#include <windows.h> #include <iostream> using namespace std; const int N = 5; // 进程数 int count = 0; // 计数器 HANDLE mutex = CreateMutex(NULL, FALSE, NULL); // 互斥量 HANDLE barrier = CreateEvent(NULL, TRUE, FALSE, NULL); // 屏障 DWORD WINAPI Process(LPVOID lpParam) { int id = *((int*)lpParam); cout << "Process " << id << " arrived at barrier." << endl; WaitForSingleObject(mutex, INFINITE); count++; ReleaseMutex(mutex); if (count == N) { cout << "All processes arrived at barrier, releasing barrier." << endl; SetEvent(barrier); } WaitForSingleObject(barrier, INFINITE); cout << "Process " << id << " starts the next phase of work." << endl; return 0; } DWORD WINAPI Broadcast(LPVOID lpParam) { WaitForSingleObject(mutex, INFINITE); cout << "Broadcast process started." << endl; ReleaseMutex(mutex); SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST); WaitForSingleObject(barrier, INFINITE); cout << "Broadcast process releasing all processes." << endl; ReleaseMutex(mutex); for (int i = 0; i < N; i++) { ReleaseSemaphore((HANDLE)lpParam, 1, NULL); } return 0; } int main() { HANDLE threads[N]; DWORD threadIds[N]; HANDLE sem = CreateSemaphore(NULL, 0, N, NULL); int ids[N]; for (int i = 0; i < N; i++) { ids[i] = i; threads[i] = CreateThread(NULL, 0, Process, &ids[i], 0, &threadIds[i]); if (threads[i] == NULL) { return 1; } } HANDLE broadcastThread = CreateThread(NULL, 0, Broadcast, sem, 0, NULL); if (broadcastThread == NULL) { return 1; } WaitForMultipleObjects(N, threads, TRUE, INFINITE); WaitForSingleObject(mutex, INFINITE); cout << "All processes completed." << endl; ReleaseMutex(mutex); return 0; }

这是一个使用 Windows API 实现的屏障同步机制的示例代码，使用了互斥量、事件和信号量等同步原语。其中，线程通过互斥量保证 count 的原子性，通过事件实现屏障，通过信号量实现进程之间的同步。具体实现方式是，每个进程到达屏障时都会将 count 加 1，当 count 等于进程数 N 时，说明所有进程都已经到达屏障，此时触发事件，释放所有进程。等到所有进程都被释放之后，进程才能继续执行下一阶段的任务。在主线程中，通过等待所有进程完成来判断整个程序的执行是否结束。

需要注意的是，该代码中没有考虑进程执行的速度问题，如果某个进程执行速度比其他进程慢，可能会导致其他进程一直等待，甚至出现死锁。因此，在实际应用中需要根据具体情况进行调整。

相关问题

#include <Windows.h> #include <iostream> #include <fstream> #include <string> #include <vector> #include <algorithm> #include <cstdlib> #include <ctime> #include <conio.h> #include <winsock.h> #include <ws2bth.h> #include <bluetoothapis.h> #pragma comment(lib, "ws2_32.lib") using namespace std; const string CONFIG_FILE = "config.ini"; const int MAX_BLUETOOTH_DEVICES = 10; int main() { // 读取配置文件 ifstream config(CONFIG_FILE); if (!config.is_open()) { cout << "无法打开配置文件！" << endl; return -1; } string line; int search_count = 0; while (getline(config, line)) { if (line.find("search_count") != string::npos) { search_count = stoi(line.substr(line.find("=") + 1)); break; } } config.close(); // 初始化蓝牙 WSAData wsaData; int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData); if (iResult != NO_ERROR) { cout << "WSAStartup 失败！" << endl; return -1; } // 枚举蓝牙设备 BLUETOOTH_DEVICE_SEARCH_PARAMS searchParams = { sizeof(BLUETOOTH_DEVICE_SEARCH_PARAMS) }; searchParams.fReturnAuthenticated = TRUE; searchParams.fReturnRemembered = TRUE; searchParams.fReturnUnknown = TRUE; searchParams.hRadio = NULL; BLUETOOTH_DEVICE_INFO deviceInfo = { sizeof(BLUETOOTH_DEVICE_INFO) }; HBLUETOOTH_DEVICE_FIND deviceFindHandle; vector<BLUETOOTH_DEVICE_INFO> devices; deviceFindHandle = BluetoothFindFirstDevice(&searchParams, &deviceInfo); if (deviceFindHandle != NULL) { do { devices.push_back(deviceInfo); } while (BluetoothFindNextDevice(deviceFindHandle, &deviceInfo)); BluetoothFindDeviceClose(deviceFindHandle); } // 检查蓝牙设备数量 if (devices.size() >= MAX_BLUETOOTH_DEVICES) { ofstream file("CheckBT.log"); file << "PASS"; // 向文档中写入"PASS"字符串 } else { ofstream file("CheckBT.log"); file << "FAIL"; // 向文档中写入"FAIL"字符串 } // 清理蓝牙 WSACleanup(); return 0; }改进这段代码，把每个蓝牙设备名称输出到文档中

#include <Windows.h>
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <conio.h>
#include <winsock.h>
#include <ws2bth.h>
#include <bluetoothapis.h>

#pragma comment(lib, "ws2_32.lib")

using namespace std;

const string CONFIG_FILE = "config.ini";
const int MAX_BLUETOOTH_DEVICES = 10;

int main() {
// 读取配置文件
ifstream config(CONFIG_FILE);
if (!config.is_open()) {
cout << "无法打开配置文件！" << endl;
return -1;
}

string line;
int search_count = 0;
while (getline(config, line)) {
if (line.find("search_count") != string::npos) {
search_count = stoi(line.substr(line.find("=") + 1));
break;
}
}
config.close();

// 初始化蓝牙
WSAData wsaData;
int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != NO_ERROR) {
cout << "WSAStartup 失败！" << endl;
return -1;
}

// 枚举蓝牙设备
BLUETOOTH_DEVICE_SEARCH_PARAMS searchParams = { sizeof(BLUETOOTH_DEVICE_SEARCH_PARAMS) };
searchParams.fReturnAuthenticated = TRUE;
searchParams.fReturnRemembered = TRUE;
searchParams.fReturnUnknown = TRUE;
searchParams.hRadio = NULL;
BLUETOOTH_DEVICE_INFO deviceInfo = { sizeof(BLUETOOTH_DEVICE_INFO) };
HBLUETOOTH_DEVICE_FIND deviceFindHandle;
vector<BLUETOOTH_DEVICE_INFO> devices;
deviceFindHandle = BluetoothFindFirstDevice(&searchParams, &deviceInfo);
if (deviceFindHandle != NULL) {
do {
devices.push_back(deviceInfo);
} while (BluetoothFindNextDevice(deviceFindHandle, &deviceInfo));
BluetoothFindDeviceClose(deviceFindHandle);
}

// 输出蓝牙设备名称到文档
ofstream file("CheckBT.log");
if (devices.size() >= MAX_BLUETOOTH_DEVICES) {
file << "PASS" << endl;
} else {
file << "FAIL" << endl;
}

for (auto device : devices) {
file << device.szName << endl;
}

// 清理蓝牙
WSACleanup();
return 0;
}

#include <stdlib.h> #include <iostream.h> int n = 20; int ClrMinus(int Arr,int m); int main() { int arr[n]={0},i; for(i=0;i<n;i++) { arr[i]=rand()%100-30; cout<<arr[i]<<'\t'; } cout<<endl; cout<<"Negative Number is"<<ClrMinus(arr[n],n)<<endl; cout<<"The Array Removed Negative Number is：\n"; for(i=0;i<=n;i++) if(arr[i]=0) cout<<arr[i]<<'\t'; cout<<endl; return 0; } int ClrMinus(int Arr[],int m) { int count=0; for(int i=0;i<m;i++) { if(Arr[i]<0) { Arr[i]=0; count++; } } return count; }

这段代码中也有几个问题：

1. 头文件 `iostream.h` 不应该有 `.h` 后缀，应该写成 `#include <iostream>`。
2. 在 `main` 函数中，调用 `ClrMinus` 函数时，应该传入数组 `arr` 而不是 `arr[n]`。
3. 在 `main` 函数中，第二个循环中的条件应该是 `i < n`，而不是 `i <= n`，因为数组下标从 0 开始计数，所以 `arr[n]` 是越界的。
4. 在第二个循环中，判断语句 `if (arr[i] = 0)` 应该写成 `if (arr[i] == 0)`，因为 `=` 是赋值操作符，而 `==` 才是相等比较操作符。

下面是修改后的代码：

#include <stdlib.h>
#include <iostream>

using namespace std;

const int n = 20;

int ClrMinus(int Arr[], int m);

int main() {
    int arr[n] = {0}, i;
    for (i = 0; i < n; i++) {
        arr[i] = rand() % 100 - 30;
        cout << arr[i] << '\t';
    }
    cout << endl;
    cout << "Negative Number is " << ClrMinus(arr, n) << endl;
    cout << "The Array Removed Negative Number is:\n";
    for (i = 0; i < n; i++)
        if (arr[i] == 0)
            cout << arr[i] << '\t';
    cout << endl;
    return 0;
}

int ClrMinus(int Arr[], int m) {
    int count = 0;
    for (int i = 0; i < m; i++) {
        if (Arr[i] < 0) {
            Arr[i] = 0;
            count++;
        }
    }
    return count;
}