windows系統調用 semaphore訊號量

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 1 #include "iostream" 2 #include "windows.h" 3 #include "cstring" 4 using namespace std; 5  6 HANDLE g_hSemThreads=INVALID_HANDLE_VALUE; 7  8 static DWORD WINAPI ThreadProc(LPVOID lpParam){ 9     LONG nPauseMs=reinterpret_cast<LONG>(lpParam);10     Sleep(nPauseMs);11 12     if(g_hSemThreads!=INVALID_HANDLE_VALUE){13         LONG nPrevCt(0);14 15         if(ReleaseSemaphore(16             g_hSemThreads,17             1,18             &nPrevCt19             )){20                 printf("%d msec thread ended ,slots left:%d\n",nPauseMs,nPrevCt+1);21         }22     }23 24     return(0);25 }26 27 28 29 void main(){30     g_hSemThreads=CreateSemaphore(31         NULL,32         5,33         5,34         NULL35         );36     for(int nTotal=20;nTotal>0;nTotal-=2){37         WaitForSingleObject(g_hSemThreads,INFINITE);38         LONG nPauseMs=nTotal*5;39 40         HANDLE hThread=CreateThread(41             NULL,42             0,43             ThreadProc,44             reinterpret_cast<LPVOID>(nPauseMs),45             0,46             NULL47             );48 49         printf("in the %d msec a thread is creates \n",nPauseMs);50         CloseHandle(hThread);51         hThread=INVALID_HANDLE_VALUE;52     }53 54     CloseHandle(g_hSemThreads);55     g_hSemThreads=INVALID_HANDLE_VALUE;56     getchar();57 }