Three stage pipeline (sample code)

pipe3.cpp
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#include <cstdlib>
#include <cstdio>
#include <ff/pipeline.hpp>
 
using namespace ff;
 
 
// generic stage
class Stage1: public ff_node {
public:
    Stage1(unsigned streamlen):streamlen(streamlen), seed(111) {}
 
    int svc_init() {
        srandom(seed);
        return 0;
    }
 
    void * svc(void *) {
        // f
        for(size_t i=0;i<streamlen;++i)
            ff_send_out(new long(random() % 1000000));
 
        return NULL;
    }
private:    
    unsigned streamlen;
    unsigned seed;
};
 
class Stage2: public ff_node {
public:
    void *svc(void *task) {
        // g
        long *t = static_cast<long*>(task);
        usleep(*t);
        return task;
    }
};
 
class Stage3: public ff_node {
public:
    void *svc(void *task) {
        // h
        long *t = static_cast<long*>(task);
        printf("received %ld\n", *t);
        delete t;
        return GO_ON;
    }
};
 
int main(int argc, char * argv[]) {
    if (argc!=2) {
        std::cerr << "use: "  << argv[0] << " streamlen\n";
        return -1;
    }
 
    // bild a 2-stage pipeline
    ff_pipeline pipe;
    pipe.add_stage(new Stage1(atoi(argv[1])));
    pipe.add_stage(new Stage2);
    pipe.add_stage(new Stage3);
 
    if (pipe.run_and_wait_end()<0) {
        error("running pipeline\n");
        return -1;
    }
    std::cerr << "DONE, pipe  time= " << pipe.ffTime() << " (ms)\n";
    //pipe.ffStats(std::cerr);
    return 0;
}