C++ Memory Management by Patrice Roy

Author:Patrice Roy
Language: eng
Format: epub
Publisher: Packt Publishing Limited
Published: 2025-02-27T00:00:00+00:00

A handmade user code example

We can, of course, write user code that uses our fictional API without resorting to specialized memory management facilities of C++, simply relying on placement new usage as seen in Chapter 7. It might be tempting to think of placement new as a specialized facility since you might have learned of it from this book, but if that is your perspective, you are invited to reconsider: the placement new mechanism is a fundamental memory management tool used in almost every program, whether user code is aware of it or not.

As a reminder, our example program will do the following:

Create a shared memory segment of some size (we will allocate much more than we need in this case).

Construct a data object at the beginning of that segment, obviously through placement new.

Start a thread that will wait for a signal on the go variable of type atomic<bool>, then obtain access to the shared memory segment, write to the value data member and then only signal that the write has occurred through the ready data member.

Start another thread that will obtain access to the shared memory segment, get a pointer to the shared data object therein, and then do some (very inefficient) busy waiting on the ready flag to change state, after which value will be read and used. Once this has been done, completion will be signaled through the done flag of type atomic<bool>.

Our program will then read a key from the keyboard, signal the threads (the writer thread, really) that it’s time to start working, and wait until they are done before freeing the shared memory segment and concluding its work.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.