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--- magistraleinformaticanetworking:spm:ffhwpipe [21/03/2012 alle 18:46 (13 anni fa)] – creata Marco Danelutto
+++ magistraleinformaticanetworking:spm:ffhwpipe [21/03/2012 alle 18:53 (13 anni fa)] (versione attuale) – Marco Danelutto
@@ Linea 1: / Linea 1: @@
 ===== Sample pipeline applications in FastFlow =====
+The code appearing on this page is commented in the course notes PDF, Appendix A: FastFlow.
+This is the code of a single concurrent activity printing an "Hello World". We use a single stage pipeline without any kind of stream.
+<code c++ hello.cpp>
+#include <iostream>
+#include <ff/pipeline.hpp>
+using namespace ff;
+class Stage1: public ff_node {
+public:
+    void * svc(void * task) {
+        std::cout << "Hello world" << std::endl;
+        return NULL;
+    }
+};
+int main(int argc, char * argv[]) {
+    ff_pipeline pipe;
+    pipe.add_stage(new Stage1());
+    ffTime(START_TIME);
+    if (pipe.run_and_wait_end()<0) {
+        error("running pipeline\n");
+        return -1;
+    }
+    ffTime(STOP_TIME);
+    std::cerr << "DONE, pipe  time= " << pipe.ffTime() << " (ms)\n";
+    std::cerr << "DONE, total time= " << ffTime(GET_TIME) << " (ms)\n";
+    pipe.ffStats(std::cerr);
+    return 0;
+}
+</code>
+The second version following uses a two stage pipeline: the first stage prints "Hello" then send "world" to be printed by the second stage. The program does not terminate.
+<code c++ hello2stages.cpp>
+#include <iostream>
+#include <ff/pipeline.hpp>
+using namespace ff;
+class Stage1: public ff_node {
+public:
+    void * svc(void * task) {
+        std::cout << "Hello " << std::endl;
+        char * p = (char *) calloc(sizeof(char),10);
+        strcpy(p,"World");
+        sleep(1);
+        return ((void *)p);
+    }
+};
+class Stage2: public ff_node {
+public:
+    void * svc(void * task) {
+      std::cout << ((char *)task) << std::endl;
+      free(task);
+      return GO_ON;
+    }
+};
+int main(int argc, char * argv[]) {
+    ff_pipeline pipe;
+    pipe.add_stage(new Stage1());
+    pipe.add_stage(new Stage2());
+    if (pipe.run_and_wait_end()<0) {
+        error("running pipeline\n");
+        return -1;
+    }
+    return 0;
+}
+</code>
+We add termination here:
+<code c++ hello2terminate.cpp>
+#include <iostream>
+#include <ff/pipeline.hpp>
+using namespace ff;
+class Stage1: public ff_node {
+public:
+  Stage1() { first = (1==1); }
+  void * svc(void * task) {
+    if(first) {
+      std::cout << "Hello " << std::endl;
+      char * p = (char *) calloc(sizeof(char),10);
+      strcpy(p,"World");
+      sleep(1);
+      first = 0;
+      return ((void *)p);
+    } else {
+      return NULL;
+    }
+  }
+private:
+  int first;
+};
+class Stage2: public ff_node {
+public:
+    void * svc(void * task) {
+      std::cout << ((char *)task) << std::endl;
+      free(task);
+      return GO_ON;
+    }
+};
+int main(int argc, char * argv[]) {
+    ff_pipeline pipe;
+    pipe.add_stage(new Stage1());
+    pipe.add_stage(new Stage2());
+    if (pipe.run_and_wait_end()<0) {
+        error("running pipeline\n");
+        return -1;
+    }
+    return 0;
+}
+</code>