Introduced a clientlock on Linux / OS X, as we have on windows.

git-svn-id: https://openmodelica.org/svn/OpenModelica/branches/MathCoreOSMC@4189 f25d12d1-65f4-0310-ae8a-bbce733d8d8e

Compiler/runtime/corbaimpl.cpp

@@ -325,10 +325,13 @@ extern "C" {
 using namespace std;
 
 pthread_mutex_t lock;
+pthread_mutex_t clientlock;
+
 // Condition variable for keeping omc waiting for client requests
 pthread_cond_t omc_waitformsg;
 pthread_mutex_t omc_waitlock;
 bool omc_waiting=false;
+
 // Condition variable for keeping corba waiting for returnvalue from omc
 pthread_cond_t corba_waitformsg;
 pthread_mutex_t corba_waitlock;
@@ -373,6 +376,7 @@ RML_BEGIN_LABEL(Corba__initialize)
   pthread_cond_init(&corba_waitformsg,NULL);
   pthread_mutex_init(&corba_waitlock,NULL);
   pthread_mutex_init(&omc_waitlock,NULL);
+  pthread_mutex_init(&clientlock, NULL);
 
 #if defined(USE_OMNIORB)  
   orb = CORBA::ORB_init(argc, dummyArgv, "omniORB4");

Compiler/runtime/omc_communication_impl.cpp

@@ -96,6 +96,8 @@ extern "C" {
   #include <pthread.h>
 }
 
+extern pthread_mutex_t clientlock;
+
 extern pthread_cond_t omc_waitformsg;
 extern pthread_mutex_t omc_waitlock;
 
@@ -119,6 +121,7 @@ OmcCommunication_impl::OmcCommunication_impl()
 
 char* OmcCommunication_impl::sendExpression( const char* expr )
 {
+  pthread_mutex_lock(&clientlock);
   char* result;
   // Signal to omc that message has arrived. 
   pthread_mutex_lock(&omc_waitlock);
@@ -133,9 +136,10 @@ char* OmcCommunication_impl::sendExpression( const char* expr )
     pthread_cond_wait(&corba_waitformsg,&corba_waitlock);
   }
   corba_waiting = false;
+  result = CORBA::string_dup(omc_reply_message);
   pthread_mutex_unlock(&corba_waitlock);
-
-  return CORBA::string_dup(omc_reply_message); // Has already been string_dup (prepared for CORBA)
+  pthread_mutex_unlock(&clientlock);
+  return result; // Has already been string_dup (prepared for CORBA)
 } 
 
 char* OmcCommunication_impl::sendClass( const char* expr )