The GCC Wiki gives a very thorough and easy to understand explanation with code examples. (excerpt edited, and emphasis added) IMPORTANT: Upon re-reading the below quote copied from the GCC Wiki in the process of adding my own wording to the answer, I noticed that the quote is actually wrong. They got acquire and consume … Read more
Since the increment method is static it will synchronize on the class object for the ThreadSafeClass. The decrement method is not static and will synchronize on the instance used to call it. I.e., they will synchronize on different objects and thus two different threads can execute the methods at the same time. Since the ++ … Read more
In my opinion, the best way is with libdispatch, aka Grand Central Dispatch (GCD). It limits you to iOS 4 and greater, but it’s just so simple and easy to use. The code to do some processing on a background thread and then do something with the results in the main run loop is incredibly … Read more
In @dotsid’s answer he says this: If you change a HashMap in any way then your code is simply broken. He is correct. A HashMap that is updated without synchronization will break even if the threads are using disjoint sets of keys. Here are just some1 of the things that can go wrong. If one … Read more
TL;DR: A function can be reentrant, thread-safe, both or neither. The Wikipedia articles for thread-safety and reentrancy are well worth reading. Here are a few citations: A function is thread-safe if: it only manipulates shared data structures in a manner that guarantees safe execution by multiple threads at the same time. A function is reentrant … Read more
When you create a thread it will have its own call stack created. Two threads will have two stacks and one thread never shares its stack with other thread. All local variables defined in your program will be allocated memory in stack (As Jatin commented, memory here means, reference-value for objects and value for primitive … Read more
Open a phpinfo() and search for the line Thread safety. For a thread-safe build you should find enable. As specified in the comments by Muhammad Gelbana you can also use: On Windows : php -i|findstr “Thread” On *nix: php -i|grep Thread
The .NET 4.0 class that supports concurrency is named ConcurrentDictionary.
Yes, it is. It extends Random, which always had a de facto threadsafe implementation, and, from Java 7, explicitly guarantees threadsafety. If many threads are using a single SecureRandom, there might be contention that hurts performance. On the other hand, initializing a SecureRandom instance can be relatively slow. Whether it is best to share a … Read more
I hear that const means thread-safe in C++11. Is that true? It is somewhat true… This is what the Standard Language has to say on thread-safety: [1.10/4] Two expression evaluations conflict if one of them modifies a memory location (1.7) and the other one accesses or modifies the same memory location. [1.10/21] The execution of … Read more