clone.cxx

// Linux
#include <sys/syscall.h>
 
// Cosmos
#include <cosmos/error/ApiError.hxx>
#include <cosmos/memory.hxx>
#include <cosmos/proc/clone.hxx>
#include <cosmos/proc/signal.hxx>
 
namespace {
 
// for clone(3) there is no glibc wrapper yet so we need to wrap it ourselves
pid_t clone3(const struct clone_args &args) {
        return syscall(SYS_clone3, &args, sizeof(args));
}
 
} // end anon ns
 
namespace cosmos {
 
void CloneArgs::clear() {
        zero_object(static_cast<clone_args&>(*this));
 
        // this must not be zero by default or we don't get any child exit
        // signal notification.
        setExitSignal(signal::CHILD);
}
 
namespace proc {
 
std::optional<ProcessID> clone(const CloneArgs &args) {
        const auto child = clone3(args);
 
        if (child == -1) {
                cosmos_throw (ApiError("clone3()"));
        } else if (child == 0) {
                return std::nullopt;
        }
 
        return ProcessID{child};
}
 
} // end ns
} // end ns