>  ... I see a recursive call to rpc_execute(): rpc_execute() calls tr_stop() calls cm_yield() calls 
> ss_suspend() calls rpc_execute()
> ... rpc_execute() cannot be called recursively - it is not re-entrant as it uses a global buffer

It turns out that rpc_server_receive() also need protection against recursive calls - it also uses
a global buffer to receive network data.

My solution is to protect rpc_server_receive() against recursive calls by detecting recursion and returning SS_SUCCESS (to ss_suspend()).

I was worried that this would cause a tight loop inside ss_suspend() but in practice, it looks like ss_suspend() tries to call
us about once per second. I am happy with this solution. Here is the diff:


@@ -12813,7 +12815,7 @@
 
 
 /********************************************************************/
-INT rpc_server_receive(INT idx, int sock, BOOL check)
+INT rpc_server_receive1(INT idx, int sock, BOOL check)
 /********************************************************************\
 
   Routine: rpc_server_receive
@@ -13047,7 +13049,28 @@
    return status;
 }
 
+/********************************************************************/
+INT rpc_server_receive(INT idx, int sock, BOOL check)
+{
+  static int level = 0;
+  int status;
 
+  // Provide protection against recursive calls to rpc_server_receive() and rpc_execute()
+  // via rpc_execute() calls tr_stop() calls cm_yield() calls ss_suspend() calls rpc_execute()
+
+  if (level != 0) {
+    //printf("*** enter rpc_server_receive level %d, idx %d sock %d %d -- protection against recursive use!\n", level, idx, sock, check);
+    return SS_SUCCESS;
+  }
+
+  level++;
+  //printf(">>> enter rpc_server_receive level %d, idx %d sock %d %d\n", level, idx, sock, check);
+  status = rpc_server_receive1(idx, sock, check);
+  //printf("<<< exit rpc_server_receive level %d, idx %d sock %d %d, status %d\n", level, idx, sock, check, status);
+  level--;
+  return status;
+}
+
 /********************************************************************/
 INT rpc_server_shutdown(void)
 /********************************************************************\


ladd02:trinat~/packages/midas>svn info src/midas.c
Path: src/midas.c
Name: midas.c
URL: svn+ssh://svn@savannah.psi.ch/repos/meg/midas/trunk/src/midas.c
Repository Root: svn+ssh://svn@savannah.psi.ch/repos/meg/midas
Repository UUID: 050218f5-8902-0410-8d0e-8a15d521e4f2
Revision: 5297
Node Kind: file
Schedule: normal
Last Changed Author: olchanski
Last Changed Rev: 5294
Last Changed Date: 2012-06-15 10:45:35 -0700 (Fri, 15 Jun 2012)
Text Last Updated: 2012-06-29 17:05:14 -0700 (Fri, 29 Jun 2012)
Checksum: 8d7907bd60723e401a3fceba7cd2ba29

K.O.