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authorAnthony Liguori <aliguori@us.ibm.com>2012-12-19 17:15:39 -0600
committerAnthony Liguori <aliguori@us.ibm.com>2012-12-19 17:15:39 -0600
commit27dd7730582be85c7d4f680f5f71146629809c86 (patch)
tree3a36db2e407711ed222de28b839744db48a75059 /include/qapi/qmp/qobject.h
parent914606d26e654d4c01bd5186f4d05e3fd445e219 (diff)
parentec5e016c9a68588bd01be387416923c7dcafb951 (diff)
Merge remote-tracking branch 'bonzini/header-dirs' into staging
* bonzini/header-dirs: (45 commits) janitor: move remaining public headers to include/ hw: move executable format header files to hw/ fpu: move public header file to include/fpu softmmu: move remaining include files to include/ subdirectories softmmu: move include files to include/sysemu/ misc: move include files to include/qemu/ qom: move include files to include/qom/ migration: move include files to include/migration/ monitor: move include files to include/monitor/ exec: move include files to include/exec/ block: move include files to include/block/ qapi: move include files to include/qobject/ janitor: add guards to headers qapi: make struct Visitor opaque qapi: remove qapi/qapi-types-core.h qapi: move inclusions of qemu-common.h from headers to .c files ui: move files to ui/ and include/ui/ qemu-ga: move qemu-ga files to qga/ net: reorganize headers net: move net.c to net/ ... Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'include/qapi/qmp/qobject.h')
-rw-r--r--include/qapi/qmp/qobject.h112
1 files changed, 112 insertions, 0 deletions
diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
new file mode 100644
index 0000000000..9124649ed2
--- /dev/null
+++ b/include/qapi/qmp/qobject.h
@@ -0,0 +1,112 @@
+/*
+ * QEMU Object Model.
+ *
+ * Based on ideas by Avi Kivity <avi@redhat.com>
+ *
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * Authors:
+ * Luiz Capitulino <lcapitulino@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ * QObject Reference Counts Terminology
+ * ------------------------------------
+ *
+ * - Returning references: A function that returns an object may
+ * return it as either a weak or a strong reference. If the reference
+ * is strong, you are responsible for calling QDECREF() on the reference
+ * when you are done.
+ *
+ * If the reference is weak, the owner of the reference may free it at
+ * any time in the future. Before storing the reference anywhere, you
+ * should call QINCREF() to make the reference strong.
+ *
+ * - Transferring ownership: when you transfer ownership of a reference
+ * by calling a function, you are no longer responsible for calling
+ * QDECREF() when the reference is no longer needed. In other words,
+ * when the function returns you must behave as if the reference to the
+ * passed object was weak.
+ */
+#ifndef QOBJECT_H
+#define QOBJECT_H
+
+#include <stddef.h>
+#include <assert.h>
+
+typedef enum {
+ QTYPE_NONE,
+ QTYPE_QINT,
+ QTYPE_QSTRING,
+ QTYPE_QDICT,
+ QTYPE_QLIST,
+ QTYPE_QFLOAT,
+ QTYPE_QBOOL,
+ QTYPE_QERROR,
+} qtype_code;
+
+struct QObject;
+
+typedef struct QType {
+ qtype_code code;
+ void (*destroy)(struct QObject *);
+} QType;
+
+typedef struct QObject {
+ const QType *type;
+ size_t refcnt;
+} QObject;
+
+/* Objects definitions must include this */
+#define QObject_HEAD \
+ QObject base
+
+/* Get the 'base' part of an object */
+#define QOBJECT(obj) (&(obj)->base)
+
+/* High-level interface for qobject_incref() */
+#define QINCREF(obj) \
+ qobject_incref(QOBJECT(obj))
+
+/* High-level interface for qobject_decref() */
+#define QDECREF(obj) \
+ qobject_decref(obj ? QOBJECT(obj) : NULL)
+
+/* Initialize an object to default values */
+#define QOBJECT_INIT(obj, qtype_type) \
+ obj->base.refcnt = 1; \
+ obj->base.type = qtype_type
+
+/**
+ * qobject_incref(): Increment QObject's reference count
+ */
+static inline void qobject_incref(QObject *obj)
+{
+ if (obj)
+ obj->refcnt++;
+}
+
+/**
+ * qobject_decref(): Decrement QObject's reference count, deallocate
+ * when it reaches zero
+ */
+static inline void qobject_decref(QObject *obj)
+{
+ if (obj && --obj->refcnt == 0) {
+ assert(obj->type != NULL);
+ assert(obj->type->destroy != NULL);
+ obj->type->destroy(obj);
+ }
+}
+
+/**
+ * qobject_type(): Return the QObject's type
+ */
+static inline qtype_code qobject_type(const QObject *obj)
+{
+ assert(obj->type != NULL);
+ return obj->type->code;
+}
+
+#endif /* QOBJECT_H */