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/*-
* Copyright (c) 2009 Robert N. M. Watson
* All rights reserved.
*
* This software was developed at the University of Cambridge Computer
* Laboratory with support from a grant from Google, Inc.
*
* 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef _SYS_PROCDESC_H_
#define _SYS_PROCDESC_H_
#ifdef _KERNEL
#include <sys/selinfo.h> /* struct selinfo */
#include <sys/_lock.h>
#include <sys/_mutex.h>
/*-
* struct procdesc describes a process descriptor, and essentially consists
* of two pointers -- one to the file descriptor, and one to the process.
* When both become NULL, the process descriptor will be freed. An important
* invariant is that there is only ever one process descriptor for a process,
* so a single file pointer will suffice.
*
* Locking key:
* (c) - Constant after initial setup.
* (p) - Protected by the process descriptor mutex.
* (r) - Atomic eference count.
* (s) - Protected by selinfo.
* (t) - Protected by the proctree_lock
*/
struct proc;
struct sigio;
struct procdesc {
/*
* Basic process descriptor state: the process, a cache of its pid to
* satisfy queries after the process exits, and process descriptor
* refcount.
*/
struct proc *pd_proc; /* (t) Process. */
pid_t pd_pid; /* (c) Cached pid. */
u_int pd_refcount; /* (r) Reference count. */
/*
* In-flight data and notification of events.
*/
int pd_flags; /* (p) PD_ flags. */
struct selinfo pd_selinfo; /* (p) Event notification. */
struct mtx pd_lock; /* Protect data + events. */
};
/*
* Locking macros for the procdesc itself.
*/
#define PROCDESC_LOCK_DESTROY(pd) mtx_destroy(&(pd)->pd_lock)
#define PROCDESC_LOCK_INIT(pd) mtx_init(&(pd)->pd_lock, "procdesc", NULL, \
MTX_DEF)
#define PROCDESC_LOCK(pd) mtx_lock(&(pd)->pd_lock)
#define PROCDESC_UNLOCK(pd) mtx_unlock(&(pd)->pd_lock)
/*
* Flags for the pd_flags field.
*/
#define PDF_CLOSED 0x00000001 /* Descriptor has closed. */
#define PDF_SELECTED 0x00000002 /* Issue selwakeup(). */
#define PDF_EXITED 0x00000004 /* Process exited. */
#define PDF_DAEMON 0x00000008 /* Don't exit when procdesc closes. */
/*
* In-kernel interfaces to process descriptors.
*/
int procdesc_exit(struct proc *);
int procdesc_find(struct thread *, int fd, cap_rights_t, struct proc **);
int kern_pdgetpid(struct thread *, int fd, cap_rights_t, pid_t *pidp);
void procdesc_new(struct proc *, int);
void procdesc_finit(struct procdesc *, struct file *);
pid_t procdesc_pid(struct file *);
void procdesc_reap(struct proc *);
#else /* !_KERNEL */
/*
* Process descriptor system calls.
*/
struct rusage;
int pdfork(int *, int);
int pdkill(int, int);
int pdgetpid(int, pid_t *);
#endif /* _KERNEL */
/*
* Flags which can be passed to pdfork(2).
*/
#define PD_DAEMON 0x00000001 /* Don't exit when procdesc closes. */
#endif /* !_SYS_PROCDESC_H_ */
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