Initial revision of MultiTasker from Pete.

git-svn-id: https://svn.microneil.com/svn/CodeDweller/branches/adeniz_1@102 d34b734f-a00e-4b39-a726-e4eeb87269ab

multitasking.cpp

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+// multitasking.cpp
+// Copyright 2015 MicroNeil Research Corporation
+
+#include "multitasking.hpp"
+
+void MultiTasker::processBatch(size_t n, MultiTaskQueue& q, bool StopOnWait) {
+    size_t batchSize = n;
+    while(batchSize--) {
+        MultiTask& t = q.get();
+        switch(t.task()) {
+            case Running: { working.put(t); break; }
+            case Waiting: { waiting.put(t); if(StopOnWait) return; break; }
+            case Finished: { finished.put(t); break; }
+        }
+    }
+}
+
+MultiTaskState MultiTasker::task() {
+    size_t workingBatchSize = working.size();
+    size_t waitingBatchSize = waiting.size();
+    processBatch(workingBatchSize, working);
+    processBatch(waitingBatchSize, waiting, true);
+
+    if(false == working.empty()) { return Running; }
+    else if (false == waiting.empty()) { return Waiting; }
+    else { return Finished; }
+}

multitasking.hpp

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+#ifndef M_MultiTasking
+#define M_MultiTasking
+
+#include <cstddef>
+#include <queue>
+
+enum MultiTaskState {Running, Waiting, Finished};
+
+class MultiTask {
+  public:
+    virtual MultiTaskState task() = 0;
+};
+
+class MultiTaskQueue : public std::queue<MultiTask*> {
+  public:
+
+    void put(MultiTask& T) { push(&T); }
+    MultiTask& get() { MultiTask& T = *(front()); pop(); return T; }
+
+};
+
+class MultiTasker : public MultiTask {
+  private:
+    void processBatch(size_t n, MultiTaskQueue& q, bool StopOnWait = false);
+
+  public:
+    MultiTaskQueue working;
+    MultiTaskQueue waiting;
+    MultiTaskQueue finished;
+    MultiTaskState task();
+
+    bool isReady() { return (false == working.empty()); }
+    bool isWaiting() { return (false == waiting.empty() && true == working.empty()); }
+    bool isFinished() { return (true == working.empty() && true == waiting.empty()); }
+    bool hasWork() { return (false == isFinished()); }
+
+    size_t completed() { return finished.size(); }
+    size_t pending() { return (working.size() + waiting.size()); }
+    size_t total() { return (working.size() + waiting.size() + finished.size()); }
+
+    void put(MultiTask& t) { working.put(t); }
+    MultiTask& get() { return finished.get(); }
+    bool canGet() { return (false == finished.empty()); }
+};
+
+#endif // M_MultiTasking

multitaskingExample.cpp

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+#include <iostream>
+#include <vector>
+#include <string>
+#include <sstream>
+#include <cstdlib>
+#include "../CodeDweller/timing.hpp"
+#include "multitasking.hpp"
+
+using namespace std;
+
+class TaskHistory : public vector<string> {
+  public:
+    void post(string stuff) {
+        push_back(stuff);
+    }
+};
+
+string makeProgressMessage(int m) {
+    stringstream messageBuilder;
+    messageBuilder << "Making Progress (" << m << ")";
+    return messageBuilder.str();
+}
+
+class TestTask : public MultiTask {
+  private:
+    string myName;
+    TaskHistory& myHistory;
+    Timeout myReadyTimeout;
+
+    MultiTaskState task() {
+        if(false == myReadyTimeout.isExpired()) return Waiting;
+        int myChangedMind = rand() % 100;
+        MultiTaskState myNewState = Running;
+        switch(myChangedMind) {
+            case 0: {
+                myHistory.post("I'm Finished!");
+                myNewState = Finished;
+                break;
+            }
+
+            case 1:
+            case 3:
+            case 5:
+            case 51:
+            case 53:
+            case 55:
+            case 71:
+            case 73:
+            case 75:
+            case 9: {
+                myHistory.post("I need a nap...");
+                myReadyTimeout.restart();
+                myNewState = Waiting;
+                break;
+            }
+
+            default: {
+                myHistory.post(makeProgressMessage(myChangedMind));
+                myNewState = Running;
+                break;
+            }
+        }
+        return myNewState;
+    }
+
+    static const int napDuration = 10;
+
+  public:
+
+    TestTask(string theName, TaskHistory& theHistory) :
+      myName(theName),
+      myHistory(theHistory),
+      myReadyTimeout(napDuration) {
+    }
+
+    string name() { return myName; }
+
+};
+
+void outputHistory(TaskHistory& H) {
+    for(vector<string>::iterator s = H.begin(); s != H.end(); ++s) {
+        cout << *s << endl;
+    }
+}
+
+int main() {
+    unsigned long seed = 1234;
+    srand(seed);
+    cout << "MultiTasker Demo! seed(" << seed << ")" << endl;
+
+    TaskHistory H0, H1, H2, H3, H4, H5, H6, H7, H8, H9;
+    TestTask T0("Random Job 0", H0);
+    TestTask T1("Random Job 1", H1);
+    TestTask T2("Random Job 2", H2);
+    TestTask T3("Random Job 3", H3);
+    TestTask T4("Random Job 4", H4);
+    TestTask T5("Random Job 5", H5);
+    TestTask T6("Random Job 6", H6);
+    TestTask T7("Random Job 7", H7);
+    TestTask T8("Random Job 8", H8);
+    TestTask T9("Random Job 9", H9);
+
+    MultiTasker M0;
+    M0.put(T0); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T1); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T2); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T3); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T4); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T5); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T6); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T7); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T8); cout << "Pending Count: " << M0.pending() << endl;
+    M0.put(T9); cout << "Pending Count: " << M0.pending() << endl;
+
+    PollTimer NothingToDo(10,50);
+
+    while(M0.hasWork()) {
+        M0.task();
+        cout
+            << "In Work: " << M0.pending()
+            << ", Working: " << M0.working.size()
+            << ", Waiting: " << M0.waiting.size()
+            << ", Finished: " << M0.finished.size();
+
+        if(M0.isReady()) {
+            cout << endl;
+            NothingToDo.reset();
+        }
+        else if(M0.isWaiting()) {
+            cout << " pause..." << endl;
+            NothingToDo.pause();
+        }
+    }
+
+    cout << endl << endl << "M0 Complete Order..." << endl;
+    bool firstT = true;
+    while(M0.canGet()) {
+        TestTask& T = (TestTask&) M0.get();
+        if(firstT) { firstT = false; }
+        else { cout << ", "; }
+        cout << T.name();
+    }
+
+    cout << endl << endl << "T0(" << T0.name() << ") History..." << endl;
+    outputHistory(H0);
+
+    cout << endl << endl << "T1(" << T1.name() << ") History..." << endl;
+    outputHistory(H1);
+
+    cout << endl << endl << "T2(" << T2.name() << ") History..." << endl;
+    outputHistory(H2);
+
+    cout << endl << endl << "T3(" << T3.name() << ") History..." << endl;
+    outputHistory(H3);
+
+    cout << endl << endl << "T4(" << T4.name() << ") History..." << endl;
+    outputHistory(H4);
+
+    cout << endl << endl << "T5(" << T5.name() << ") History..." << endl;
+    outputHistory(H5);
+
+    cout << endl << endl << "T6(" << T6.name() << ") History..." << endl;
+    outputHistory(H6);
+
+    cout << endl << endl << "T7(" << T7.name() << ") History..." << endl;
+    outputHistory(H7);
+
+    cout << endl << endl << "T8(" << T8.name() << ") History..." << endl;
+    outputHistory(H8);
+
+    cout << endl << endl << "T9(" << T9.name() << ") History..." << endl;
+    outputHistory(H9);
+
+    return 0;
+}
+