From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MgLwy-0002q0-AX for qemu-devel@nongnu.org; Wed, 26 Aug 2009 13:06:20 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MgLwu-0002jq-Kf for qemu-devel@nongnu.org; Wed, 26 Aug 2009 13:06:19 -0400 Received: from [199.232.76.173] (port=45796 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MgLwu-0002jE-Ff for qemu-devel@nongnu.org; Wed, 26 Aug 2009 13:06:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1027) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MgLwt-0000dl-86 for qemu-devel@nongnu.org; Wed, 26 Aug 2009 13:06:15 -0400 From: Luiz Capitulino Date: Wed, 26 Aug 2009 14:05:24 -0300 Message-Id: <1251306352-31316-2-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1251306352-31316-1-git-send-email-lcapitulino@redhat.com> References: <1251306352-31316-1-git-send-email-lcapitulino@redhat.com> Subject: [Qemu-devel] [PATCH 01/29] Introduce QObject List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aliguori@us.ibm.com, avi@redhat.com This commit introduces the qobject.h header file, it contains basic QObject definitions and helper macros. Signed-off-by: Luiz Capitulino --- qobject.h | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 108 insertions(+), 0 deletions(-) create mode 100644 qobject.h diff --git a/qobject.h b/qobject.h new file mode 100644 index 0000000..86c9737 --- /dev/null +++ b/qobject.h @@ -0,0 +1,108 @@ +/* + * QEMU Object Model. + * + * Based on ideas by Avi Kivity + * + * Copyright (C) 2009 Red Hat Inc. + * + * Authors: + * Luiz Capitulino + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING 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. + * + * (By Paolo Bonzini ) + */ +#ifndef QOBJECT_H +#define QOBJECT_H + +#include +#include + +typedef enum { + QTYPE_NONE, +} 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) \ + assert(obj != NULL); \ + qobject_incref(QOBJECT(obj)) + +/* High-level interface for qobject_decref() */ +#define QDECREF(obj) \ + assert(obj != NULL); \ + qobject_decref(QOBJECT(obj)) + +/* 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) +{ + obj->refcnt++; +} + +/** + * qobject_decref(): Decrement QObject's reference count, deallocate + * when it reaches zero + */ +static inline void qobject_decref(QObject *obj) +{ + if (--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 */ -- 1.6.4.1.184.g2e117