Tasks
Tasks were one of the latest additions to the C++11 standard. They give you a better abstraction than threads. In the general case, they should be your first choice.
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Entries by Rainer Grimm
Condition Variables
Condition variables allow us to synchronize threads via notifications. So, you can implement workflows like sender/receiver or producer/consumer. In such a workflow, the receiver waits for the sender’s notification. If the receiver gets the notification, it continues its work.
Thread-Local Data
By using the keyword thread_local, you define the thread local data. Thread-local can easily be explained in a few words.
Thread-Safe Initialization of Data
The story is simple if the data is not modified when shared between threads. The data has only to be initialized in the thread-safe way. It is not necessary to use an expensive lock for each access.
Prefer Locks to Mutexes
If the previous post showed something, it’s that you should use mutexes with great care. That’s why you should wrap them in a lock.
The Risks of Mutexes
The usage of mutexes seems extremely simple. There is a critical section in the code that a single thread can only access at any point in time. It’s ensured by a mutex m. The calls m.lock() and m.unlock() guarantee this exclusivity. But the devil is in the details.
Reader-Writer Locks
With C++14 came reader-writer locks. The idea is straightforward and promising. Arbitrary reading threads can access the critical region simultaneously, but only one thread is allowed to write.
Source Code Repository
I created a repository for the source code. It’s on GitHub and has the name ModernesCppSource:https://github.com/RainerGrimm/ModernesCppSource.git
Threads Sharing Data
One of the biggest challenges of thread management begins when the threads share non-const data
Thread Arguments
A thread gets its data by copy or by reference. By default, you should use by copy. Why? In case your thread gets its data by reference, you have to be extremely careful about the lifetime of the arguments.