Re-undo commit 11966 (which is the fix for #5325 that caused #5578) to be synchronized with 4.01 and have a safe trunk.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13860 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

3 files changed, 30 insertions, 2 deletions

diff --git a/Changes b/Changes
index 92713954b..49d8deb27 100644
--- a/Changes
+++ b/Changes
@@ -378,8 +378,6 @@ Bug Fixes:
 - PR#5318: segfault on stack overflow when reading marshaled data
 - PR#5319: %r11 clobbered by Lswitch in Windows AMD64 native-code compilation
 - PR#5322: type abbreviations expanding to a universal type variable
-- PR#5325: (Windows) blocked Unix.recv in one thread blocks Unix.send in
-  another thread
 - PR#5328: under Windows, Unix.select leaves sockets in non-blocking mode
 - PR#5330: thread tag with '.top' and '.inferred.mli' targets
 - PR#5331: ocamlmktop is not always a shell script
diff --git a/otherlibs/win32unix/accept.c b/otherlibs/win32unix/accept.c
index 6776a4ac3..f2e14467a 100644
--- a/otherlibs/win32unix/accept.c
+++ b/otherlibs/win32unix/accept.c
@@ -25,15 +25,30 @@ CAMLprim value unix_accept(sock)
   SOCKET sconn = Socket_val(sock);
   SOCKET snew;
   value fd = Val_unit, adr = Val_unit, res;
+  int oldvalue, oldvaluelen, newvalue, retcode;
   union sock_addr_union addr;
   socklen_param_type addr_len;
   DWORD err = 0;
 
+  oldvaluelen = sizeof(oldvalue);
+  retcode = getsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE,
+                       (char *) &oldvalue, &oldvaluelen);
+  if (retcode == 0) {
+    /* Set sockets to synchronous mode */
+    newvalue = SO_SYNCHRONOUS_NONALERT;
+    setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE,
+               (char *) &newvalue, sizeof(newvalue));
+  }
   addr_len = sizeof(sock_addr);
   enter_blocking_section();
   snew = accept(sconn, &addr.s_gen, &addr_len);
   if (snew == INVALID_SOCKET) err = WSAGetLastError ();
   leave_blocking_section();
+  if (retcode == 0) {
+    /* Restore initial mode */
+    setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE,
+               (char *) &oldvalue, oldvaluelen);
+  }
   if (snew == INVALID_SOCKET) {
     win32_maperr(err);
     uerror("accept", Nothing);
diff --git a/otherlibs/win32unix/socket.c b/otherlibs/win32unix/socket.c
index f6e7038ce..ad8165b29 100644
--- a/otherlibs/win32unix/socket.c
+++ b/otherlibs/win32unix/socket.c
@@ -32,6 +32,7 @@ CAMLprim value unix_socket(domain, type, proto)
      value domain, type, proto;
 {
   SOCKET s;
+  int oldvalue, oldvaluelen, newvalue, retcode;
 
   #ifndef HAS_IPV6
   /* IPv6 requires WinSock2, we must raise an error on PF_INET6 */
@@ -41,9 +42,23 @@ CAMLprim value unix_socket(domain, type, proto)
   }
   #endif
 
+  oldvaluelen = sizeof(oldvalue);
+  retcode = getsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE,
+                       (char *) &oldvalue, &oldvaluelen);
+  if (retcode == 0) {
+    /* Set sockets to synchronous mode */
+    newvalue = SO_SYNCHRONOUS_NONALERT;
+    setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE,
+               (char *) &newvalue, sizeof(newvalue));
+  }
   s = socket(socket_domain_table[Int_val(domain)],
                    socket_type_table[Int_val(type)],
                    Int_val(proto));
+  if (retcode == 0) {
+    /* Restore initial mode */
+    setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE,
+               (char *) &oldvalue, oldvaluelen);
+  }
   if (s == INVALID_SOCKET) {
     win32_maperr(WSAGetLastError());
     uerror("socket", Nothing);