void insertAtRank (int rank, const Object& element)// insert at given rank
{
if (rank == size()) // no checkRank if last
insertLast(element);
else {
checkRank(rank);
insertBefore( atRank(rank), element );
}
}
NodeSequence<Object>::Position NodeSequence<Object>::
atRank(int rank) const // position of rank
{
NodePtr v;
checkRank(rank);
if (rank <= size()/2) { // scan forward from head
v = header->next;
for (int i = 0; i < rank; i++)
v = v->next;
}
else { // scan back from tail
v = trailer->prev;
for (int i = 1; i < size()-rank; i++)
v = v->prev;
}
return Position(v);
}
// acquire: also returns true if we are already the writer.
bool Lease::acquire(bool blocking /* = false */ ) {
if (amOwner()) {
return true;
}
if (!threadCanAcquire && !blocking) {
return false;
}
int64_t expire = m_hintExpire;
int64_t expireDiff = expire - Timer::GetCurrentTimeMicros();
if (!blocking && (m_held.load(std::memory_order_acquire) ||
(expireDiff > 0 && m_owner != pthread_self()))) {
return false;
}
checkRank(RankWriteLease);
auto const locked = blocking ? pthread_mutex_lock(&m_lock)
: pthread_mutex_trylock(&m_lock);
if (locked == 0) {
TRACE(4, "thr%" PRIx64 ": acquired lease, called by %p,%p\n",
Process::GetThreadIdForTrace(), __builtin_return_address(0),
__builtin_return_address(1));
if (debug) {
pushRank(RankWriteLease);
if (expire != 0 && m_owner != pthread_self()) {
m_hintGrabbed++;
TRACE(3,
"thr%" PRIx64 ": acquired hinted lease"
", expired %" PRId64 "us ago\n",
Process::GetThreadIdForTrace(), -expireDiff);
} else if (expire != 0 && m_owner == pthread_self()) {
m_hintKept++;
}
}
m_owner = pthread_self();
m_hintExpire = 0;
m_held.store(true, std::memory_order_release);
return true;
}
always_assert(!blocking && "Failed to acquire write lease in blocking mode");
return false;
}
// acquire: also returns true if we are already the writer.
bool Lease::acquire(bool blocking /* = false */ ) {
if (amOwner()) {
return true;
}
int64_t expire = m_hintExpire;
int64_t expireDiff = expire - Timer::GetCurrentTimeMicros();
if (!blocking && (m_held ||
(expireDiff > 0 && m_owner != pthread_self()))) {
return false;
}
checkRank(RankWriteLease);
if (0 == (blocking ?
pthread_mutex_lock(&m_lock) :
pthread_mutex_trylock(&m_lock))) {
TRACE(4, "thr%" PRIx64 ": acquired lease, called by %p,%p\n",
Process::GetThreadIdForTrace(), __builtin_return_address(0),
__builtin_return_address(1));
if (debug) {
pushRank(RankWriteLease);
if (expire != 0 && m_owner != pthread_self()) {
m_hintGrabbed++;
TRACE(3,
"thr%" PRIx64 ": acquired hinted lease"
", expired %" PRId64 "us ago\n",
Process::GetThreadIdForTrace(), -expireDiff);
} else if (expire != 0 && m_owner == pthread_self()) {
m_hintKept++;
}
tx64->unprotectCode();
}
m_owner = pthread_self();
m_hintExpire = 0;
m_held = true;
return true;
}
if (blocking) {
TRACE(3, "thr%" PRIx64 ": failed to acquired lease in blocking mode\n",
Process::GetThreadIdForTrace());
}
return false;
}
void replaceAtRank (int rank, const Object& element)// replace at rank
{
checkRank(rank);
replaceElement( atRank(rank), element );
}
void removeAtRank (int rank) // remove from rank
{
checkRank(rank);
Position p = atRank(rank); // position to remove
remove(p);
}
Object elemAtRank (int rank) const // element at this rank
{
checkRank(rank);
return atRank(rank).element();
}
void pushRank(Rank r) {
checkRank(r);
assert(tl_curRankDepth < kMaxLockDepth);
tl_rankStack[tl_curRankDepth++] = r;
}
