CppCon 2014 Defensive Programming Done Right, Part II--John Lakos

By Adrien Hamelin | May 13, 2015 08:00 AM | Tags: community advanced

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Defensive Programming Done Right, Part II

by John Lakos

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

In our component-based development methodology, each developer is responsible for ensuring that the software he or she creates is easy to understand and use, and not especially easy to misuse. One common form of misuse is to invoke a library function or method under circumstances where not all of its preconditions are satisfied, leading to undefined behavior. Contracts having undefined behavior are not necessarily undesirable, and (for many engineering reasons) are often optimal. Most would agree that a well-implemented library should do something other than silently continue when a pre-condition violation is detected, although these same folks might not agree on what specific action should be taken. Unfortunately, validating preconditions implies writing additional code that will execute at runtime. More code runs slower, and some would fairly argue that they should not be forced to pay for redundant runtime checks in the library software they use. Whether and to what extent library functions should validate their preconditions, and what should happen if a precondition violation is detected are questions that are best answered on an application by application basis - i.e., by the owner of main. "Defensive Programming Done Right" makes it all possible.

In this talk, we begin by reviewing the basic concepts of Design-By-Contract (DbC), and what we mean by the term "Defensive Programming" (DP). We then explore our overall approach to institutionalizing defensive programming in robust reusable library software such that each application can conveniently specify both the runtime budget (e.g., none, some, lots) for defensive checking, and also the specific action to be taken (e.g., abort, throw, spin) should a precondition violation occur. Along the way, we touch on how modern compilers and linkers work, binary compatibility, and the consequences of possibly violating the one-definition rule in mixed-mode builds. We conclude the talk by describing and then demonstrating our "negative testing" strategy (and supporting test apparatus) for readily verifying, in our component-level test drivers, that our defensive checks detect and report out-of-contract client use as intended. Actual source for the supporting utility components will be presented throughout the talk and made available afterwards.

CppCon 2014 Defensive Programming Done Right, Part I--John Lakos

By Adrien Hamelin | May 11, 2015 08:00 AM | Tags: community advanced

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Defensive Programming Done Right, Part I

by John Lakos

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

In our component-based development methodology, each developer is responsible for ensuring that the software he or she creates is easy to understand and use, and not especially easy to misuse. One common form of misuse is to invoke a library function or method under circumstances where not all of its preconditions are satisfied, leading to undefined behavior. Contracts having undefined behavior are not necessarily undesirable, and (for many engineering reasons) are often optimal. Most would agree that a well-implemented library should do something other than silently continue when a pre-condition violation is detected, although these same folks might not agree on what specific action should be taken. Unfortunately, validating preconditions implies writing additional code that will execute at runtime. More code runs slower, and some would fairly argue that they should not be forced to pay for redundant runtime checks in the library software they use. Whether and to what extent library functions should validate their preconditions, and what should happen if a precondition violation is detected are questions that are best answered on an application by application basis - i.e., by the owner of main. "Defensive Programming Done Right" makes it all possible.

In this talk, we begin by reviewing the basic concepts of Design-By-Contract (DbC), and what we mean by the term "Defensive Programming" (DP). We then explore our overall approach to institutionalizing defensive programming in robust reusable library software such that each application can conveniently specify both the runtime budget (e.g., none, some, lots) for defensive checking, and also the specific action to be taken (e.g., abort, throw, spin) should a precondition violation occur. Along the way, we touch on how modern compilers and linkers work, binary compatibility, and the consequences of possibly violating the one-definition rule in mixed-mode builds. We conclude the talk by describing and then demonstrating our "negative testing" strategy (and supporting test apparatus) for readily verifying, in our component-level test drivers, that our defensive checks detect and report out-of-contract client use as intended. Actual source for the supporting utility components will be presented throughout the talk and made available afterwards.

CppCon 2014 How you can make a Boost C++ Library--Robert Ramey

By Adrien Hamelin | May 8, 2015 08:00 AM | Tags: intermediate boost

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

How you can make a Boost C++ Library

by Robert Ramey

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

The purpose of this presentation is to encourage C++ programmers to create and submit new quality C++ libraries to Boost.

Premises: a) C++ needs more quality libraries b) There are many C++ programmers who would like to contribute libraries but they are discouraged by the amount of effort and associated heartache.

Methodology: Walk through the website www.blincubator.com from the point of view of a C++ library contributor. It will address issues related to requirements, suggested tools, user feedback, library promotion. It will assume that the attendee is an intermediate to advanced C++ programmer with an idea for a library.

CppCast Episode 10: SQLpp11 with Roland Bock

By robwirving | May 7, 2015 08:00 AM | Tags: sql podcast community

Episode 10 of CppCast the only podcast by C++ developers for C++ developers. In this episode Rob and Jason are joined by Roland Bock to talk about sqlpp11 and some of Rolands ideas for the future of C++.

CppCast Episode 10: SQLpp11 with Roland Bock

by Rob Irving and Jason Turner

About the interviewee:

Roland Bock is Head of Development at PPRO Financial Ltd, an FCA regulated e-Money institute offering prepaid MasterCard card programs and comprehensive financial solutions for international electronic payment transactions. Since 2008 he has been using SQL in C++. Being unhappy with the string-based approach of most SQL libraries, he decided to do something about it and developed a type-safe EDSL for SQL in C++: sqlpp11. In his spare time Roland is working on sqlpp11, experimenting with Concepts Lite and trying to write a proposal about compile-time configurable names for C++ standard. He lives and codes in Munich (Germany).

CppCon 2014 Optimization Tips - Mo' Hustle Mo' Problems--Andrei Alexandrescu

By Adrien Hamelin | May 6, 2015 08:00 AM | Tags: performance efficiency

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Optimization Tips - Mo' Hustle Mo' Problems

by Andrei Alexandrescu

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Reasonably-written C++ code will be naturally fast. This is to C++'s excellent low-penalty abstractions and a memory model close to the machine.

However, a large category of applications have no boundaries on desired speed, meaning there's no point of diminishing returns in making code faster. Better speed means less power consumed for the same work, more workload with the same data center expense, better features for the end user, more features for machine learning, better analytics, and more.

Optimizing has always been an art, and in particular optimizing C++ on contemporary hardware has become a task of formidable complexity. This is because modern hardware has a few peculiarities about it that are not sufficiently understood and explored. This talk discusses a few such effects, and guides the attendee on how to navigate design and implementation options in search for better performance.

CppCon 2014 Lock-Free Programming (or, Juggling Razor Blades), Part II--Herb Sutter

By Adrien Hamelin | May 4, 2015 07:59 AM | Tags: performance efficiency

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Lock-Free Programming (or, Juggling Razor Blades), Part II

by Herb Sutter

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Example-driven talk on how to design and write lock-free algorithms and data structures using C++ atomic -- something that can look deceptively simple, but contains very deep topics. (Important note: This is not the same as my "atomic Weapons" talk; that talk was about the "what they are and why" of the C++ memory model and atomics, and did not cover how to actually use atomics to implement highly concurrent algorithms and data structures.)

CppCon 2014 Lock-Free Programming (or, Juggling Razor Blades), Part I--Herb Sutter

By Adrien Hamelin | May 1, 2015 07:59 AM | Tags: performance efficiency

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Lock-Free Programming (or, Juggling Razor Blades), Part I

by Herb Sutter

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Example-driven talk on how to design and write lock-free algorithms and data structures using C++ atomic -- something that can look deceptively simple, but contains very deep topics. (Important note: This is not the same as my "atomic Weapons" talk; that talk was about the "what they are and why" of the C++ memory model and atomics, and did not cover how to actually use atomics to implement highly concurrent algorithms and data structures.)

CppCon 2014 Another fundamental shift in Parallelism Paradigm?--Michael Wong

By Adrien Hamelin | Apr 29, 2015 08:00 AM | Tags: performance efficiency

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Another fundamental shift in Parallelism Paradigm?

by Michael Wong

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Another fundamental shift in Parallelism Paradigm? Sure. When was the last time you heard that before?

But seriously, as the number of threads/cores continue to increase, there is a growing pressure on applications to exploit more of the available parallelism in their codes, including coarse-, medium-, and fine-grain parallelism. OpenMP has been one of the dominant shared-memory programming models but is evolving beyond that with a new Mission Statement (no, really!) making it well suited for exploiting medium- and fine-grained parallelism.

OpenMP 4.0 exhibits many of these features to support the next step in both consumer, high-performance and exascale computing, with one of the world's first programming model for high-level language support for GPU/Accelerators and vector SIMD across not 1 but 3 high-level languages: C++, C, and that language whose name we dare not speak, but starts with F.

CppCon 2014 Lock-free by Example--Tony Van Eerd

By Adrien Hamelin | Apr 27, 2015 08:00 AM | Tags: efficiency advanced

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

Lock-free by Example

by Tony Van Eerd

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

Dive into and follow along making a lock-free queue.

In particular, a multi-producer, multi-consumer, growing, shrinking, mostly contiguous, lock-free circular queue.

With this single (complicated!) example, we will come across, and attempt to solve, many of the typical problems found in lockfree programming, and delve into the pros and cons of various solutions to those problems.

CppCon 2014 STL Features And Implementation Techniques--Stephan Lavavej

By Adrien Hamelin | Apr 24, 2015 08:00 AM | Tags: intermediate c++14

While we wait for CppCon 2015 in September, we’re featuring videos of some of the 100+ talks from CppCon 2014. Here is today’s feature:

STL Features And Implementation Techniques

by Stephan Lavavej

(watch on YouTube) (watch on Channel 9)

Summary of the talk:

This session will cover selected STL features from C++11/14, both explaining how to use them and delving into implementation techniques that could be useful outside the STL.

I will avoid covering popular features you're already using (e.g. make_shared, make_unique) and obscure features of limited use (e.g. forward_list). The focus will be on useful but underappreciated features like dual-range algorithms, minimal allocators, and heterogeneous associative lookup.