Fix the logic to handle ffi.gc(x) being called several times with equal

values of x.  (PyPy 2.6.0's RPython version is already correct, which I
guess is why the problem was noticed.)

2 files changed, 98 insertions, 0 deletions

diff --git a/testing/cffi0/backend_tests.py b/testing/cffi0/backend_tests.py
index 80b2420..21af727 100644
--- a/testing/cffi0/backend_tests.py
+++ b/testing/cffi0/backend_tests.py
@@ -1457,6 +1457,63 @@ class BackendTests:
         import gc; gc.collect(); gc.collect(); gc.collect()
         assert seen == [1]
 
+    def test_gc_2(self):
+        ffi = FFI(backend=self.Backend())
+        p = ffi.new("int *", 123)
+        seen = []
+        q1 = ffi.gc(p, lambda p: seen.append(1))
+        q2 = ffi.gc(q1, lambda p: seen.append(2))
+        import gc; gc.collect()
+        assert seen == []
+        del q1, q2
+        import gc; gc.collect(); gc.collect(); gc.collect(); gc.collect()
+        assert seen == [2, 1]
+
+    def test_gc_3(self):
+        ffi = FFI(backend=self.Backend())
+        p = ffi.new("int *", 123)
+        r = ffi.new("int *", 123)
+        seen = []
+        seen_r = []
+        q1 = ffi.gc(p, lambda p: seen.append(1))
+        s1 = ffi.gc(r, lambda r: seen_r.append(4))
+        q2 = ffi.gc(q1, lambda p: seen.append(2))
+        s2 = ffi.gc(s1, lambda r: seen_r.append(5))
+        q3 = ffi.gc(q2, lambda p: seen.append(3))
+        import gc; gc.collect()
+        assert seen == []
+        assert seen_r == []
+        del q1, q2, q3, s2, s1
+        import gc; gc.collect(); gc.collect(); gc.collect(); gc.collect()
+        assert seen == [3, 2, 1]
+        assert seen_r == [5, 4]
+
+    def test_gc_4(self):
+        ffi = FFI(backend=self.Backend())
+        p = ffi.new("int *", 123)
+        seen = []
+        q1 = ffi.gc(p, lambda p: seen.append(1))
+        q2 = ffi.gc(q1, lambda p: seen.append(2))
+        q3 = ffi.gc(q2, lambda p: seen.append(3))
+        import gc; gc.collect()
+        assert seen == []
+        del q1, q3     # q2 remains, and has a hard ref to q1
+        import gc; gc.collect(); gc.collect(); gc.collect()
+        assert seen == [3]
+
+    def test_gc_finite_list(self):
+        ffi = FFI(backend=self.Backend())
+        p = ffi.new("int *", 123)
+        keepalive = []
+        for i in range(10):
+            keepalive.append(ffi.gc(p, lambda p: None))
+            assert len(ffi.gc_weakrefs.data) == i + 1  #should be a private attr
+        del keepalive[:]
+        import gc; gc.collect(); gc.collect()
+        for i in range(10):
+            keepalive.append(ffi.gc(p, lambda p: None))
+        assert len(ffi.gc_weakrefs.data) == 10
+
     def test_CData_CType(self):
         ffi = FFI(backend=self.Backend())
         assert isinstance(ffi.cast("int", 0), ffi.CData)
diff --git a/testing/cffi1/test_new_ffi_1.py b/testing/cffi1/test_new_ffi_1.py
index f600a27..e317c88 100644
--- a/testing/cffi1/test_new_ffi_1.py
+++ b/testing/cffi1/test_new_ffi_1.py
@@ -1409,6 +1409,47 @@ class TestNewFFI1:
         import gc; gc.collect(); gc.collect(); gc.collect()
         assert seen == [1]
 
+    def test_gc_2(self):
+        p = ffi.new("int *", 123)
+        seen = []
+        q1 = ffi.gc(p, lambda p: seen.append(1))
+        q2 = ffi.gc(q1, lambda p: seen.append(2))
+        import gc; gc.collect()
+        assert seen == []
+        del q1, q2
+        import gc; gc.collect(); gc.collect(); gc.collect(); gc.collect()
+        assert seen == [2, 1]
+
+    def test_gc_3(self):
+        p = ffi.new("int *", 123)
+        r = ffi.new("int *", 123)
+        seen = []
+        seen_r = []
+        q1 = ffi.gc(p, lambda p: seen.append(1))
+        s1 = ffi.gc(r, lambda r: seen_r.append(4))
+        q2 = ffi.gc(q1, lambda p: seen.append(2))
+        s2 = ffi.gc(s1, lambda r: seen_r.append(5))
+        q3 = ffi.gc(q2, lambda p: seen.append(3))
+        import gc; gc.collect()
+        assert seen == []
+        assert seen_r == []
+        del q1, q2, q3, s2, s1
+        import gc; gc.collect(); gc.collect(); gc.collect(); gc.collect()
+        assert seen == [3, 2, 1]
+        assert seen_r == [5, 4]
+
+    def test_gc_4(self):
+        p = ffi.new("int *", 123)
+        seen = []
+        q1 = ffi.gc(p, lambda p: seen.append(1))
+        q2 = ffi.gc(q1, lambda p: seen.append(2))
+        q3 = ffi.gc(q2, lambda p: seen.append(3))
+        import gc; gc.collect()
+        assert seen == []
+        del q1, q3     # q2 remains, and has a hard ref to q1
+        import gc; gc.collect(); gc.collect(); gc.collect()
+        assert seen == [3]
+
     def test_CData_CType(self):
         assert isinstance(ffi.cast("int", 0), ffi.CData)
         assert isinstance(ffi.new("int *"), ffi.CData)