
* Verify that the fd/type tuple is not present in any list
|
|
*/
|
|
LIST_FOREACH(lp, &global_head, me_list) {
|
|
if (type != EVF_TIMER && lp->me_fd == tfd &&
|
|
lp->me_type == type) {
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
LIST_FOREACH(lp, &change_head, me_list) {
|
|
if (type != EVF_TIMER && lp->me_fd == tfd &&
|
|
lp->me_type == type) {
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocate an entry, populate it, and add it to the change list.
|
|
*/
|
|
mevp = malloc(sizeof(struct mevent));
|
|
if (mevp == NULL) {
|
|
goto exit;
|
|
}
|
|
|
|
memset(mevp, 0, sizeof(struct mevent));
|
|
if (type == EVF_TIMER) {
|
|
mevp->me_msecs = tfd;
|
|
mevp->me_timid = mevent_timid++;
|
|
} else
|
|
mevp->me_fd = tfd;
|
|
mevp->me_type = type;
|
|
mevp->me_func = func;
|
|
mevp->me_param = param;
|
|
|
|
LIST_INSERT_HEAD(&change_head, mevp, me_list);
|
|
mevp->me_cq = 1;
|
|
mevp->me_state = MEV_ENABLE;
|
|
mevent_notify();
|
|
|
|
exit:
|
|
mevent_qunlock();
|
|
|
|
return (mevp);
|
|
}
|
|
|
|
static int
|
|
mevent_update(struct mevent *evp, int newstate)
|
|
{
|
|
/*
|
|
* It's not possible to enable/disable a deleted event
|
|
*/
|
|
if (evp->me_state == MEV_DEL_PENDING)
|
|
return (EINVAL);
|
|
|
|
/*
|
|
* No update needed if state isn't changing
|
|
*/
|
|
if (evp->me_state == newstate)
|
|
return (0);
|
|
|
|
mevent_qlock();
|
|
|
|
evp->me_state = newstate;
|
|
|
|
/*
|
|
* Place the entry onto the changed list if not already there.
|
|
*/
|
|
if (evp->me_cq == 0) {
|
|
evp->me_cq = 1;
|
|
LIST_REMOVE(evp, me_list);
|
|
LIST_INSERT_HEAD(&change_head, evp, me_list);
|
|
mevent_notify();
|
|
}
|
|
|
|
mevent_qunlock();
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mevent_enable(struct mevent *evp)
|
|
{
|
|
|
|
return (mevent_update(evp, MEV_ENABLE));
|
|
}
|
|
|
|
int
|
|
mevent_disable(struct mevent *evp)
|
|
{
|
|
|
|
return (mevent_update(evp, MEV_DISABLE));
|
|
}
|
|
|
|
static int
|
|
mevent_delete_event(struct mevent *evp, int closefd)
|
|
{
|
|
mevent_qlock();
|
|
|
|
/*
|
|
* Place the entry onto the changed list if not already there, and
|
|
* mark as to be deleted.
|
|
*/
|
|
if (evp->me_cq == 0) {
|
|
evp->me_cq = 1;
|
|
LIST_REMOVE(evp, me_list);
|
|
LIST_INSERT_HEAD(&change_head, evp, me_list);
|
|
mevent_notify();
|
|
}
|
|
evp->me_state = MEV_DEL_PENDING;
|
|
|
|
if (closefd)
|
|
evp->me_closefd = 1;
|
|
|
|
mevent_qunlock();
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
mevent_delete(struct mevent *evp)
|
|
{
|
|
|
|
return (mevent_delete_event(evp, 0));
|
|
}
|
|
|
|
int
|
|
mevent_delete_close(struct mevent *evp)
|
|
{
|
|
|
|
return (mevent_delete_event(evp, 1));
|
|
}
|
|
|
|
static void
|
|
mevent_set_name(void)
|
|
{
|
|
char tname[MAXCOMLEN + 1];
|
|
|
|
snprintf(tname, sizeof(tname), "%s mevent", vmname);
|
|
pthread_set_name_np(mevent_tid, tname);
|
|
}
|
|
|
|
void
|
|
mevent_dispatch(void)
|
|
{
|
|
struct kevent changelist[MEVENT_MAX];
|
|
struct kevent eventlist[MEVENT_MAX];
|
|
struct mevent *pipev;
|
|
int mfd;
|
|
int numev;
|
|
int ret;
|
|
|
|
mevent_tid = pthread_self();
|
|
mevent_set_name();
|
|
|
|
mfd = kqueue();
|
|
assert(mfd > 0);
|
|
|
|
/*
|
|
* Open the pipe that will be used for other threads to force
|
|
* the blocking kqueue call to exit by writing to it. Set the
|
|
* descriptor to non-blocking.
|
|
*/
|
|
ret = pipe(mevent_pipefd);
|
|
if (ret < 0) {
|
|
perror("pipe");
|
|
exit(0);
|
|
}
|
|
|
|
/*
|
|
* Add internal event handler for the pipe write fd
|
|
*/
|
|
pipev = mevent_add(mevent_pipefd[0], EVF_READ, mevent_pipe_read, NULL);
|
|
assert(pipev != NULL);
|
|
|
|
for (;;) {
|
|
/*
|
|
* Build changelist if required.
|
|
* XXX the changelist can be put into the blocking call
|
|
* to eliminate the extra syscall. Currently better for
|
|
* debug.
|
|
*/
|
|
numev = mevent_build(mfd, changelist);
|
|
if (numev) {
|
|
ret = kevent(mfd, changelist, numev, NULL, 0, NULL);
|
|
if (ret == -1) {
|
|
perror("Error return from kevent change");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Block awaiting events
|
|
*/
|
|
ret = kevent(mfd, NULL, 0, eventlist, MEVENT_MAX, NULL);
|
|
if (ret == -1) {
|
|
perror("Error return from kevent monitor");
|
|
}
|
|
|
|
/*
|
|
* Handle reported events
|
|
*/
|
|
mevent_handle(eventlist, ret);
|
|
}
|
|
}
|