Does Kaffe handle threaded network I/O?

[Bernie Solomon]

Stewart Allen wrote:
> 
>  I sent this to the list last week, but I haven't heard back.
>  I'm writing an application that has a background thread handling
>  communications via UDP. Kaffe seems to block all threads whenever
>  I do a receive() on a UDP socket. Sun's VM doesn't do this.
> 
>  I haven't tested for other forms of I/O (like file), but I'm curious if
>  this is a known problem (Tim?).

This peeked my interest so I had a quick look. Basically the recvfrom
inside DatagramSocket wasn't threaded like other I/O calls. I just
copied what read did and your example works. This has had no other
testing other than your example.

sdlhpp5% diff ~/orig-kaffe-0.8.4/kaffe/kaffevm/threadCalls.h
master/kaffe/kaffevm
24a25
> extern ssize_t threadedRecvfrom(int, void *, size_t, int, struct sockaddr *, size_t *);
sdlhpp5% diff -c ~/orig-kaffe-0.8.4/kaffe/kaffevm/threadCalls.h
master/kaffe/kaffevm
*** /users/bernard/orig-kaffe-0.8.4/kaffe/kaffevm/threadCalls.h Fri Apr
18 15:58:35 1997
--- master/kaffe/kaffevm/threadCalls.h  Thu Apr 24 09:35:03 1997
***************
*** 22,26 ****
--- 22,27 ----
  extern int threadedAccept(int, struct sockaddr*, size_t*);
  extern ssize_t threadedRead(int, char*, size_t);
  extern ssize_t threadedWrite(int, const char*, size_t);
+ extern ssize_t threadedRecvfrom(int, void *, size_t, int, struct
sockaddr *, size_t *);
  
  #endif
sdlhpp5% diff -c ~/orig-kaffe-0.8.4/kaffe/kaffevm/threadCalls.c
master/kaffe/kaffevm
*** /users/bernard/orig-kaffe-0.8.4/kaffe/kaffevm/threadCalls.c Fri Apr
18 15:58:35 1997
--- master/kaffe/kaffevm/threadCalls.c  Thu Apr 24 09:37:52 1997
***************
*** 158,163 ****
--- 158,187 ----
  }
  
  /*
+  * Recvfrom but only if we can.
+  */
+ ssize_t 
+ threadedRecvfrom(int fd, void *buf, size_t len, int flags, struct
sockaddr *from, size_t *fromlen)
+ {
+       ssize_t r;
+ 
+ #if defined(BLOCKING_CALLS)
+       if (blockOnFile(fd, TH_READ) < 0) {
+               return (-1);
+       }
+ #endif
+       for (;;) {
+               r = recvfrom(fd, buf, len, flags, from, fromlen);
+               if (r >= 0 || !(errno == EAGAIN || errno == EWOULDBLOCK
|| errno == EINTR)) {
+                       return (r);
+               }
+               if (blockOnFile(fd, TH_READ) < 0) {
+                       return (-1);
+               }
+       }
+ }
+ 
+ /*
   * Read but only if we can.
   */
  ssize_t
sdlhpp5% diff -c
~/orig-kaffe-0.8.4/packages/tjwassoc.co.uk/APInet/lib/java.net/DatagramSocket.c
master/packages/tjwassoc.co.uk/APInet/lib/java.net/
***
/users/bernard/orig-kaffe-0.8.4/packages/tjwassoc.co.uk/APInet/lib/java.net/DatagramSocket.c       
Fri Apr 18 15:58:48 1997
---
master/packages/tjwassoc.co.uk/APInet/lib/java.net//DatagramSocket.c       
Thu Apr 24 09:35:37 1997
***************
*** 108,114 ****
        size_t alen = sizeof(addr);
        struct Hjava_net_InetAddress **fromaddr;
  
!       r = recvfrom(unhand(unhand(this)->fd)->fd,
unhand(unhand(pkt)->buf)->body, unhand(pkt)->length, 0, (struct
sockaddr*)&addr, &alen);
        if (r < 0) {
                SignalError(NULL, "java.net.SocketException",
SYS_ERROR);
        }
--- 108,114 ----
        size_t alen = sizeof(addr);
        struct Hjava_net_InetAddress **fromaddr;
  
!       r = threadedRecvfrom(unhand(unhand(this)->fd)->fd,
unhand(unhand(pkt)->buf)->body, unhand(pkt)->length, 0, (struct
sockaddr*)&addr, &alen);
        if (r < 0) {
                SignalError(NULL, "java.net.SocketException",
SYS_ERROR);
        }

-- 
Bernie Solomon (bernard at edsug.com or Bernard.Solomon at acm.org)
Unigraphics Architecture, EDS-Unigraphics, Cambridge, UK