1 files changed, 34 insertions, 9 deletions

diff --git a/xrdp/xrdp.c b/xrdp/xrdp.c
index 8fbbd8f7..ec019222 100644
--- a/xrdp/xrdp.c
+++ b/xrdp/xrdp.c
@@ -23,6 +23,8 @@
 #include "xrdp.h"
 #include "log.h"
 
+#define THREAD_WAITING 100
+
 static struct xrdp_listen* g_listen = 0;
 static long g_threadid = 0; /* main threadid */
 
@@ -38,6 +40,9 @@ static long g_sync_param2 = 0;
 static long (*g_sync_func)(long param1, long param2);
 
 /*****************************************************************************/
+/* This function is used to run a function from the main thread.
+   Sync_func is the function pointer that will run from main thread
+   The function can have two long in parameters and must return long */
 long APP_CC
 g_xrdp_sync(long (*sync_func)(long param1, long param2), long sync_param1,
             long sync_param2)
@@ -45,32 +50,46 @@ g_xrdp_sync(long (*sync_func)(long param1, long param2), long sync_param1,
   long sync_result;
   int sync_command;
 
+  /* If the function is called from the main thread, the function can 
+   * be called directly. g_threadid= main thread ID*/
   if (tc_threadid_equal(tc_get_threadid(), g_threadid))
   {
     /* this is the main thread, call the function directly */
     /* in fork mode, this always happens too */
     sync_result = sync_func(sync_param1, sync_param2);
+    /*g_writeln("g_xrdp_sync processed IN main thread -> continue");*/
   }
   else
   {
+    /* All threads have to wait here until the main thread 
+     * process the function. g_process_waiting_function() is called 
+     * from the listening thread. g_process_waiting_function() process the function*/  
     tc_mutex_lock(g_sync1_mutex);
     tc_mutex_lock(g_sync_mutex);
     g_sync_param1 = sync_param1;
     g_sync_param2 = sync_param2;
     g_sync_func = sync_func;
-    g_sync_command = 100;
+    /* set a value THREAD_WAITING so the g_process_waiting_function function 
+     * know if any function must be processed */
+    g_sync_command = THREAD_WAITING; 
     tc_mutex_unlock(g_sync_mutex);
-    g_set_wait_obj(g_sync_event);
+    /* set this event so that the main thread know if 
+     * g_process_waiting_function() must be called */
+    g_set_wait_obj(g_sync_event); 
     do
     {
       g_sleep(100);
       tc_mutex_lock(g_sync_mutex);
-      sync_command = g_sync_command;
+      /* load new value from global to see if the g_process_waiting_function() 
+       * function has processed the function */
+      sync_command = g_sync_command; 
       sync_result = g_sync_result;
       tc_mutex_unlock(g_sync_mutex);
     }
-    while (sync_command != 0);
+    while (sync_command != 0); /* loop until g_process_waiting_function() 
+				* has processed the request*/
     tc_mutex_unlock(g_sync1_mutex);
+    /*g_writeln("g_xrdp_sync processed BY main thread -> continue");*/
   }
   return sync_result;
 }
@@ -160,15 +179,17 @@ pipe_sig(int sig_num)
 }
 
 /*****************************************************************************/
+/*Some function must be called from the main thread.
+ if g_sync_command==THREAD_WAITING a function is waiting to be processed*/
 void APP_CC
-g_loop(void)
+g_process_waiting_function(void)
 {
   tc_mutex_lock(g_sync_mutex);
   if (g_sync_command != 0)
   {
     if (g_sync_func != 0)
     {
-      if (g_sync_command == 100)
+      if (g_sync_command == THREAD_WAITING)
       {
         g_sync_result = g_sync_func(g_sync_param1, g_sync_param2);
       }
@@ -490,13 +511,17 @@ main(int argc, char** argv)
   pid = g_getpid();
   g_snprintf(text, 255, "xrdp_%8.8x_main_term", pid);
   g_term_event = g_create_wait_obj(text);
-  g_snprintf(text, 255, "xrdp_%8.8x_main_sync", pid);
-  g_sync_event = g_create_wait_obj(text);
   if (g_term_event == 0)
   {
     g_writeln("error creating g_term_event");
   }
-  g_listen->startup_params = startup_params;
+  g_snprintf(text, 255, "xrdp_%8.8x_main_sync", pid);
+  g_sync_event = g_create_wait_obj(text);
+  if (g_sync_event == 0)
+  {
+    g_writeln("error creating g_sync_event");
+  }
+  g_listen->startup_params = startup_params;  
   xrdp_listen_main_loop(g_listen);
   xrdp_listen_delete(g_listen);
   tc_mutex_delete(g_sync_mutex);