Method MonitoringSnapshot

src/jrd/Monitoring.cpp:444–692

MonitoringSnapshot::MonitoringSnapshot(thread_db* tdbb, MemoryPool& pool)
	: SnapshotData(pool)
{
	PAG_header(tdbb, true);

	const auto dbb = tdbb->getDatabase();
	const auto attachment = tdbb->getAttachment();

	const auto selfAttId = attachment->att_attachment_id;

	// Initialize record buffers
	const auto dbb_buffer = allocBuffer(tdbb, pool, rel_mon_database);
	const auto att_buffer = allocBuffer(tdbb, pool, rel_mon_attachments);
	const auto tra_buffer = allocBuffer(tdbb, pool, rel_mon_transactions);
	const auto cmp_stmt_buffer = dbb->getEncodedOdsVersion() >= ODS_13_1 ?
		allocBuffer(tdbb, pool, rel_mon_compiled_statements) :
		nullptr;
	const auto stmt_buffer = allocBuffer(tdbb, pool, rel_mon_statements);
	const auto call_buffer = allocBuffer(tdbb, pool, rel_mon_calls);
	const auto io_stat_buffer = allocBuffer(tdbb, pool, rel_mon_io_stats);
	const auto rec_stat_buffer = allocBuffer(tdbb, pool, rel_mon_rec_stats);
	const auto ctx_var_buffer = allocBuffer(tdbb, pool, rel_mon_ctx_vars);
	const auto mem_usage_buffer = allocBuffer(tdbb, pool, rel_mon_mem_usage);
	const auto tab_stat_buffer = allocBuffer(tdbb, pool, rel_mon_tab_stats);

	// Increment the global monitor generation

	const auto generation = dbb->newMonitorGeneration();

	// Dump state of our own attachment

	Monitoring::dumpAttachment(tdbb, attachment, generation);

	// Enumerate active sessions and ensure they have dumped their state.
	// Check that by comparing the session generation with the current one.

	const auto locksmith = attachment->locksmith(tdbb, MONITOR_ANY_ATTACHMENT);
	const auto userName = attachment->getEffectiveUserName();
	const auto userNamePtr = locksmith ? nullptr : userName.c_str();

	Lock temp_lock(tdbb, sizeof(AttNumber), LCK_monitor), *lock = &temp_lock;
	MonitoringData::SessionList sessions(pool);

	do
	{
		ThreadStatusGuard tempStatus(tdbb);

		{ // scope for the guard

			MonitoringData::Guard guard(dbb->dbb_monitoring_data);
			dbb->dbb_monitoring_data->enumerate(userNamePtr, generation, sessions);
		}

		if (!sessions.hasData())
			break;

		const auto attId = sessions.pop();
		fb_assert(attId != selfAttId);