From 6c08fae048eb2808ae4db92ee6aaf937eb1d684a Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Wed, 8 Jul 2020 12:38:10 -0700
Subject: [PATCH] SHMEM: Fix Linux code to properly use built-in's and cleanup
 on shutdown

As reported in #909
---
 sim_fio.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/sim_fio.c b/sim_fio.c
index eb97b9eb..8df4c06b 100644
--- a/sim_fio.c
+++ b/sim_fio.c
@@ -569,7 +569,7 @@ struct SHMEM {
 
 t_stat sim_shmem_open (const char *name, size_t size, SHMEM **shmem, void **addr)
 {
-#ifdef HAVE_SHM_OPEN
+#if defined (HAVE_SHM_OPEN) && defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 *shmem = (SHMEM *)calloc (1, sizeof(**shmem));
 mode_t orig_mask;
 
@@ -636,15 +636,17 @@ if (shmem == NULL)
     return;
 if (shmem->shm_base != MAP_FAILED)
     munmap (shmem->shm_base, shmem->shm_size);
-if (shmem->shm_fd != -1)
+if (shmem->shm_fd != -1) {
+    shm_unlink (shmem->shm_name);
     close (shmem->shm_fd);
+    }
 free (shmem->shm_name);
 free (shmem);
 }
 
 int32 sim_shmem_atomic_add (int32 *p, int32 v)
 {
-#if defined (HAVE_GCC_SYNC_BUILTINS)
+#if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 return __sync_add_and_fetch((int *) p, v);
 #else
 return *p + v;
@@ -653,7 +655,7 @@ return *p + v;
 
 t_bool sim_shmem_atomic_cas (int32 *ptr, int32 oldv, int32 newv)
 {
-#if defined (HAVE_GCC_SYNC_BUILTINS)
+#if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 return __sync_bool_compare_and_swap (ptr, oldv, newv);
 #else
 if (*ptr == oldv) {