cpu-exec: Add "nochain" debug flag

[qemu.git] / include / qemu / rcu.h

diff --git a/include/qemu/rcu.h b/include/qemu/rcu.h
index cfef36e25adb406fcd4fdffad7e2f123999c4fe0..f6d1d56375d9618f81f542b69b2a3155d5aff6a0 100644 (file)
--- a/include/qemu/rcu.h
+++ b/include/qemu/rcu.h
@@ -68,7 +68,10 @@ struct rcu_reader_data {
     unsigned long ctr;
     bool waiting;
 
-    /* Data used for registry, protected by rcu_gp_lock */
+    /* Data used by reader only */
+    unsigned depth;
+
+    /* Data used for registry, protected by rcu_registry_lock */
     QLIST_ENTRY(rcu_reader_data) node;
 };
 
@@ -77,8 +80,13 @@ extern __thread struct rcu_reader_data rcu_reader;
 static inline void rcu_read_lock(void)
 {
     struct rcu_reader_data *p_rcu_reader = &rcu_reader;
+    unsigned ctr;
+
+    if (p_rcu_reader->depth++ > 0) {
+        return;
+    }
 
-    unsigned ctr = atomic_read(&rcu_gp_ctr);
+    ctr = atomic_read(&rcu_gp_ctr);
     atomic_xchg(&p_rcu_reader->ctr, ctr);
     if (atomic_read(&p_rcu_reader->waiting)) {
         atomic_set(&p_rcu_reader->waiting, false);
@@ -90,6 +98,11 @@ static inline void rcu_read_unlock(void)
 {
     struct rcu_reader_data *p_rcu_reader = &rcu_reader;
 
+    assert(p_rcu_reader->depth != 0);
+    if (--p_rcu_reader->depth > 0) {
+        return;
+    }
+
     atomic_xchg(&p_rcu_reader->ctr, 0);
     if (atomic_read(&p_rcu_reader->waiting)) {
         atomic_set(&p_rcu_reader->waiting, false);
@@ -104,6 +117,37 @@ extern void synchronize_rcu(void);
  */
 extern void rcu_register_thread(void);
 extern void rcu_unregister_thread(void);
+extern void rcu_after_fork(void);
+
+struct rcu_head;
+typedef void RCUCBFunc(struct rcu_head *head);
+
+struct rcu_head {
+    struct rcu_head *next;
+    RCUCBFunc *func;
+};
+
+extern void call_rcu1(struct rcu_head *head, RCUCBFunc *func);
+
+/* The operands of the minus operator must have the same type,
+ * which must be the one that we specify in the cast.
+ */
+#define call_rcu(head, func, field)                                      \
+    call_rcu1(({                                                         \
+         char __attribute__((unused))                                    \
+            offset_must_be_zero[-offsetof(typeof(*(head)), field)],      \
+            func_type_invalid = (func) - (void (*)(typeof(head)))(func); \
+         &(head)->field;                                                 \
+      }),                                                                \
+      (RCUCBFunc *)(func))
+
+#define g_free_rcu(obj, field) \
+    call_rcu1(({                                                         \
+        char __attribute__((unused))                                     \
+            offset_must_be_zero[-offsetof(typeof(*(obj)), field)];       \
+        &(obj)->field;                                                   \
+      }),                                                                \
+      (RCUCBFunc *)g_free);
 
 #ifdef __cplusplus
 }