static int trace_return()

in src/samplers/xfs/bpf.c [36:70]

• 21 lines of code
• 6 McCabe index (conditional complexity)

static int trace_return(struct pt_regs *ctx, int op)
{
    // get pid
    u32 pid = bpf_get_current_pid_tgid();

    // lookup start time
    u64 *tsp = start.lookup(&pid);

    // skip events without start
    if (tsp == 0) {
        return 0;
    }

    // calculate latency in microseconds
    u64 delta = (bpf_ktime_get_ns() - *tsp) / 1000;

    // calculate index
    u64 index = value_to_index2(delta);

    // store into correct histogram for OP
    if (op == 0) {
        read.increment(index);
    } else if (op == 1) {
        write.increment(index);
    } else if (op == 2) {
        open.increment(index);
    } else if (op == 3) {
        fsync.increment(index);
    }

    // clear the start time
    start.delete(&pid);

    return 0;
}