[IGNITE-6719] Get rid of noop segment lock-unlock in PageMemoryImpl

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3
• Fix Version/s: 2.4
• Assignee: Alexey Goncharuk
• Reporter: Alexey Goncharuk
• Created: 24/Oct/17 08:19
• Updated: 24/Oct/17 08:22
• Resolved: 24/Oct/17 08:22

Description

We have the following pattern in PageMemoryImpl#stop():

volatile boolean closed;

...
closed = true;
writeLock.lock();
writeLock.unlock();

An empty lock/unlock pair can be eliminated, so the code must be changed and the flag should be moved to the segment class.