project1.cpp

利用银行家算法避免死锁。掌握银行家算法中的数据结构

#pragma hdrstop
#include <condefs.h>
#include <iostream.h>         // C++ standard I/O
#include <fstream.h>          // C++ file I/O
#include <string>             // C++ string functions

#include "Banker.h"           // defines the banker

//---------------------------------------------------------------------------
USEUNIT("Banker.cpp");
//---------------------------------------------------------------------------
ofstream ofsLog1;
ofstream ofsLog2;

void tryRequest(Banker *pBanker, int iPID, int iF, int iP, int iM)
{
   cout << "PID " << iPID << " requests (";
   cout << iF << ", " << iP << ", " << iM << ") ";

   // Try to request memory; see if the Banker can be spoofed
   // into allowing an unsafe system condition

   try
   {
      pBanker->request(iPID, iF, iP, iM);
      cout << "...made it." << endl;
   }
   catch(BankerUnsafePidException)
   {
     cout << "...UNSAFE:  Invalid PID." << endl;
   }
   catch(BankerUnsafeContractException)
   {
     cout << "...UNSAFE:  Violates PID contract." << endl;
   }
   catch(BankerUnsafeTotalException)
   {
     cout << "...UNSAFE:  Exceeds total system resources." << endl;
   }
   catch(BankerUnsafeCommittedException)
   {
     cout << "...UNSAFE:  Resources would be overcommitted." << endl;
   }
}

void tryMemoryTest(Banker *pBanker, bool bHello, bool bLimits, bool bRequest)
{
  static int i=0;

   cout << "BEGIN MEMORY TEST " << i << endl;
   cout << "pBanker points to " << pBanker << endl;
   if(bHello==true)
   {
     cout << "calling helloWorld()" << endl;
     pBanker->helloWorld();
     cout << "helloWorld() succeeded." << endl;
   }
   if(bLimits==true)
   {
     cout << "calling showLimits()" << endl;
     pBanker->showLimits();
     cout << "...showLimits() succeeded." << endl;
   }
   if(bRequest==true)
   {
     cout << "calling request()" << endl;
     pBanker->request(1, 0, 0, 0);
     cout << "...request() succeeded." << endl;
   }
   cout << "...completed memory test " << i++ << endl;
   cout << endl << endl;
}

#pragma argsused
int main(int argc, char **argv)
{
  string sLog1 = "bankerDebug1.txt";
  string sLog2 = "bankerDebug2.txt";
  ofsLog1.open(sLog1.c_str());
	ofsLog2.open(sLog2.c_str());

   Banker * pBanker = new Banker(10, 5, 7);      // create the banker

   // assign PIDs and max resources required for each
   pBanker->openAccount(0, 7, 5, 3);
   pBanker->openAccount(1, 3, 2, 2);
   pBanker->openAccount(2, 9, 0, 2);
   pBanker->openAccount(3, 2, 2, 2);
   pBanker->openAccount(4, 4, 3, 3);

   // try series of requests as suggested by the textbook, page 222
   tryRequest(pBanker, 0, 0, 1, 0);
   tryRequest(pBanker, 1, 2, 0, 0);
   tryRequest(pBanker, 2, 3, 0, 2);
   tryRequest(pBanker, 3, 2, 1, 1);
   tryRequest(pBanker, 4, 0, 0, 2);
   tryRequest(pBanker, 1, 1, 0, 2);
   tryRequest(pBanker, 4, 3, 3, 0);
   tryRequest(pBanker, 0, 0, 2, 0);
   cout << "...done with Silberschatz part..." << endl;

   cout << endl << endl;
   cout << "Begin trying other things." << endl;
   tryRequest(pBanker, 1, 0, 0, 0);
   tryRequest(pBanker, 9, 0, 0, 0);
   tryRequest(pBanker, 1, 0, 4, 0);

   cout << endl << endl << endl;
   cout << "Begining memory tests; pBanker initially " << pBanker << endl;
   cout << endl;

   tryMemoryTest(pBanker, true, true, true);      // test 0

   delete pBanker;
   tryMemoryTest(pBanker, true, true, false);     // test 1

   pBanker = (Banker *)new int[sizeof (Banker)];
   tryMemoryTest(pBanker, true, true, false);     // test 2

   pBanker = (Banker *)2346735687;
   tryMemoryTest(pBanker, true, false, false);    // test 3

   return 0;            // success
}