greg/xv6
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Reorder spinlock.c: acquire and release first

Browse source
This commit is contained in:
rsc 2007-08-24 20:06:14 +00:00
parent 4bcd0f6a77
commit 5af5f6aa7f
1 changed files with 26 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

51
spinlock.c
View file

@ -18,31 +18,6 @@ initlock(struct spinlock *lock, char *name)
lock->cpu = 0xffffffff;
}
// Record the current call stack in pcs[] by following the %ebp chain.
void
getcallerpcs(void *v, uint pcs[])
{
uint *ebp;
int i;
ebp = (uint*)v - 2;
for(i = 0; i < 10; i++){
if(ebp == 0 || ebp == (uint*)0xffffffff)
break;
pcs[i] = ebp[1]; // saved %eip
ebp = (uint*)ebp[0]; // saved %ebp
}
for(; i < 10; i++)
pcs[i] = 0;
}
// Check whether this cpu is holding the lock.
int
holding(struct spinlock *lock)
{
return lock->locked && lock->cpu == cpu() + 10;
}
// Acquire the lock.
// Loops (spins) until the lock is acquired.
// (Because contention is handled by spinning,
@ -90,3 +65,29 @@ release(struct spinlock *lock)
if(--cpus[cpu()].nlock == 0)
sti();
}
// Record the current call stack in pcs[] by following the %ebp chain.
void
getcallerpcs(void *v, uint pcs[])
{
uint *ebp;
int i;
ebp = (uint*)v - 2;
for(i = 0; i < 10; i++){
if(ebp == 0 || ebp == (uint*)0xffffffff)
break;
pcs[i] = ebp[1]; // saved %eip
ebp = (uint*)ebp[0]; // saved %ebp
}
for(; i < 10; i++)
pcs[i] = 0;
}
// Check whether this cpu is holding the lock.
int
holding(struct spinlock *lock)
{
return lock->locked && lock->cpu == cpu() + 10;
}