C ++11 std::thread vs Posix threads

When comparing C++11 threads with POSIX threads, we should evaluate them across several key aspects: portability, ease of use, functionality, and performance.

1. Portability

C++11 threads: The C++11 thread library is part of the C++ standard, so it can be used on all compilers supporting C++11 or later without regard to the operating system. This greatly facilitates the development of cross-platform applications.

POSIX threads: POSIX threads, also known as pthread, is a threading standard based on UNIX/Linux systems. Although implementations exist on many systems, its support on non-UNIX/Linux platforms is not guaranteed, which limits its applicability in cross-platform development.

2. Ease of Use

C++11 threads: The C++11 thread library is designed to be concise and user-friendly. It provides high-level APIs such as std::thread for creating and managing threads; std::mutex and std::lock_guard for thread synchronization; and std::async and std::future for handling asynchronous tasks and results. These features allow developers to focus more on implementing business logic.

For instance, creating a thread to execute a function can be done simply as:

cpp
#include <thread>
#include <iostream>

void hello() {
    std::cout << "Hello, World!" << std::endl;
}

int main() {
    std::thread t(hello);
    t.join();  // Wait for the thread to finish
    return 0;
}

POSIX threads: In contrast, POSIX threads offer a lower-level and more complex API. For example, creating and managing threads requires manual handling of thread attributes and error code checks, which increases programming complexity and the likelihood of errors.

Similarly, creating the same functionality in POSIX would be:

c
#include <pthread.h>
#include <stdio.h>

void* hello(void* arg) {
    printf("Hello, World!\n");
    return NULL;
}

int main() {
    pthread_t t;
    pthread_create(&t, NULL, hello, NULL);
    pthread_join(t, NULL);  // Wait for the thread to finish
    return 0;
}

3. Functionality

Both libraries provide robust functionality for thread creation, termination, and synchronization. However, the C++11 thread library integrates more seamlessly with C++ features like RAII and exception handling due to its standardization.

4. Performance

In terms of performance, both approaches are comparable, as they rely on underlying OS thread support. However, from the perspective of error handling and code maintainability, the C++11 thread library offers higher stability and maintainability.

Conclusion

In summary, if you are developing cross-platform applications or prefer modern C++ language features, the C++11 thread library is recommended. If you are working on UNIX/Linux-specific applications or need tight integration with POSIX-based libraries, POSIX threads remain a suitable choice.