diff options
author | Anand Avati <avati@redhat.com> | 2013-03-06 01:11:59 -0800 |
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committer | Anand Avati <avati@redhat.com> | 2013-09-03 11:25:33 -0700 |
commit | 0d60175bd684cf6a14f750579d82dbd1ba97fcbc (patch) | |
tree | 1571f530548196006526442f3fc027cb623bb6fa /contrib/qemu/include/qapi/qmp/qobject.h | |
parent | 7dbfbfd3694e02b90e8f3ce509f5279da1523a02 (diff) |
contrib/qemu: Import qemu block source code
This qemu block format source code and its minimal
dependency files will be used in the next patch to implement
a qemu-block format translator.
Change-Id: Ic87638972f7ea9b3df84d7a0539512a250c11c1c
BUG: 986775
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/5366
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Diffstat (limited to 'contrib/qemu/include/qapi/qmp/qobject.h')
-rw-r--r-- | contrib/qemu/include/qapi/qmp/qobject.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/contrib/qemu/include/qapi/qmp/qobject.h b/contrib/qemu/include/qapi/qmp/qobject.h new file mode 100644 index 00000000..9124649e --- /dev/null +++ b/contrib/qemu/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 */ |