#include "pathlocks.hh"

    /* Acquire the global queue runner lock, or null if somebody else
       has it. */
    std::shared_ptr<PathLocks> acquireGlobalLock();

}
std::shared_ptr<PathLocks> State::acquireGlobalLock()
{
    Path lockPath = hydraData + "/queue-runner";
    auto lock = std::make_shared<PathLocks>();
    if (!lock->lockPaths(PathSet({lockPath}), "", false)) return 0;
    return lock;

    auto lock = acquireGlobalLock();
    if (!lock)
        throw Error("hydra-queue-runner is currently running");

    auto lock = acquireGlobalLock();
    if (!lock)
        throw Error("hydra-queue-runner is already running");