From 402fc269c0aaa671d84a6d15918735ad4b90e6b2 Mon Sep 17 00:00:00 2001
From: Douglas Rumbaugh <dbr4@psu.edu>
Date: Fri, 9 Feb 2024 12:30:21 -0500
Subject: Comment updates/fixes

---
 include/framework/scheduling/Epoch.h         | 7 -------
 include/framework/scheduling/FIFOScheduler.h | 9 +++++++++
 include/framework/scheduling/Task.h          | 5 +++++
 include/framework/scheduling/statistics.h    | 5 +++++
 4 files changed, 19 insertions(+), 7 deletions(-)

(limited to 'include/framework/scheduling')

diff --git a/include/framework/scheduling/Epoch.h b/include/framework/scheduling/Epoch.h
index e58bd11..3ffa145 100644
--- a/include/framework/scheduling/Epoch.h
+++ b/include/framework/scheduling/Epoch.h
@@ -44,13 +44,6 @@ public:
     }
 
     ~Epoch() {
-        /* FIXME: this is needed to keep the destructor from sometimes locking
-         * up here. But there *shouldn't* be any threads waiting on this signal
-         * at object destruction, so something else is going on here that needs
-         * looked into
-         */
-        // m_active_cv.notify_all();
-
         if (m_structure) {
             m_structure->release_reference();
         }
diff --git a/include/framework/scheduling/FIFOScheduler.h b/include/framework/scheduling/FIFOScheduler.h
index c6baf9b..3ed4f49 100644
--- a/include/framework/scheduling/FIFOScheduler.h
+++ b/include/framework/scheduling/FIFOScheduler.h
@@ -5,6 +5,15 @@
  *
  * Distributed under the Modified BSD License.
  *
+ * This scheduler runs just concurrently, using a standard FIFO queue to
+ * determine which jobs to run next. If more jobs are scheduled than there
+ * are available threads, the excess will stall until a thread becomes
+ * available and then run in the order they were received by the scheduler.
+ *
+ * TODO: We need to set up a custom threadpool based on jthreads to support
+ * thread preemption for a later phase of this project. That will allow us
+ * to avoid blocking epoch transitions on long-running queries, or to pause
+ * reconstructions on demand.
  */
 #pragma once
 
diff --git a/include/framework/scheduling/Task.h b/include/framework/scheduling/Task.h
index 008f232..d5d4266 100644
--- a/include/framework/scheduling/Task.h
+++ b/include/framework/scheduling/Task.h
@@ -5,6 +5,11 @@
  *
  * Distributed under the Modified BSD License.
  *
+ * An abstraction to represent a job to be scheduled. Currently the
+ * supported task types are queries and merges. Based on the current plan,
+ * simple buffer inserts will likely also be made into a task at some
+ * point.
+ *
  */
 #pragma once
 
diff --git a/include/framework/scheduling/statistics.h b/include/framework/scheduling/statistics.h
index 50ba196..6c479cd 100644
--- a/include/framework/scheduling/statistics.h
+++ b/include/framework/scheduling/statistics.h
@@ -5,6 +5,11 @@
  *
  * Distributed under the Modified BSD License.
  *
+ * This is a stub for a statistics tracker to be used in scheduling. It
+ * currently only tracks simple aggregated statistics, but should be
+ * updated in the future for more fine-grained statistics. These will be
+ * used for making scheduling decisions and predicting the runtime of a
+ * given job.
  */
 #pragma once
 
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