odb: carefully preserve the object ids across recycling

Currently the code assumes that placement new won't change the oid but that doesn't appear to be true in newer compilers. Fixes The-OpenROAD-Project#5142 Signed-off-by: Matt Liberty <[email protected]>
andyfox-rushc · May 22, 2024 · 08cbc8f · 08cbc8f
1 parent f0cc0ee
commit 08cbc8f
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Showing 2 changed files with 12 additions and 7 deletions.
diff --git a/src/odb/src/db/dbArrayTable.hpp b/src/odb/src/db/dbArrayTable.hpp
@@ -248,9 +248,10 @@ T* dbArrayTable<T>::create()
   }
 
   _dbFreeObject* o = popQ(_free_list);
-  o->_oid |= DB_ALLOC_BIT;
+  const uint oid = o->_oid;
   new (o) T(_db);
   T* t = (T*) o;
+  t->_oid = oid | DB_ALLOC_BIT;
 
   dbArrayTablePage* page = (dbArrayTablePage*) t->getObjectPage();
   page->_alloccnt++;
@@ -302,8 +303,9 @@ void dbArrayTable<T>::destroy(T* t)
   _dbFreeObject* o = (_dbFreeObject*) t;
 
   page->_alloccnt--;
+  const uint oid = t->_oid;
   t->~T();  // call destructor
-  o->_oid &= ~DB_ALLOC_BIT;
+  o->_oid = oid & ~DB_ALLOC_BIT;
 
   // Add to freelist
   pushQ(_free_list, o);
@@ -395,8 +397,8 @@ void dbArrayTable<T>::copy_page(uint page_id, dbArrayTablePage* page)
 
   for (; t < e; t++, o++) {
     if (t->_oid & DB_ALLOC_BIT) {
-      o->_oid = t->_oid;
       new (o) T(_db, *t);
+      o->_oid = t->_oid;
     } else {
       *((_dbFreeObject*) o) = *((_dbFreeObject*) t);
     }

diff --git a/src/odb/src/db/dbTable.hpp b/src/odb/src/db/dbTable.hpp
@@ -249,9 +249,10 @@ T* dbTable<T>::create()
   }
 
   _dbFreeObject* o = popQ(_free_list);
+  const uint oid = o->_oid;
   new (o) T(_db);
-  o->_oid |= DB_ALLOC_BIT;
   T* t = (T*) o;
+  t->_oid = oid | DB_ALLOC_BIT;
 
   dbTablePage* page = (dbTablePage*) t->getObjectPage();
   page->_alloccnt++;
@@ -279,9 +280,10 @@ T* dbTable<T>::duplicate(T* c)
   }
 
   _dbFreeObject* o = popQ(_free_list);
-  o->_oid |= DB_ALLOC_BIT;
+  uint oid = o->_oid;
   new (o) T(_db, *c);
   T* t = (T*) o;
+  t->_oid = oid | DB_ALLOC_BIT;
 
   dbTablePage* page = (dbTablePage*) t->getObjectPage();
   page->_alloccnt++;
@@ -422,8 +424,9 @@ void dbTable<T>::destroy(T* t)
   _dbFreeObject* o = (_dbFreeObject*) t;
 
   page->_alloccnt--;
+  const uint oid = t->_oid;
   t->~T();  // call destructor
-  o->_oid &= ~DB_ALLOC_BIT;
+  o->_oid = oid & ~DB_ALLOC_BIT;
 
   uint offset = t - (T*) page->_objects;
   uint id = page->_page_addr + offset;
@@ -613,8 +616,8 @@ void dbTable<T>::copy_page(uint page_id, dbTablePage* page)
 
   for (; t < e; t++, o++) {
     if (t->_oid & DB_ALLOC_BIT) {
-      o->_oid = t->_oid;
       new (o) T(_db, *t);
+      o->_oid = t->_oid;
     } else {
       *((_dbFreeObject*) o) = *((_dbFreeObject*) t);
     }