bool ConnectionPool::tryRemoveIdle() {
//first, if we find an idle queue with more the minIdle connection, we destroy one of them.
//otherwise, we try to destroy and connection from the longer idle queue.
const int minIdle = configuration.getMinIdle();
do {
const InetSocketAddress* keyToRemove = NULL;
int longerQueueSize = 0;
for (std::map<InetSocketAddress, TransportQueuePtr>::iterator it = idle.begin(); it != idle.end(); ++it) {
TransportQueuePtr idleQ = it->second;
if (minIdle > 0 && (int) idleQ->size() > minIdle) {
keyToRemove = &it->first;
break;
} else if ((int) idleQ->size() > longerQueueSize) {
keyToRemove = &it->first;
longerQueueSize = idleQ->size();
}
}
if (keyToRemove != NULL) {
TcpTransport* t = NULL;
if (idle[*keyToRemove]->poll(t)) { //in case of concurrent removal, avoid blocking
factory->destroyObject(*keyToRemove, *t);
totalIdle--;
return true;
}
} else {
return false;
}
} while (true);
}
void ConnectionPool::clear(const InetSocketAddress& key) {
sys::ScopedLock<sys::Mutex> l(lock);
TransportQueuePtr idleQ = idle[key];
totalIdle -= idleQ->size();
clear(key, idleQ);
idle.erase(key);
}
int ConnectionPool::calculateMinIdleGrow(const InetSocketAddress& key) {
TransportQueuePtr idleQ = idle[key];
int grown = configuration.getMinIdle() - idleQ->size();
//Note: if we need to check maxActive, uncomment the code above
/*if (configuration.getMaxActive() > 0) {
int growLimit = std::max(0, configuration.getMaxActive() - (int) busy[key]->size() - (int) idleQ->size());
grown = std::min(grown, growLimit);
}*/
if (configuration.getMaxTotal() > 0) {
int growLimit = std::max(0, configuration.getMaxTotal() - totalIdle - totalActive);
grown = std::min(grown, growLimit);
}
return grown;
}
TcpTransport& ConnectionPool::borrowObject(const InetSocketAddress& key) {
if (closed) {
throw new HotRodClientException("Pool is closed");
}
if (!idle.count(key) || !busy.count(key)) {
throw new HotRodClientException("Pool is closed");
}
TransportQueuePtr idleQ = idle[key];
TransportQueuePtr busyQ = busy[key];
// See if an object is readily available
TcpTransport* obj;
bool ok = idleQ->poll(obj);
for (;;) {
if (ok) {
// Check if the object is still valid, if not destroy it
if (configuration.isTestOnBorrow() && !factory->validateObject(key, *obj)) {
factory->destroyObject(key, *obj);
ok = false;
}
// We have a valid object
if (ok) {
busyQ->push(obj);
break;
}
}
// See if we can create a new one
if (busyQ->size() < configuration.getMaxActive()) {
obj = &factory->makeObject(key);
} else {
// Wait for an object to become idle
obj = idleQ->pop();
}
ok = true;
}
factory->activateObject(key, *obj);
return *obj;
}
TcpTransport& ConnectionPool::borrowObject(const InetSocketAddress& key) {
sys::ScopedLock<sys::Mutex> l(lock);
if (closed) {
throw HotRodClientException("Pool is closed");
}
if (!idle.count(key) || !busy.count(key)) {
throw HotRodClientException("Pool has no idle or no busy transports.");
}
TransportQueuePtr idleQ = idle[key];
TransportQueuePtr busyQ = busy[key];
// See if an object is readily available
TcpTransport* obj = NULL;
bool ok = idleQ->poll(obj);
if (ok) {
totalIdle--;
}
for (;;) {
if (ok) {
// Check if the object is still valid, if not destroy it
if (configuration.isTestOnBorrow() && !factory->validateObject(key, *obj)) {
factory->destroyObject(key, *obj);
ok = false;
}
// We have a valid object
if (ok) {
busyQ->push(obj);
totalActive++;
break;
}
}
// See if we can create a new one
if (idleQ->size() == 0 && //the idle queue is empty
(configuration.getMaxActive() < 0 || busyQ->size() < (size_t) configuration.getMaxActive()) && //max active not reached!
!hasReachedMaxTotal()) {
obj = &factory->makeObject(key);
} else if (hasReachedMaxTotal()) {
//max total reached. try to destroy a existing idle connection. if not possible, wait until some other connection is available.
if (tryRemoveIdle()) { //removal successful.
obj = &factory->makeObject(key);
} else {
allocationQueue.push(key);
{
sys::ScopedUnlock<sys::Mutex> u(lock);
obj = idleQ->pop();
}
totalIdle--;
}
} else {
// Wait for an object to become idle
{
sys::ScopedUnlock<sys::Mutex> u(lock);
obj = idleQ->pop();
}
totalIdle--;
}
ok = true;
}
factory->activateObject(key, *obj);
return *obj;
}
void ConnectionPool::clear(const InetSocketAddress& key, TransportQueuePtr queue) {
while (queue->size() > 0) {
TcpTransport* transport = queue->pop();
factory->destroyObject(key, *transport);
}
}