os161/kern/include/proc.h
2015-12-23 00:50:04 +00:00

102 lines
3.6 KiB
C

/*
* Copyright (c) 2013
* The President and Fellows of Harvard College.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY 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 UNIVERSITY 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.
*/
#ifndef _PROC_H_
#define _PROC_H_
/*
* Definition of a process.
*
* Note: curproc is defined by <current.h>.
*/
#include <spinlock.h>
struct addrspace;
struct thread;
struct vnode;
/*
* Process structure.
*
* Note that we only count the number of threads in each process.
* (And, unless you implement multithreaded user processes, this
* number will not exceed 1 except in kproc.) If you want to know
* exactly which threads are in the process, e.g. for debugging, add
* an array and a sleeplock to protect it. (You can't use a spinlock
* to protect an array because arrays need to be able to call
* kmalloc.)
*
* You will most likely be adding stuff to this structure, so you may
* find you need a sleeplock in here for other reasons as well.
* However, note that p_addrspace must be protected by a spinlock:
* thread_switch needs to be able to fetch the current address space
* without sleeping.
*/
struct proc {
char *p_name; /* Name of this process */
struct spinlock p_lock; /* Lock for this structure */
unsigned p_numthreads; /* Number of threads in this process */
/* VM */
struct addrspace *p_addrspace; /* virtual address space */
/* VFS */
struct vnode *p_cwd; /* current working directory */
/* add more material here as needed */
};
/* This is the process structure for the kernel and for kernel-only threads. */
extern struct proc *kproc;
/* Call once during system startup to allocate data structures. */
void proc_bootstrap(void);
/* Create a fresh process for use by runprogram(). */
struct proc *proc_create_runprogram(const char *name);
/* Destroy a process. */
void proc_destroy(struct proc *proc);
/* Attach a thread to a process. Must not already have a process. */
int proc_addthread(struct proc *proc, struct thread *t);
/* Detach a thread from its process. */
void proc_remthread(struct thread *t);
/* Fetch the address space of the current process. */
struct addrspace *proc_getas(void);
/* Change the address space of the current process, and return the old one. */
struct addrspace *proc_setas(struct addrspace *);
#endif /* _PROC_H_ */