int main(int argc, char* argv[]) {
int res,pdelay;
pdelay=0;
if (argc==2) {
pdelay=atoi(argv[1]);
if (pdelay<0 || pdelay > MAX_DELAY) {
fail("wrong delay value");
}
}
report("p lock:",mcs_lock(MUTEX));
if (fork()) {
/* parent */
if (pdelay) sleep(pdelay);
report("p wait:", mcs_wait(CV,MUTEX));
report("p unlock:",mcs_unlock(MUTEX));
wait(NULL);
exit(0);
} else {
report("ch lock:",mcs_lock(MUTEX));
report("ch broadcast:",mcs_broadcast(CV));
report("ch unlock:",mcs_unlock(MUTEX));
exit(0);
}
}
/*
* trylock GF_cskl_nodes;
* if GF_cskl_nodes != NULL, transfer a bunch of nodes to _lf_cskl_nodes,
* otherwise add a few nodes to _lf_cskl_nodes.
*/
static void
csklnode_populate_lfl(
int maxheight,
mem_alloc m_alloc)
{
mcs_node_t me;
bool acquired = mcs_trylock(&GFCN_lock, &me);
if (acquired) {
if (GF_cskl_nodes) {
// transfer a bunch of nodes the global free list to the local free list
int n = 0;
while (GF_cskl_nodes && n < NUM_NODES) {
csklnode_t *head = GF_cskl_nodes;
GF_cskl_nodes = GF_cskl_nodes->nexts[0];
head->nexts[0] = _lf_cskl_nodes;
_lf_cskl_nodes = head;
n++;
}
}
mcs_unlock(&GFCN_lock, &me);
}
if (!_lf_cskl_nodes) {
csklnode_add_nodes_to_lfl(maxheight, m_alloc);
}
}
setval_t set_remove(set_t *s, setkey_t k)
{
ptst_t *ptst;
node_t *y, *z;
qnode_t z_qn;
setval_t ov = NULL;
k = CALLER_TO_INTERNAL_KEY(k);
ptst = critical_enter();
z = &s->root;
while ( (y = (k <= z->k) ? z->l : z->r) != NULL )
z = y;
if ( z->k == k )
{
mcs_lock(&z->lock, &z_qn);
if ( !IS_GARBAGE(z) )
{
ov = GET_VALUE(z->v);
SET_VALUE(z->v, NULL);
}
mcs_unlock(&z->lock, &z_qn);
}
if ( ov != NULL )
delete_finish(ptst, z);
critical_exit(ptst);
return ov;
}
void mwrite(char n, int fd) {
char mc[2];
mc[0]='a'+n;
mc[1]='\n';
if (mcs_lock(mutex_id+fd)) fail("lock failed");
write(fd,&mc,1);
sleep(1);
write(fd,&mc,2);
if (mcs_unlock(mutex_id+fd)) fail("unlock failed");
}
error_t rwlock_wrlock(struct rwlock_s *rwlock)
{
uint_t irq_state;
mcs_lock(&rwlock->lock, &irq_state);
//spinlock_lock(&rwlock->lock);
if(rwlock->count == 0)
{
rwlock->count --;
//spinlock_unlock(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
return 0;
}
wait_on(&rwlock->wr_wait_queue, WAIT_LAST);
//spinlock_unlock_nosched(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
sched_sleep(current_thread);
return 0;
}
error_t rwlock_rdlock(struct rwlock_s *rwlock)
{
uint_t irq_state;
//spinlock_lock(&rwlock->lock);
mcs_lock(&rwlock->lock, &irq_state);
/* priority is given to writers */
if((rwlock->count >= 0) && (wait_queue_isEmpty(&rwlock->wr_wait_queue)))
{
rwlock->count ++;
//spinlock_unlock(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
return 0;
}
wait_on(&rwlock->rd_wait_queue, WAIT_LAST);
//spinlock_unlock_nosched(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
sched_sleep(current_thread);
return 0;
}
error_t rwlock_destroy(struct rwlock_s *rwlock)
{
register error_t err = 0;
uint_t irq_state;
//spinlock_lock(&rwlock->lock);
mcs_lock(&rwlock->lock, &irq_state);
if(rwlock->count != 0)
err = EBUSY;
//spinlock_unlock(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
return err;
}
/*
* only free non null csklnode_t*
* pre-condition: anode is of type csklnpde_t*
*/
void
cskl_free(void* anode)
{
if (!anode) return;
// add node to the front of the global free csklnode list.
mcs_node_t me;
csklnode_t *node = (csklnode_t*)anode;
for (int i = 0; i < node->height; i++) {
node->nexts[i] = NULL;
}
mcs_lock(&GFCN_lock, &me);
node->nexts[0] = GF_cskl_nodes;
GF_cskl_nodes = node;
mcs_unlock(&GFCN_lock, &me);
}
static void inline
unlock_preds
(csklnode_t *preds[],
mcs_node_t mcs_nodes[],
int highestLocked)
{
// unlock each of my predecessors, as necessary
csklnode_t *prevPred = NULL;
for (int layer = 0; layer <= highestLocked; layer++) {
csklnode_t *pred = preds[layer];
if (pred != prevPred) {
mcs_unlock(&pred->lock, &mcs_nodes[layer]);
}
prevPred = pred;
}
}
error_t rwlock_tryrdlock(struct rwlock_s *rwlock)
{
register error_t err = 0;
uint_t irq_state;
//spinlock_lock(&rwlock->lock);
mcs_lock(&rwlock->lock, &irq_state);
if((rwlock->count >= 0) && (wait_queue_isEmpty(&rwlock->wr_wait_queue)))
rwlock->count ++;
else
err = EBUSY;
//spinlock_unlock(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
return err;
}
error_t rwlock_unlock(struct rwlock_s *rwlock)
{
register error_t err = 0;
uint_t irq_state;
//spinlock_lock(&rwlock->lock);
mcs_lock(&rwlock->lock, &irq_state);
if(rwlock->count == 0)
{
printk(ERROR, "ERROR: Unexpected rwlock_unlock\n");
err = EPERM;
goto fail_eperm;
}
if(rwlock->count > 1) /* caller is a reader and no waiting writers */
{
rwlock->count --;
goto unlock_end;
}
/* We are the last reader or a writer */
rwlock->count = 0;
if((wakeup_one(&rwlock->wr_wait_queue, WAIT_FIRST)))
{
rwlock->count --;
goto unlock_end;
}
/* No pending writer was found */
rwlock->count += wakeup_all(&rwlock->rd_wait_queue);
fail_eperm:
unlock_end:
//spinlock_unlock(&rwlock->lock);
mcs_unlock(&rwlock->lock, irq_state);
return err;
}
/*
* TODO: this function is not used anywhere and leaks memory.
*/
bool
cskl_delete(cskiplist_t *cskl, void *value)
{
int max_height = cskl->max_height;
bool node_is_marked = false;
csklnode_t *node = NULL;
for (;;) {
csklnode_t *preds[max_height];
csklnode_t *succs[max_height];
mcs_node_t mcs_nodes[max_height];
int height = -1;
//--------------------------------------------------------------------------
// Look for a node matching v
//--------------------------------------------------------------------------
int layer = cskiplist_find_helper(cskl->compare, cskl, value,
preds, succs, cskiplist_find_full);
//--------------------------------------------------------------------------
// A matching node is available to remove. We may have marked it earlier as
// we began its removal.
//--------------------------------------------------------------------------
if (node_is_marked ||
(layer != NO_LAYER &&
cskiplist_node_is_removable(succs[layer], layer))) {
//------------------------------------------------------------------------
// if I haven't already marked this node for deletion, do so.
//------------------------------------------------------------------------
if (!node_is_marked) {
node = succs[layer];
height = node->height;
mcs_lock(&node->lock, &mcs_nodes[layer]);
if (node->marked) {
mcs_unlock(&node->lock, &mcs_nodes[layer]);
return false;
}
node->marked = true;
node_is_marked = true;
}
//------------------------------------------------------------------------
// Post-condition: Node is marked and locked.
//------------------------------------------------------------------------
//------------------------------------------------------------------------
// Acquire a lock on node's predecessor at each layer.
//
// valid condition:
// no predecessor is marked
// each of my predecessors still points to the successor I recorded (me)
//
// If the valid condition is not satisfied, unlock all of my predecessors
// and retry.
//------------------------------------------------------------------------
int highestLocked = -1;
csklnode_t *pred, *succ;
csklnode_t *prevPred = NULL;
bool valid = true;
for (int layer = 0; valid && (layer < height); layer++) {
pred = preds[layer];
succ = succs[layer];
if (pred != prevPred) {
mcs_lock(&pred->lock, &mcs_nodes[layer]);
highestLocked = layer;
prevPred = pred;
}
valid = !pred->marked && pred->nexts[layer] == succ;
}
if (!valid) {
unlock_preds(preds, mcs_nodes, highestLocked);
continue;
}
//-----------------------------------------------------------------------
// Post-condition: All predecessors are locked for delete.
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
// Complete the deletion: Splice out node at each layer and release lock
// on node's predecessor at each layer.
//-----------------------------------------------------------------------
for (int layer = height - 1; layer >= 0; layer--) {
// Splice out node at layer.
preds[layer]->nexts[layer] = node->nexts[layer];
}
// Unlock self.
mcs_unlock(&node->lock, &mcs_nodes[layer]);
unlock_preds(preds, mcs_nodes, highestLocked);
return true;
} else {
return false;
}
}
}
static void fix_unbalance_up(ptst_t *ptst, node_t *x)
{
qnode_t x_qn, g_qn, p_qn, w_qn, gg_qn;
node_t *g, *p, *w, *gg;
int done = 0;
do {
assert(IS_UNBALANCED(x->v));
if ( IS_GARBAGE(x) ) return;
p = x->p;
g = p->p;
gg = g->p;
mcs_lock(&gg->lock, &gg_qn);
if ( !ADJACENT(gg, g) || IS_UNBALANCED(gg->v) || IS_GARBAGE(gg) )
goto unlock_gg;
mcs_lock(&g->lock, &g_qn);
if ( !ADJACENT(g, p) || IS_UNBALANCED(g->v) ) goto unlock_ggg;
mcs_lock(&p->lock, &p_qn);
if ( !ADJACENT(p, x) || IS_UNBALANCED(p->v) ) goto unlock_pggg;
mcs_lock(&x->lock, &x_qn);
assert(IS_RED(x->v));
assert(IS_UNBALANCED(x->v));
if ( IS_BLACK(p->v) )
{
/* Case 1. Nothing to do. */
x->v = MK_BALANCED(x->v);
done = 1;
goto unlock_xpggg;
}
if ( IS_ROOT(x) )
{
/* Case 2. */
x->v = MK_BLACK(MK_BALANCED(x->v));
done = 1;
goto unlock_xpggg;
}
if ( IS_ROOT(p) )
{
/* Case 2. */
p->v = MK_BLACK(p->v);
x->v = MK_BALANCED(x->v);
done = 1;
goto unlock_xpggg;
}
if ( g->l == p ) w = g->r; else w = g->l;
mcs_lock(&w->lock, &w_qn);
if ( IS_RED(w->v) )
{
/* Case 5. */
/* In all other cases, doesn't change colour or subtrees. */
if ( IS_UNBALANCED(w->v) ) goto unlock_wxpggg;
g->v = MK_UNBALANCED(MK_RED(g->v));
p->v = MK_BLACK(p->v);
w->v = MK_BLACK(w->v);
x->v = MK_BALANCED(x->v);
done = 2;
goto unlock_wxpggg;
}
/* Cases 3 & 4. Both of these need the great-grandfather locked. */
if ( p == g->l )
{
if ( x == p->l )
{
/* Case 3. Single rotation. */
x->v = MK_BALANCED(x->v);
p->v = MK_BLACK(p->v);
g->v = MK_RED(g->v);
right_rotate(ptst, g);
}
else
{
/* Case 4. Double rotation. */
x->v = MK_BALANCED(MK_BLACK(x->v));
g->v = MK_RED(g->v);
left_rotate(ptst, p);
right_rotate(ptst, g);
}
}
else /* SYMMETRIC CASE */
{
if ( x == p->r )
{
/* Case 3. Single rotation. */
x->v = MK_BALANCED(x->v);
p->v = MK_BLACK(p->v);
g->v = MK_RED(g->v);
left_rotate(ptst, g);
}
else
{
/* Case 4. Double rotation. */
x->v = MK_BALANCED(MK_BLACK(x->v));
g->v = MK_RED(g->v);
right_rotate(ptst, p);
left_rotate(ptst, g);
}
}
done = 1;
unlock_wxpggg:
mcs_unlock(&w->lock, &w_qn);
unlock_xpggg:
mcs_unlock(&x->lock, &x_qn);
unlock_pggg:
mcs_unlock(&p->lock, &p_qn);
unlock_ggg:
mcs_unlock(&g->lock, &g_qn);
unlock_gg:
mcs_unlock(&gg->lock, &gg_qn);
if ( done == 2 )
{
x = g;
done = 0;
}
}
while ( !done );
}
static void fix_unbalance_down(ptst_t *ptst, node_t *x)
{
/* WN == W_NEAR, WF == W_FAR (W_FAR is further, in key space, from X). */
qnode_t x_qn, w_qn, p_qn, g_qn, wn_qn, wf_qn;
node_t *w, *p, *g, *wn, *wf;
int done = 0;
do {
if ( !IS_UNBALANCED(x->v) || IS_GARBAGE(x) ) return;
p = x->p;
g = p->p;
mcs_lock(&g->lock, &g_qn);
if ( !ADJACENT(g, p) || IS_UNBALANCED(g->v) || IS_GARBAGE(g) )
goto unlock_g;
mcs_lock(&p->lock, &p_qn);
if ( !ADJACENT(p, x) || IS_UNBALANCED(p->v) ) goto unlock_pg;
mcs_lock(&x->lock, &x_qn);
if ( !IS_BLACK(x->v) || !IS_UNBALANCED(x->v) )
{
done = 1;
goto unlock_xpg;
}
if ( IS_ROOT(x) )
{
x->v = MK_BALANCED(x->v);
done = 1;
goto unlock_xpg;
}
w = (x == p->l) ? p->r : p->l;
mcs_lock(&w->lock, &w_qn);
if ( IS_UNBALANCED(w->v) )
{
if ( IS_BLACK(w->v) )
{
/* Funky relaxed rules to the rescue. */
x->v = MK_BALANCED(x->v);
w->v = MK_BALANCED(w->v);
if ( IS_BLACK(p->v) )
{
p->v = MK_UNBALANCED(p->v);
done = 2;
}
else
{
p->v = MK_BLACK(p->v);
done = 1;
}
}
goto unlock_wxpg;
}
assert(!IS_LEAF(w));
if ( x == p->l )
{
wn = w->l;
wf = w->r;
}
else
{
wn = w->r;
wf = w->l;
}
mcs_lock(&wn->lock, &wn_qn);
/* Hanke has an extra relaxed transform here. It's not needed. */
if ( IS_UNBALANCED(wn->v) ) goto unlock_wnwxpg;
mcs_lock(&wf->lock, &wf_qn);
if ( IS_UNBALANCED(wf->v) ) goto unlock_wfwnwxpg;
if ( IS_RED(w->v) )
{
/* Case 1. Rotate at parent. */
assert(IS_BLACK(p->v) && IS_BLACK(wn->v) && IS_BLACK(wf->v));
w->v = MK_BLACK(w->v);
p->v = MK_RED(p->v);
if ( x == p->l ) left_rotate(ptst, p); else right_rotate(ptst, p);
goto unlock_wfwnwxpg;
}
if ( IS_BLACK(wn->v) && IS_BLACK(wf->v) )
{
if ( IS_RED(p->v) )
{
/* Case 2. Simple recolouring. */
p->v = MK_BLACK(p->v);
done = 1;
}
else
{
/* Case 5. Simple recolouring. */
p->v = MK_UNBALANCED(p->v);
done = 2;
}
w->v = MK_RED(w->v);
x->v = MK_BALANCED(x->v);
goto unlock_wfwnwxpg;
}
if ( x == p->l )
{
if ( IS_RED(wf->v) )
{
/* Case 3. Single rotation. */
wf->v = MK_BLACK(wf->v);
w->v = SET_COLOUR(w->v, GET_COLOUR(p->v));
p->v = MK_BLACK(p->v);
x->v = MK_BALANCED(x->v);
left_rotate(ptst, p);
}
else
{
/* Case 4. Double rotation. */
assert(IS_RED(wn->v));
wn->v = SET_COLOUR(wn->v, GET_COLOUR(p->v));
p->v = MK_BLACK(p->v);
x->v = MK_BALANCED(x->v);
right_rotate(ptst, w);
left_rotate(ptst, p);
}
}
else /* SYMMETRIC CASE: X == P->R */
{
if ( IS_RED(wf->v) )
{
/* Case 3. Single rotation. */
wf->v = MK_BLACK(wf->v);
w->v = SET_COLOUR(w->v, GET_COLOUR(p->v));
p->v = MK_BLACK(p->v);
x->v = MK_BALANCED(x->v);
right_rotate(ptst, p);
}
else
{
/* Case 4. Double rotation. */
assert(IS_RED(wn->v));
wn->v = SET_COLOUR(wn->v, GET_COLOUR(p->v));
p->v = MK_BLACK(p->v);
x->v = MK_BALANCED(x->v);
left_rotate(ptst, w);
right_rotate(ptst, p);
}
}
done = 1;
unlock_wfwnwxpg:
mcs_unlock(&wf->lock, &wf_qn);
unlock_wnwxpg:
mcs_unlock(&wn->lock, &wn_qn);
unlock_wxpg:
mcs_unlock(&w->lock, &w_qn);
unlock_xpg:
mcs_unlock(&x->lock, &x_qn);
unlock_pg:
mcs_unlock(&p->lock, &p_qn);
unlock_g:
mcs_unlock(&g->lock, &g_qn);
if ( done == 2 )
{
x = p;
done = 0;
}
}
while ( !done );
}
int main(int argc, char* argv[]){
int res,turns,i;
int pp[2];
char * text;
if (argc!=2){
fail("one argument needed");
}
turns=atoi(argv[1]);
if (turns<0 || turns > MAX_DELAY){
fail("wrong number of turns");
}
pipe(pp);
setsid();
mutex= getpid();
cv1= mutex<<1;
cv2= (mutex<<1)+1;
if (fork()){
/* parent */
int r;
char buf[10];
for (i=0;i< turns; i++){
mcs_wait(cv1,mutex);
r= read(pp[0],buf,2);
if (r!=2){
if (r!=1){
fprintf(stderr,"FAIL: pipe read failed.\n");
kill(0, SIGTERM);
}
mcs_wait(cv1,mutex);
r= read(pp[0],buf,2);
if (r!=1){
fprintf(stderr,"FAIL: unexpected number of bytes in pipe.\n");
kill(0, SIGTERM);
}
}
write(1,"TI",2);
sleep(1);
write(1,"C\n",2);
mcs_broadcast(cv2);
}
mcs_unlock(mutex);
} else {
fork();
mcs_lock(mutex);
mcs_broadcast(cv1);
write(pp[1],"0",1);
for (i=0;i< turns; i++){
mcs_wait(cv2,mutex);
write(1,"TA",2);
sleep(1);
write(1,"C\n",2);
mcs_broadcast(cv1);
write(pp[1],"0",1);
}
mcs_unlock(mutex);
}
wait(NULL);
exit(0);
}
static void delete_finish(ptst_t *ptst, node_t *x)
{
qnode_t g_qn, p_qn, w_qn, x_qn;
node_t *g, *p, *w;
int done = 0;
do {
if ( IS_GARBAGE(x) ) return;
p = x->p;
g = p->p;
mcs_lock(&g->lock, &g_qn);
if ( !ADJACENT(g, p) || IS_UNBALANCED(g->v) || IS_GARBAGE(g) )
goto unlock_g;
mcs_lock(&p->lock, &p_qn);
/* Removing unbalanced red nodes is okay. */
if ( !ADJACENT(p, x) || (IS_UNBALANCED(p->v) && IS_BLACK(p->v)) )
goto unlock_pg;
mcs_lock(&x->lock, &x_qn);
if ( IS_UNBALANCED(x->v) ) goto unlock_xpg;
if ( GET_VALUE(x->v) != NULL )
{
done = 1;
goto unlock_xpg;
}
if ( p->l == x ) w = p->r; else w = p->l;
assert(w != x);
mcs_lock(&w->lock, &w_qn);
if ( IS_UNBALANCED(w->v) ) goto unlock_wxpg;
if ( g->l == p ) g->l = w; else g->r = w;
MK_GARBAGE(p); gc_free(ptst, p, gc_id);
MK_GARBAGE(x); gc_free(ptst, x, gc_id);
w->p = g;
if ( IS_BLACK(p->v) && IS_BLACK(w->v) )
{
w->v = MK_UNBALANCED(w->v);
done = 2;
}
else
{
w->v = MK_BLACK(w->v);
done = 1;
}
unlock_wxpg:
mcs_unlock(&w->lock, &w_qn);
unlock_xpg:
mcs_unlock(&x->lock, &x_qn);
unlock_pg:
mcs_unlock(&p->lock, &p_qn);
unlock_g:
mcs_unlock(&g->lock, &g_qn);
}
while ( !done );
if ( done == 2 ) fix_unbalance_down(ptst, w);
}
setval_t set_update(set_t *s, setkey_t k, setval_t v, int overwrite)
{
ptst_t *ptst;
qnode_t y_qn, z_qn;
node_t *y, *z, *new_internal, *new_leaf;
int fix_up = 0;
setval_t ov = NULL;
k = CALLER_TO_INTERNAL_KEY(k);
ptst = critical_enter();
retry:
z = &s->root;
while ( (y = (k <= z->k) ? z->l : z->r) != NULL )
z = y;
y = z->p;
mcs_lock(&y->lock, &y_qn);
if ( (((k <= y->k) ? y->l : y->r) != z) || IS_GARBAGE(y) )
{
mcs_unlock(&y->lock, &y_qn);
goto retry;
}
mcs_lock(&z->lock, &z_qn);
assert(!IS_GARBAGE(z) && IS_LEAF(z));
if ( z->k == k )
{
ov = GET_VALUE(z->v);
if ( overwrite || (ov == NULL) )
SET_VALUE(z->v, v);
}
else
{
new_leaf = gc_alloc(ptst, gc_id);
new_internal = gc_alloc(ptst, gc_id);
new_leaf->k = k;
new_leaf->v = MK_BLACK(v);
new_leaf->l = NULL;
new_leaf->r = NULL;
new_leaf->p = new_internal;
mcs_init(&new_leaf->lock);
if ( z->k < k )
{
new_internal->k = z->k;
new_internal->l = z;
new_internal->r = new_leaf;
}
else
{
new_internal->k = k;
new_internal->l = new_leaf;
new_internal->r = z;
}
new_internal->p = y;
mcs_init(&new_internal->lock);
if ( IS_UNBALANCED(z->v) )
{
z->v = MK_BALANCED(z->v);
new_internal->v = MK_BLACK(INTERNAL_VALUE);
}
else if ( IS_RED(y->v) )
{
new_internal->v = MK_UNBALANCED(MK_RED(INTERNAL_VALUE));
fix_up = 1;
}
else
{
new_internal->v = MK_RED(INTERNAL_VALUE);
}
WMB();
z->p = new_internal;
if ( y->l == z ) y->l = new_internal; else y->r = new_internal;
}
mcs_unlock(&y->lock, &y_qn);
mcs_unlock(&z->lock, &z_qn);
if ( fix_up )
fix_unbalance_up(ptst, new_internal);
out:
critical_exit(ptst);
return ov;
}
