add error log when tid depleted, and return correct errno when clone failed

Author: zmshahaha

components/lwp/lwp_syscall.c

@@ -1832,6 +1832,7 @@ long _sys_clone(void *arg[])
     rt_thread_t thread = RT_NULL;
     rt_thread_t self = RT_NULL;
     int tid = 0;
+    rt_err_t err;
 
     unsigned long flags = 0;
     void *user_stack = RT_NULL;
@@ -1935,6 +1936,8 @@ long _sys_clone(void *arg[])
     rt_thread_startup(thread);
     return (long)tid;
 fail:
+    RT_ASSERT(err < 0);
+
     lwp_tid_put(tid);
     if (thread)
     {
@@ -1944,7 +1947,7 @@ long _sys_clone(void *arg[])
     {
         lwp_ref_dec(lwp);
     }
-    return GET_ERRNO();
+    return (long)err;
 }
 
 rt_weak long sys_clone(void *arg[])

components/lwp/lwp_tid.c

@@ -88,6 +88,12 @@ int lwp_tid_get(void)
         current_tid = tid;
     }
     lwp_mutex_release_safe(&tid_lock);
+
+    if (tid <= 0)
+    {
+        LOG_W("resource TID exhausted.");
+    }
+
     return tid;
 }