int main(int argc, char *argv[]) {
int size = argc > 1 ? atoi(argv[1]) : 10000;
volatile int* a = (volatile int *) malloc(size * sizeof(int));
printf("Array size: %d\n", size);
int failures;
int attempts;
int loops = argc > 2 ? atoi(argv[2]) : 100000;
int i;
for (i = 0; i < loops; i++) {
retry: attempts++;
if (_xbegin() == _XBEGIN_STARTED) {
for (int i = 0; i < size; i++) {
a[i]++;
}
_xend();
} else {
failures++;
// goto retry;
}
}
free((void*) a);
printf("Loops: %d\n", loops);
printf("Attempts: %d\n", attempts);
printf("Failures: %d (Rate: %.2f%%)\n", failures,
(float) failures * 100 / attempts);
return 0;
}
static void fe_mt_tsx_lock_x86rtm(fe_mt_tsx *tsx) {
static const char *TAG = "fe_mt";
/* Currently, we prevent nested transactions.
* FIXME Prove it is actually required. */
if(_xtest())
return;
retry:
unsigned status = _xbegin();
if(status == _XBEGIN_STARTED)
return;
if(status & _XABORT_RETRY)
goto retry;
fe_logv("x86 RTM transaction aborted."
"Falling back to regular lock. Reason :\n\t");
if(status & _XABORT_EXPLICIT)
fe_logv(TAG, "Explicit abort. Code : %d\n", _XABORT_CODE(status));
if(status & _XABORT_CONFLICT)
fe_logv(TAG, "Memory conflict with another thread.\n");
if(status & _XABORT_CAPACITY)
fe_logv(TAG, "Too much memory used by the transaction.\n");
if(status & _XABORT_DEBUG)
fe_logv(TAG, "Debug trap.\n");
if(status & _XABORT_NESTED)
fe_logv(TAG, "Abort in an inner nested transaction.\n");
fe_mt_tsx_lock_fallback(tsx);
}
int main()
{
unsigned status;
if ((status = _xbegin()) == _XBEGIN_STARTED) {
_xend();
} else {
_xabort(_XABORT_CONFLICT);
}
}
TransactionalScope::TransactionalScope(spinlock_t &fallback_mutex, bool writeAccess) :
// initializaer list
spinlock(fallback_mutex)
{
unsigned int xact_status;
threadstate_t &ts = tstate;
ts.txCount++;
// we are already executing transactionally, continue.
if (_xtest()) return;
do {
xact_status = _xbegin();
if (xact_status == _XBEGIN_STARTED) {
if ( *(reinterpret_cast<int*>(&fallback_mutex)) == 0 ) {
return;
} else {
_xabort(0xFF);
}
} else {
/** We have aborted. */
++ts.totalAborts;
++ts.successiveAborts;
// if we xaborted because the lock was held, acquire the lock
if ((xact_status & _XABORT_EXPLICIT) && _XABORT_CODE(xact_status) == 0xFF) {
ts.maxAborts = 1;
ts.maxTxLen = 1;
break;
}
//if xabort:retry or xabort:conflict is set retry
if (xact_status & (_XABORT_RETRY | _XABORT_CONFLICT)) {
ts.maxTxLen = 1;
}
// // if we used too much buffer space inside the transaction half the max transaction length
if ((xact_status & _XABORT_CAPACITY)) {
ts.maxTxLen = 1;
}
_mm_pause();
}
} while (ts.successiveAborts < ts.maxAborts);
ts.fallbackTaken++;
// Fallback to lock
if (writeAccess) {
spinlock.lock();
} else {
spinlock.lock_read();
}
}
int main(void)
{
int status;
if ((status = _xbegin()) == _XBEGIN_STARTED) {
if (_xtest())
_xabort(1);
_xend();
} else
printf("aborted %x, %d", status, _XABORT_CODE(status));
return 0;
}
int main(void)
{
unsigned status;
if ((status = _xbegin()) == 0) {
TXN_ASSERT_ONLY(!foo);
} else {
txn_assert_abort_hook(status);
}
f2();
return 0;
}
int HTM_start(htm_thread_data_t *self) {
unsigned int status = 0;
status = _xbegin();
if (status != _XBEGIN_STARTED)
{
self->last_htm_abort = status;
HTM_status_collect(self, status);
return 0;
}
return 1;
}
int run_seq_write(volatile type *array[], int size) {
if (_xbegin() == _XBEGIN_STARTED) {
for (int i = 0; i < size; i++) {
(*array)[i]++; // write
}
_xend();
return 1;
} else {
return 0;
}
}
int run_seq_read(volatile type *array[], int size) {
type dummy;
if (_xbegin() == _XBEGIN_STARTED) {
for (int i = 0; i < size; i++) {
dummy = (*array)[i]; // read - GCC option O0 needed!
}
_xend();
return 1;
} else {
return 0;
}
}
/*
* [lyj] Disable the interpretation of "deleted" field.
*/
void fraser_insert(sl_intset_t *set, uint32_t v, bool lin)
{
sl_node_t *NEW, *new_next, *pred, *succ, *succs[LEVELMAX], *preds[LEVELMAX];
uint32_t i;
uint32_t status;
// uint32_t attempts = 0;
NEW = sl_new_simple_node(v, get_rand_level(), lin);
retry:
fraser_search(set, v, preds, succs);
for (i = 0; i < NEW->toplevel; i++)
NEW->nexts[i] = succs[i];
/* Node is visible once inserted at lowest level */
if (!ATOMIC_CAS_MB(&preds[0]->nexts[0], succs[0], NEW))
goto retry;
//retry_HTM:
status = _xbegin();
if(status == _XBEGIN_STARTED)
{
for (i = 1; i < NEW->toplevel; i++) {
if(preds[i]->nexts[i] == succs[i])
preds[i]->nexts[i] = NEW;
else
_xabort(66);
}
_xend();
return;
}/*else
{
if ((status & _XABORT_EXPLICIT) && _XABORT_CODE(status) == 66) {
}
else if (++attempts < MAX_ATTEMPT_NUM) {
goto retry_HTM;
}
}*/
for (i = 1; i < NEW->toplevel; i++) {
while (1) {
pred = preds[i];
succ = succs[i];
/* Update the forward pointer if it is stale */
new_next = NEW->nexts[i];
if ((new_next != succ) &&
(!ATOMIC_CAS_MB(&NEW->nexts[i], unset_mark((uint32_t)new_next), succ)))
break;
/* Give up if pointer is marked */
/* We retry the search if the CAS fails */
if (ATOMIC_CAS_MB(&pred->nexts[i], succ, NEW))
break;
fraser_search(set, v, preds, succs);
}
}
}
inline int mark_node_ptrs(sl_node_t *n)
{
sl_node_t *n_next;
uint32_t status;
//uint32_t attempts = 0;
uint32_t i = n->toplevel - 1;
//retry:
status = _xbegin();
if(status == _XBEGIN_STARTED)
{
while ( i > 0 )
{
if(!is_marked((uint32_t)n->nexts[i]))
n->nexts[i] = (sl_node_t*)set_mark((uint32_t)n->nexts[i]);
i--;
}
if (is_marked((uint32_t)n->nexts[0]))
{
_xend();
return 0;
}else
{
n->nexts[0] = (sl_node_t*)set_mark((uint32_t)n->nexts[0]);
_xend();
return 1;
}
}/*else{
if (++attempts < MAX_ATTEMPT_NUM) {
goto retry;
}
}*/
for (int i=n->toplevel-1; i>0; i--) {
do {
n_next = n->nexts[i];
if (is_marked((uint32_t)n_next))
break;
if (ATOMIC_CAS_MB(&n->nexts[i], n_next, (sl_node_t*)set_mark((uint32_t)n_next)))
break;
} while (true);
}
do {
n_next = n->nexts[0];
if (is_marked((uint32_t)n_next))
return 0;
if (ATOMIC_CAS_MB(&n->nexts[0], n_next, (sl_node_t*)set_mark((uint32_t)n_next)))
return 1;
} while (true);
}
int main(int argc, char *argv[]) {
int loops = 100, inner_loops = 100;
int smin = 0, smax = 100000, sstep = 5000;
int *values[] = { &loops, &smin, &smin, &smax, &smax, &sstep, &sstep };
const char *identifier[] = { "-l", "-smin", "-rmin", "-smax", "-rmax",
"-sstep", "-rstep" };
handle_args(argc, argv, 7, values, identifier);
printf("Loops: %d\n", loops);
printf("Sizes: %d - %d, steps of %d\n", smin, smax, sstep);
printf("Size;Expected Value;Standard deviation\n");
for (int size = smin; size <= smax; size += sstep) {
printf("%d", size);
Stats stats;
for (int l = 0; l < loops; l++) {
int failures = 0;
for (int il = 0; il < inner_loops; il++) {
// init
unsigned char a[size];
for (int i = 0; i < size; i++)
a[i] = 0;
// run
int flip = 0; // alternates between 0 (read) and 1 (write)
int dummy;
if (_xbegin() == _XBEGIN_STARTED) {
for (int i = 0; i < size; i++) {
if (flip)
dummy = a[i]; // -O0!
else
a[i]++;
flip ^= 1;
}
_xend();
} else {
failures++;
}
}
float failure_rate = (float) failures * 100 / inner_loops;
stats.addValue(failure_rate);
}
printf(";%.2f;%.2f\n", stats.getExpectedValue(),
stats.getStandardDeviation());
}
}
int BST::addRTM(Node *node) {
int state = TRANSACTION;
int attempt = 1;
int nabort = 0;
int res;
while (1) {
UINT status = _XBEGIN_STARTED;
if (state == TRANSACTION) {
status = _xbegin();
}
else {
tatas_lock.acquireOptimistic();
}
if (status == _XBEGIN_STARTED) {
if (state == TRANSACTION && tatas_lock.getValue()) {
_xabort(0xA0);
nabort++;
}
res = add(node);
if (state == TRANSACTION) {
_xend();
}
else {
tatas_lock.release();
}
break;
}
else {
if (tatas_lock.getValue()) {
do {
_mm_pause();
} while (tatas_lock.getValue());
}
else {
volatile UINT64 wait = attempt;
while (wait--);
}
if (++attempt >= MAXATTEMPT) {
state = LOCK;
}
}
}
return res;
}
int run_rnd_read(volatile type *array[], int size) {
type dummy;
int failures = 0;
retry:
// srand(rnd);
rnd = RAND(size);
if (_xbegin() == _XBEGIN_STARTED) {
for (int i = 0; i < size; i++) {
dummy = (*array)[RAND(size)]; // read - GCC option O0 needed!
}
_xend();
return 1;
} else {
if (failures++ < max_retries)
goto retry;
return 0;
}
}
void *child(void *dummy)
{
int status;
retry:
if ((status = _xbegin()) == _XBEGIN_STARTED) {
count = 0;
_xend();
} else if ((status & _XABORT_RETRY) != 0) {
assert(0 && "please run with -X -A -S to suppress retries");
goto retry;
} else {
assert((status & _XABORT_CONFLICT) != 0 && "unexpected abort mode");
// it would be a causality violation for this to be visible to
// the parent's xadd, which has to happen first for us to abort
__sync_fetch_and_add(&count, 1);
}
return NULL;
}
void txn()
{
int status;
if ((status = _xbegin()) == _XBEGIN_STARTED) {
count++;
// TODO -
// omitting xend should not cause a "deadlock" in which the
// second thread "blocks" forever at xbegin,
// but rather should force the 1st txn to abort.
// double bonus TODO: how should we behave if the "last" thread
// exits w/o xending, without any contender to abort it?
// _xend();
} else {
mutex_lock(&lock);
count++;
mutex_unlock(&lock);
}
}
int run_rnd_write(volatile type *array[], int size) {
int failures = 0;
retry:
// srand(rnd); // generate new randomness
// (otherwise, the old "random" values would occur again after a retry
// since the internal rand()-value would be aborted and therefore reset)
rnd = RAND(size);
if (_xbegin() == _XBEGIN_STARTED) {
for (int i = 0; i < size; i++) {
(*array)[RAND(size)]++; // write
}
_xend();
return 1;
} else {
if (failures++ < max_retries)
goto retry;
return 0;
}
}
int
__lll_trylock_elision (int *futex, short *adapt_count)
{
/* Implement POSIX semantics by forbiding nesting
trylock. Sorry. After the abort the code is re-executed
non transactional and if the lock was already locked
return an error. */
_xabort (_ABORT_NESTED_TRYLOCK);
/* Only try a transaction if it's worth it. */
if (*adapt_count <= 0)
{
unsigned status;
if ((status = _xbegin()) == _XBEGIN_STARTED)
{
if (*futex == 0)
return 0;
/* Lock was busy. Fall back to normal locking.
Could also _xend here but xabort with 0xff code
is more visible in the profiler. */
_xabort (_ABORT_LOCK_BUSY);
}
if (!(status & _XABORT_RETRY))
{
/* Internal abort. No chance for retry. For future
locks don't try speculation for some time. */
if (*adapt_count != aconf.skip_trylock_internal_abort)
*adapt_count = aconf.skip_trylock_internal_abort;
}
/* Could do some retries here. */
}
else
{
/* Lost updates are possible, but harmless. */
(*adapt_count)--;
}
return lll_trylock (*futex);
}
JNIEXPORT jobject JNICALL Java_javartm_Transaction_doTransactionally(JNIEnv *env, jclass cls, jobject atomicBlock, jobject fallbackBlock) {
// TODO: Add some caching
jclass atomicBlockClass = (*env)->GetObjectClass(env, atomicBlock);
jmethodID callMethodId = (*env)->GetMethodID(env, atomicBlockClass, "call", "()Ljava/lang/Object;");
if (!callMethodId) return NULL;
printf("Preparing execution...\n");
int res = _xbegin();
if (_xtest()) {
jobject retValue = (*env)->CallObjectMethod(env, atomicBlock, callMethodId);
_xend();
printf("Successful commit\n");
return retValue;
}
printf("Abort or failed to start tx res = %d\n", res);
jclass fallbackBlockClass = (*env)->GetObjectClass(env, fallbackBlock);
callMethodId = (*env)->GetMethodID(env, fallbackBlockClass, "call", "()Ljava/lang/Object;");
if (!callMethodId) return NULL;
return (*env)->CallObjectMethod(env, fallbackBlock, callMethodId);
}
// Begin is used in multiple methods, but we force it to be inlined to avoid extra work after
// the transaction is started
__attribute__((always_inline)) inline int begin() {
int status;
int failtimes = 0;
while ((status = _xbegin()) == (_XABORT_RETRY | _XABORT_CONFLICT)) {
// When there are multiple processors fighting for the same memory zones,
// we get an abort with RETRY + CONFLICT flags set. For now, we use a simple
// backoff strategy, using the x86 pause instruction (which was introduced
// as a better means of doing backoff during spinlocks).
//
// Some open issues/notes on this approach:
// - Should we just give up after a while instead of eternally looping?
// - Should backoff be more agressive than linearly increasing failtimes?
// - What's the best value for the limit?
failtimes++;
for (int i = 0; i < failtimes; i++) {
_mm_pause(); _mm_pause(); _mm_pause(); _mm_pause(); _mm_pause();
}
failtimes = failtimes < PAUSETIMES_LIMIT ? failtimes : PAUSETIMES_LIMIT;
}
return status;
}
void spin_lock_rtm(int *lock)
{
int i;
unsigned status;
unsigned retry = RETRY_OTHER;
for (i = 0; i < retry; i++) {
if ((status = _xbegin()) == _XBEGIN_STARTED) {
if (lock_is_free(lock))
return;
_xabort(0xff);
}
trace_abort(status);
if ((status & _XABORT_EXPLICIT) && _XABORT_CODE(status) == 0xff) {
while (!lock_is_free(lock))
pause();
} else if (!(status & _XABORT_RETRY) && !(status & _XABORT_CAPACITY))
break;
if (status & _XABORT_CONFLICT) {
retry = RETRY_CON;
while (!lock_is_free(lock))
pause();
/* Could do various kinds of backoff here. */
} else if (status & _XABORT_CAPACITY) {
retry = RETRY_CAP;
} else {
retry = RETRY_OTHER;
}
}
/* Could do adaptation here */
while (__sync_sub_and_fetch(lock, 1) < 0) {
do
pause();
while (!lock_is_free(lock));
/* Could do respeculation here */
}
}
JNIEXPORT jint JNICALL Java_javartm_Transaction_begin(JNIEnv *env, jclass cls) {
return _xbegin();
}
unsigned int test_xbegin(void) {
// CHECK: i32 @llvm.x86.xbegin()
return _xbegin();
}
unsigned int __attribute__((__target__("rtm"))) xbegin_wrap(void) {
return _xbegin();
}
void mem_write(tid_t tid, uint32_t *addr, uint32_t val) {
version_t version;
objid_t objid = calc_objid(addr);
struct objinfo *info = &g_objinfo[objid];
if ((g_sim_bbcnt % RTM_BATCH_N) == 0) {
assert(!_xtest());
int ret = _xbegin();
(void)ret;
#ifdef RTM_STAT
if (ret != _XBEGIN_STARTED) {
fprintf(stderr, "T%d W%ld aborted %x, %d\n", g_tid, memop, ret,
_XABORT_CODE(ret));
g_rtm_abort_cnt++;
}
#endif
}
int in_rtm = _xtest();
if (in_rtm) {
version = info->version;
// XXX To ensure exclusion of write tx and fallback. Same as in read
// transaction.
if (info->write_lock) {
_xabort(3);
}
barrier();
*addr = val;
barrier();
info->version += 2;
// XXX The barrier is necessary, because there are reordering inside a
// transaction. The reason is the same as in seqlock implementation.
__sync_synchronize();
} else {
spin_lock(&info->write_lock);
version = info->version;
barrier();
// Odd version means that there's writer trying to update value.
info->version++;
barrier();
*addr = val;
// This barrier disallows read to happen before the write.
// The explicit barrier here may also make the compiler unnecessary here.
__sync_synchronize();
info->version++;
spin_unlock(&info->write_lock);
}
if (in_rtm && (g_sim_bbcnt % RTM_BATCH_N == RTM_BATCH_N - 1)) {
// XXX Update: since we have checked lock in tx region, we
// will abort for parallel execution of write tx and write fallback.
// So no need to check for lock here.
/*
*if (info->write_lock) {
* _xabort(4);
*}
*/
_xend();
// Avoid taking log inside transaction.
batch_write_log(objid, version);
batch_process_log();
} else {
batch_write_log(objid, version);
}
g_sim_bbcnt++;
}
uint32_t mem_read(tid_t tid, uint32_t *addr) {
version_t version;
uint32_t val;
objid_t objid = calc_objid(addr);
struct objinfo *info = &g_objinfo[objid];
if ((g_sim_bbcnt % RTM_BATCH_N) == 0) { // Simulate basic block begin.
assert(!_xtest());
int ret = _xbegin();
(void)ret;
#ifdef RTM_STAT
if (ret != _XBEGIN_STARTED) {
fprintf(stderr, "T%d R%ld aborted %x, %d\n", g_tid, memop, ret,
_XABORT_CODE(ret));
g_rtm_abort_cnt++;
}
#endif
}
int in_rtm = _xtest();
if (in_rtm) {
version = info->version;
// XXX It's possible the transaction commits while another write is in
// fallback handler and has increased version by 1, thus we would get an
// odd version here. Also refer to read tx in rtmseq.
if (version & 1) {
_xabort(1);
}
val = *addr;
} else {
do {
version = info->version;
while (unlikely(version & 1)) {
cpu_relax();
version = info->version;
}
barrier();
val = *addr;
barrier();
} while (version != info->version);
}
if (in_rtm && (g_sim_bbcnt % RTM_BATCH_N == RTM_BATCH_N - 1)) { // Simulate basic block end.
// XXX Update: since we have checked odd version in tx region, we
// will abort for parallel execution of read tx and write fallback.
// So no need to check for lock here.
// XXX A transaction is accessing different shared objects. Here we only
// check for a single object's write lock, it's not enough. That's why
// we need the odd version check in the transaction region.
/*
*if (info->write_lock) {
* _xabort(2);
*}
*/
_xend();
// Avoid taking log inside transaction.
batch_read_log(objid, version);
batch_process_log();
} else {
batch_read_log(objid, version);
}
g_sim_bbcnt++;
return val;
}
