In the traffic intersection problem, vehicles are trying to pass through an
intersection of two roads, one north/south, the other east/west, without
colliding. Each vehicle arrives at the intersection from one of four
directions (north, south, east, or west), called it’s origin . It is trying to pass
through the intersection and exit in some direction other than its origin,
called it’s destination.
Each arriving vehicle is simulated by a thread, and the intersection is a
critical section. Each vehicle (thread) enters the intersection (critical
section) and eventually leaves. However, you may not change this file in
any way. The vehicle simulation works by creating a fixed number of
concurrent threads. Each thread simulates a sequence of vehicles
attempting to pass through the intersection. In a loop, each thread
generates a random vehicle (randomly choosing an origin and destination
for the vehicle) and then enters and leaves the critical section to simulate
the vehicle passing through the intersection. Threads then sleep for a
configurable period of time before generating another random vehicle and
repeating the process. Each thread simulates one vehicle at a time.
However, since there are multiple concurrent threads, there may be
multiple vehicles attempting to enter the critical section (intersection) concurrently.
Your job is to synchronize the vehicles so that they do not collide in the
intersection. Informally, it is OK for more than one vehicle to be in the
intersection at the same time as long as their paths will not result in a
collision. For example, it is OK for a vehicle that
is traveling from north to south to share the intersection with another
vehicle that is traveling from south to north, but not with one that is
traveling
from east to west.
For the purposes of this assignment, we’ve codified a specific set of
conditions under which vehicles can safely share the intersection (critical
section). If two vehicles, Va and Vb , are in the intersection
simultaneously, then at least one of the following must be true:
Va and Vb entered the intersection from the same direction, i.e.,
Va.origin = Vb .origin , or
Va and Vb are going in opposite directions, i.e.,
Va .origin = Vb .destination and Va .destination = Vb .origin , or
Va and Vb have different destinations, and at least one of them is
makin g a right turn, e.g., Va is right-turning from north to west, and
Vb is going from south to north.
Note that it is possible for more than two vehicles to be in the intersection
at the same time, as long as all pairs of vehicles satisfy one of the above
conditions.
These conditions are less flexible than what is allowed at some real road
intersections. For example, the conditions above do not allow cars
traveling in opposite directions to make left turns concurrently.
Nonetheless, for the purposes of this assignment, these somewhat
simplified conditions will serve as our definition of correctness.
-
Notifications
You must be signed in to change notification settings - Fork 0
salexus/osproject
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Folders and files
Name | Name | Last commit message | Last commit date | |
---|---|---|---|---|
Repository files navigation
About
No description, website, or topics provided.
Resources
Stars
Watchers
Forks
Releases
No releases published
Packages 0
No packages published