Set SingleThreadProcessor as the default processor (#904)

* Set `SingleThreadProcessor` as the default processor

* Disallow multiple `data_kind`s processing with single thread processor

* Fix bug

* Fix bugs

* Debug

strax/context.py

@@ -1545,6 +1545,15 @@ def get_iter(
         # (otherwise potentially overwritten in temp-plugin)
         targets_list = targets
 
+        if processor is None:
+            processor = list(self.processors)[0]
+
+        if isinstance(processor, str):
+            processor = self.processors[processor]
+
+        if not hasattr(processor, "iter"):
+            raise ValueError("Processors must implement a iter methed.")
+
         is_superrun = run_id.startswith("_")
 
         # If multiple targets of the same kind, create a MergeOnlyPlugin
@@ -1557,7 +1566,7 @@ def get_iter(
                 p = type(temp_name, (strax.MergeOnlyPlugin,), dict(depends_on=tuple(targets)))
                 self.register(p)
                 targets = (temp_name,)
-            elif not allow_multiple:
+            elif not allow_multiple or processor is strax.SingleThreadProcessor:
                 raise RuntimeError("Cannot automerge different data kinds!")
             elif self.context_config["timeout"] > 7200 or (
                 self.context_config["allow_lazy"] and not self.context_config["allow_multiprocess"]
@@ -1582,15 +1591,6 @@ def get_iter(
             if k.startswith("_temp"):
                 del self._plugin_class_registry[k]
 
-        if processor is None:
-            processor = list(self.processors)[0]
-
-        if isinstance(processor, str):
-            processor = self.processors[processor]
-
-        if not hasattr(processor, "iter"):
-            raise ValueError("Processors must implement a iter methed.")
-
         seen_a_chunk = False
         generator = processor(
             components,

strax/processors/__init__.py

@@ -8,7 +8,7 @@
 from .single_thread import SingleThreadProcessor
 
 PROCESSORS = {
-    "default": ThreadedMailboxProcessor,
+    "default": SingleThreadProcessor,
     "threaded_mailbox": ThreadedMailboxProcessor,
     "single_thread": SingleThreadProcessor,
 }

tests/test_core.py

@@ -426,13 +426,15 @@ def test_allow_multiple(targets=("peaks", "records")):
             raise ValueError(f"{function} could run with allow_multiple")
 
         try:
-            mystrax.make(run_id=run_id, targets=targets)
+            mystrax.make(run_id=run_id, targets=targets, processor="threaded_mailbox")
         except RuntimeError:
             # Great, we shouldn't be allowed
             pass
 
         assert not mystrax.is_stored(run_id, "peaks")
-        mystrax.make(run_id=run_id, allow_multiple=True, targets=targets)
+        mystrax.make(
+            run_id=run_id, allow_multiple=True, targets=targets, processor="threaded_mailbox"
+        )
 
         for t in targets:
             assert mystrax.is_stored(run_id, t)

tests/test_inline_plugin.py

@@ -56,6 +56,7 @@ def test_inline(self, **make_kwargs):
             run_id,
             targets,
             allow_multiple=True,
+            processor="threaded_mailbox",
             **make_kwargs,
         )
         for target in list(st._plugin_class_registry.keys()):

tests/test_loop_plugins.py

@@ -40,6 +40,7 @@ def _loop_test_inner(
     target="added_thing",
     time_selection="fully_contained",
     force_value_error=False,
+    processor=None,
 ):
     """Test loop plugins for random data. For this test we are going to setup two plugins that will
     be looped over and combined into a loop plugin (depending on the target, this may be a multi
@@ -161,7 +162,7 @@ def compute_loop(self, big_kinda_data, small_kinda_data):
         st.register((BigThing, SmallThing, AddBigToSmall, AddBigToSmallMultiOutput))
 
         # Make small thing in order to allow re-chunking
-        st.make(run_id="some_run", targets="small_thing")
+        st.make(run_id="some_run", targets="small_thing", processor=processor)
 
         # Make the loop plugin
         result = st.get_array(run_id="some_run", targets=target)
@@ -212,16 +213,18 @@ def test_loop_plugin_multi_output(
 )
 @settings(deadline=None)
 @example(big_data=np.array([], dtype=full_dt_dtype), nchunks=2)
-def test_value_error_for_loop_plugin(big_data, nchunks):
+def test_error_for_loop_plugin(big_data, nchunks):
     """Make sure that we are are getting the right ValueError."""
-    try:
-        _loop_test_inner(big_data, nchunks, force_value_error=True)
-        raise RuntimeError(
-            "did not run into ValueError despite the fact we are having multiple none-type chunks"
-        )
-    except ValueError:
-        # Good we got the ValueError we wanted
-        pass
+    for error, processor in zip([RuntimeError, ValueError], ["single_thread", "threaded_mailbox"]):
+        try:
+            _loop_test_inner(big_data, nchunks, force_value_error=True, processor=processor)
+            raise RuntimeError(
+                f"Did not run into {error.__name__} despite the fact "
+                "we are having multiple none-type chunks"
+            )
+        except error:
+            # Good we got the Error we wanted
+            pass
 
 
 @given(

tests/test_mongo_frontend.py

@@ -149,7 +149,9 @@ def test_allow_incomplete(self):
 
         self.log.info(f"Starting with empty db {self.chunk_summary}")
         # Get the iterator separately and complete with "next(iterator)
-        iterator = self.st.get_iter(self.test_run_id, self.mongo_target)
+        iterator = self.st.get_iter(
+            self.test_run_id, self.mongo_target, processor="threaded_mailbox"
+        )
 
         self.log.info(f"Got iterator, still no data?: {self.chunk_summary}")
         # Chunk 0