From adc3a37e96936c11862d113cf986a00fd277ff12 Mon Sep 17 00:00:00 2001
From: Quincey Koziol <quincey@koziol.cc>
Date: Mon, 19 Aug 2024 08:53:10 -0500
Subject: [PATCH] Fix semaphore test (#4725)

* Make counter in semaphore test an atomic variable

* Revert using atomic counter and fix counter access outside of semaphore
---
 src/H5TSsemaphore.h     |  2 +-
 test/ttsafe.c           |  2 --
 test/ttsafe.h           |  2 --
 test/ttsafe_semaphore.c | 14 ++++++++------
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/H5TSsemaphore.h b/src/H5TSsemaphore.h
index 0db1a888809..340b1cf9a11 100644
--- a/src/H5TSsemaphore.h
+++ b/src/H5TSsemaphore.h
@@ -179,7 +179,7 @@ H5TS_semaphore_wait(H5TS_semaphore_t *sem)
  *
  * Purpose:  Increments (unlocks) the semaphore.  If the semaphore's value
  *           becomes greater than zero, then another thread blocked in a wait
- *           call will be woken up and proceed to lock the semaphore.
+ *           call will proceed to lock the semaphore.
  *
  * Return:   Non-negative on success / Negative on failure
  *
diff --git a/test/ttsafe.c b/test/ttsafe.c
index 08022eb1992..76dfa22bcbd 100644
--- a/test/ttsafe.c
+++ b/test/ttsafe.c
@@ -138,9 +138,7 @@ main(int argc, char *argv[])
     AddTest("rec_rwlock_4", tts_rec_rw_lock_smoke_check_4, NULL,
             "recursive R/W lock smoke check 4 -- mixed mob", NULL);
 #endif /* !H5_HAVE_WIN_THREADS */
-#ifdef H5_HAVE_STDATOMIC_H
     AddTest("semaphore", tts_semaphore, NULL, "lightweight system semaphores", NULL);
-#endif /* H5_HAVE_STDATOMIC_H */
 
 #ifdef H5_HAVE_THREADSAFE
     AddTest("thread_id", tts_thread_id, NULL, "thread IDs", NULL);
diff --git a/test/ttsafe.h b/test/ttsafe.h
index d2066782b6b..f551e40462a 100644
--- a/test/ttsafe.h
+++ b/test/ttsafe.h
@@ -38,9 +38,7 @@ void tts_is_threadsafe(void);
 #ifdef H5_HAVE_THREADS
 void tts_thread_pool(void);
 void tts_atomics(void);
-#ifdef H5_HAVE_STDATOMIC_H
 void tts_semaphore(void);
-#endif /* H5_HAVE_STDATOMIC_H */
 void tts_rec_rw_lock_smoke_check_1(void);
 void tts_rec_rw_lock_smoke_check_2(void);
 void tts_rec_rw_lock_smoke_check_3(void);
diff --git a/test/ttsafe_semaphore.c b/test/ttsafe_semaphore.c
index 41076632a4f..313508fe315 100644
--- a/test/ttsafe_semaphore.c
+++ b/test/ttsafe_semaphore.c
@@ -18,7 +18,7 @@
 
 #include "ttsafe.h"
 
-#if defined(H5_HAVE_THREADS) && defined(H5_HAVE_STDATOMIC_H)
+#if defined(H5_HAVE_THREADS)
 
 #define NUM_PINGPONG     (1000 * 1000)
 #define NUM_CLIENTSERVER (50 * 1000)
@@ -40,6 +40,7 @@ static H5TS_THREAD_RETURN_TYPE
 ping(void *_test_info)
 {
     pingpong_t       *test_info = (pingpong_t *)_test_info;
+    unsigned          count;
     herr_t            result;
     H5TS_thread_ret_t ret_value = 0;
 
@@ -47,11 +48,11 @@ ping(void *_test_info)
         result = H5TS_semaphore_wait(&test_info->ping_sem);
         CHECK_I(result, "H5TS_semaphore_wait");
 
-        test_info->counter++;
+        count = ++test_info->counter;
 
         result = H5TS_semaphore_signal(&test_info->pong_sem);
         CHECK_I(result, "H5TS_semaphore_signal");
-    } while (test_info->counter < NUM_PINGPONG);
+    } while (count < NUM_PINGPONG);
 
     return ret_value;
 }
@@ -60,6 +61,7 @@ static H5TS_THREAD_RETURN_TYPE
 pong(void *_test_info)
 {
     pingpong_t       *test_info = (pingpong_t *)_test_info;
+    unsigned          count;
     herr_t            result;
     H5TS_thread_ret_t ret_value = 0;
 
@@ -67,11 +69,11 @@ pong(void *_test_info)
         result = H5TS_semaphore_wait(&test_info->pong_sem);
         CHECK_I(result, "H5TS_semaphore_wait");
 
-        test_info->counter++;
+        count = ++test_info->counter;
 
         result = H5TS_semaphore_signal(&test_info->ping_sem);
         CHECK_I(result, "H5TS_semaphore_signal");
-    } while (test_info->counter < NUM_PINGPONG);
+    } while (count < NUM_PINGPONG);
 
     return ret_value;
 }
@@ -268,4 +270,4 @@ tts_semaphore(void)
     tts_semaphore_clientserver();
 } /* end tts_semaphore() */
 
-#endif /* defined(H5_HAVE_THREADS) && defined(H5_HAVE_STDATOMIC_H) */
+#endif /* defined(H5_HAVE_THREADS) */