oldExampleDoc.md

Example Programs

Example programs were compiled and tested with g++ 7.3.0 and clang 6.0.1 on Ubuntu 18.04. g++ settings were:

g++ -std=c++17 -Wall -Werror -g3 -fsanitize=address

erase_where_demo.cpp

It is a common mistake to forget to erase an elment from a container after calling remove. The demo illustrates how the container size is unchanged after remove, but decreases after erase. chops::erase_where combines the two operations.

repeat_demo.cpp

A convenience function to repeat code N times. The lambda or function object can access the iteration count, if desired.

chops::repeat is also used in shared_buffer_demo.cpp and threaded_queue_buffer_demo.cpp.

shared_buffer_demo.cpp

Demonstration of chops::mutable_shared_buffer, a modifiable std::byte buffer with convenience methods, and internally reference counting for efficient copying. The demo code has utility functions for casting the buffer std::byte* pointer to char* and std::uint16_t*. The code also shows how to use the boost endian facilities to handle endian byte order when the buffer is used over a network connection.

See threaded_queue_buffer_demo.cpp for how to use the shared_buffer in mutltithreaded code.

threaded_queue_buffer_demo.cpp

Demo code showing use of chops::wait_queue in multithreaded environment. The program has 1...N data generators (default 20) that each place 20 random nubmers in a wait_queue<int>; each generator is in a separate thread. Then 1...N data processors (default 5) periodically convert the int data into strings that are placed into a chops::wait_queue<chops::mutable_shared_buffer>>. A single database thread puts the data from the second wait_queue into a simple database.

The demo program can take 2 command line arguments that set the number of data generators and data processors, respectively.

timer_demo.cpp

Demo code showing utiltiy functions that create periodic timers from the Asio libraray.

wait_queue_demo.cpp

Brief demonstation of using the chops::wait_queue API, with the queue semantics chops::wait_queue::push and chops::wait_queue::try_pop. The example also uses the wait_queue::apply method to iterate a non-modifying function over the queue elements. See threaded_queue_buffer_demo.cpp for a more in depth example using wait_queue in multithreaded code.