Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- /*
- * 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.
- */
- /*
- * Process support.
- *
- * There is (intentionally) not much here; you will need to add stuff
- * and maybe change around what's already present.
- *
- * p_lock is intended to be held when manipulating the pointers in the
- * proc structure, not while doing any significant work with the
- * things they point to. Rearrange this (and/or change it to be a
- * regular lock) as needed.
- *
- * Unless you're implementing multithreaded user processes, the only
- * process that will have more than one thread is the kernel process.
- */
- #include <types.h>
- #include <spl.h>
- #include <proc.h>
- #include <current.h>
- #include <addrspace.h>
- #include <vnode.h>
- //per wait_pid
- #include <synch.h>
- // per l'opzionalità
- #include <opt-pidtable.h>
- #define MAXPROC 64
- /*
- * The process for the kernel; this holds all the kernel-only threads.
- */
- struct proc *kproc;
- struct proc* pidtable[MAXPROC]; //vettore di puntatori
- /*
- * Create a proc structure.
- */
- static
- struct proc *
- proc_create(const char *name)
- {
- struct proc *proc;
- proc = kmalloc(sizeof(*proc));
- if (proc == NULL) {
- return NULL;
- }
- proc->p_name = kstrdup(name);
- if (proc->p_name == NULL) {
- kfree(proc);
- return NULL;
- }
- proc->p_numthreads = 0;
- spinlock_init(&proc->p_lock);
- /* VM fields */
- proc->p_addrspace = NULL;
- /* VFS fields */
- proc->p_cwd = NULL;
- //added by me
- //start at zero, 1 is set when a process ends
- proc->sem = sem_create(name, 0);
- //
- #if OPT_PIDTABLE==1
- proc-> pid = proc_addToTable(proc);
- kprintf("New process assigned pid: %d\n", proc->pid);
- #endif
- return proc;
- }
- /*
- * Destroy a proc structure.
- *
- * Note: nothing currently calls this. Your wait/exit code will
- * probably want to do so.
- */
- void
- proc_destroy(struct proc *proc)
- {
- /*
- * You probably want to destroy and null out much of the
- * process (particularly the address space) at exit time if
- * your wait/exit design calls for the process structure to
- * hang around beyond process exit. Some wait/exit designs
- * do, some don't.
- */
- KASSERT(proc != NULL);
- KASSERT(proc != kproc);
- /*
- * We don't take p_lock in here because we must have the only
- * reference to this structure. (Otherwise it would be
- * incorrect to destroy it.)
- */
- /* VFS fields */
- if (proc->p_cwd) {
- VOP_DECREF(proc->p_cwd);
- proc->p_cwd = NULL;
- }
- /* VM fields */
- if (proc->p_addrspace) {
- /*
- * If p is the current process, remove it safely from
- * p_addrspace before destroying it. This makes sure
- * we don't try to activate the address space while
- * it's being destroyed.
- *
- * Also explicitly deactivate, because setting the
- * address space to NULL won't necessarily do that.
- *
- * (When the address space is NULL, it means the
- * process is kernel-only; in that case it is normally
- * ok if the MMU and MMU- related data structures
- * still refer to the address space of the last
- * process that had one. Then you save work if that
- * process is the next one to run, which isn't
- * uncommon. However, here we're going to destroy the
- * address space, so we need to make sure that nothing
- * in the VM system still refers to it.)
- *
- * The call to as_deactivate() must come after we
- * clear the address space, or a timer interrupt might
- * reactivate the old address space again behind our
- * back.
- *
- * If p is not the current process, still remove it
- * from p_addrspace before destroying it as a
- * precaution. Note that if p is not the current
- * process, in order to be here p must either have
- * never run (e.g. cleaning up after fork failed) or
- * have finished running and exited. It is quite
- * incorrect to destroy the proc structure of some
- * random other process while it's still running...
- */
- struct addrspace *as;
- if (proc == curproc) {
- as = proc_setas(NULL);
- as_deactivate();
- }
- else {
- as = proc->p_addrspace;
- proc->p_addrspace = NULL;
- }
- as_destroy(as);
- }
- KASSERT(proc->p_numthreads == 0);
- spinlock_cleanup(&proc->p_lock);
- sem_destroy(proc->sem);
- #if OPT_PIDTABLE==1
- int value = proc_removeFromTable((int)proc->pid);
- if( value == 0)
- kprintf("Process correctly removed from table\n");
- #endif
- kfree(proc->p_name);
- kfree(proc);
- }
- /*
- * Create the process structure for the kernel.
- */
- void
- proc_bootstrap(void)
- {
- kproc = proc_create("[kernel]");
- if (kproc == NULL) {
- panic("proc_create for kproc failed\n");
- }
- }
- /*
- * Create a fresh proc for use by runprogram.
- *
- * It will have no address space and will inherit the current
- * process's (that is, the kernel menu's) current directory.
- */
- struct proc *
- proc_create_runprogram(const char *name)
- {
- struct proc *newproc;
- newproc = proc_create(name);
- if (newproc == NULL) {
- return NULL;
- }
- /* VM fields */
- newproc->p_addrspace = NULL;
- /* VFS fields */
- /*
- * Lock the current process to copy its current directory.
- * (We don't need to lock the new process, though, as we have
- * the only reference to it.)
- */
- spinlock_acquire(&curproc->p_lock);
- if (curproc->p_cwd != NULL) {
- VOP_INCREF(curproc->p_cwd);
- newproc->p_cwd = curproc->p_cwd;
- }
- spinlock_release(&curproc->p_lock);
- #if OPT_PIDTABLE==1
- newproc-> pid = proc_addToTable(newproc);
- kprintf("New process assigned pid: %d\n", newproc->pid);
- #endif
- return newproc;
- }
- /*
- * Add a thread to a process. Either the thread or the process might
- * or might not be current.
- *
- * Turn off interrupts on the local cpu while changing t_proc, in
- * case it's current, to protect against the as_activate call in
- * the timer interrupt context switch, and any other implicit uses
- * of "curproc".
- */
- int
- proc_addthread(struct proc *proc, struct thread *t)
- {
- int spl;
- KASSERT(t->t_proc == NULL);
- spinlock_acquire(&proc->p_lock);
- proc->p_numthreads++;
- spinlock_release(&proc->p_lock);
- spl = splhigh();
- t->t_proc = proc;
- splx(spl);
- return 0;
- }
- /*
- * Remove a thread from its process. Either the thread or the process
- * might or might not be current.
- *
- * Turn off interrupts on the local cpu while changing t_proc, in
- * case it's current, to protect against the as_activate call in
- * the timer interrupt context switch, and any other implicit uses
- * of "curproc".
- */
- void
- proc_remthread(struct thread *t)
- {
- struct proc *proc;
- int spl;
- proc = t->t_proc;
- KASSERT(proc != NULL);
- spinlock_acquire(&proc->p_lock);
- KASSERT(proc->p_numthreads > 0);
- proc->p_numthreads--;
- spinlock_release(&proc->p_lock);
- spl = splhigh();
- t->t_proc = NULL;
- splx(spl);
- }
- /*
- * Fetch the address space of (the current) process.
- *
- * Caution: address spaces aren't refcounted. If you implement
- * multithreaded processes, make sure to set up a refcount scheme or
- * some other method to make this safe. Otherwise the returned address
- * space might disappear under you.
- */
- struct addrspace *
- proc_getas(void)
- {
- struct addrspace *as;
- struct proc *proc = curproc;
- if (proc == NULL) {
- return NULL;
- }
- spinlock_acquire(&proc->p_lock);
- as = proc->p_addrspace;
- spinlock_release(&proc->p_lock);
- return as;
- }
- /*
- * Change the address space of (the current) process. Return the old
- * one for later restoration or disposal.
- */
- struct addrspace *
- proc_setas(struct addrspace *newas)
- {
- struct addrspace *oldas;
- struct proc *proc = curproc;
- KASSERT(proc != NULL);
- spinlock_acquire(&proc->p_lock);
- oldas = proc->p_addrspace;
- proc->p_addrspace = newas;
- spinlock_release(&proc->p_lock);
- return oldas;
- }
- //added by me
- int
- proc_wait(struct proc *p) { //p è il figlio
- P(p->sem); //il processo si ferma e aspetta
- int status = p->lastStatus;
- /* get address space of current process and destroy */
- while( p->p_numthreads != 0); //destroy si può fare solo quando numthread è 0
- proc_destroy(p);
- //as_destroy(as); // libera as: già fatto in proc destroy
- return status;
- }
- #if OPT_PIDTABLE==1
- // pidtable functions:::::::::::::::::::::
- void proc_initTable(void) {
- int i;
- // 1 e 0 dovrebbero essere vietati
- for( i=2 ; i<MAXPROC ; i++){
- pidtable[i] = NULL;
- }
- }
- int proc_addToTable(struct proc *p) {
- int i;
- // 1 e 0 dovrebbero essere vietati
- for( i=2 ; i<MAXPROC ; i++){
- if(pidtable[i] == NULL ) {
- pidtable[i] = p;
- return i;
- }
- }
- return -1;
- }
- int proc_removeFromTable(int pid) {
- if( pid == 1 || pid == 0)
- return -1;
- //ATTENZIONE: è un altro processo che rimuove spesso
- pidtable[pid] = NULL;
- return 0;
- }
- pid_t proc_getpid(void) {
- return curproc-> pid;
- }
- struct proc* proc_getproc(int pid) {
- return pidtable[pid];
- }
- #endif
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement