[PATCH v2 2/2] lockable: add QemuRecMutex support

[Stefan Hajnoczi]

The polymorphic locking macros don't support QemuRecMutex yet.  Add it
so that lock guards can be used with QemuRecMutex.

Convert TCG plugins functions that benefit from these macros.  Manual
qemu_rec_mutex_lock/unlock() callers are left unmodified in cases where
clarity would not improve by switching to the macros.

Signed-off-by: Stefan Hajnoczi <address@hidden>
---
 include/qemu/lockable.h |  2 ++
 plugins/core.c          |  7 +++----
 plugins/loader.c        | 16 ++++++++--------
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h
index 2b52c7c1e5..44b3f4be72 100644
--- a/include/qemu/lockable.h
+++ b/include/qemu/lockable.h
@@ -50,6 +50,7 @@ qemu_make_lockable(void *x, QemuLockable *lockable)
 #define QEMU_LOCK_FUNC(x) ((QemuLockUnlockFunc *)    \
     QEMU_GENERIC(x,                                  \
                  (QemuMutex *, qemu_mutex_lock),     \
+                 (QemuRecMutex *, qemu_rec_mutex_lock), \
                  (CoMutex *, qemu_co_mutex_lock),    \
                  (QemuSpin *, qemu_spin_lock),       \
                  unknown_lock_type))
@@ -57,6 +58,7 @@ qemu_make_lockable(void *x, QemuLockable *lockable)
 #define QEMU_UNLOCK_FUNC(x) ((QemuLockUnlockFunc *)  \
     QEMU_GENERIC(x,                                  \
                  (QemuMutex *, qemu_mutex_unlock),   \
+                 (QemuRecMutex *, qemu_rec_mutex_unlock), \
                  (CoMutex *, qemu_co_mutex_unlock),  \
                  (QemuSpin *, qemu_spin_unlock),     \
                  unknown_lock_type))
diff --git a/plugins/core.c b/plugins/core.c
index ed863011ba..51bfc94787 100644
--- a/plugins/core.c
+++ b/plugins/core.c
@@ -15,6 +15,7 @@
 #include "qemu/error-report.h"
 #include "qemu/config-file.h"
 #include "qapi/error.h"
+#include "qemu/lockable.h"
 #include "qemu/option.h"
 #include "qemu/rcu_queue.h"
 #include "qemu/xxhash.h"
@@ -150,11 +151,11 @@ do_plugin_register_cb(qemu_plugin_id_t id, enum 
qemu_plugin_event ev,
 {
     struct qemu_plugin_ctx *ctx;
 
-    qemu_rec_mutex_lock(&plugin.lock);
+    QEMU_LOCK_GUARD(&plugin.lock);
     ctx = plugin_id_to_ctx_locked(id);
     /* if the plugin is on its way out, ignore this request */
     if (unlikely(ctx->uninstalling)) {
-        goto out_unlock;
+        return;
     }
     if (func) {
         struct qemu_plugin_cb *cb = ctx->callbacks[ev];
@@ -178,8 +179,6 @@ do_plugin_register_cb(qemu_plugin_id_t id, enum 
qemu_plugin_event ev,
     } else {
         plugin_unregister_cb__locked(ctx, ev);
     }
- out_unlock:
-    qemu_rec_mutex_unlock(&plugin.lock);
 }
 
 void plugin_register_cb(qemu_plugin_id_t id, enum qemu_plugin_event ev,
diff --git a/plugins/loader.c b/plugins/loader.c
index 15fc7e5515..685d334e1a 100644
--- a/plugins/loader.c
+++ b/plugins/loader.c
@@ -19,6 +19,7 @@
 #include "qemu/error-report.h"
 #include "qemu/config-file.h"
 #include "qapi/error.h"
+#include "qemu/lockable.h"
 #include "qemu/option.h"
 #include "qemu/rcu_queue.h"
 #include "qemu/qht.h"
@@ -367,15 +368,14 @@ void plugin_reset_uninstall(qemu_plugin_id_t id,
     struct qemu_plugin_reset_data *data;
     struct qemu_plugin_ctx *ctx;
 
-    qemu_rec_mutex_lock(&plugin.lock);
-    ctx = plugin_id_to_ctx_locked(id);
-    if (ctx->uninstalling || (reset && ctx->resetting)) {
-        qemu_rec_mutex_unlock(&plugin.lock);
-        return;
+    WITH_QEMU_LOCK_GUARD(&plugin.lock) {
+        ctx = plugin_id_to_ctx_locked(id);
+        if (ctx->uninstalling || (reset && ctx->resetting)) {
+            return;
+        }
+        ctx->resetting = reset;
+        ctx->uninstalling = !reset;
     }
-    ctx->resetting = reset;
-    ctx->uninstalling = !reset;
-    qemu_rec_mutex_unlock(&plugin.lock);
 
     data = g_new(struct qemu_plugin_reset_data, 1);
     data->ctx = ctx;
-- 
2.24.1