From 0018338afc0745849656f42cbfd7d9ed621ec8a7 Mon Sep 17 00:00:00 2001
From: Philipp Schafft <lion@lion.leolix.org>
Date: Sun, 15 Sep 2019 09:03:50 +0000
Subject: [PATCH] Feature: Assign default instance if any on new if type is not
 instance

---
 src/libigloo.c | 27 +++++++++++++++++++++++++++
 src/private.h  |  5 ++++-
 src/ro.c       |  3 +++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/libigloo.c b/src/libigloo.c
index 04ca615..1e3e955 100644
--- a/src/libigloo.c
+++ b/src/libigloo.c
@@ -28,6 +28,7 @@ typedef struct igloo_instance_tag igloo_instance_t;
 #define igloo_RO_PRIVATETYPES igloo_RO_TYPE(igloo_instance_t)
 
 #include "../include/igloo/ro.h"
+#include "../include/igloo/error.h"
 #include "private.h"
 
 struct igloo_instance_tag {
@@ -35,9 +36,18 @@ struct igloo_instance_tag {
 };
 
 static size_t igloo_initialize__refc;
+static igloo_ro_t default_instance = igloo_RO_NULL;
+
 
 static void igloo_initialize__free(igloo_ro_t self)
 {
+
+    if (igloo_RO_IS_SAME(default_instance, self)) {
+        /* This is hacky, but needed to avoid free-before-unlock. */
+        igloo_RO__GETBASE(default_instance)->wrefc--;
+        default_instance = igloo_RO_NULL;
+    }
+
     igloo_initialize__refc--;
     if (igloo_initialize__refc)
         return;
@@ -75,5 +85,22 @@ igloo_ro_t     igloo_initialize(void)
 
     igloo_initialize__refc++;
 
+    if (igloo_RO_IS_NULL(default_instance)) {
+        if (igloo_ro_weak_ref(ret) == igloo_ERROR_NONE) {
+            default_instance = (igloo_ro_t)ret;
+        }
+    }
+
     return (igloo_ro_t)ret;
 }
+
+igloo_ro_t igloo_get_default_instance(void)
+{
+    if (igloo_RO_IS_NULL(default_instance))
+        return igloo_RO_NULL;
+
+    if (igloo_ro_ref(default_instance) != igloo_ERROR_NONE)
+        return igloo_RO_NULL;
+
+    return default_instance;
+}
diff --git a/src/private.h b/src/private.h
index eb6ebad..7b312e2 100644
--- a/src/private.h
+++ b/src/private.h
@@ -38,7 +38,8 @@ void igloo_log_shutdown(void);
 
 /* Instance type internal forwarding */
 const igloo_ro_type_t **igloo_instance_type;
-#define igloo_IS_INSTANCE(x) (igloo_RO_GET_TYPE((x)) == *igloo_instance_type)
+#define igloo_IS_INSTANCE(x)        (igloo_RO_GET_TYPE((x)) == *igloo_instance_type)
+#define igloo_IS_INSTANCE_TYPE(x)   ((x) == *igloo_instance_type)
 
 /* Basic interface */
 #define igloo_interface_base(type) \
@@ -67,4 +68,6 @@ size_t igloo_private__vsnprintf_Hstrlen(const char *str, int is_alt, int allow_s
 void igloo_private__vsnprintf(char *str, size_t size, const char *format, va_list ap);
 void igloo_private__snprintf(char *str, size_t size, const char *format, ...);
 
+igloo_ro_t igloo_get_default_instance(void);
+
 #endif
diff --git a/src/ro.c b/src/ro.c
index d74b244..cfd407a 100644
--- a/src/ro.c
+++ b/src/ro.c
@@ -113,6 +113,9 @@ igloo_ro_t      igloo_ro_new__raw(const igloo_ro_type_t *type, const char *name,
         }
 
         base->instance = instance;
+    } else {
+        if (!igloo_IS_INSTANCE_TYPE(type))
+            base->instance = igloo_get_default_instance();
     }
 
     return (igloo_ro_t)base;