Device Manager

The libxdaq function xdaq::get_device_manager() loads a xdaq::DeviceManager for managing XDAQ devices. Two manager types, ok and thor, are available for interfacing with USB and Thunderbolt devices, respectively.

Device Manager Name	Interface
ok	Opal Kelly USB
thor	Thunderbolt

The actual file name of the manager depends on the platform.

Platform	Device Manager Name
Windows	xxx _device_manager.dll
macOS	lib xxx _device_manager.dylib
Linux	lib xxx _device_manager.so

Example

#include <xdaq/device_manager.h>
#include <filesystem>
#include <iostream>

int main() {
    const std::filesystem::path manager_path{"libthor_device_manager.so"};
    try {
        auto manager = xdaq::get_device_manager(manager_path);
        std::cout << "Device Manager loaded successfully" << std::endl;
    } catch (const std::exception &e) {
        std::cerr << "Failed to load manager" << std::endl;
        std::cerr << e.what() << std::endl;
        return 1;
    }
    return 0;
}

Manager Caching

xdaq::get_device_manager() caches loaded managers by their canonical file path. Calling it again with the same library while a previous instance is still alive returns the same shared instance instead of loading the library twice. The underlying shared library is unloaded once the last reference to the manager is released.

Device Ownership

Devices created through a manager are protected by a cross-process ownership lock. When a device is opened, an exclusive lock file is acquired under the system temporary directory (libxdaq_locks). If another process already holds the lock, xdaq::DeviceManager::create_device() fails with a “Device is already occupied” error. The lock is derived from the manager’s file name and the device configuration, so different applications bundling their own copy of the same manager library still contend for the same physical device.

Device Discovery

To enumerate devices across multiple managers without permanently claiming them, use the device scanner (see Device Scanner). It reports each device as available, occupied by another process, or failed to query.