Gather stats on uv_handler_t allocs in debug mode

uvloop/_testbase.py

@@ -87,6 +87,11 @@ class BaseTestCase(unittest.TestCase, metaclass=BaseTestCaseMeta):
             gc.collect()
             gc.collect()
 
+            self.assertEqual(
+                self.loop._debug_uv_handles_total,
+                self.loop._debug_uv_handles_freed,
+                'not all uv_handle_t handles were freed')
+
             self.assertEqual(
                 self.loop._debug_cb_handles_count, 0,
                 'not all callbacks (call_soon) are GCed')

uvloop/handles/handle.pyx

@@ -68,6 +68,12 @@ cdef class UVHandle:
             self._free()
 
     cdef inline _free(self):
+        if self._handle == NULL:
+            return
+
+        IF DEBUG:
+            self._loop._debug_uv_handles_freed += 1
+
         PyMem_Free(self._handle)
         self._handle = NULL
 
@@ -101,6 +107,8 @@ cdef class UVHandle:
         self._handle.data = <void*>self
         if self._loop._debug:
             self._source_traceback = tb_extract_stack(sys_getframe(0))
+        IF DEBUG:
+            self._loop._debug_uv_handles_total += 1
 
     cdef inline _start_init(self, Loop loop):
         IF DEBUG:
@@ -303,6 +311,13 @@ cdef void __uv_close_handle_cb(uv.uv_handle_t* handle) with gil:
     if handle.data is NULL:
         # The original UVHandle is long dead. Just free the mem of
         # the uv_handle_t* handler.
+
+        IF DEBUG:
+            if handle.loop == NULL or handle.loop.data == NULL:
+                raise RuntimeError(
+                    '__uv_close_handle_cb: handle.loop is invalid')
+            (<Loop>handle.loop.data)._debug_uv_handles_freed += 1
+
         PyMem_Free(handle)
     else:
         h = <UVHandle>handle.data

uvloop/loop.pxd

@@ -87,6 +87,9 @@ cdef class Loop:
             readonly object _debug_handles_closed
             readonly object _debug_handles_current
 
+            readonly uint64_t _debug_uv_handles_total
+            readonly uint64_t _debug_uv_handles_freed
+
             readonly uint64_t _debug_cb_handles_total
             readonly uint64_t _debug_cb_handles_count
             readonly uint64_t _debug_cb_timer_handles_total

uvloop/loop.pyx

@@ -98,6 +98,9 @@ cdef class Loop:
             self._debug_handles_closed = col_Counter()
             self._debug_handles_total = col_Counter()
 
+            self._debug_uv_handles_total = 0
+            self._debug_uv_handles_freed = 0
+
             self._debug_stream_read_cb_total = 0
             self._debug_stream_read_eof_total = 0
             self._debug_stream_read_errors_total = 0
@@ -871,6 +874,12 @@ cdef class Loop:
                     self._debug_handles_total[name]))
             print()
 
+            print('uv_handle_t (current: {}; freed: {}; total: {})'.format(
+                self._debug_uv_handles_total - self._debug_uv_handles_freed,
+                self._debug_uv_handles_freed,
+                self._debug_uv_handles_total))
+            print()
+
             print('--- Streams debug info: ---')
             print('Write errors:              {}'.format(
                 self._debug_stream_write_errors_total))