Process' ppid method does not behave correctly on Windows

Corrected the category.

It's possible to get the ppid on Windows, with the caveat that the parent may have exited.

It should be possible to implement this properly with CreateToolhelp32Snapshot + Process32First/Next.

Here's the implementation I'm using in Sapphire. Works like a champ:

#ifdef _WIN32
#include <tlhelp32.h>
#endif

static VALUE get_ppid(VALUE self)
{
   VALUE v_ppid;

#ifdef _WIN32
   HANDLE handle;
   PROCESSENTRY32 proc_entry;
   int pid = getpid();
   v_ppid = INT2FIX(0);

   rb_secure(2);

   if(pid){
      handle = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

      if(handle == INVALID_HANDLE_VALUE)
         rb_sys_fail(0);

      proc_entry.dwSize = sizeof(PROCESSENTRY32);

      if(!Process32First(handle, &proc_entry)){
         errno = GetLastError();
         CloseHandle(handle);
         rb_sys_fail(0);
      }

      while(Process32Next(handle, &proc_entry)){
         if(proc_entry.th32ProcessID == pid){
            v_ppid = INT2FIX(proc_entry.th32ParentProcessID);
            break;
         }
      }

      CloseHandle(handle);
   }
#else
   rb_secure(2);
   v_ppid = INT2FIX(getppid());
#endif

   return v_ppid;
}

While I have no question that Daniel's code works and is a better way to get ppid, we're somewhat constrained by what's roughly specified for Ruby (and the original bug even asked for that behavior), and the code given is, if nothing else, a little problematic to try to implement solely through JNA. We'd love help implementing that, but I would request that a separate bug be opened for adding "enhanced ppid on Windows" functionality so we can track progress there.

This issue has not been fully fixed.

On windows:

jruby -e "p Process.ppid" #===>
:1: ppid unsupported on this platform (NotImplementedError)

Sorry, reopening this again, since while Process.ppid works with x32 JVM, but it still raises NotImplementedError on Windows x64 on JDK x64.

bumping until we have a JNA which support win32-amd64. This only affects 64 bit windows.

This appears to be fixed.

$ jruby -v -e "p Process.ppid"
jruby 1.6.0.dev (ruby 1.8.7 patchlevel 249) (2010-07-26 49cf9ce) (Java HotSpot(T
M) 64-Bit Server VM 1.6.0_21) [amd64-java]
0