Use assert() on RMW arguments

The macros ut_ad() and DBUG_ASSERT() can evaluate their argument twice. That is wrong for any read-modify-write arguments. Thanks to Nikita Malyavin for pointing this out.
MariaDB · Jan 9, 2025 · 1b8358d · 1b8358d
1 parent addc828
commit 1b8358d
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Showing 3 changed files with 7 additions and 9 deletions.
diff --git a/storage/innobase/include/buf0buf.h b/storage/innobase/include/buf0buf.h
@@ -799,7 +799,7 @@ class buf_page_t
   /** Prepare to release a file page to buf_pool.free. */
   void free_file_page() noexcept
   {
-    ut_ad((zip.fix.fetch_sub(REMOVE_HASH - MEMORY)) == REMOVE_HASH);
+    assert((zip.fix.fetch_sub(REMOVE_HASH - MEMORY)) == REMOVE_HASH);
     /* buf_LRU_block_free_non_file_page() asserts !oldest_modification() */
     ut_d(oldest_modification_= 0;)
     id_= page_id_t(~0ULL);

diff --git a/storage/innobase/include/sux_lock.h b/storage/innobase/include/sux_lock.h
@@ -121,15 +121,13 @@ class sux_lock final
   @param id the new owner of the U or X lock */
   void set_new_owner(pthread_t id)
   {
-    IF_DBUG(DBUG_ASSERT(writer.exchange(id, std::memory_order_relaxed)),
-            writer.store(id, std::memory_order_relaxed));
+    writer.store(id, std::memory_order_relaxed);
   }
   /** Assign the ownership of a write lock to a thread
   @param id the owner of the U or X lock */
   void set_first_owner(pthread_t id)
   {
-    IF_DBUG(DBUG_ASSERT(!writer.exchange(id, std::memory_order_relaxed)),
-            writer.store(id, std::memory_order_relaxed));
+    writer.store(id, std::memory_order_relaxed);
   }
 #ifdef UNIV_DEBUG
   /** Register the current thread as a holder of a shared lock */

diff --git a/storage/innobase/include/trx0trx.h b/storage/innobase/include/trx0trx.h
@@ -618,14 +618,14 @@ struct trx_t : ilist_node<>
   {
     ut_ad(!mutex_is_owner());
     mutex.wr_lock();
-    ut_ad(!mutex_owner.exchange(pthread_self(),
-                                std::memory_order_relaxed));
+    assert(!mutex_owner.exchange(pthread_self(),
+                                 std::memory_order_relaxed));
   }
   /** Release the mutex */
   void mutex_unlock()
   {
-    ut_ad(mutex_owner.exchange(0, std::memory_order_relaxed)
-	  == pthread_self());
+    assert(mutex_owner.exchange(0, std::memory_order_relaxed) ==
+           pthread_self());
     mutex.wr_unlock();
   }
 #ifndef SUX_LOCK_GENERIC