Astobj2: Add ao2_weakproxy_ref_object function.

This function allows code to run ao2_ref against the real
object associated with a weakproxy.  It is useful when
all of the following conditions are true:
* You have a pointer to weakproxy.
* You do not have or need a pointer to the real object.
* You need to ensure the real object exists and is not
  destroyed during a process.

In this case it's wasteful to store a pointer to the real
object just for the sake of releasing it later.

Change-Id: I38a319b83314de75be74207a8771aab269bcca46

diff --git a/include/asterisk/astobj2.h b/include/asterisk/astobj2.h
index de35bb3..e02a4cd 100644 (file)
--- a/include/asterisk/astobj2.h
+++ b/include/asterisk/astobj2.h
@@ -560,6 +560,29 @@ int __ao2_weakproxy_set_object(void *weakproxy, void *obj, int flags,
 
 /*!
  * \since 14.0.0
+ * \brief Run ao2_t_ref on the object associated with weakproxy.
+ *
+ * \param weakproxy The weakproxy to read from.
+ * \param delta Value to add to the reference counter.
+ * \param flags OBJ_NOLOCK to avoid locking weakproxy.
+ *
+ * \retval -2 weakproxy is not a valid ao2_weakproxy.
+ * \retval -1 weakproxy has no associated object.
+ *
+ * \return The value of the reference counter before the operation.
+ */
+int __ao2_weakproxy_ref_object(void *weakproxy, int delta, int flags,
+       const char *tag, const char *file, int line, const char *func);
+
+#define ao2_t_weakproxy_ref_object(weakproxy, delta, flags, tag) \
+       __ao2_weakproxy_ref_object(weakproxy, delta, flags, \
+               tag, __FILE__, __LINE__, __PRETTY_FUNCTION__)
+
+#define ao2_weakproxy_ref_object(weakproxy, delta, flags) \
+       ao2_t_weakproxy_ref_object(weakproxy, delta, flags, "")
+
+/*!
+ * \since 14.0.0
  * \brief Get the object associated with weakproxy.
  *
  * \param weakproxy The weakproxy to read from.

diff --git a/main/astobj2.c b/main/astobj2.c
index c5b5cd9..f9dd8d4 100644 (file)
--- a/main/astobj2.c
+++ b/main/astobj2.c
@@ -836,6 +836,33 @@ int __ao2_weakproxy_set_object(void *weakproxy, void *obj, int flags,
        return ret;
 }
 
+int __ao2_weakproxy_ref_object(void *weakproxy, int delta, int flags,
+       const char *tag, const char *file, int line, const char *func)
+{
+       struct astobj2 *internal = __INTERNAL_OBJ_CHECK(weakproxy, file, line, func);
+       int ret = -1;
+
+       if (!internal || internal->priv_data.magic != AO2_WEAK) {
+               /* This method is meant to be run on weakproxy objects! */
+               return -2;
+       }
+
+       /* We have a weak object, grab lock. */
+       if (!(flags & OBJ_NOLOCK)) {
+               ao2_lock(weakproxy);
+       }
+
+       if (internal->priv_data.weakptr) {
+               ret = __ao2_ref(internal->priv_data.weakptr, delta, tag, file, line, func);
+       }
+
+       if (!(flags & OBJ_NOLOCK)) {
+               ao2_unlock(weakproxy);
+       }
+
+       return ret;
+}
+
 void *__ao2_weakproxy_get_object(void *weakproxy, int flags,
        const char *tag, const char *file, int line, const char *func)
 {

diff --git a/tests/test_astobj2_weaken.c b/tests/test_astobj2_weaken.c
index e53ab7a..6a5eaeb 100644 (file)
--- a/tests/test_astobj2_weaken.c
+++ b/tests/test_astobj2_weaken.c
@@ -223,7 +223,29 @@ AST_TEST_DEFINE(astobj2_weak1)
                goto fail_cleanup;
        }
 
+       if (ao2_t_weakproxy_ref_object(obj3, +1, 0, "ao2_ref should never see this") != -2) {
+               ast_test_status_update(test,
+                       "Expected -2 from ao2_t_weakproxy_ref_object against normal ao2 object.\n");
+               goto fail_cleanup;
+       }
+
+       if (ao2_t_weakproxy_ref_object(weakref2, +1, 0, "weakref2 ref_object") != 2) {
+               ast_test_status_update(test, "Expected 2 from weakref2 ref_object.\n");
+               goto fail_cleanup;
+       }
+
+       if (ao2_t_ref(obj3, -1, "balance weakref2 ref_object") != 3) {
+               ast_test_status_update(test, "Expected 3 from obj3 ao2_t_ref.\n");
+               goto fail_cleanup;
+       }
+
        ao2_ref(obj3, -1);
+
+       if (ao2_weakproxy_ref_object(weakref2, +1, 0) != -1) {
+               ast_test_status_update(test, "Expected -1 from weakref2 ref_object because obj3 is gone.\n");
+               goto fail_cleanup;
+       }
+
        ao2_t_ref(weakref2, -1, "weakref2");
 
        if (!weakproxydestroyed) {