bpo-42972: Fully implement GC protocol for ssl heap types (GH-26370) (GH-26399)

(cherry picked from commit dcb8786)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Author: miss-islington

Modules/_ssl.c

@@ -434,11 +434,11 @@ static PyType_Slot sslerror_type_slots[] = {
 };
 
 static PyType_Spec sslerror_type_spec = {
-    "ssl.SSLError",
-    sizeof(PyOSErrorObject),
-    0,
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_IMMUTABLETYPE,
-    sslerror_type_slots
+    .name = "ssl.SSLError",
+    .basicsize = sizeof(PyOSErrorObject),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
+              Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC),
+    .slots = sslerror_type_slots
 };
 
 static void
@@ -789,7 +789,8 @@ newPySSLSocket(PySSLContext *sslctx, PySocketSockObject *sock,
     SSL_CTX *ctx = sslctx->ctx;
     _PySSLError err = { 0 };
 
-    self = PyObject_New(PySSLSocket, get_state_ctx(sslctx)->PySSLSocket_Type);
+    self = PyObject_GC_New(PySSLSocket,
+                           get_state_ctx(sslctx)->PySSLSocket_Type);
     if (self == NULL)
         return NULL;
 
@@ -896,6 +897,8 @@ newPySSLSocket(PySSLContext *sslctx, PySocketSockObject *sock,
             return NULL;
         }
     }
+
+    PyObject_GC_Track(self);
     return self;
 }
 
@@ -2169,6 +2172,7 @@ PySSL_traverse(PySSLSocket *self, visitproc visit, void *arg)
     Py_VISIT(self->exc_type);
     Py_VISIT(self->exc_value);
     Py_VISIT(self->exc_tb);
+    Py_VISIT(Py_TYPE(self));
     return 0;
 }
 
@@ -2185,13 +2189,15 @@ static void
 PySSL_dealloc(PySSLSocket *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
-    if (self->ssl)
+    PyObject_GC_UnTrack(self);
+    if (self->ssl) {
         SSL_free(self->ssl);
+    }
     Py_XDECREF(self->Socket);
     Py_XDECREF(self->ctx);
     Py_XDECREF(self->server_hostname);
     Py_XDECREF(self->owner);
-    PyObject_Free(self);
+    PyObject_GC_Del(self);
     Py_DECREF(tp);
 }
 
@@ -2903,11 +2909,11 @@ static PyType_Slot PySSLSocket_slots[] = {
 };
 
 static PyType_Spec PySSLSocket_spec = {
-    "_ssl._SSLSocket",
-    sizeof(PySSLSocket),
-    0,
-    Py_TPFLAGS_DEFAULT  | Py_TPFLAGS_IMMUTABLETYPE,
-    PySSLSocket_slots,
+    .name = "_ssl._SSLSocket",
+    .basicsize = sizeof(PySSLSocket),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE |
+              Py_TPFLAGS_HAVE_GC),
+    .slots = PySSLSocket_slots,
 };
 
 /*
@@ -3159,6 +3165,7 @@ context_traverse(PySSLContext *self, visitproc visit, void *arg)
 {
     Py_VISIT(self->set_sni_cb);
     Py_VISIT(self->msg_cb);
+    Py_VISIT(Py_TYPE(self));
     return 0;
 }
 
@@ -4641,11 +4648,11 @@ static PyType_Slot PySSLContext_slots[] = {
 };
 
 static PyType_Spec PySSLContext_spec = {
-    "_ssl._SSLContext",
-    sizeof(PySSLContext),
-    0,
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE,
-    PySSLContext_slots,
+    .name = "_ssl._SSLContext",
+    .basicsize = sizeof(PySSLContext),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC |
+              Py_TPFLAGS_IMMUTABLETYPE),
+    .slots = PySSLContext_slots,
 };
 
 
@@ -4689,10 +4696,18 @@ _ssl_MemoryBIO_impl(PyTypeObject *type)
     return (PyObject *) self;
 }
 
+static int
+memory_bio_traverse(PySSLMemoryBIO *self, visitproc visit, void *arg)
+{
+    Py_VISIT(Py_TYPE(self));
+    return 0;
+}
+
 static void
 memory_bio_dealloc(PySSLMemoryBIO *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
+    PyObject_GC_UnTrack(self);
     BIO_free(self->bio);
     Py_TYPE(self)->tp_free(self);
     Py_DECREF(tp);
@@ -4843,15 +4858,16 @@ static PyType_Slot PySSLMemoryBIO_slots[] = {
     {Py_tp_getset, memory_bio_getsetlist},
     {Py_tp_new, _ssl_MemoryBIO},
     {Py_tp_dealloc, memory_bio_dealloc},
+    {Py_tp_traverse, memory_bio_traverse},
     {0, 0},
 };
 
 static PyType_Spec PySSLMemoryBIO_spec = {
-    "_ssl.MemoryBIO",
-    sizeof(PySSLMemoryBIO),
-    0,
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE,
-    PySSLMemoryBIO_slots,
+    .name = "_ssl.MemoryBIO",
+    .basicsize = sizeof(PySSLMemoryBIO),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_IMMUTABLETYPE |
+              Py_TPFLAGS_HAVE_GC),
+    .slots = PySSLMemoryBIO_slots,
 };
 
 /*
@@ -4934,6 +4950,7 @@ static int
 PySSLSession_traverse(PySSLSession *self, visitproc visit, void *arg)
 {
     Py_VISIT(self->ctx);
+    Py_VISIT(Py_TYPE(self));
     return 0;
 }
 
@@ -5022,11 +5039,11 @@ static PyType_Slot PySSLSession_slots[] = {
 };
 
 static PyType_Spec PySSLSession_spec = {
-    "_ssl.SSLSession",
-    sizeof(PySSLSession),
-    0,
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_IMMUTABLETYPE,
-    PySSLSession_slots,
+    .name = "_ssl.SSLSession",
+    .basicsize = sizeof(PySSLSession),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
+              Py_TPFLAGS_IMMUTABLETYPE),
+    .slots = PySSLSession_slots,
 };