如何使用C语言重启Oracle数据库服务
在开发过程中,有时候需要通过编程语言来控制一些系统服务,这需要我们了解操作系统的底层机制并掌握一些相关的编程技巧。本文将介绍如何使用C语言来重启Oracle数据库服务。
1. 确定服务名称
在Windows平台上,将Oracle数据库安装为Windows服务时,默认服务名称为“OracleService{SID}”,其中{SID}是数据库实例的名称。因此,要重启Oracle数据库服务,我们需要知道数据库实例的名称。
2. 查找服务句柄
为了控制Windows服务,我们需要使用Windows API中的一些函数。在C语言中,可以使用以下代码查找服务句柄:
“`c
SERVICE_STATUS_PROCESS serviceStatus;
SC_HANDLE hSCManager = OpenSCManager(NULL, NULL, SC_MANAGER_CONNECT);
SC_HANDLE hService = OpenService(hSCManager, serviceName, SERVICE_QUERY_STATUS | SERVICE_START | SERVICE_STOP | SERVICE_PAUSE_CONTINUE);
其中,serviceName是服务名称,hSCManager和hService分别是服务管理器句柄和服务句柄。
3. 检查服务状态
在重启服务之前,我们需要判断服务是否正在运行。可以使用以下代码检查服务状态:
```c
if (!QueryServiceStatusEx(hService, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatus, sizeof(SERVICE_STATUS_PROCESS), &dwBytesNeeded))
{
printf("QueryServiceStatusEx fled (%d)\n", GetLastError());
return;
}
if (serviceStatus.dwCurrentState != SERVICE_STOPPED && serviceStatus.dwCurrentState != SERVICE_STOP_PENDING)
{
printf("The service is not stopped (%d)\n", serviceStatus.dwCurrentState);
return;
}
当服务状态不是停止状态时,我们应该先停止服务。
4. 停止服务
停止服务可以使用以下代码:
“`c
if (!ControlService(hService, SERVICE_CONTROL_STOP, (LPSERVICE_STATUS)&serviceStatus))
{
printf(“ControlService fled (%d)\n”, GetLastError());
return;
}
while (serviceStatus.dwCurrentState != SERVICE_STOPPED)
{
Sleep(serviceStatus.dwWtHint);
if (!QueryServiceStatusEx(hService, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatus, sizeof(SERVICE_STATUS_PROCESS), &dwBytesNeeded))
break;
if (serviceStatus.dwCurrentState == SERVICE_STOPPED)
break;
if (GetTickCount() – dwStartTime > dwTimeout)
{
printf(“Timeout wting for service to stop\n”);
return;
}
}
该代码将发送一个停止服务的请求,并通过循环等待服务停止。在等待期间,我们需要检查服务的等待时间(serviceStatus.dwWtHint)以及超时时间(dwTimeout)。
5. 启动服务
停止服务成功后,我们就可以启动服务了:
```c
if (!StartService(hService, 0, NULL))
{
printf("StartService fled (%d)\n", GetLastError());
return;
}
while (serviceStatus.dwCurrentState == SERVICE_START_PENDING)
{
Sleep(serviceStatus.dwWtHint);
if (!QueryServiceStatusEx(hService, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatus, sizeof(SERVICE_STATUS_PROCESS), &dwBytesNeeded))
break;
if (serviceStatus.dwCurrentState != SERVICE_START_PENDING)
break;
if (GetTickCount() - dwStartTime > dwTimeout)
{
printf("Timeout wting for service to start\n");
return;
}
}
该代码将发送一个启动服务的请求,并等待服务启动。在等待期间,我们需要检查服务的等待时间(serviceStatus.dwWtHint)以及超时时间(dwTimeout)。
6. 关闭句柄
我们需要关闭服务句柄和服务管理器句柄:
“`c
CloseServiceHandle(hService);
CloseServiceHandle(hSCManager);
完整代码:
```c
#include
#include
void RestartOracleService(const char* serviceName, DWORD dwTimeout = 30000)
{
SERVICE_STATUS_PROCESS serviceStatus;
DWORD dwStartTime = GetTickCount();
DWORD dwBytesNeeded = 0;
SC_HANDLE hSCManager = OpenSCManager(NULL, NULL, SC_MANAGER_CONNECT);
if (!hSCManager)
{
printf("OpenSCManager fled (%d)\n", GetLastError());
return;
}
SC_HANDLE hService = OpenService(hSCManager, serviceName, SERVICE_QUERY_STATUS | SERVICE_START | SERVICE_STOP | SERVICE_PAUSE_CONTINUE);
if (!hService)
{
printf("OpenService fled (%d)\n", GetLastError());
CloseServiceHandle(hSCManager);
return;
}
if (!QueryServiceStatusEx(hService, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatus, sizeof(SERVICE_STATUS_PROCESS), &dwBytesNeeded))
{
printf("QueryServiceStatusEx fled (%d)\n", GetLastError());
CloseServiceHandle(hService);
CloseServiceHandle(hSCManager);
return;
}
if (serviceStatus.dwCurrentState != SERVICE_STOPPED && serviceStatus.dwCurrentState != SERVICE_STOP_PENDING)
{
if (ControlService(hService, SERVICE_CONTROL_STOP, (LPSERVICE_STATUS)&serviceStatus))
{
while (serviceStatus.dwCurrentState != SERVICE_STOPPED)
{
Sleep(serviceStatus.dwWtHint);
if (!QueryServiceStatusEx(hService, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatus, sizeof(SERVICE_STATUS_PROCESS), &dwBytesNeeded))
break;
if (serviceStatus.dwCurrentState == SERVICE_STOPPED)
break;
if (GetTickCount() - dwStartTime > dwTimeout)
{
printf("Timeout wting for service to stop\n");
CloseServiceHandle(hService);
CloseServiceHandle(hSCManager);
return;
}
}
}
}
if (!StartService(hService, 0, NULL))
{
printf("StartService fled (%d)\n", GetLastError());
CloseServiceHandle(hService);
CloseServiceHandle(hSCManager);
return;
}
while (serviceStatus.dwCurrentState == SERVICE_START_PENDING)
{
Sleep(serviceStatus.dwWtHint);
if (!QueryServiceStatusEx(hService, SC_STATUS_PROCESS_INFO, (LPBYTE)&serviceStatus, sizeof(SERVICE_STATUS_PROCESS), &dwBytesNeeded))
break;
if (serviceStatus.dwCurrentState != SERVICE_START_PENDING)
break;
if (GetTickCount() - dwStartTime > dwTimeout)
{
printf("Timeout wting for service to start\n");
CloseServiceHandle(hService);
CloseServiceHandle(hSCManager);
return;
}
}
CloseServiceHandle(hService);
CloseServiceHandle(hSCManager);
}
使用方法:
“`c
int mn()
{
RestartOracleService(“OracleServiceORCL”);
return 0;
}
通过以上代码,我们可以使用C语言来重启Oracle数据库服务。当然,类似的方法也可以用于控制其他Windows服务。