PPT Slide
Two-phase locking
- 2nd phase = changing phase: database records are actually updated at this time; since no other locks are permitted to be acquired, no deadlock is possible. All locks are released when this phase is complete.
Starvation
- Case where a process may never get to proceed due to an inefficient allocation algorithm or unfair deadlock algorithm (aging can solve starvation).
- Random scheduling or even FCFS (DAT & CDROM example) can cause process resource starvation.
- Solutions to the deadlock problem can make starvation more likely and solutions to the starvation problem can make deadlock more likely!