Why I need times in closing files in flow

Question

I'm new to c++ and I have question.
I have code like:

    void FlowState::closeFile() {
        if (outfile) {
//from here
            struct timeval times[2];
            times[0] = myflow.tstart;
            times[1] = myflow.tstart;
            outfile->flush();
            outfile->close();
//to here
        }
    }

I have question about selected part. Why I need this? How is it working?

This may be helpful:

class FlowState {
public:
    string flowid;
    class Streamdemux &demux;
    Flow myflow;            

    // ...

    FlowState(class Streamdemux &demux_, const Flow &flow_,
            u_int32_t isn_, bool tcp);
    virtual ~FlowState();

    // ...

};

And:

 class Flow: public flowAddr {
    public:
        int32_t vlan;               
        struct timeval tstart;      
        struct timeval tlast;       
        uint64_t packet_count;      
        uint64_t connection_count;      
        string fileNameTemplate;

        Flow() :
                vlan(), tstart(), tlast(), packet_count(), connection_count() {
            fileNameTemplate = "%S:%s-%D:%d"; //brakuje ID połączenia
        }

        Flow(const flowAddr &flowAddr_, uint16_t vlan_,
                const struct timeval &t1, const struct timeval &t2,
                uint64_t connection_count_) :
                flowAddr(flowAddr_), vlan(vlan_), tstart(t1), tlast(t2), packet_count(
                        0), connection_count(connection_count_) {
            fileNameTemplate = "%S:%s-%D:%d";
        }

        virtual ~Flow() {
        }

    };

Answer 1

Think about it like this: You have a program that runs a long time, opening files from time to time. However, file handles, like everything else on a computer, is a limited resource. So if the program doesn't close the files it will sooner or later run out of available file handles.