C++ Based Simple Publish Subscribe Library

compiling and running the application:

On Linux:

• simply execute compile_and_run.sh shell script

./compile_and_run.sh

• this script will compile the shared library, link it to the sample application and run the application

Classes:

• Subscriber
• Publisher
• subscriberList

Publisher APIs:

void publish(const std::string&)
void addSubscriber(class Subscriber*)
void removeSubscriber(class Subscriber*)

Subscriber APIs:

void receive(const std::string& )
void start()
void stop()
void run()

SubscriberList APIs:

void addSubscriber(Subscriber*)
void removeSubscriber(Subscriber*)
std::vector<Subscriber*> getSubscribers() const

Design

Publisher

• The Publisher class is used for publishing a message to all of its subscribers
• It keeps a list of registered subscribers in vector
• The subscriber is added or removed from this list when subscribed or unsubscribed

Subscriber

• The Subscriber class is used for receiving the message from the publisher
• When start() is called, new thread is created for receiving the message from publisher
• std::queue <std::string> is used to store all the messages
• 'm_lock' mutex is used to synchronize access to the queue by same thread
• 'global_lock' mutex is used to synchronize all threads for printing messages to stdout
• Thread stops when stop() is called

SubscriberList

• The SubscriberList class is used just to keep track of all the subscribers so that subscriber objects can be deleted later
• The subscribers are stored in vector and added or removed as per requirement