threadpool-decl.hh

// Copyright © 2011, Université catholique de Louvain
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#ifndef __THREADPOOL_DECL_H
#define __THREADPOOL_DECL_H

#include <queue>

#include "core-forward-decl.hh"
#include "runnable-decl.hh"

namespace mozart {

/////////////////
// ThreadQueue //
/////////////////

class ThreadQueue : public std::queue<Runnable*> {
public:
  void remove(Runnable* item) {
    for (auto iterator = c.begin(); iterator != c.end(); iterator++) {
      if (*iterator == item) {
        c.erase(iterator);
        return;
      }
    }
  }

  // Implemented in gcollect.hh
  inline
  void gCollect(GC gc);
};

////////////////
// ThreadPool //
////////////////

const int HiToMiddlePriorityRatio = 10;
const int MiddleToLowPriorityRatio = 10;

class ThreadPool {
public:
  ThreadPool() {
    remainings[tpLow] = 0;
    remainings[tpMiddle] = 0;
    remainings[tpHi] = 0;
  }

  bool empty() {
    // ordered from most probably non-empty too most probably empty
    return empty(tpMiddle) && empty(tpHi) && empty(tpLow);
  }

  void schedule(Runnable* thread) {
    queues[thread->getPriority()].push(thread);
  }

  void unschedule(Runnable* thread) {
    queues[tpLow].remove(thread);
    queues[tpMiddle].remove(thread);
    queues[tpHi].remove(thread);
  }

  void reschedule(Runnable* thread) {
    unschedule(thread);
    schedule(thread);
  }

  void gCollect(GC gc) {
    queues[tpLow].gCollect(gc);
    queues[tpMiddle].gCollect(gc);
    queues[tpHi].gCollect(gc);
  }

  inline
  Runnable* popNext();
private:
  bool empty(ThreadPriority priority) {
    return queues[priority].empty();
  }

  inline
  Runnable* popNext(ThreadPriority priority);

  ThreadQueue queues[tpCount];
  int remainings[tpCount];
};

}

#endif // __THREADPOOL_DECL_H