refactor: decouple Context from Stream and Event objects (#579)

Remove some unnecessary weak reference usage by decoupling `Context`
objects from `Stream` and `Event`.

Author: cpcloud

ci/test_conda.sh

@@ -4,14 +4,6 @@
 
 set -euo pipefail
 
-DISTRO=`cat /etc/os-release | grep "^ID=" | awk 'BEGIN {FS="="} { print $2 }'`
-
-if [ "$DISTRO" = "ubuntu" ]; then
-  apt-get update
-  apt remove --purge `dpkg --get-selections | grep cuda-nvvm | awk '{print $1}'` -y
-  apt remove --purge `dpkg --get-selections | grep cuda-nvrtc | awk '{print $1}'` -y
-fi
-
 # Constrain oldest supported dependencies for testing
 if [ "${NUMBA_VERSION:-*}" != "*" ]; then
     # add to the default environment's dependencies

numba_cuda/numba/cuda/cudadrv/driver.py

@@ -1305,19 +1305,19 @@ def unload_module(self, module):
 
     def get_default_stream(self):
         handle = drvapi.cu_stream(int(binding.CUstream(CU_STREAM_DEFAULT)))
-        return Stream(weakref.proxy(self), handle, None)
+        return Stream(handle)
 
     def get_legacy_default_stream(self):
         handle = drvapi.cu_stream(
             int(binding.CUstream(binding.CU_STREAM_LEGACY))
         )
-        return Stream(weakref.proxy(self), handle, None)
+        return Stream(handle)
 
     def get_per_thread_default_stream(self):
         handle = drvapi.cu_stream(
             int(binding.CUstream(binding.CU_STREAM_PER_THREAD))
         )
-        return Stream(weakref.proxy(self), handle, None)
+        return Stream(handle)
 
     def create_stream(self):
         # The default stream creation flag, specifying that the created
@@ -1327,26 +1327,22 @@ def create_stream(self):
         flags = binding.CUstream_flags.CU_STREAM_DEFAULT.value
         handle = drvapi.cu_stream(int(driver.cuStreamCreate(flags)))
         return Stream(
-            weakref.proxy(self),
-            handle,
-            _stream_finalizer(self.deallocations, handle),
+            handle, finalizer=_stream_finalizer(self.deallocations, handle)
         )
 
     def create_external_stream(self, ptr):
         if not isinstance(ptr, int):
             raise TypeError("ptr for external stream must be an int")
         handle = drvapi.cu_stream(int(binding.CUstream(ptr)))
-        return Stream(weakref.proxy(self), handle, None, external=True)
+        return Stream(handle, external=True)
 
     def create_event(self, timing=True):
         flags = 0
         if not timing:
             flags |= enums.CU_EVENT_DISABLE_TIMING
         handle = drvapi.cu_event(int(driver.cuEventCreate(flags)))
         return Event(
-            weakref.proxy(self),
-            handle,
-            finalizer=_event_finalizer(self.deallocations, handle),
+            handle, finalizer=_event_finalizer(self.deallocations, handle)
         )
 
     def synchronize(self):
@@ -1359,7 +1355,7 @@ def defer_cleanup(self):
                 yield
 
     def __repr__(self):
-        return "<CUDA context %s of device %d>" % (self.handle, self.device.id)
+        return f"<CUDA context {self.handle} of device {self.device.id:d}>"
 
     def __eq__(self, other):
         if isinstance(other, Context):
@@ -2034,9 +2030,8 @@ class ManagedOwnedPointer(OwnedPointer, mviewbuf.MemAlloc):
     pass
 
 
-class Stream(object):
-    def __init__(self, context, handle, finalizer, external=False):
-        self.context = context
+class Stream:
+    def __init__(self, handle, finalizer=None, external=False):
         self.handle = handle
         self.external = external
         if finalizer is not None:
@@ -2053,18 +2048,18 @@ def __cuda_stream__(self):
 
     def __repr__(self):
         default_streams = {
-            drvapi.CU_STREAM_DEFAULT: "<Default CUDA stream on %s>",
-            drvapi.CU_STREAM_LEGACY: "<Legacy default CUDA stream on %s>",
-            drvapi.CU_STREAM_PER_THREAD: "<Per-thread default CUDA stream on %s>",
+            drvapi.CU_STREAM_DEFAULT: "<Default CUDA stream>",
+            drvapi.CU_STREAM_LEGACY: "<Legacy default CUDA stream>",
+            drvapi.CU_STREAM_PER_THREAD: "<Per-thread default CUDA stream>",
         }
         ptr = self.handle.value or drvapi.CU_STREAM_DEFAULT
 
         if ptr in default_streams:
-            return default_streams[ptr] % self.context
+            return default_streams[ptr]
         elif self.external:
-            return "<External CUDA stream %d on %s>" % (ptr, self.context)
+            return f"<External CUDA stream {ptr:d}>"
         else:
-            return "<CUDA stream %d on %s>" % (ptr, self.context)
+            return f"<CUDA stream {ptr:d}>"
 
     def synchronize(self):
         """
@@ -2166,9 +2161,8 @@ def callback(stream, status, future):
         return future
 
 
-class Event(object):
-    def __init__(self, context, handle, finalizer=None):
-        self.context = context
+class Event:
+    def __init__(self, handle, finalizer=None):
         self.handle = handle
         if finalizer is not None:
             weakref.finalize(self, finalizer)