// ------------------------------- // // -------- Start of File -------- // // ------------------------------- // // ----------------------------------------------------------- // // C++ Source Code File Name: testprog.cpp // Compiler Used: MSVC, BCC32, GCC, HPUX aCC, SOLARIS CC // Produced By: Doug Gaer // File Creation Date: 03/25/2000 // Date Last Modified: 08/10/2000 // Copyright (c) 2000 Douglas M. Gaer // ----------------------------------------------------------- // // ------------- Program Description and Details ------------- // // ----------------------------------------------------------- // /* This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA vbMutex example program demonstrating how to protect access to shared data. */ // ----------------------------------------------------------- // #include <iostream.h> #include "vbthread.h" #include "vbmutex.h" // Constants const int NUMTHREADS = 3; // Mutex that will be shared by threads within this process vbMutex mutex; // Shared data int sharedData1 = 0; int sharedData2 = 0; class SimpleThread : public vbThread { public: SimpleThread() { } ~SimpleThread() { } public: void Begin(); void End(); private: // Base class interface void *ThreadEntryRoutine(vbThread_t *thread); public: vbThread_t *thread[NUMTHREADS]; }; void *SimpleThread::ThreadEntryRoutine(vbThread_t *thread) { cout << "Entering thread" << endl; mutex.MutexLock(); //********** Critical Section *******************// cout << "Start critical section, holding lock" << endl; // Access to shared data goes here ++sharedData1; --sharedData2; cout << "sharedData1 = " << sharedData1 << ", sharedData2 = " << sharedData2 << endl; cout << "End critical section, release lock" << endl; //********** Critical Section *******************// mutex.MutexUnlock(); return 0; } void SimpleThread::Begin() { for(int i = 0; i < NUMTHREADS; ++i) thread[i] = CreateThread(); } void SimpleThread::End() { for(int i = 0; i < NUMTHREADS; ++i) JoinThread(thread[i]); } int main() { SimpleThread t; cout << "Hold Mutex to prevent access to shared data" << endl; cout << "sharedData1 = " << sharedData1 << ", sharedData2 = " << sharedData2 << endl; mutex.MutexLock(); cout << "Create/start threads" << endl; t.Begin(); cout << "Wait a until we are done with the shared data" << endl; t.sSleep(3); cout << "Unlock shared data" << endl; mutex.MutexUnlock(); cout << "Wait for the threads to complete, and release their resources" << endl; t.End(); return 0; // Exit the process } // ----------------------------------------------------------- // // ------------------------------- // // --------- End of File --------- // // ------------------------------- //