How to Manage Concurrent Access to Objects Using Mutexes in a Vector?

Accessing Concurrently Accessed Objects with Mutex Vector

Managing concurrent access to data objects requires proper synchronization techniques. While using a vector of mutexes (std::vector) seems intuitive, it's not feasible due to the absence of copy or move constructors for std::mutex. This limitation hinders the required resizing operations for the vector.

Alternative Solutions:

To overcome this conundrum, consider the following recommended solutions:

1. Fixed Number of Mutexes with Hashing:

Allocate a fixed number of mutexes and map objects to mutexes using a hash function. Collisions are likely but can be minimized if the number of mutexes is significantly larger than the number of threads.

2. Wrapper Class with Copy Constructor:

Create a wrapper class that inherits from std::mutex and provides a copy constructor. Use std::vector to store the mutexes.

3. Dynamic Array of Mutexes:

Use std::unique_ptr to manage individual mutexes. However, this involves allocating and deallocating mutexes dynamically, which may incur performance overhead.

4. Dynamically Resizing Mutex Array:

Initialize an std::unique_ptr with a specific number of mutexes. If more mutexes are needed, resize the array accordingly. This approach offers more flexibility than solution 3 and avoids unnecessary heap allocations.

Implementation Considerations:

The choice of the most appropriate solution depends on the following factors:

• Number of objects and threads involved
• Performance requirements
• Acceptable memory overhead

For cases where the number of mutexes can be fixed in advance, solution 1 offers simplicity and good performance. Solution 2 with a custom wrapper class provides flexibility but requires implementing additional functionalities. Solution 4 is recommended for situations where the number of mutexes needs to be adjusted dynamically and performance is critical.

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