From: Park Heesob <phasis@...>
Date: 2003-12-24T11:50:14+09:00
Subject: Re: bug: threads and win32


Hi,
From: "anon luker" <hatespyware@yahoo.com>
>
> > >
> > >Is this a common problem?  Are there good workarounds?  I thought Ruby
> > >implemented the threads in some internal system independant way, so
> > >this is confusing to me.  Any help/info would be greatly appreciated.
> >
> > I may be wrong but there is no workaround for this. Ruby Threads do
> > block on IO within windows.
> > IIRC that should be because ruby transparently uses select() to hnadle
> > IO, but select() on windows only works with sockets, and thus any
> > other IO blocks the whole interpreter.
> Yuck!  On a hunch, I tried the cygwin version.  It works, but _very_
> slowly.  Far too slow for socket programming.  I must be missing
> something, since the official tagline for Ruby includes "Ruby features
> OS independent threading. Thus, for all platforms on which Ruby runs,
> you also have multithreading, regardless of if the OS supports it or
> not, even on MS-DOS! ;-)"  What I want to do seems pretty basic,
> though, so if Ruby supports threads and can't meet my needs, then
> something is wrong.
>
> > Feel free to hack ruby and fix
> > this :)
> I'll just use java or something for this project.  Maybe I'll be lucky
> enough to get paid to hack on ruby one day... until then, I'm
> constrained to using _working_ solutions.
>
> My followup question is: How does one do asynch io (ala sockets) in
> Ruby under Windows?  Threads seemed like the most natural way, but
> nonblocking IO may work, too.  Unfortunately, the langauge reference
> that I have doesn't really document all of the SO_* flags that the
> recv line of socket methods support and a quick look at the constants
> doesn't show anything obvious like SO_NOBLOCK.  Any advice would be
> appreciated.
>
> thanks
>
>

Try this patch to win32/win32.c ( ruby 1.8.0 )
I adoted this from php 5.0.0 beta 3 source code.
I belive it will fix thread and blocking IO problem whinin Windows.
===================================================================
@@ -1775,6 +1775,13 @@
 rb_w32_select (int nfds, fd_set *rd, fd_set *wr, fd_set *ex,
         struct timeval *timeout)
 {
+    DWORD ms_total, limit;
+    HANDLE handles[MAXIMUM_WAIT_OBJECTS];
+    int handle_slot_to_fd[MAXIMUM_WAIT_OBJECTS];
+    int n_handles = 0, i;
+    fd_set aread, awrite, aexcept;
+    int retcode;
+
     long r;
     fd_set file_rd;
     fd_set file_wr;
@@ -1783,6 +1790,28 @@
 #endif /* USE_INTERRUPT_WINSOCK */
     int file_nfds;

+#define SAFE_FD_ISSET(fd, set) (set != NULL && rb_w32_fdisset(fd, set))
+
+ /* calculate how long we need to wait in milliseconds */
+ if (timeout == NULL) {
+  ms_total = INFINITE;
+ } else {
+  ms_total = timeout->tv_sec * 1000;
+  ms_total += timeout->tv_usec / 1000;
+ }
+
+ /* build an array of handles for non-sockets */
+ for (i = 0; i < nfds; i++) {
+  if (SAFE_FD_ISSET(i, rd) || SAFE_FD_ISSET(i, wr) || SAFE_FD_ISSET(i, ex))
{
+   handles[n_handles] = (HANDLE)_get_osfhandle(i);
+   if ((DWORD)handles[n_handles] != 0xffffffff) {
+    handle_slot_to_fd[n_handles] = i;
+    n_handles++;
+   }
+  }
+ }
+
+
     if (!NtSocketsInitialized) {
  StartSockets();
     }
@@ -1799,10 +1828,49 @@
     file_nfds += extract_file_fd(wr, &file_wr);
     if (file_nfds)
     {
- // assume normal files are always readable/writable
- // fake read/write fd_set and return value
- if (rd) *rd = file_rd;
- if (wr) *wr = file_wr;
+ FD_ZERO(&aread);
+ FD_ZERO(&awrite);
+ FD_ZERO(&aexcept);
+
+        limit = GetTickCount() + ms_total;
+        do {
+     DWORD wret;
+            retcode = 0;
+
+     wret = MsgWaitForMultipleObjects(n_handles, handles, FALSE, retcode >
0 ? 0 : 100, QS_ALLEVENTS);
+
+     if (wret == WAIT_TIMEOUT) {
+   /* set retcode to 0; this is the default.
+    * select() may have set it to something else,
+    * in which case we leave it alone, so this branch
+    * does nothing */
+   ;
+        } else if (wret == WAIT_FAILED) {
+  if (retcode == 0) {
+   retcode = -1;
+  }
+      } else {
+  if (retcode < 0) {
+   retcode = 0;
+  }
+         for (i = 0; i < n_handles; i++) {
+      if (WAIT_OBJECT_0 == WaitForSingleObject(handles[i], 0)) {
+   if (SAFE_FD_ISSET(handle_slot_to_fd[i], rd)) {
+    rb_w32_fdset(handle_slot_to_fd[i], &aread);
+   }
+   if (SAFE_FD_ISSET(handle_slot_to_fd[i], wr)) {
+    rb_w32_fdset(handle_slot_to_fd[i], &awrite);
+   }
+   if (SAFE_FD_ISSET(handle_slot_to_fd[i], ex)) {
+    rb_w32_fdset(handle_slot_to_fd[i], &aexcept);
+   }
+   retcode++;
+      }
+  }
+            }
+        } while (retcode == 0 && (ms_total == INFINITE || GetTickCount() <
limit));
+ if (rd) *rd = aread;
+ if (wr) *wr = awrite;
  return file_nfds;
     }
===============================================================

Regards,

Park Heesob