diff --git a/sesman/lock.c b/sesman/lock.c
index 912084a2..4c404fdc 100644
--- a/sesman/lock.c
+++ b/sesman/lock.c
@@ -34,6 +34,9 @@ pthread_mutexattr_t lock_chain_attr;  /* mutex attributes */
 pthread_mutex_t lock_config;          /* configuration access lock */
 pthread_mutexattr_t lock_config_attr; /* mutex attributes */
 
+static tbus g_sync_mutex;
+static tbus g_sync_sem;
+
 sem_t lock_socket;
 
 void DEFAULT_CC
@@ -49,6 +52,9 @@ lock_init(void)
   /* initializing config lock */
   pthread_mutexattr_init(&lock_config_attr);
   pthread_mutex_init(&lock_config, &lock_config_attr);
+
+  g_sync_mutex = tc_mutex_create();
+  g_sync_sem = tc_sem_create(0);
 }
 
 /******************************************************************************/
@@ -87,3 +93,38 @@ lock_socket_release(void)
   sem_post(&lock_socket);
 }
 
+/******************************************************************************/
+void APP_CC
+lock_sync_acquire(void)
+{
+  /* lock sync variable */
+  LOG_DBG(&(g_cfg->log), "lock_sync_acquire()");
+  tc_mutex_lock(g_sync_mutex);
+}
+
+/******************************************************************************/
+void APP_CC
+lock_sync_release(void)
+{
+  /* unlock socket variable */
+  LOG_DBG(&(g_cfg->log), "lock_socket_release()");
+  tc_mutex_unlock(g_sync_mutex);
+}
+
+/******************************************************************************/
+void APP_CC
+lock_sync_sem_acquire(void)
+{
+  /* dec sem */
+  LOG_DBG(&(g_cfg->log), "lock_sync_dec()");
+  tc_sem_dec(g_sync_sem);
+}
+
+/******************************************************************************/
+void APP_CC
+lock_sync_sem_release(void)
+{
+  /* inc sem */
+  LOG_DBG(&(g_cfg->log), "lock_sync_inc()");
+  tc_sem_inc(g_sync_sem);
+}
diff --git a/sesman/lock.h b/sesman/lock.h
index 4d2a8655..5ea5e7f4 100644
--- a/sesman/lock.h
+++ b/sesman/lock.h
@@ -78,5 +78,36 @@ lock_socket_acquire(void);
 void DEFAULT_CC
 lock_socket_release(void);
 
-#endif
+/**
+ *
+ * @brief request the main sync lock
+ *
+ */
+void APP_CC
+lock_sync_acquire(void);
 
+/**
+ *
+ * @brief releases the main sync lock
+ *
+ */
+void APP_CC
+lock_sync_release(void);
+
+/**
+ *
+ * @brief request the sync sem lock
+ *
+ */
+void APP_CC
+lock_sync_sem_acquire(void);
+
+/**
+ *
+ * @brief releases the sync sem lock
+ *
+ */
+void APP_CC
+lock_sync_sem_release(void);
+
+#endif
diff --git a/sesman/scp_v0.c b/sesman/scp_v0.c
index e006ad33..918badc9 100644
--- a/sesman/scp_v0.c
+++ b/sesman/scp_v0.c
@@ -34,7 +34,7 @@ void DEFAULT_CC
 scp_v0_process(struct SCP_CONNECTION* c, struct SCP_SESSION* s)
 {
   int display = 0;
-  long data;
+  tbus data;
   struct session_item* s_item;
 
   data = auth_userpass(s->username, s->password);
diff --git a/sesman/sesman.c b/sesman/sesman.c
index c9c5992e..4ce3cdfd 100644
--- a/sesman/sesman.c
+++ b/sesman/sesman.c
@@ -33,6 +33,7 @@ unsigned char g_fixedkey[8] = { 23, 82, 107, 6, 35, 78, 88, 7 };
 struct config_sesman* g_cfg; /* config.h */
 
 tbus g_term_event = 0;
+tbus g_sync_event = 0;
 
 extern int g_thread_sck; /* in thread.c */
 
@@ -70,6 +71,7 @@ sesman_main_loop(void)
         robjs_count = 0;
         robjs[robjs_count++] = sck_obj;
         robjs[robjs_count++] = g_term_event;
+        robjs[robjs_count++] = g_sync_event;
         /* wait */
         if (g_obj_wait(robjs, robjs_count, 0, 0, -1) != 0)
         {
@@ -80,6 +82,11 @@ sesman_main_loop(void)
         {
           break;
         }
+        if (g_is_wait_obj_set(g_sync_event)) /* sync */
+        {
+          g_reset_wait_obj(g_sync_event);
+          session_sync_start();
+        }
         if (g_is_wait_obj_set(sck_obj)) /* incomming connection */
         {
           in_sck = g_tcp_accept(g_sck);
@@ -318,10 +325,13 @@ main(int argc, char** argv)
 
   g_snprintf(text, 255, "xrdp-sesman_%8.8x_main_term", g_pid);
   g_term_event = g_create_wait_obj(text);
+  g_snprintf(text, 255, "xrdp-sesman_%8.8x_main_sync", g_pid);
+  g_sync_event = g_create_wait_obj(text);
 
   sesman_main_loop();
 
   g_delete_wait_obj(g_term_event);
+  g_delete_wait_obj(g_sync_event);
 
   if (!daemon)
   {
diff --git a/sesman/session.c b/sesman/session.c
index 08e5efad..1e67ae1a 100644
--- a/sesman/session.c
+++ b/sesman/session.c
@@ -31,11 +31,21 @@
 #include <errno.h>
 //#include <time.h>
 
+extern tbus g_sync_event;
 extern unsigned char g_fixedkey[8];
 extern struct config_sesman* g_cfg; /* config.h */
 struct session_chain* g_sessions;
 int g_session_count;
 
+static int g_sync_width;
+static int g_sync_height;
+static int g_sync_bpp;
+static char* g_sync_username;
+static char* g_sync_password;
+static tbus g_sync_data;
+static tui8 g_sync_type;
+static int g_sync_result;
+
 /******************************************************************************/
 struct session_item* DEFAULT_CC
 session_get_bydata(char* name, int width, int height, int bpp)
@@ -171,9 +181,10 @@ session_start_sessvc(int xpid, int wmpid, long data)
 }
 
 /******************************************************************************/
-int DEFAULT_CC
-session_start(int width, int height, int bpp, char* username, char* password,
-              long data, unsigned char type)
+/* called with the main thread */
+static int APP_CC
+session_start_fork(int width, int height, int bpp, char* username,
+                   char* password, tbus data, tui8 type)
 {
   int display;
   int pid;
@@ -191,21 +202,14 @@ session_start(int width, int height, int bpp, char* username, char* password,
   time_t ltime;
   struct tm stime;
 
-  /*THREAD-FIX lock to control g_session_count*/
-  lock_chain_acquire();
   /* check to limit concurrent sessions */
   if (g_session_count >= g_cfg->sess.max_sessions)
   {
-    /*THREAD-FIX unlock chain*/
-    lock_chain_release();
     log_message(&(g_cfg->log), LOG_LEVEL_INFO, "max concurrent session limit exceeded. login \
 for user %s denied", username);
     return 0;
   }
 
-  /*THREAD-FIX unlock chain*/
-  lock_chain_release();
-
   temp = (struct session_chain*)g_malloc(sizeof(struct session_chain), 0);
   if (temp == 0)
   {
@@ -228,8 +232,6 @@ for user %s denied", username);
   /* we search for a free display up to max_sessions */
   /* we should need no more displays than this       */
 
-  /* block all the threads running to enable forking */
-  scp_lock_fork_request();
   while (x_server_running(display))
   {
     display++;
@@ -412,9 +414,6 @@ for user %s denied", username);
   }
   else /* parent sesman process */
   {
-    /* let the other threads go on */
-    scp_lock_fork_release();
-
     temp->item->pid = pid;
     temp->item->display = display;
     temp->item->width = width;
@@ -436,19 +435,59 @@ for user %s denied", username);
     temp->item->type=type;
     temp->item->status=SESMAN_SESSION_STATUS_ACTIVE;
 
-    /*THREAD-FIX lock the chain*/
-    lock_chain_acquire();
     temp->next=g_sessions;
     g_sessions=temp;
     g_session_count++;
-    /*THERAD-FIX free the chain*/
-    lock_chain_release();
+  }
+  return display;
+}
 
+/******************************************************************************/
+/* called by a worker thread, ask the main thread to call session_sync_start
+   and wait till done */
+int DEFAULT_CC
+session_start(int width, int height, int bpp, char* username, char* password,
+              long data, unsigned char type)
+{
+  int display;
+
+  /* lock mutex */
+  lock_sync_acquire();
+  /* set shared vars */
+  g_sync_width = width;
+  g_sync_height = height;
+  g_sync_bpp = bpp;
+  g_sync_username = username;
+  g_sync_password = password;
+  g_sync_data = data;
+  g_sync_type = type;
+  /* set event for main thread to see */
+  g_set_wait_obj(g_sync_event);
+  /* wait for main thread to get done */
+  lock_sync_sem_acquire();
+  /* read result(display) from shared var */
+  display = g_sync_result;
+  /* unlock mutex */
+  lock_sync_release();
+  if (display != 0)
+  {
     g_sleep(5000);
   }
   return display;
 }
 
+/******************************************************************************/
+/* called with the main thread */
+int APP_CC
+session_sync_start(void)
+{
+  g_sync_result = session_start_fork(g_sync_width, g_sync_height, g_sync_bpp,
+                                     g_sync_username, g_sync_password,
+                                     g_sync_data, g_sync_type);
+  lock_sync_sem_release();
+  return 0;
+}
+
 /******************************************************************************/
 int DEFAULT_CC
 session_kill(int pid)
diff --git a/sesman/session.h b/sesman/session.h
index 41acea2a..c434a104 100644
--- a/sesman/session.h
+++ b/sesman/session.h
@@ -103,7 +103,16 @@ session_get_bydata(char* name, int width, int height, int bpp);
  */
 int DEFAULT_CC
 session_start(int width, int height, int bpp, char* username, char* password,
-              long data, unsigned char type);
+              tbus data, tui8 type);
+
+/**
+ *
+ * @brief starts a session
+ * @return error
+ *
+ */
+int APP_CC
+session_sync_start(void);
 
 /**
  *