void
Group::onSessionInitiateFailure(const ProcessPtr &process, Session *session) {
	vector<Callback> actions;

	TRACE_POINT();
	// Standard resource management boilerplate stuff...
	PoolPtr pool = getPool();
	boost::unique_lock<boost::mutex> lock(pool->syncher);
	assert(process->isAlive());
	assert(isAlive() || getLifeStatus() == SHUTTING_DOWN);

	UPDATE_TRACE_POINT();
	P_DEBUG("Could not initiate a session with process " <<
		process->inspect() << ", detaching from pool if possible");
	if (!pool->detachProcessUnlocked(process, actions)) {
		P_DEBUG("Process was already detached");
	}
	pool->fullVerifyInvariants();
	lock.unlock();
	runAllActions(actions);
}
void
Group::onSessionClose(const ProcessPtr &process, Session *session) {
	TRACE_POINT();
	// Standard resource management boilerplate stuff...
	PoolPtr pool = getPool();
	boost::unique_lock<boost::mutex> lock(pool->syncher);
	assert(process->isAlive());
	assert(isAlive() || getLifeStatus() == SHUTTING_DOWN);

	P_TRACE(2, "Session closed for process " << process->inspect());
	verifyInvariants();
	UPDATE_TRACE_POINT();
	
	/* Update statistics. */
	process->sessionClosed(session);
	assert(process->getLifeStatus() == Process::ALIVE);
	assert(process->enabled == Process::ENABLED
		|| process->enabled == Process::DISABLING
		|| process->enabled == Process::DETACHED);
	if (process->enabled == Process::ENABLED) {
		pqueue.decrease(process->pqHandle, process->busyness());
	}

	/* This group now has a process that's guaranteed to be not
	 * totally busy.
	 */
	assert(!process->isTotallyBusy());

	bool detachingBecauseOfMaxRequests = false;
	bool detachingBecauseCapacityNeeded = false;
	bool shouldDetach =
		( detachingBecauseOfMaxRequests = (
			options.maxRequests > 0
			&& process->processed >= options.maxRequests
		)) || (
			detachingBecauseCapacityNeeded = (
				process->sessions == 0
				&& getWaitlist.empty()
				&& (
					!pool->getWaitlist.empty()
					|| anotherGroupIsWaitingForCapacity()
				)
			)
		);
	bool shouldDisable =
		process->enabled == Process::DISABLING
		&& process->sessions == 0
		&& enabledCount > 0;

	if (shouldDetach || shouldDisable) {
		vector<Callback> actions;

		if (shouldDetach) {
			if (detachingBecauseCapacityNeeded) {
				/* Someone might be trying to get() a session for a different
				 * group that couldn't be spawned because of lack of pool capacity.
				 * If this group isn't under sufficiently load (as apparent by the
				 * checked conditions) then now's a good time to detach
				 * this process or group in order to free capacity.
				 */
				P_DEBUG("Process " << process->inspect() << " is no longer totally "
					"busy; detaching it in order to make room in the pool");
			} else {
				/* This process has processed its maximum number of requests,
				 * so we detach it.
				 */
				P_DEBUG("Process " << process->inspect() <<
					" has reached its maximum number of requests (" <<
					options.maxRequests << "); detaching it");
			}
			pool->detachProcessUnlocked(process, actions);
		} else {
			removeProcessFromList(process, disablingProcesses);
			addProcessToList(process, disabledProcesses);
			removeFromDisableWaitlist(process, DR_SUCCESS, actions);
			maybeInitiateOobw(process);
		}
		
		pool->fullVerifyInvariants();
		lock.unlock();
		runAllActions(actions);

	} else {
		// This could change process->enabled.
		maybeInitiateOobw(process);

		if (!getWaitlist.empty() && process->enabled == Process::ENABLED) {
			/* If there are clients on this group waiting for a process to
			 * become available then call them now.
			 */
			UPDATE_TRACE_POINT();
			// Already calls verifyInvariants().
			assignSessionsToGetWaitersQuickly(lock);
		}
	}
}