static simgrid::xbt::signal<void(VirtualMachine&)> on_start;
static simgrid::xbt::signal<void(VirtualMachine&)> on_started;
static simgrid::xbt::signal<void(VirtualMachine&)> on_shutdown;
static simgrid::xbt::signal<void(VirtualMachine&)> on_start;
static simgrid::xbt::signal<void(VirtualMachine&)> on_started;
static simgrid::xbt::signal<void(VirtualMachine&)> on_shutdown;