分析代码的数据结构:#include <stdio.h> #include <stdlib.h> #include <Windows.h> #define MAX_READERS 5 #define MAX_WRITERS 3 /* 定义读者优先信号量 */ HANDLE readerSemaphore; /* 定义写者优先信号量 */ HANDLE writerSemaphore; /* 定义读者计数器 */ int readerCount = 0; /* 定义写者计数器 */ int writerCount = 0; /* 定义读者互斥锁 */ CRITICAL_SECTION readerMutex; /* 定义写者互斥锁 */ CRITICAL_SECTION writerMutex; /* 定义共享资源 */ int sharedResource = 0; /* 读者线程函数 */ DWORD WINAPI ReaderThread(LPVOID lpParameter) { while (1) { WaitForSingleObject(readerSemaphore, INFINITE); EnterCriticalSection(&readerMutex); readerCount++; if (readerCount == 1) { WaitForSingleObject(writerSemaphore, INFINITE); } LeaveCriticalSection(&readerMutex); ReleaseSemaphore(readerSemaphore, 1, NULL); /* 读共享资源 */ printf("Reader %d read shared resource: %d\n", lpParameter, sharedResource); EnterCriticalSection(&readerMutex); readerCount--; if (readerCount == 0) { ReleaseSemaphore(writerSemaphore, 1, NULL); } LeaveCriticalSection(&readerMutex); /* 等待一段时间 */ Sleep(rand() % 1000); } } /* 写者线程函数 */ DWORD WINAPI WriterThread(LPVOID lpParameter) { while (1) { WaitForSingleObject(&writerMutex, INFINITE); writerCount++; if (writerCount == 1) { WaitForSingleObject(readerSemaphore, INFINITE); } LeaveCriticalSection(&writerMutex); /* 写共享资源 */ sharedResource++; printf("Writer %d wrote shared resource: %d\n", lpParameter, sharedResource); EnterCriticalSection(&writerMutex); writerCount--; if (writerCount == 0) { ReleaseSemaphore(readerSemaphore, 1, NULL); } LeaveCriticalSection(&writerMutex); /* 等待一段时间 */ Sleep(rand() % 1000); } } int main() { /* 初始化互斥锁和信号量 */ InitializeCriticalSection(&readerMutex); InitializeCriticalSection(&writerMutex);
时间: 2024-02-15 09:26:52 浏览: 64
C语言__编程答案_大题.docx
这段代码是一个多线程程序,使用了Windows API中的信号量和临界区(互斥锁)来实现读写锁。其中,MAX_READERS和MAX_WRITERS是预定义的常量,用于限制最大的读者和写者数量。readerSemaphore和writerSemaphore分别是读者优先和写者优先的信号量,用于控制读者和写者的访问顺序。readerCount和writerCount是读者和写者的计数器,用于记录当前读者和写者的数量。readerMutex和writerMutex是读者和写者的互斥锁,用于保护读者计数器和写者计数器的访问。sharedResource是共享资源,读者和写者都可以读写它。ReaderThread和WriterThread是读者和写者的线程函数,使用了无限循环来不断地读写共享资源。在主函数中,使用了InitializeCriticalSection来初始化互斥锁和信号量。
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