From c1f249ec661882dbd4258895eed9c7d2bf94aa51 Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Fri, 1 Jun 2018 23:16:14 -0700
Subject: [PATCH] SCP: Add atomic routines for temporary shmem access

---
 sim_fio.c | 20 ++++++++++++++++++++
 sim_fio.h |  2 ++
 2 files changed, 22 insertions(+)

diff --git a/sim_fio.c b/sim_fio.c
index 1446f225..894f5e17 100644
--- a/sim_fio.c
+++ b/sim_fio.c
@@ -458,6 +458,16 @@ if (shmem->hMapping != INVALID_HANDLE_VALUE)
 free (shmem);
 }
 
+int32 sim_shmem_atomic_add (int32 *p, int32 v)
+{
+return InterlockedExchangeAdd ((volatile long *) p,v) + (v);
+}
+
+t_bool sim_shmem_atomic_cas (int32 *ptr, int32 oldv, int32 newv)
+{
+return (InterlockedCompareExchange ((LONG volatile *) ptr, newv, oldv) == oldv);
+}
+
 #else /* !defined(_WIN32) */
 #include <unistd.h>
 int sim_set_fsize (FILE *fptr, t_addr size)
@@ -604,6 +614,16 @@ if (shmem->shm_fd != -1)
 free (shmem);
 }
 
+int32 sim_shmem_atomic_add (int32 *p, int32 v)
+{
+return __sync_add_and_fetch((int *) p, v);
+}
+
+t_bool sim_shmem_atomic_cas (int32 *ptr, int32 oldv, int32 newv)
+{
+return __sync_bool_compare_and_swap (ptr, oldv, newv);
+}
+
 #endif
 
 #if defined(__VAX)
diff --git a/sim_fio.h b/sim_fio.h
index 7d7feca2..5f3b0e74 100644
--- a/sim_fio.h
+++ b/sim_fio.h
@@ -76,6 +76,8 @@ const char *sim_get_os_error_text (int error);
 typedef struct SHMEM SHMEM;
 t_stat sim_shmem_open (const char *name, size_t size, SHMEM **shmem, void **addr);
 void sim_shmem_close (SHMEM *shmem);
+int32 sim_shmem_atomic_add (int32 *ptr, int32 val);
+t_bool sim_shmem_atomic_cas (int32 *ptr, int32 oldv, int32 newv);
 
 extern t_bool sim_taddr_64;         /* t_addr is > 32b and Large File Support available */
 extern t_bool sim_toffset_64;       /* Large File (>2GB) file I/O support */