A network device in a communication network includes a controller and processing circuitry. The controller is configured to manage execution of an operation whose execution depends on inputs from a group of one or more work-request initiators. The processing circuitry is configured to read one or more values, which are set by the work-request initiators in one or more memory locations that are accessible to the work-request initiators and to the network device, and to trigger execution of the operation in response to verifying that the one or more values read from the one or more memory locations indicate that the work-request initiators in the group have provided the respective inputs.