#6394: Add os.getppid() support for Windows.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index a83a06b..9811329 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -121,6 +121,7 @@
#else
#ifdef _MSC_VER /* Microsoft compiler */
#define HAVE_GETCWD 1
+#define HAVE_GETPPID 1
#define HAVE_SPAWNV 1
#define HAVE_EXECV 1
#define HAVE_PIPE 1
@@ -4363,16 +4364,65 @@
#endif /* HAVE_SETPGRP */
#ifdef HAVE_GETPPID
+
+#ifdef MS_WINDOWS
+#include <tlhelp32.h>
+
+static PyObject*
+win32_getppid()
+{
+ HANDLE snapshot;
+ pid_t mypid;
+ PyObject* result = NULL;
+ BOOL have_record;
+ PROCESSENTRY32 pe;
+
+ mypid = getpid(); /* This function never fails */
+
+ snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
+ if (snapshot == INVALID_HANDLE_VALUE)
+ return PyErr_SetFromWindowsErr(GetLastError());
+
+ pe.dwSize = sizeof(pe);
+ have_record = Process32First(snapshot, &pe);
+ while (have_record) {
+ if (mypid == (pid_t)pe.th32ProcessID) {
+ /* We could cache the ulong value in a static variable. */
+ result = PyLong_FromPid((pid_t)pe.th32ParentProcessID);
+ break;
+ }
+
+ have_record = Process32Next(snapshot, &pe);
+ }
+
+ /* If our loop exits and our pid was not found (result will be NULL)
+ * then GetLastError will return ERROR_NO_MORE_FILES. This is an
+ * error anyway, so let's raise it. */
+ if (!result)
+ result = PyErr_SetFromWindowsErr(GetLastError());
+
+ CloseHandle(snapshot);
+
+ return result;
+}
+#endif /*MS_WINDOWS*/
+
PyDoc_STRVAR(posix_getppid__doc__,
"getppid() -> ppid\n\n\
-Return the parent's process id.");
+Return the parent's process id. If the parent process has already exited,\n\
+Windows machines will still return its id; others systems will return the id\n\
+of the 'init' process (1).");
static PyObject *
posix_getppid(PyObject *self, PyObject *noargs)
{
+#ifdef MS_WINDOWS
+ return win32_getppid();
+#else
return PyLong_FromPid(getppid());
-}
#endif
+}
+#endif /* HAVE_GETPPID */
#ifdef HAVE_GETLOGIN