address PR comments

Author: ndgrigorian

dpctl/_sycl_queue.pxd

@@ -43,7 +43,6 @@ cdef public api class _SyclQueue [
     cdef DPCTLSyclQueueRef _queue_ref
     cdef SyclContext _context
     cdef SyclDevice _device
-    cdef object __weakref__
 
 
 cdef public api class SyclQueue (_SyclQueue) [

dpctl/apis/include/dpctl4pybind11.hpp

@@ -141,7 +141,9 @@ class dpctl_capi
 
         static std::mutex init_mtx;
 
-        // release gil while holding lock
+        // initialization requires calls into Python C-API, so initializing
+        // thread must hold the GIL, while other threads must not block on the
+        // mutex while holding the GIL, as this creates a deadlock
         py::gil_scoped_release release;
         std::lock_guard<std::mutex> lock(init_mtx);
 

dpctl/utils/src/sequential_order_keeper.hpp

@@ -186,7 +186,7 @@ class SequentialOrder
 
     void wait()
     {
-        // snapeshot events outside of mutex to avoid
+        // snapshot events outside of mutex to avoid
         // calling wait inside mutex
         std::vector<sycl::event> sub_copy;
         std::vector<sycl::event> ht_copy;