让GTK程序在同一时刻只运行一个实例

who9394

前提条件：在windows系统中，采用mingw32编译器，C语言的程序。
在主文件的头部定义变量：

1. int g_lAppInstance __attribute__((section ("shared"), shared)) = 0;

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在主函数int main (int argc, char *argv[])的开头部分加入对变量g_lAppInstance 的判断，“0”即没有运行实例，“1”即已经运行一个实例。

1. if (0 == g_lAppInstance)
2.     {
3.      g_lAppInstance = 1;
4.          //继续运行
5.     }
6.     else
7.     {
8.      return 0;  //退出程序
9.     }

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在其它编辑语言（如python）或不同的操作系统（如linux）应该如何实现呢？请大家多多指教。

为什么说这个只限在windows中呢？请看网址：http://gcc.gnu.org/onlinedocs/gc ... able-attribute-1817
里面有说到：
shared
On Microsoft Windows, in addition to putting variable definitions in a named section, the section can also be shared among all running copies of an executable or DLL. For example, this small program defines shared data by putting it in a named section shared and marking the section shareable:
          int foo __attribute__((section ("shared"), shared)) = 0;
          
          int
          main()
          {
            /* Read and write foo.  All running
               copies see the same value.  */
            return 0;
          }
    
You may only use the shared attribute along with section attribute with a fully initialized global definition because of the way linkers work. See section attribute for more information.

The shared attribute is only available on Microsoft Windows.

ACTom

调用ps?查看当前是否有2个自己的进程，如果有，则提示已经启动？

yetist

跨平台的解决方案：
一、简单点的，使用unique, 见：Unique 1.1.6 Reference Manua Unique 3.0.0 Reference Manual
二、复杂点的，使用dbus。

yetist

正好最近写的程序中也要求单实例运行，代码贴给你看看吧。

2. ......
3. #ifdef G_OS_WIN32
4. #include <windows.h>
5. #include <tlhelp32.h>
6. #endif
8. gboolean    helloworld_is_running                  (void)
9. {
10. #ifdef G_OS_UNIX
11.     const gchar* uconfig_path;
12.     gchar *path;
14.     FILE *pf;
15.     gchar buffer[1024];
16.     pid_t pid = -1;
18.     uconfig_path = helloworld_dirs_get_user_config_dir();
19.     path = g_build_filename (uconfig_path, "helloworld.pid", NULL);
20.     if (!g_file_test(path, G_FILE_TEST_EXISTS))
21.     {
22.         g_free(path);
23.         return FALSE;
24.     }
26.     pf = g_fopen (path, "r");
27.     if (pf == NULL) {
28.         g_free(path);
29.         return FALSE;
30.     }
31.     g_free(path);
33.     if (fgets (buffer, sizeof (buffer), pf) == NULL)
34.     {
35.         fclose(pf);
36.         return FALSE;
37.     }
38.     fclose(pf);
40.     pid = atoi(buffer);
41.     if (pid == -1 || kill (pid, 0) != 0)
42.     {
43.         return FALSE;
44.     }
45.     return TRUE;
46. #endif
48. #ifdef G_OS_WIN32
49.     BOOL bFlag;
50.     gint cnt = -1;
51.     HANDLE hSnapShot = NULL;
52.     PROCESSENTRY32 procentry;
53.     // Get a handle to a Toolhelp snapshot of all processes.
54.     hSnapShot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
55.     if (hSnapShot == INVALID_HANDLE_VALUE)
56.     {
57.         return NULL;
58.     }
60.     // Get the first process' information.
61.     procentry.dwSize = sizeof(PROCESSENTRY32);
62.     bFlag = Process32First(hSnapShot, &procentry);
64.     // While there are processes, keep looping.
65.     while (bFlag) {
66.         // Did we just bump into an NTVDM?
67.         if (_stricmp(procentry.szExeFile, g_get_prgname()) == 0) {
68.             cnt += 1;
69.         }
71.         procentry.dwSize = sizeof(PROCESSENTRY32);
72.         bFlag = Process32Next(hSnapShot, &procentry);
73.     }
75.     if (cnt < 1)
76.         return FALSE;
77.     else
78.         return TRUE;
79. #endif
80. }

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