From 1d19a72bf39744158458222dc01588005787af25 Mon Sep 17 00:00:00 2001
From: Kevin Huck <khuck@cs.uoregon.edu>
Date: Wed, 10 Apr 2024 13:18:52 -0700
Subject: [PATCH] Removing sleep during shutdown if the background thread is
 already done.

---
 src/apex/proc_read.cpp | 4 ++++
 src/apex/proc_read.h   | 9 ++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/apex/proc_read.cpp b/src/apex/proc_read.cpp
index a4f4d961..c23de038 100644
--- a/src/apex/proc_read.cpp
+++ b/src/apex/proc_read.cpp
@@ -834,6 +834,7 @@ namespace apex {
                break;
             }
             if (done) break;
+            reading = true;
             if (apex_options::use_tau()) {
                 tau_listener::Tau_start_wrapper("proc_data_reader::read_proc: main loop");
             }
@@ -873,7 +874,10 @@ namespace apex {
             if (apex_options::use_tau()) {
                 tau_listener::Tau_stop_wrapper("proc_data_reader::read_proc: main loop");
             }
+            reading = false;
         }
+        // in case we broke from while loop
+        reading = false;
 #ifdef APEX_HAVE_LM_SENSORS
         delete(mysensors);
 #endif
diff --git a/src/apex/proc_read.h b/src/apex/proc_read.h
index 06e8d231..59884b5f 100644
--- a/src/apex/proc_read.h
+++ b/src/apex/proc_read.h
@@ -48,6 +48,7 @@ class proc_data_reader {
 private:
     //pthread_wrapper * worker_thread;
     std::atomic<bool> done;
+    std::atomic<bool> reading;
     std::thread worker_thread;
     std::condition_variable cv;
     std::mutex cv_m;
@@ -61,7 +62,7 @@ class proc_data_reader {
     };
     */
     void* read_proc(void);
-    proc_data_reader(void) : done(false) {
+    proc_data_reader(void) : done(false), reading(false) {
         worker_thread = std::thread(&proc_data_reader::read_proc, this);
         worker_thread.detach();
     }
@@ -73,8 +74,10 @@ class proc_data_reader {
         if (worker_thread.joinable()) {
             worker_thread.join();
         }
-        // this is helpful if we are sampling frequently
-        usleep(apex_options::proc_period());
+        if(reading) {
+            // this is helpful if we are sampling frequently
+            usleep(apex_options::proc_period());
+        }
     }
 
     ~proc_data_reader(void) {