From df5ff92d2d1ee9252461501fe9d6902ad8cb7f69 Mon Sep 17 00:00:00 2001
From: Oleksandr Pavlyk <oleksandr.pavlyk@intel.com>
Date: Wed, 27 Apr 2022 13:06:53 -0500
Subject: [PATCH] Remove unnecessary arg member of SyclEvent/_SyclEvent classes

This used to solve the problem of keeps Python arguments that
SYCL kernels work on to stay "alive" for the duration of kernel
execution.

This mechanism was them changed to use host_task, but args member
was not removed.

This should lower the overhead of constructing/destroying SyclEvent
objects.
---
 dpctl/_sycl_event.pxd | 3 +--
 dpctl/_sycl_event.pyx | 9 ++-------
 dpctl/_sycl_queue.pyx | 4 ++--
 3 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/dpctl/_sycl_event.pxd b/dpctl/_sycl_event.pxd
index 72d8e4eb3d..714502007a 100644
--- a/dpctl/_sycl_event.pxd
+++ b/dpctl/_sycl_event.pxd
@@ -30,7 +30,6 @@ cdef public api class _SyclEvent [
     """ Data owner for SyclEvent
     """
     cdef DPCTLSyclEventRef _event_ref
-    cdef object args
 
 
 cdef public api class SyclEvent(_SyclEvent) [
@@ -40,7 +39,7 @@ cdef public api class SyclEvent(_SyclEvent) [
     """ Python wrapper class for a ``cl::sycl::event``
     """
     @staticmethod
-    cdef SyclEvent _create (DPCTLSyclEventRef event, object args=*)
+    cdef SyclEvent _create (DPCTLSyclEventRef event)
     cdef int _init_event_default(self)
     cdef int _init_event_from__SyclEvent(self, _SyclEvent other)
     cdef int _init_event_from_capsule(self, object caps)
diff --git a/dpctl/_sycl_event.pyx b/dpctl/_sycl_event.pyx
index c64478d3c6..90b942d12f 100644
--- a/dpctl/_sycl_event.pyx
+++ b/dpctl/_sycl_event.pyx
@@ -100,7 +100,6 @@ cdef class _SyclEvent:
         if (self._event_ref):
             DPCTLEvent_Delete(self._event_ref)
         self._event_ref = NULL
-        self.args = None
 
 
 cdef class SyclEvent(_SyclEvent):
@@ -140,7 +139,7 @@ cdef class SyclEvent(_SyclEvent):
     """
 
     @staticmethod
-    cdef SyclEvent _create(DPCTLSyclEventRef eref, object args=None):
+    cdef SyclEvent _create(DPCTLSyclEventRef eref):
         """"
         This function calls DPCTLEvent_Delete(eref).
 
@@ -149,21 +148,18 @@ cdef class SyclEvent(_SyclEvent):
         """
         cdef _SyclEvent ret = _SyclEvent.__new__(_SyclEvent)
         _init_helper(ret, eref)
-        ret.args=args
         return SyclEvent(ret)
 
     cdef int _init_event_default(self):
         self._event_ref = DPCTLEvent_Create()
         if (self._event_ref is NULL):
             return -1
-        self.args=None
         return 0
 
     cdef int _init_event_from__SyclEvent(self, _SyclEvent other):
         self._event_ref = DPCTLEvent_Copy(other._event_ref)
         if (self._event_ref is NULL):
             return -1
-        self.args = other.args
         return 0
 
     cdef int _init_event_from_capsule(self, object cap):
@@ -183,7 +179,6 @@ cdef class SyclEvent(_SyclEvent):
             if (ERef_copy is NULL):
                 return -3
             self._event_ref = ERef_copy
-            self.args = None
             return 0
         else:
             return -128
@@ -331,7 +326,7 @@ cdef class SyclEvent(_SyclEvent):
         events = []
         for i in range(num_events):
             ERef = DPCTLEventVector_GetAt(EVRef, i)
-            events.append(SyclEvent._create(ERef, args=None))
+            events.append(SyclEvent._create(ERef))
         DPCTLEventVector_Delete(EVRef)
         return events
 
diff --git a/dpctl/_sycl_queue.pyx b/dpctl/_sycl_queue.pyx
index 30a64fec4c..ccd5a1dec0 100644
--- a/dpctl/_sycl_queue.pyx
+++ b/dpctl/_sycl_queue.pyx
@@ -845,7 +845,7 @@ cdef class SyclQueue(_SyclQueue):
         # free memory
         free(arg_objects)
 
-        return SyclEvent._create(Eref, [])
+        return SyclEvent._create(Eref)
 
     cpdef void wait(self):
         with nogil: DPCTLQueue_Wait(self._queue_ref)
@@ -996,7 +996,7 @@ cdef class SyclQueue(_SyclQueue):
                 "Barrier submission to Sycl queue failed."
             )
 
-        return SyclEvent._create(ERef, [])
+        return SyclEvent._create(ERef)
 
     @property
     def name(self):