CCDB: ensure the right number of bytes is deleted for libuv handlers (#13272)

* CCDB: cast to the concrete pointer type before deleting a uv_handle_t*

libuv handlers use c-style polymorphism, so deleting uv_handle_t* pointing to a derived class will in fact delete wrong number of bytes.
As ugly as it is, it seems we have to check for all the possible types here.

* CCDB: use malloc/free for uv_handle_t to release the correct size on heap

While the previous approach was probably also OK, it's indeed more concise with C...
Asan output for testCcdbApiDownloader is now perfectly clean.

Author: knopers8

CCDB/src/CCDBDownloader.cxx

@@ -80,7 +80,7 @@ CCDBDownloader::CCDBDownloader(uv_loop_t* uv_loop)
   }
 
   // Preparing timer to be used by curl
-  mTimeoutTimer = new uv_timer_t();
+  mTimeoutTimer = (uv_timer_t*)malloc(sizeof(*mTimeoutTimer));
   mTimeoutTimer->data = this;
   uvErrorCheck(uv_timer_init(mUVLoop, mTimeoutTimer));
   mHandleMap[(uv_handle_t*)mTimeoutTimer] = true;
@@ -136,7 +136,7 @@ void closeHandles(uv_handle_t* handle, void* arg)
 void onUVClose(uv_handle_t* handle)
 {
   if (handle != nullptr) {
-    delete handle;
+    free(handle);
   }
 }
 
@@ -174,7 +174,7 @@ curl_socket_t opensocketCallback(void* clientp, curlsocktype purpose, struct cur
   }
 
   if (CD->mExternalLoop) {
-    CD->mSocketTimerMap[sock] = new uv_timer_t();
+    CD->mSocketTimerMap[sock] = (uv_timer_t*)malloc(sizeof(*CD->mSocketTimerMap[sock]));
     uvErrorCheck(uv_timer_init(CD->mUVLoop, CD->mSocketTimerMap[sock]));
     CD->mHandleMap[(uv_handle_t*)CD->mSocketTimerMap[sock]] = true;
 
@@ -323,7 +323,7 @@ CCDBDownloader::curl_context_t* CCDBDownloader::createCurlContext(curl_socket_t
   context = (curl_context_t*)malloc(sizeof(*context));
   context->CD = this;
   context->sockfd = sockfd;
-  context->poll_handle = new uv_poll_t();
+  context->poll_handle = (uv_poll_t*)malloc(sizeof(*context->poll_handle));
 
   uvErrorCheck(uv_poll_init_socket(mUVLoop, context->poll_handle, sockfd));
   mHandleMap[(uv_handle_t*)(context->poll_handle)] = true;
@@ -335,7 +335,7 @@ CCDBDownloader::curl_context_t* CCDBDownloader::createCurlContext(curl_socket_t
 void CCDBDownloader::curlCloseCB(uv_handle_t* handle)
 {
   auto* context = (curl_context_t*)handle->data;
-  delete context->poll_handle;
+  free(context->poll_handle);
   free(context);
 }
 

CCDB/test/testCcdbApiDownloader.cxx

@@ -302,7 +302,7 @@ BOOST_AUTO_TEST_CASE(test_with_break)
 void onUVClose(uv_handle_t* handle)
 {
   if (handle != nullptr) {
-    delete handle;
+    free(handle);
   }
 }
 
@@ -325,7 +325,7 @@ BOOST_AUTO_TEST_CASE(external_loop_test)
   uv_loop_init(uvLoop);
 
   // Prepare test timer. It will be used to check whether the downloader affects external handles.
-  auto testTimer = new uv_timer_t();
+  auto testTimer = (uv_timer_t*)malloc(sizeof(uv_timer_t));
   uv_timer_init(uvLoop, testTimer);
   uv_timer_start(testTimer, testTimerCB, 10, 10);
 
@@ -358,7 +358,7 @@ BOOST_AUTO_TEST_CASE(external_loop_test)
   // The reason for that are the uv_poll handles attached to the curl multi handle.
   // The multi handle must be cleaned (via destuctor) before poll handles attached to them are removed (via walking and closing).
   delete downloader;
-  while (uv_loop_alive(uvLoop) && uv_loop_close(uvLoop) == UV_EBUSY) {
+  while (uv_loop_alive(uvLoop) || uv_loop_close(uvLoop) == UV_EBUSY) {
     uv_walk(uvLoop, closeAllHandles, nullptr);
     uv_run(uvLoop, UV_RUN_ONCE);
   }