ilmCommon: ilm_init() to be thread-safe.

If ilm_init() is called from another thread it will wait until the first of
the initialization is complete. Then, when the initialization is complete,
and then exits with a ILM_SUCCESS without anything.
Also print the following message.

1 files changed, 36 insertions, 13 deletions

diff --git a/ivi-layermanagement-api/ilmCommon/src/ilm_common.c b/ivi-layermanagement-api/ilmCommon/src/ilm_common.c
index b669c66..8152968 100644
--- a/ivi-layermanagement-api/ilmCommon/src/ilm_common.c
+++ b/ivi-layermanagement-api/ilmCommon/src/ilm_common.c
@@ -35,6 +35,8 @@
 ILM_EXPORT ilmErrorTypes ilmControl_init(t_ilm_nativedisplay);
 ILM_EXPORT void ilmControl_destroy(void);
 
+static pthread_mutex_t g_initialize_lock = PTHREAD_MUTEX_INITIALIZER;
+
 ILM_EXPORT ilmErrorTypes
 ilm_init(void)
 {
@@ -45,26 +47,47 @@ ILM_EXPORT ilmErrorTypes
 ilm_initWithNativedisplay(t_ilm_nativedisplay nativedisplay)
 {
     ilmErrorTypes err = ILM_SUCCESS;
+    ilmErrorTypes ret = ILM_FAILED;
     t_ilm_nativedisplay display = 0;
 
-    init_ilmCommonPlatformTable();
+    pthread_mutex_lock(&g_initialize_lock);
 
-    err = gIlmCommonPlatformFunc.init(nativedisplay);
-    if (ILM_SUCCESS != err)
+    do
     {
-        return err;
-    }
+        init_ilmCommonPlatformTable();
 
-    display = gIlmCommonPlatformFunc.getNativedisplay();
+        if (ilm_isInitialized())
+        {
+            fprintf(stderr, "[Warning] ilm_init or ilm_initWithNativedisplay is called,\n"
+                            "          but ilmClientLib has been already initialized.\n"
+                            "          Returning success and initialization is skipped\n"
+                            "          at this time.\n");
+            ret = ILM_SUCCESS;
+            break;
+        }
 
-    err = ilmControl_init(display);
-    if (ILM_SUCCESS != err)
-    {
-        gIlmCommonPlatformFunc.destroy();
-        return err;
-    }
+        err = gIlmCommonPlatformFunc.init(nativedisplay);
+        if (ILM_SUCCESS != err)
+        {
+            break;
+        }
+
+        display = gIlmCommonPlatformFunc.getNativedisplay();
+
+        err = ilmControl_init(display);
+        if (ILM_SUCCESS != err)
+        {
+            gIlmCommonPlatformFunc.destroy();
+            break;
+        }
+
+        ret = ILM_SUCCESS;
+
+    } while (0);
+
+    pthread_mutex_unlock(&g_initialize_lock);
 
-    return ILM_SUCCESS;
+    return ret;
 }
 
 ILM_EXPORT t_ilm_bool