[Qemu-devel] [PATCH 03/15] qom: introduce reclaimer to release obj

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

Collect unused object and release them at caller demand.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 include/qemu/reclaimer.h |   28 ++++++++++++++++++++++
 main-loop.c              |    5 ++++
 qemu-tool.c              |    5 ++++
 qom/Makefile.objs        |    2 +-
 qom/reclaimer.c          |   58 ++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 97 insertions(+), 1 deletions(-)
 create mode 100644 include/qemu/reclaimer.h
 create mode 100644 qom/reclaimer.c

diff --git a/include/qemu/reclaimer.h b/include/qemu/reclaimer.h
new file mode 100644
index 0000000..9307e93
--- /dev/null
+++ b/include/qemu/reclaimer.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU reclaimer
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_RECLAIMER
+#define QEMU_RECLAIMER
+
+typedef void ReleaseHandler(void *opaque);
+typedef struct Chunk {
+    QLIST_ENTRY(Chunk) list;
+    void *opaque;
+    ReleaseHandler *release;
+} Chunk;
+
+typedef struct ChunkHead {
+        struct Chunk *lh_first;
+} ChunkHead;
+
+void reclaimer_enqueue(ChunkHead *head, void *opaque, ReleaseHandler *release);
+void reclaimer_worker(ChunkHead *head);
+void qemu_reclaimer_enqueue(void *opaque, ReleaseHandler *release);
+void qemu_reclaimer(void);
+#endif
diff --git a/main-loop.c b/main-loop.c
index eb3b6e6..be9d095 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -26,6 +26,7 @@
 #include "qemu-timer.h"
 #include "slirp/slirp.h"
 #include "main-loop.h"
+#include "qemu/reclaimer.h"
 
 #ifndef _WIN32
 
@@ -505,5 +506,9 @@ int main_loop_wait(int nonblocking)
        them.  */
     qemu_bh_poll();
 
+    /* ref to device from iohandler/bh/timer do not obey the rules, so delay
+     * reclaiming until now.
+     */
+    qemu_reclaimer();
     return ret;
 }
diff --git a/qemu-tool.c b/qemu-tool.c
index 318c5fc..f5fe319 100644
--- a/qemu-tool.c
+++ b/qemu-tool.c
@@ -21,6 +21,7 @@
 #include "main-loop.h"
 #include "qemu_socket.h"
 #include "slirp/libslirp.h"
+#include "qemu/reclaimer.h"
 
 #include <sys/time.h>
 
@@ -75,6 +76,10 @@ void qemu_mutex_unlock_iothread(void)
 {
 }
 
+void qemu_reclaimer(void)
+{
+}
+
 int use_icount;
 
 void qemu_clock_warp(QEMUClock *clock)
diff --git a/qom/Makefile.objs b/qom/Makefile.objs
index 5ef060a..a579261 100644
--- a/qom/Makefile.objs
+++ b/qom/Makefile.objs
@@ -1,4 +1,4 @@
-qom-obj-y = object.o container.o qom-qobject.o
+qom-obj-y = object.o container.o qom-qobject.o reclaimer.o
 qom-obj-twice-y = cpu.o
 common-obj-y = $(qom-obj-twice-y)
 user-obj-y = $(qom-obj-twice-y)
diff --git a/qom/reclaimer.c b/qom/reclaimer.c
new file mode 100644
index 0000000..6cb53e3
--- /dev/null
+++ b/qom/reclaimer.c
@@ -0,0 +1,58 @@
+/*
+ * QEMU reclaimer
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu-common.h"
+#include "qemu-thread.h"
+#include "main-loop.h"
+#include "qemu-queue.h"
+#include "qemu/reclaimer.h"
+
+static struct QemuMutex reclaimer_lock;
+static QLIST_HEAD(rcl, Chunk) reclaimer_list;
+
+void reclaimer_enqueue(ChunkHead *head, void *opaque, ReleaseHandler *release)
+{
+    Chunk *r = g_malloc0(sizeof(Chunk));
+    r->opaque = opaque;
+    r->release = release;
+    QLIST_INSERT_HEAD_RCU(head, r, list);
+}
+
+void reclaimer_worker(ChunkHead *head)
+{
+    Chunk *cur, *next;
+
+    QLIST_FOREACH_SAFE(cur, head, list, next) {
+        QLIST_REMOVE(cur, list);
+        cur->release(cur->opaque);
+        g_free(cur);
+    }
+}
+
+void qemu_reclaimer_enqueue(void *opaque, ReleaseHandler *release)
+{
+    Chunk *r = g_malloc0(sizeof(Chunk));
+    r->opaque = opaque;
+    r->release = release;
+    qemu_mutex_lock(&reclaimer_lock);
+    QLIST_INSERT_HEAD_RCU(&reclaimer_list, r, list);
+    qemu_mutex_unlock(&reclaimer_lock);
+}
+
+
+void qemu_reclaimer(void)
+{
+    Chunk *cur, *next;
+
+    QLIST_FOREACH_SAFE(cur, &reclaimer_list, list, next) {
+        QLIST_REMOVE(cur, list);
+        cur->release(cur->opaque);
+        g_free(cur);
+    }
+}
-- 
1.7.4.4