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[Qemu-devel] [PATCH 06/15] memory: use refcnt to manage MemoryRegion
From: |
Liu Ping Fan |
Subject: |
[Qemu-devel] [PATCH 06/15] memory: use refcnt to manage MemoryRegion |
Date: |
Wed, 8 Aug 2012 14:25:47 +0800 |
From: Liu Ping Fan <address@hidden>
Using refcnt for mr, so we can separate mr's life cycle management
from refered object.
When mr->ref 0->1, inc the refered object.
When mr->ref 1->0, dec the refered object.
The refered object can be DeviceStae, another mr, or other opaque.
Signed-off-by: Liu Ping Fan <address@hidden>
---
memory.c | 18 ++++++++++++++++++
memory.h | 5 +++++
2 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/memory.c b/memory.c
index 80c7529..5dc8b59 100644
--- a/memory.c
+++ b/memory.c
@@ -811,6 +811,7 @@ void memory_region_init(MemoryRegion *mr,
if (size == UINT64_MAX) {
mr->size = int128_2_64();
}
+ atomic_set(&mr->ref, 0);
mr->life_ops = &nops;
mr->addr = 0;
mr->subpage = false;
@@ -1090,6 +1091,23 @@ static const MemoryRegionOps reservation_ops = {
.endianness = DEVICE_NATIVE_ENDIAN,
};
+void memory_region_get(MemoryRegion *mr)
+{
+ if (atomic_add_and_return(1, &mr->ref) == 1) {
+ mr->life_ops->get(mr);
+ }
+}
+
+void memory_region_put(MemoryRegion *mr)
+{
+ assert(atomic_read(&mr->ref) > 0);
+
+ if (atomic_dec_and_test(&mr->ref)) {
+ /* to fix, using call_rcu( ,release) */
+ mr->life_ops->put(mr);
+ }
+}
+
void memory_region_init_reservation(MemoryRegion *mr,
const char *name,
uint64_t size)
diff --git a/memory.h b/memory.h
index 8fb543b..740f018 100644
--- a/memory.h
+++ b/memory.h
@@ -18,6 +18,7 @@
#include <stdint.h>
#include <stdbool.h>
+#include "qemu/atomic.h"
#include "qemu-common.h"
#include "cpu-common.h"
#include "targphys.h"
@@ -26,6 +27,7 @@
#include "ioport.h"
#include "int128.h"
#include "qemu-thread.h"
+#include "qemu/reclaimer.h"
typedef struct MemoryRegionOps MemoryRegionOps;
typedef struct MemoryRegionLifeOps MemoryRegionLifeOps;
@@ -126,6 +128,7 @@ typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
struct MemoryRegion {
/* All fields are private - violators will be prosecuted */
const MemoryRegionOps *ops;
+ Atomic ref;
MemoryRegionLifeOps *life_ops;
void *opaque;
MemoryRegion *parent;
@@ -766,6 +769,8 @@ void memory_global_dirty_log_stop(void);
void mtree_info(fprintf_function mon_printf, void *f);
+void memory_region_get(MemoryRegion *mr);
+void memory_region_put(MemoryRegion *mr);
#endif
#endif
--
1.7.4.4
[Qemu-devel] [PATCH 05/15] memory: introduce life_ops to MemoryRegion, Liu Ping Fan, 2012/08/08
[Qemu-devel] [PATCH 06/15] memory: use refcnt to manage MemoryRegion,
Liu Ping Fan <=
[Qemu-devel] [PATCH 10/15] memory: change tcg related code to using PhysMap, Liu Ping Fan, 2012/08/08
[Qemu-devel] [PATCH 09/15] memory: prepare flatview and radix-tree for rcu style access, Liu Ping Fan, 2012/08/08