diff --git a/src/core/interface.c b/src/core/interface.c index 15df49d3..8498425c 100644 --- a/src/core/interface.c +++ b/src/core/interface.c @@ -16,7 +16,6 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include #include /** @file @@ -25,30 +24,6 @@ * */ -/** - * Obtain reference to interface - * - * @v intf Interface - * @ret intf Interface - * - * Increases the reference count on the interface. - */ -static struct interface * intf_get ( struct interface *intf ) { - intf->refcnt ( intf, +1 ); - return intf; -} - -/** - * Drop reference to interface - * - * @v intf Interface - * - * Decreases the reference count on the interface. - */ -static void intf_put ( struct interface *intf ) { - intf->refcnt ( intf, -1 ); -} - /** * Plug an interface into a new destination interface * @@ -63,19 +38,7 @@ static void intf_put ( struct interface *intf ) { * interface into a null interface. */ void plug ( struct interface *intf, struct interface *dest ) { - intf_put ( intf->dest ); - intf->dest = intf_get ( dest ); -} - -/** - * Null update reference count - * - * @v intf Interface - * @v delta Change to apply to reference count - * - * Use this as the refcnt() method for an interface that does not need - * to support reference counting. - */ -void null_refcnt ( struct interface *intf __unused, int delta __unused ) { - /* Do nothing */ + ref_put ( intf->refcnt ); + ref_get ( dest->refcnt ); + intf->dest = dest; } diff --git a/src/core/job.c b/src/core/job.c index fc60f4ec..d6ec27bc 100644 --- a/src/core/job.c +++ b/src/core/job.c @@ -71,7 +71,7 @@ struct job_interface_operations null_job_ops = { struct job_interface null_job = { .intf = { .dest = &null_job.intf, - .refcnt = null_refcnt, + .refcnt = NULL, }, .op = &null_job_ops, }; diff --git a/src/core/refcnt.c b/src/core/refcnt.c new file mode 100644 index 00000000..4efd9d71 --- /dev/null +++ b/src/core/refcnt.c @@ -0,0 +1,73 @@ +/* + * Copyright (C) 2007 Michael Brown . + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include + +/** @file + * + * Reference counting + * + */ + +/** + * Increment reference count + * + * @v refcnt Reference counter, or NULL + * + * If @c refcnt is NULL, no action is taken. + */ +void ref_get ( struct refcnt *refcnt ) { + + if ( ! refcnt ) + return; + + refcnt->refcnt++; + + DBGC ( refcnt, "REFCNT %p incremented to %d\n", + refcnt, refcnt->refcnt ); +} + +/** + * Decrement reference count + * + * @v refcnt Reference counter, or NULL + * + * If the reference count decreases below zero, the object's free() + * method will be called. + * + * If @c refcnt is NULL, no action is taken. + */ +void ref_put ( struct refcnt *refcnt ) { + + if ( ! refcnt ) + return; + + refcnt->refcnt--; + DBGC ( refcnt, "REFCNT %p decremented to %d\n", + refcnt, refcnt->refcnt ); + + if ( refcnt->refcnt >= 0 ) + return; + + if ( refcnt->free ) { + refcnt->free ( refcnt ); + } else { + free ( refcnt ); + } +} diff --git a/src/core/xfer.c b/src/core/xfer.c index d3480816..f927269e 100644 --- a/src/core/xfer.c +++ b/src/core/xfer.c @@ -230,7 +230,7 @@ struct xfer_interface_operations null_xfer_ops = { struct xfer_interface null_xfer = { .intf = { .dest = &null_xfer.intf, - .refcnt = null_refcnt, + .refcnt = NULL, }, .op = &null_xfer_ops, }; diff --git a/src/include/gpxe/interface.h b/src/include/gpxe/interface.h index 38e62721..6ec9b146 100644 --- a/src/include/gpxe/interface.h +++ b/src/include/gpxe/interface.h @@ -7,6 +7,8 @@ * */ +#include + /** An object communication interface */ struct interface { /** Destination interface @@ -18,19 +20,14 @@ struct interface { * unplugged, it should point to a null interface. */ struct interface *dest; - /** Update reference count + /** Reference counter * - * @v intf Interface - * @v delta Change to apply to reference count - * - * This method updates the reference count for the object - * containing the interface. + * If this interface is not part of a reference-counted + * object, this field may be NULL. */ - void ( * refcnt ) ( struct interface *intf, int delta ); + struct refcnt *refcnt; }; extern void plug ( struct interface *intf, struct interface *dest ); -extern void null_refcnt ( struct interface *intf, int delta ); - #endif /* _GPXE_INTERFACE_H */ diff --git a/src/include/gpxe/job.h b/src/include/gpxe/job.h index 3adc6e17..ded6c846 100644 --- a/src/include/gpxe/job.h +++ b/src/include/gpxe/job.h @@ -76,12 +76,11 @@ extern void ignore_progress ( struct job_interface *job, * * @v job Job control interface * @v op Job control interface operations - * @v refcnt Job control interface reference counting method + * @v refcnt Containing object reference counter, or NULL */ static inline void job_init ( struct job_interface *job, - struct job_interface_operations *op, - void ( * refcnt ) ( struct interface *intf, - int delta ) ) { + struct job_interface_operations *op, + struct refcnt *refcnt ) { job->intf.dest = &null_job.intf; job->intf.refcnt = refcnt; job->op = op; diff --git a/src/include/gpxe/refcnt.h b/src/include/gpxe/refcnt.h new file mode 100644 index 00000000..ed147b9a --- /dev/null +++ b/src/include/gpxe/refcnt.h @@ -0,0 +1,39 @@ +#ifndef _GPXE_REFCNT_H +#define _GPXE_REFCNT_H + +/** @file + * + * Reference counting + * + */ + +/** + * A reference counter + * + * This data structure is designed to be embedded within a + * reference-counted object. + */ +struct refcnt { + /** Current reference count + * + * When this count is decremented below zero, the free() + * method will be called. + */ + int refcnt; + /** Free containing object + * + * This method is called when the reference count is + * decremented below zero. + * + * If this method is left NULL, the standard library free() + * function will be called. The upshot of this is that you + * may omit the free() method if the @c refcnt object is the + * first element of your reference-counted struct. + */ + void ( * free ) ( struct refcnt *refcnt ); +}; + +extern void ref_get ( struct refcnt *refcnt ); +extern void ref_put ( struct refcnt *refcnt ); + +#endif /* _GPXE_REFCNT_H */ diff --git a/src/include/gpxe/xfer.h b/src/include/gpxe/xfer.h index dfbde89d..2423c03c 100644 --- a/src/include/gpxe/xfer.h +++ b/src/include/gpxe/xfer.h @@ -114,12 +114,11 @@ extern int ignore_deliver_raw ( struct xfer_interface *xfer, * * @v xfer Data transfer interface * @v op Data transfer interface operations - * @v refcnt Data transfer interface reference counting method + * @v refcnt Containing object reference counter, or NULL */ static inline void xfer_init ( struct xfer_interface *xfer, struct xfer_interface_operations *op, - void ( * refcnt ) ( struct interface *intf, - int delta ) ) { + struct refcnt *refcnt ) { xfer->intf.dest = &null_xfer.intf; xfer->intf.refcnt = refcnt; xfer->op = op;