Destroying a command pool

When all command buffers allocated from a given pool are not used any more, and we also don't need the pool, we can safely destroy it.

How to do it...

1. Take the handle of a logical device and store it in a variable of type VkDevice named logical_device.
2. Use a handle of the pool that should be destroyed to initialize a variable of type VkCommandPool named command_pool.
3. Call vkDestroyCommandPool( logical_device, command_pool, nullptr ), for which provide the handles of the logical device and the command pool, and a nullptr value.
4. For safety reasons, assign the VK_NULL_HANDLE value to the command_pool variable.

How it works...

The command pool is destroyed with the following code:

if( VK_NULL_HANDLE != command_pool ) { 
  vkDestroyCommandPool( logical_device, command_pool, nullptr ); 
  command_pool = VK_NULL_HANDLE; 
}

But, we can't destroy the pool until all command buffers allocated from it are not pending for execution on a device. To do that, we can wait on fences or use...