From b6095304b7ee2b69d2ee4a9a7265999d1a2b9675 Mon Sep 17 00:00:00 2001
From: rsc <rsc>
Date: Fri, 10 Aug 2007 16:37:27 +0000
Subject: [PATCH] Make cp a magic symbol.
---
console.c | 2 +-
fs.c | 11 +++++------
kalloc.c | 14 ++++++--------
pipe.c | 4 ++--
proc.c | 14 ++++----------
proc.h | 10 ++++++++++
syscall.c | 5 +----
sysfile.c | 7 +------
sysproc.c | 5 ++---
trap.c | 1 -
10 files changed, 32 insertions(+), 41 deletions(-)
diff --git a/console.c b/console.c
index cd52570..d119a29 100644
--- a/console.c
+++ b/console.c
@@ -397,7 +397,7 @@ console_read(int minor, char *dst, int n)
acquire(&kbd_lock);
while(n > 0){
while(kbd_r == kbd_w){
- if(curproc[cpu()]->killed){
+ if(cp->killed){
release(&kbd_lock);
return -1;
}
diff --git a/fs.c b/fs.c
index 7c5e0ca..66d8c73 100644
--- a/fs.c
+++ b/fs.c
@@ -557,7 +557,6 @@ namei(char *path, int mode, uint *ret_off,
char **ret_last, struct inode **ret_ip)
{
struct inode *dp;
- struct proc *cp = curproc[cpu()];
char *name;
int namelen;
uint off, dev, inum;
@@ -648,15 +647,15 @@ wdir(struct inode *dp, char *name, uint ino)
panic("wdir write");
}
-// Create the path cp and return its locked inode structure.
+// Create the path and return its locked inode structure.
// If cp already exists, return 0.
struct inode*
-mknod(char *cp, short type, short major, short minor)
+mknod(char *path, short type, short major, short minor)
{
struct inode *ip, *dp;
char *last;
- if((dp = namei(cp, NAMEI_CREATE, 0, &last, 0)) == 0)
+ if((dp = namei(path, NAMEI_CREATE, 0, &last, 0)) == 0)
return 0;
ip = mknod1(dp, last, type, major, minor);
@@ -691,13 +690,13 @@ mknod1(struct inode *dp, char *name, short type, short major, short minor)
// Unlink the inode named cp.
int
-unlink(char *cp)
+unlink(char *path)
{
struct inode *ip, *dp;
struct dirent de;
uint off, inum, dev;
- dp = namei(cp, NAMEI_DELETE, &off, 0, 0);
+ dp = namei(path, NAMEI_DELETE, &off, 0, 0);
if(dp == 0)
return -1;
diff --git a/kalloc.c b/kalloc.c
index bfa9207..cc2faac 100644
--- a/kalloc.c
+++ b/kalloc.c
@@ -40,24 +40,22 @@ kinit(void)
kfree(start, mem * PAGE);
}
-// Free the len bytes of memory pointed at by cp,
+// Free the len bytes of memory pointed at by v,
// which normally should have been returned by a
-// call to kalloc(cp). (The exception is when
+// call to kalloc(len). (The exception is when
// initializing the allocator; see kinit above.)
void
-kfree(char *cp, int len)
+kfree(char *v, int len)
{
struct run **rr;
- struct run *p = (struct run*) cp;
- struct run *pend = (struct run*) (cp + len);
- int i;
+ struct run *p = (struct run*)v;
+ struct run *pend = (struct run*)(v + len);
if(len % PAGE)
panic("kfree");
// Fill with junk to catch dangling refs.
- for(i = 0; i < len; i++)
- cp[i] = 1;
+ memset(v, 1, len);
acquire(&kalloc_lock);
diff --git a/pipe.c b/pipe.c
index 284d4ee..b866a0e 100644
--- a/pipe.c
+++ b/pipe.c
@@ -87,7 +87,7 @@ pipe_write(struct pipe *p, char *addr, int n)
for(i = 0; i < n; i++){
while(((p->writep + 1) % PIPESIZE) == p->readp){
- if(p->readopen == 0 || curproc[cpu()]->killed){
+ if(p->readopen == 0 || cp->killed){
release(&p->lock);
return -1;
}
@@ -111,7 +111,7 @@ pipe_read(struct pipe *p, char *addr, int n)
acquire(&p->lock);
while(p->readp == p->writep){
- if(p->writeopen == 0 || curproc[cpu()]->killed){
+ if(p->writeopen == 0 || cp->killed){
release(&p->lock);
return 0;
}
diff --git a/proc.c b/proc.c
index 89eb1d4..6df3814 100644
--- a/proc.c
+++ b/proc.c
@@ -59,7 +59,6 @@ setupsegs(struct proc *p)
int
growproc(int n)
{
- struct proc *cp = curproc[cpu()];
char *newmem, *oldmem;
newmem = kalloc(cp->sz + n);
@@ -183,14 +182,14 @@ scheduler(void)
// before jumping back to us.
setupsegs(p);
- curproc[cpu()] = p;
+ cp = p;
p->state = RUNNING;
if(setjmp(&cpus[cpu()].jmpbuf) == 0)
longjmp(&p->jmpbuf);
// Process is done running for now.
// It should have changed its p->state before coming back.
- curproc[cpu()] = 0;
+ cp = 0;
setupsegs(0);
}
@@ -204,7 +203,6 @@ scheduler(void)
void
sched(void)
{
- struct proc *cp = curproc[cpu()];
if(cp->state == RUNNING)
panic("sched running");
@@ -213,7 +211,7 @@ sched(void)
if(cpus[cpu()].nlock != 1)
panic("sched locks");
- if(setjmp(&p->jmpbuf) == 0)
+ if(setjmp(&cp->jmpbuf) == 0)
longjmp(&cpus[cpu()].jmpbuf);
}
@@ -221,7 +219,6 @@ sched(void)
void
yield(void)
{
- struct proc *cp = curproc[cpu()];
acquire(&proc_table_lock);
cp->state = RUNNABLE;
@@ -238,7 +235,7 @@ forkret(void)
release(&proc_table_lock);
// Jump into assembly, never to return.
- forkret1(curproc[cpu()]->tf);
+ forkret1(cp->tf);
}
// Atomically release lock and sleep on chan.
@@ -246,7 +243,6 @@ forkret(void)
void
sleep(void *chan, struct spinlock *lk)
{
- struct proc *cp = curproc[cpu()];
if(cp == 0)
panic("sleep");
@@ -332,7 +328,6 @@ void
proc_exit(void)
{
struct proc *p;
- struct proc *cp = curproc[cpu()];
int fd;
if(cp->pid == 1)
@@ -376,7 +371,6 @@ int
proc_wait(void)
{
struct proc *p;
- struct proc *cp = curproc[cpu()];
int i, havekids, pid;
acquire(&proc_table_lock);
diff --git a/proc.h b/proc.h
index 2848ecd..7a04cd5 100644
--- a/proc.h
+++ b/proc.h
@@ -50,7 +50,17 @@ struct proc {
// expandable heap
extern struct proc proc[];
+
+// If xv6 was only for uniprocessors, this could be
+// struct proc *cp;
+// Instead we have an array curproc, one per
+// processor, and #define cp to the right element
+// in the array. In general such preprocessor
+// subterfuge is to be avoided, but cp is used
+// so often that having the shorthand is worth the ugliness.
extern struct proc *curproc[NCPU]; // Current (running) process per CPU
+#define cp (curproc[cpu()]) // Current process on this CPU
+
#define MPSTACK 512
diff --git a/syscall.c b/syscall.c
index adc2b58..d697337 100644
--- a/syscall.c
+++ b/syscall.c
@@ -53,7 +53,6 @@ fetchstr(struct proc *p, uint addr, char **pp)
int
argint(int argno, int *ip)
{
- struct proc *cp = curproc[cpu()];
return fetchint(cp, cp->tf->esp + 4 + 4*argno, ip);
}
@@ -65,7 +64,6 @@ int
argptr(int argno, char **pp, int size)
{
int i;
- struct proc *cp = curproc[cpu()];
if(argint(argno, &i) < 0)
return -1;
@@ -85,7 +83,7 @@ argstr(int argno, char **pp)
int addr;
if(argint(argno, &addr) < 0)
return -1;
- return fetchstr(curproc[cpu()], addr, pp);
+ return fetchstr(cp, addr, pp);
}
extern int sys_chdir(void);
@@ -133,7 +131,6 @@ static int (*syscalls[])(void) = {
void
syscall(void)
{
- struct proc *cp = curproc[cpu()];
int num = cp->tf->eax;
if(num >= 0 && num < NELEM(syscalls) && syscalls[num])
diff --git a/sysfile.c b/sysfile.c
index ecddd2b..a73f250 100644
--- a/sysfile.c
+++ b/sysfile.c
@@ -22,7 +22,6 @@ argfd(int argno, int *pfd, struct file **pf)
{
int fd;
struct file *f;
- struct proc *cp = curproc[cpu()];
if(argint(argno, &fd) < 0)
return -1;
@@ -41,7 +40,6 @@ static int
fdalloc(struct file *f)
{
int fd;
- struct proc *cp = curproc[cpu()];
for(fd = 0; fd < NOFILE; fd++){
if(cp->ofile[fd] == 0){
@@ -58,7 +56,6 @@ sys_pipe(void)
int *fd;
struct file *rf = 0, *wf = 0;
int fd0, fd1;
- struct proc *cp = curproc[cpu()];
if(argptr(0, (void*)&fd, 2*sizeof fd[0]) < 0)
return -1;
@@ -109,7 +106,7 @@ sys_close(void)
if(argfd(0, &fd, &f) < 0)
return -1;
- curproc[cpu()]->ofile[fd] = 0;
+ cp->ofile[fd] = 0;
fileclose(f);
return 0;
}
@@ -242,7 +239,6 @@ sys_mkdir(void)
int
sys_chdir(void)
{
- struct proc *cp = curproc[cpu()];
struct inode *ip;
char *path;
@@ -316,7 +312,6 @@ sys_link(void)
int
sys_exec(void)
{
- struct proc *cp = curproc[cpu()];
uint sz=0, ap, sp, p1, p2;
int i, nargs, argbytes, len;
struct inode *ip;
diff --git a/sysproc.c b/sysproc.c
index 14b85c5..9d599de 100644
--- a/sysproc.c
+++ b/sysproc.c
@@ -20,7 +20,7 @@ sys_fork(void)
{
struct proc *np;
- if((np = copyproc(curproc[cpu()])) == 0)
+ if((np = copyproc(cp)) == 0)
return -1;
np->state = RUNNABLE;
return np->pid;
@@ -52,7 +52,7 @@ sys_kill(void)
int
sys_getpid(void)
{
- return curproc[cpu()]->pid;
+ return cp->pid;
}
int
@@ -60,7 +60,6 @@ sys_sbrk(void)
{
int addr;
int n;
- struct proc *cp = curproc[cpu()];
if(argint(0, &n) < 0)
return -1;
diff --git a/trap.c b/trap.c
index 0c4a956..7a47516 100644
--- a/trap.c
+++ b/trap.c
@@ -31,7 +31,6 @@ void
trap(struct trapframe *tf)
{
int v = tf->trapno;
- struct proc *cp = curproc[cpu()];
if(v == T_SYSCALL){
if(cp->killed)
--
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