[pypy-commit] stmgc use-gcc: questions with failing test about finalizers

[Raemi]

Author: Remi Meier <remi.meier at inf.ethz.ch>
Branch: use-gcc
Changeset: r1945:824bc70d6f36
Date: 2015-08-26 16:43 +0200
http://bitbucket.org/pypy/stmgc/changeset/824bc70d6f36/

Log:	questions with failing test about finalizers

diff --git a/c8/stm/finalizer.c b/c8/stm/finalizer.c
--- a/c8/stm/finalizer.c
+++ b/c8/stm/finalizer.c
@@ -481,6 +481,13 @@
     LIST_FREE(f->run_finalizers);
 }
 
+/* XXX: can there be a race between _invoke_general_finalizers
+        and _commit_finalizer on g_finalizers (+other places?)?
+   XXX: what happens in _execute_finalizer if the transaction
+        conflicts (or fails to become inevitable) in a finalizer?
+        (the run_finalizers list is half-way cleared?)
+*/
+
 static void _invoke_general_finalizers(stm_thread_local_t *tl)
 {
     /* called between transactions */
@@ -496,6 +503,7 @@
     stm_rewind_jmp_enterframe(tl, &rjbuf);
     _stm_start_transaction(tl);
 
+    fprintf(stderr, "run_finalizers: %lu\n", list_count(g_finalizers.run_finalizers));
     _execute_finalizers(&g_finalizers);
 
     _stm_commit_transaction();
diff --git a/c8/test/test_finalizer.py b/c8/test/test_finalizer.py
--- a/c8/test/test_finalizer.py
+++ b/c8/test/test_finalizer.py
@@ -139,6 +139,7 @@
         self.expect_finalized([lp1], from_tlnum=0)
 
 
+
 class TestRegularFinalizer(BaseTest):
     expect_content_character = None
     run_major_collect_in_finalizer = False
@@ -272,3 +273,59 @@
         self.expect_finalized([])
         stm_major_collect()
         self.expect_finalized([lp1])
+
+
+class TestMoreRegularFinalizers(BaseTest):
+
+    def test_inevitable_in_finalizer(self):
+        lpo = stm_allocate_old(16)
+
+        self._first_time = True
+        @ffi.callback("void(object_t *)")
+        def finalizer(obj):
+            print "finalizing!", obj
+            stm_set_char(lpo, 'a')
+
+            if self._first_time:
+                self._first_time = False
+                # we will switch to the other TX and
+                # make it inevitable, so that our TX
+                # will abort on commit (or validate)
+                self.switch(0, validate=False)
+                self.become_inevitable()
+                self.switch(1, validate=False)
+
+        lib.stmcb_finalizer = finalizer
+        self._finalizer_keepalive = finalizer
+
+        # start a transaction with a finalizing obj
+        self.switch(1)
+        self.start_transaction()
+        lpf = stm_allocate_with_finalizer(16)
+
+        self.push_root(lpf)
+        stm_minor_collect()
+
+
+        self.switch(0)
+        self.start_transaction()
+        stm_set_char(lpo, 'x')
+        self.switch(1)
+        lpf = self.pop_root()
+        # commit this TX, start a new one, let lpf
+        # die with a major-gc:
+        self.commit_transaction()
+        self.start_transaction()
+        stm_major_collect()
+        # commit and run finalizer in separate TX
+        # that will abort because of a conflict
+        self.commit_transaction()
+
+        self.switch(0, validate=False)
+        assert stm_get_char(lpo) == 'x'
+        # commit the now-inevitable TX and run
+        # the aborted finalizer again
+        self.commit_transaction()
+        self.start_transaction()
+        # should now see the value set by finalizer
+        assert stm_get_char(lpo) == 'a'