Disengaging imsgev is tricky. First imsgev_clear as we know there
isn't anything left to be written. Signal imsgev termination by
setting iev->terminate = 1(Mind that we are setting it from with
the callback). As imsgev would again callback dispatch with
IMSGEV_DONE, we cannot free imsgev yet. So iev_maildrop need to
exist beyond lifetime of session until IMSGEV_DONE. Allocating it
seperately from session.
imsgev_close is avoided as it schedules another EV_WRITE which is
not needed in our case.
This fixes a crash observed consistently with a little perl script
to simulate concurrent sessions. Thanks MALLOC_OPTIONS='SFG<<'
/*
* Copyright (c) 2009 Eric Faurot <eric@openbsd.org>
*
* 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
#ifndef __IMSGEV_H__
#define __IMSGEV_H__
#include <event.h>
#include <imsg.h>
#define IMSG_LEN(m) ((m)->hdr.len - IMSG_HEADER_SIZE)
struct imsgev {
struct imsgbuf ibuf;
void (*handler)(int, short, void *);
struct event ev;
void *data;
short events;
int terminate;
void (*callback)(struct imsgev *, int, struct imsg *);
void (*needfd)(struct imsgev *);
};
#define IMSGEV_IMSG 0
#define IMSGEV_DONE 1
#define IMSGEV_EREAD 2
#define IMSGEV_EWRITE 3
#define IMSGEV_EIMSG 4
void imsgev_init(struct imsgev *, int, void *, void (*)(struct imsgev *,
int, struct imsg *), void (*)(struct imsgev *));
int imsgev_compose(struct imsgev *, u_int16_t, u_int32_t, u_int32_t, int,
void *, u_int16_t);
void imsgev_close(struct imsgev *);
void imsgev_clear(struct imsgev *);
#endif /* __IMSGEV_H__ */