void
ck_barrier_centralized(struct ck_barrier_centralized *barrier,
struct ck_barrier_centralized_state *state,
unsigned int n_threads)
{
unsigned int sense, value;
/*
* Every execution context has a sense associated with it.
* This sense is reversed when the barrier is entered. Every
* thread will spin on the global sense until the last thread
* reverses it.
*/
sense = state->sense = ~state->sense;
value = ck_pr_faa_uint(&barrier->value, 1);
if (value == n_threads - 1) {
ck_pr_store_uint(&barrier->value, 0);
ck_pr_fence_memory();
ck_pr_store_uint(&barrier->sense, sense);
return;
}
ck_pr_fence_load();
while (sense != ck_pr_load_uint(&barrier->sense))
ck_pr_stall();
ck_pr_fence_memory();
return;
}
void
ck_barrier_mcs_subscribe(struct ck_barrier_mcs *barrier, struct ck_barrier_mcs_state *state)
{
state->sense = ~0;
state->vpid = ck_pr_faa_uint(&barrier->tid, 1);
return;
}
void
ck_barrier_dissemination_subscribe(struct ck_barrier_dissemination *barrier,
struct ck_barrier_dissemination_state *state)
{
state->parity = 0;
state->sense = ~0;
state->tid = ck_pr_faa_uint(&barrier->tid, 1);
return;
}
static void
ck_barrier_combining_aux(struct ck_barrier_combining *barrier,
struct ck_barrier_combining_group *tnode,
unsigned int sense)
{
/*
* If this is the last thread in the group, it moves on to the parent group.
* Otherwise, it spins on this group's sense.
*/
if (ck_pr_faa_uint(&tnode->count, 1) == tnode->k - 1) {
/*
* If we are and will be the last thread entering the barrier for the
* current group then signal the parent group if one exists.
*/
if (tnode->parent != NULL)
ck_barrier_combining_aux(barrier, tnode->parent, sense);
/*
* Once the thread returns from its parent(s), it reinitializes the group's
* arrival count and signals other threads to continue by flipping the group
* sense. Order of these operations is not important since we assume a static
* number of threads are members of a barrier for the lifetime of the barrier.
* Since count is explicitly reinitialized, it is guaranteed that at any point
* tnode->count is equivalent to tnode->k if and only if that many threads
* are at the barrier.
*/
ck_pr_store_uint(&tnode->count, 0);
ck_pr_fence_store();
ck_pr_store_uint(&tnode->sense, ~tnode->sense);
} else {
ck_pr_fence_memory();
while (sense != ck_pr_load_uint(&tnode->sense))
ck_pr_stall();
}
return;
}
#define ITERATE 1000000
#endif
static struct affinity a;
static unsigned int locked;
static unsigned int tid = 2;
static int nthr;
static ck_rwlock_t lock = CK_RWLOCK_INITIALIZER;
static ck_rwlock_recursive_t r_lock = CK_RWLOCK_RECURSIVE_INITIALIZER;
static void *
thread_recursive(void *null CK_CC_UNUSED)
{
int i = ITERATE;
unsigned int l;
unsigned int t = ck_pr_faa_uint(&tid, 1);
if (aff_iterate(&a)) {
perror("ERROR: Could not affine thread");
exit(EXIT_FAILURE);
}
while (i--) {
while (ck_rwlock_recursive_write_trylock(&r_lock, t) == false)
ck_pr_stall();
ck_rwlock_recursive_write_lock(&r_lock, t);
ck_rwlock_recursive_write_lock(&r_lock, t);
ck_rwlock_recursive_write_lock(&r_lock, t);
{
static void *
test_spmc(void *c)
{
unsigned int observed = 0;
unsigned long previous = 0;
unsigned int seed;
int i, k, j, tid;
struct context *context = c;
ck_ring_buffer_t *buffer;
buffer = context->buffer;
if (aff_iterate(&a)) {
perror("ERROR: Could not affine thread");
exit(EXIT_FAILURE);
}
tid = ck_pr_faa_int(&eb, 1);
ck_pr_fence_memory();
while (ck_pr_load_int(&eb) != nthr - 1);
for (i = 0; i < ITERATIONS; i++) {
for (j = 0; j < size; j++) {
struct entry *o;
int spin;
/* Keep trying until we encounter at least one node. */
if (j & 1) {
while (ck_ring_dequeue_spmc(&ring_spmc, buffer,
&o) == false);
} else {
while (ck_ring_trydequeue_spmc(&ring_spmc, buffer,
&o) == false);
}
observed++;
if (o->value < 0
|| o->value != o->tid
|| o->magic != 0xdead
|| (previous != 0 && previous >= o->value_long)) {
ck_error("[0x%p] (%x) (%d, %d) >< (0, %d)\n",
(void *)o, o->magic, o->tid, o->value, size);
}
o->magic = 0xbeef;
o->value = -31337;
o->tid = -31338;
previous = o->value_long;
if (ck_pr_faa_uint(&o->ref, 1) != 0) {
ck_error("[%p] We dequeued twice.\n", (void *)o);
}
if ((i % 4) == 0) {
spin = common_rand_r(&seed) % 16384;
for (k = 0; k < spin; k++) {
ck_pr_stall();
}
}
free(o);
}
}
fprintf(stderr, "[%d] Observed %u\n", tid, observed);
return NULL;
}
