fix pointer release list

src/pythonrun.rs

@@ -71,8 +71,6 @@ pub fn prepare_pyo3_library() {
     START_PYO3.call_once(|| unsafe {
         // initialize release pool
         POINTERS = Box::into_raw(Box::new(Pointers::new()));
-        let p: &'static mut Pointers = mem::transmute(POINTERS);
-        p.init();
     });
 }
 
@@ -111,6 +109,7 @@ impl Drop for GILGuard {
 
 
 struct Pointers {
+    rc: usize,
     owned: Vec<*mut ffi::PyObject>,
     borrowed: Vec<*mut ffi::PyObject>,
     pointers: *mut Vec<*mut ffi::PyObject>,
@@ -120,16 +119,13 @@ struct Pointers {
 impl Pointers {
     fn new() -> Pointers {
         Pointers {
+            rc: 0,
             owned: Vec::with_capacity(250),
             borrowed: Vec::with_capacity(250),
             pointers: Box::into_raw(Box::new(Vec::with_capacity(250))),
-            p: spin::Mutex::new(0 as *mut _),
+            p: spin::Mutex::new(Box::into_raw(Box::new(Vec::with_capacity(250)))),
         }
     }
-    fn init(&mut self) {
-        let v = Box::into_raw(Box::new(Vec::with_capacity(250)));
-        *self.p.lock() = v;
-    }
 
     unsafe fn release_pointers(&mut self) {
         let mut v = self.p.lock();
@@ -161,6 +157,8 @@ impl Pointers {
         }
 
         self.release_pointers();
+
+        self.rc -= 1;
     }
 }
 
@@ -176,9 +174,18 @@ impl Pool {
     #[inline]
     pub unsafe fn new() -> Pool {
         let p: &'static mut Pointers = mem::transmute(POINTERS);
-        Pool{ owned: p.owned.len(),
+        p.rc += 1;
+        Pool {owned: p.owned.len(),
               borrowed: p.borrowed.len(),
-              no_send: marker::PhantomData }
+              no_send: marker::PhantomData}
+    }
+    pub unsafe fn new_if_needed() -> Option<Pool> {
+        let p: &'static mut Pointers = mem::transmute(POINTERS);
+        if p.rc == 0 {
+            Some(Pool::new())
+        } else {
+            None
+        }
     }
 }
 
@@ -226,6 +233,7 @@ impl GILGuard {
         unsafe {
             let gstate = ffi::PyGILState_Ensure(); // acquire GIL
             let pool: &'static mut Pointers = mem::transmute(POINTERS);
+            pool.rc += 1;
 
             GILGuard { owned: pool.owned.len(),
                        borrowed: pool.borrowed.len(),

src/typeob.rs

@@ -279,7 +279,7 @@ unsafe extern "C" fn tp_dealloc_callback<T>(obj: *mut ffi::PyObject)
     debug!("DEALLOC: {:?} - {:?}", obj,
            CStr::from_ptr((*(*obj).ob_type).tp_name).to_string_lossy());
     let guard = AbortOnDrop("Cannot unwind out of tp_dealloc");
-    let _pool = pythonrun::Pool::new();
+    let _pool = pythonrun::Pool::new_if_needed();
     let py = Python::assume_gil_acquired();
     let r = <T as PyObjectAlloc<T>>::dealloc(py, obj);
     mem::forget(guard);

tests/test_class.rs

@@ -62,13 +62,9 @@ fn class_with_docstr() {
     {
         let gil = Python::acquire_gil();
         let py = gil.python();
-        println!("TEST1");
         let typeobj = py.get_type::<ClassWithDocs>();
-        println!("TEST2");
         py_run!(py, typeobj, "assert typeobj.__doc__ == 'Line1\\nLine2\\n Line3'");
-        println!("TEST3");
     }
-    println!("TEST4");
 }
 
 #[py::class(name=CustomName)]
@@ -177,19 +173,27 @@ struct ClassWithFreelist{token: PyToken}
 
 #[test]
 fn class_with_freelist() {
+    let ptr;
+    {
         let gil = Python::acquire_gil();
         let py = gil.python();
 
         let inst = Py::new(py, |t| ClassWithFreelist{token: t}).unwrap();
         let inst2 = Py::new(py, |t| ClassWithFreelist{token: t}).unwrap();
-    let ptr = inst.as_ptr();
+        ptr = inst.as_ptr();
         drop(inst);
+    }
+
+    {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
 
         let inst3 = Py::new(py, |t| ClassWithFreelist{token: t}).unwrap();
         assert_eq!(ptr, inst3.as_ptr());
 
         let inst4 = Py::new(py, |t| ClassWithFreelist{token: t}).unwrap();
         assert_ne!(ptr, inst4.as_ptr())
+    }
 }
 
 struct TestDropCall {
@@ -210,11 +214,12 @@ struct DataIsDropped {
 
 #[test]
 fn data_is_dropped() {
-    let gil = Python::acquire_gil();
-    let py = gil.python();
-
     let drop_called1 = Arc::new(AtomicBool::new(false));
     let drop_called2 = Arc::new(AtomicBool::new(false));
+
+    {
+        let gil = Python::acquire_gil();
+        let py = gil.python();
         let inst = py.init(|t| DataIsDropped{
             member1: TestDropCall { drop_called: drop_called1.clone() },
             member2: TestDropCall { drop_called: drop_called2.clone() },
@@ -223,6 +228,8 @@ fn data_is_dropped() {
         assert!(drop_called1.load(Ordering::Relaxed) == false);
         assert!(drop_called2.load(Ordering::Relaxed) == false);
         drop(inst);
+    }
+
     assert!(drop_called1.load(Ordering::Relaxed) == true);
     assert!(drop_called2.load(Ordering::Relaxed) == true);
 }