Improvement CORE-3323 : Ability to cancel waiting in lock manager

src/jrd/jrd.cpp

@@ -1583,6 +1583,7 @@ ISC_STATUS FB_CANCEL_OPERATION(ISC_STATUS* user_status, Attachment** handle, USH
 			{
 				attachment->att_flags |= ATT_cancel_raise;
 				attachment->cancelExternalConnection(tdbb);
+				LCK_cancel_wait(attachment);
 			}
 			break;
 
@@ -4033,84 +4034,24 @@ bool JRD_reschedule(thread_db* tdbb, SLONG quantum, bool punt)
 		THREAD_YIELD();
 	}
 
-	// Test various flags and unwind/throw if required.
+	try {
-	// But do that only if we're neither in the verb cleanup state
+		tdbb->checkCancelState(punt);
-	// nor currently detaching, as these actions should never be interrupted.
+	}
-
+	catch (const status_exception& ex)
-	if (!(tdbb->tdbb_flags & (TDBB_verb_cleanup | TDBB_detaching)))
 	{
-		// If database has been shutdown then get out
+		tdbb->tdbb_flags |= TDBB_sys_error;
 
-		Attachment* const attachment = tdbb->getAttachment();
+		const Arg::StatusVector status(ex.value());
-		jrd_tra* const transaction = tdbb->getTransaction();
-		jrd_req* const request = tdbb->getRequest();
 
-		try
+		if (punt)
 		{
-			if (attachment)
+			CCH_unwind(tdbb, false);
-			{
+			ERR_post(status);
-				if (attachment->att_flags & ATT_shutdown)
-				{
-					if (dbb->dbb_ast_flags & DBB_shutdown)
-					{
-						status_exception::raise(Arg::Gds(isc_shutdown) <<
-												Arg::Str(attachment->att_filename));
-					}
-					else if (!(tdbb->tdbb_flags & TDBB_shutdown_manager))
-					{
-						status_exception::raise(Arg::Gds(isc_att_shutdown));
-					}
-				}
-
-				// If a cancel has been raised, defer its acknowledgement
-				// when executing in the context of an internal request or
-				// the system transaction.
-
-				if ((attachment->att_flags & ATT_cancel_raise) &&
-					!(attachment->att_flags & ATT_cancel_disable))
-				{
-					if ((!request ||
-						 !(request->req_flags & (req_internal | req_sys_trigger))) &&
-						(!transaction || !(transaction->tra_flags & TRA_system)))
-					{
-						attachment->att_flags &= ~ATT_cancel_raise;
-						status_exception::raise(Arg::Gds(isc_cancelled));
-					}
-				}
-			}
-
-			// Handle request cancellation
-
-			if (transaction && (transaction->tra_flags & TRA_cancel_request))
-			{
-				transaction->tra_flags &= ~TRA_cancel_request;
-				status_exception::raise(Arg::Gds(isc_cancelled));
-			}
-
-			// Check the thread state for already posted system errors. If any still persists,
-			// then someone tries to ignore our attempts to interrupt him. Let's insist.
-
-			if (tdbb->tdbb_flags & TDBB_sys_error)
-			{
-				status_exception::raise(Arg::Gds(isc_cancelled));
-			}
 		}
-		catch (const status_exception& ex)
+		else
 		{
-			tdbb->tdbb_flags |= TDBB_sys_error;
+			ERR_build_status(tdbb->tdbb_status_vector, status);
-
+			return true;
-			const Arg::StatusVector status(ex.value());
-
-			if (punt)
-			{
-				CCH_unwind(tdbb, false);
-				ERR_post(status);
-			}
-			else
-			{
-				ERR_build_status(tdbb->tdbb_status_vector, status);
-				return true;
-			}
 		}
 	}
 
@@ -5785,6 +5726,7 @@ static unsigned int purge_transactions(thread_db*	tdbb,
 			if ((transaction->tra_flags & TRA_prepared) || (dbb->dbb_ast_flags & DBB_shutdown) ||
 				(att_flags & ATT_shutdown))
 			{
+				EDS::Transaction::jrdTransactionEnd(tdbb, transaction, false, false, true);
 				TRA_release_transaction(tdbb, transaction);
 			}
 			else if (force_flag)
@@ -6235,6 +6177,81 @@ static THREAD_ENTRY_DECLARE shutdown_thread(THREAD_ENTRY_PARAM arg)
 	return 0;
 }
 
+bool thread_db::checkCancelState(bool punt)
+{
+	// Test various flags and unwind/throw if required.
+	// But do that only if we're neither in the verb cleanup state
+	// nor currently detaching, as these actions should never be interrupted.
+	// Also don't break wait in LM if it is not safe.
+
+	if (tdbb_flags & (TDBB_verb_cleanup | TDBB_detaching | TDBB_wait_cancel_disable))
+		return false;
+
+	if (attachment)
+	{
+		if (attachment->att_flags & ATT_shutdown)
+		{
+			if (database->dbb_ast_flags & DBB_shutdown)
+			{
+				if (!punt) 
+					return true;
+
+				status_exception::raise(Arg::Gds(isc_shutdown) <<
+										Arg::Str(attachment->att_filename));
+			}
+			else if (!(tdbb_flags & TDBB_shutdown_manager))
+			{
+				if (!punt) 
+					return true;
+
+				status_exception::raise(Arg::Gds(isc_att_shutdown));
+			}
+		}
+
+		// If a cancel has been raised, defer its acknowledgement
+		// when executing in the context of an internal request or
+		// the system transaction.
+
+		if ((attachment->att_flags & ATT_cancel_raise) &&
+			!(attachment->att_flags & ATT_cancel_disable))
+		{
+			if ((!request ||
+				 !(request->req_flags & (req_internal | req_sys_trigger))) &&
+				(!transaction || !(transaction->tra_flags & TRA_system)))
+			{
+				if (!punt) 
+					return true;
+
+				attachment->att_flags &= ~ATT_cancel_raise;
+				status_exception::raise(Arg::Gds(isc_cancelled));
+			}
+		}
+	}
+
+	// Handle request cancellation
+
+	if (transaction && (transaction->tra_flags & TRA_cancel_request))
+	{
+		if (!punt) 
+			return true;
+
+		transaction->tra_flags &= ~TRA_cancel_request;
+		status_exception::raise(Arg::Gds(isc_cancelled));
+	}
+
+	// Check the thread state for already posted system errors. If any still persists,
+	// then someone tries to ignore our attempts to interrupt him. Let's insist.
+
+	if (tdbb_flags & TDBB_sys_error)
+	{
+		if (!punt) 
+			return true;
+
+		status_exception::raise(Arg::Gds(isc_cancelled));
+	}
+
+	return false;
+}
 
 void thread_db::setTransaction(jrd_tra* val)
 {

src/jrd/jrd.h

@@ -313,6 +313,7 @@ public:
 	ULONG		att_flags;					// Flags describing the state of the attachment
 	SSHORT		att_charset;				// user's charset specified in dpb
 	Lock*		att_long_locks;				// outstanding two phased locks
+	Lock*		att_wait_lock;				// lock at which attachment waits currently
 	vec<Lock*>*	att_compatibility_table;	// hash table of compatible locks
 	vcl*		att_val_errors;
 	Firebird::PathName	att_working_directory;	// Current working directory is cached
@@ -778,6 +779,8 @@ public:
 		//attStat->bumpValue(index, relation_id);
 		//dbbStat->bumpValue(index, relation_id);
 	}
+
+	bool checkCancelState(bool punt);
 };
 
 // tdbb_flags
@@ -793,6 +796,7 @@ const USHORT TDBB_sys_error				= 128;	// error shouldn't be handled by the loope
 const USHORT TDBB_verb_cleanup			= 256;	// verb cleanup is in progress
 const USHORT TDBB_use_db_page_space		= 512;	// use database (not temporary) page space in GTT operations
 const USHORT TDBB_detaching				= 1024;	// detach is in progress
+const USHORT TDBB_wait_cancel_disable	= 2048;	// don't cancel current waiting operation
 
 
 class ThreadContextHolder

src/jrd/lck.cpp

@@ -211,6 +211,61 @@ inline bool checkLock(const Lock* l)
 #define LCK_CHECK_LOCK(x)	true	// nothing
 #endif
 
+namespace {
+// This class is used as a guard around long waiting call into LM and have 
+// two purposes :
+//	- set and restore att_wait_lock while waiting inside the LM
+//	- set or clear and restore TDBB_wait_cancel_disable flag in dependence
+//	  of safety of cancelling lock waiting. Currently we can safely cancel
+//	  only LCK_tra locks
+
+class WaitCancelGuard
+{
+public:
+	WaitCancelGuard(thread_db* tdbb, Lock* lock, int wait) :
+	  m_tdbb(tdbb),
+	  m_save_lock(NULL)
+	{
+		Attachment* att = m_tdbb->getAttachment();
+		m_save_lock = att->att_wait_lock;
+
+		m_cancel_disabled = (m_tdbb->tdbb_flags & TDBB_wait_cancel_disable); 
+		m_tdbb->tdbb_flags |= TDBB_wait_cancel_disable;
+
+		if (!wait)
+			return;
+
+		switch (lock->lck_type)
+		{
+		case LCK_tra:
+			m_tdbb->tdbb_flags &= ~TDBB_wait_cancel_disable;
+			att->att_wait_lock = lock;
+		break;
+
+		default:
+			;
+		}
+	}
+
+	~WaitCancelGuard()
+	{
+		Attachment* att = m_tdbb->getAttachment();
+		att->att_wait_lock = m_save_lock;
+
+		if (m_cancel_disabled) 
+			m_tdbb->tdbb_flags |= TDBB_wait_cancel_disable;
+		else
+			m_tdbb->tdbb_flags &= ~TDBB_wait_cancel_disable;
+	}
+
+private:
+	thread_db* m_tdbb;
+	Lock* m_save_lock;
+	bool m_cancel_disabled;
+};
+
+} // namespace
+
 
 void LCK_assert(thread_db* tdbb, Lock* lock)
 {
@@ -259,6 +314,7 @@ bool LCK_convert(thread_db* tdbb, Lock* lock, USHORT level, SSHORT wait)
 	Attachment* const old_attachment = lock->lck_attachment;
 	set_lock_attachment(lock, tdbb->getAttachment());
 
+	WaitCancelGuard guard(tdbb, lock, wait);
 	const bool result = CONVERT(tdbb, lock, level, wait);
 
 	if (!result)
@@ -270,6 +326,7 @@ bool LCK_convert(thread_db* tdbb, Lock* lock, USHORT level, SSHORT wait)
 		case isc_deadlock:
 		case isc_lock_conflict:
 		case isc_lock_timeout:
+			tdbb->checkCancelState(true);
 			return false;
 		case isc_lockmanerr:
 			dbb->dbb_flags |= DBB_bugcheck;
@@ -316,6 +373,27 @@ bool LCK_convert_opt(thread_db* tdbb, Lock* lock, USHORT level)
 }
 
 
+bool LCK_cancel_wait(Attachment* attachment)
+{
+/**************************************
+ *
+ *	L C K _ c a n c e l _ w a i t
+ *
+ **************************************
+ *
+ * Functional description
+ *	Try to cancel waiting of attachment inside the LM	
+ *
+ **************************************/
+	Database *dbb = attachment->att_database;
+
+	if (attachment->att_wait_lock)
+		return dbb->dbb_lock_mgr->cancelWait(attachment->att_wait_lock->lck_owner_handle);
+
+	return false;
+}
+
+
 void LCK_downgrade(thread_db* tdbb, Lock* lock)
 {
 /**************************************
@@ -535,6 +613,7 @@ bool LCK_lock(thread_db* tdbb, Lock* lock, USHORT level, SSHORT wait)
 	Database* dbb = lock->lck_dbb;
     set_lock_attachment(lock, tdbb->getAttachment());
 
+	WaitCancelGuard guard(tdbb, lock, wait);
 	ENQUEUE(tdbb, lock, level, wait);
 	fb_assert(LCK_CHECK_LOCK(lock));
 	if (!lock->lck_id)
@@ -548,6 +627,7 @@ bool LCK_lock(thread_db* tdbb, Lock* lock, USHORT level, SSHORT wait)
 		case isc_deadlock:
 		case isc_lock_conflict:
 		case isc_lock_timeout:
+			tdbb->checkCancelState(true);
 			return false;
 		case isc_lockmanerr:
 			dbb->dbb_flags |= DBB_bugcheck;

src/jrd/lck_proto.h

@@ -32,6 +32,7 @@ namespace Jrd {
 }
 
 void	LCK_assert(Jrd::thread_db*, Jrd::Lock*);
+bool	LCK_cancel_wait(Jrd::Attachment*);
 bool	LCK_convert(Jrd::thread_db*, Jrd::Lock*, USHORT, SSHORT);
 bool	LCK_convert_opt(Jrd::thread_db*, Jrd::Lock*, USHORT);
 void	LCK_downgrade(Jrd::thread_db*, Jrd::Lock*);

src/jrd/pag.cpp

@@ -2044,6 +2044,7 @@ static int blocking_ast_attachment(void* ast_object)
 
 		attachment->att_flags |= ATT_shutdown;
 		attachment->cancelExternalConnection(tdbb);
+		LCK_cancel_wait(attachment);
 
 		JRD_shutdown_attachments(dbb);
 

src/jrd/shut.cpp

@@ -563,6 +563,7 @@ static bool shutdown_locks(thread_db* tdbb, SSHORT flag)
 		{
 			attachment->att_flags |= ATT_shutdown;
 			attachment->cancelExternalConnection(tdbb);
+			LCK_cancel_wait(attachment);
 		}
 	}
 

src/jrd/tra.cpp

@@ -1989,6 +1989,7 @@ static int blocking_ast_transaction(void* ast_object)
 		transaction->tra_flags |= TRA_cancel_request;
 
 		att->cancelExternalConnection(tdbb);
+		LCK_cancel_wait(att);
 	}
 	catch (const Firebird::Exception&)
 	{} // no-op

src/lock/lock.cpp

@@ -829,6 +829,38 @@ void LockManager::repost(thread_db* tdbb, lock_ast_t ast, void* arg, SRQ_PTR own
 }
 
 
+bool LockManager::cancelWait(SRQ_PTR owner_offset)
+{
+/**************************************
+ *
+ *	c a n c e l W a i t
+ *
+ **************************************
+ *
+ * Functional description
+ *	Wakeup waiting owner to make it check if wait should be cancelled.
+ *	As this routine could be called asyncronous, take extra care and 
+ *	don't trust the input params blindly.
+ *
+ **************************************/
+	LOCK_TRACE(("cancelWait (%ld)\n", owner_offset));
+
+	if (!owner_offset)
+		return false;
+
+	Firebird::MutexLockGuard guard(m_localMutex);
+
+	acquire_shmem(DUMMY_OWNER);
+	
+	own* owner = (own*) SRQ_ABS_PTR(owner_offset);
+	if (owner->own_type == type_own)
+		post_wakeup(owner);
+	
+	release_shmem(DUMMY_OWNER);
+	return true;
+}
+
+
 SLONG LockManager::queryData(SRQ_PTR parent_request, const USHORT series, const USHORT aggregate)
 {
 /**************************************
@@ -1196,7 +1228,7 @@ void LockManager::acquire_shmem(SRQ_PTR owner_offset)
 	// the lock mutex.  In that event, lets see if there is any unfinished work
 	// left around that we need to finish up.
 
-	if (prior_active)
+	if (prior_active > 0)
 	{
 		post_history(his_active, owner_offset, prior_active, (SRQ_PTR) 0, false);
 		shb* const recover = (shb*) SRQ_ABS_PTR(m_header->lhb_secondary);
@@ -4033,7 +4065,9 @@ USHORT LockManager::wait_for_request(thread_db* tdbb, lrq* request, SSHORT lck_w
 		// See if we've waited beyond the lock timeout -
 		// if so we mark our own request as rejected
 
-		if (lck_wait < 0 && lock_timeout <= current_time)
+		const bool cancelled = tdbb->checkCancelState(false); 
+
+		if (cancelled || lck_wait < 0 && lock_timeout <= current_time)
 		{
 			// We're going to reject our lock - it's the callers responsibility
 			// to do cleanup and make sure post_pending() is called to wakeup
@@ -4041,6 +4075,7 @@ USHORT LockManager::wait_for_request(thread_db* tdbb, lrq* request, SSHORT lck_w
 			request->lrq_flags |= LRQ_rejected;
 			request->lrq_flags &= ~LRQ_pending;
 			lock->lbl_pending_lrq_count--;
+			
 			// and test - may be timeout due to missing process to deliver request
 			probe_processes();
 			release_shmem(owner_offset);

src/lock/lock_proto.h

@@ -329,6 +329,7 @@ public:
 	bool dequeue(const SRQ_PTR);
 
 	void repost(thread_db*, lock_ast_t, void*, SRQ_PTR);
+	bool cancelWait(SRQ_PTR);
 
 	SLONG queryData(SRQ_PTR, const USHORT, const USHORT);
 	SLONG readData(SRQ_PTR);