How Can You Efficiently Protect Concurrent Access to a Varying Number of Objects Using Mutexes?

Alternative Solutions for Container of Mutexes

While using a std::vector might seem straightforward for protecting concurrent access to a varying number of objects, its limitations pose a challenge. Since mutexes lack copy and move constructors, resizing a std::vector of mutexes becomes infeasible.

To overcome this issue, several alternative solutions have emerged:

• Hash Function:
  Map objects to a fixed number of mutexes using a hash function. This approach can introduce collisions, but these can be minimized if the number of mutexes significantly exceeds the number of threads and falls below the number of objects.
• Wrapper Class:
  Create a wrapper class that provides a copy constructor and equality operator. By storing instances of this wrapper class in a std::vector, you can effectively manage mutexes without the need for copy or move semantics.
• Unique Pointers:
  Use std::unique_ptr to create an array of mutexes. This approach allows for dynamic allocation and deallocation of individual mutexes.
• Unique Pointers to Mutexes:
  Manage individual mutexes using std::unique_ptr. While this approach offers flexibility, it incurs the overhead of individual allocation and deallocation on the heap.

When choosing among these solutions, consider the following factors:

• Collision Risk: Hash function approach
• Performance: Wrapper class approach
• Heap Management: Unique pointer approaches

Ultimately, the choice depends on the specific requirements and preferences for your application.

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