lib: memtypes: restore atomicity

the original version of this code already used _Atomic and atomic_*().
Restore this functionality for future multithreading.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

2 files changed, 12 insertions, 8 deletions

diff --git a/lib/memory.c b/lib/memory.c
index ad55366f64..28e358dfc1 100644
--- a/lib/memory.c
+++ b/lib/memory.c
@@ -30,19 +30,22 @@ DEFINE_MTYPE(LIB, TMP, "Temporary memory")
 static inline void
 mt_count_alloc (struct memtype *mt, size_t size)
 {
-  mt->n_alloc++;
+  size_t oldsize;
 
-  if (mt->size == 0)
-    mt->size = size;
-  else if (mt->size != size)
-    mt->size = SIZE_VAR;
+  atomic_fetch_add_explicit(&mt->n_alloc, 1, memory_order_relaxed);
+
+  oldsize = atomic_load_explicit(&mt->size, memory_order_relaxed);
+  if (oldsize == 0)
+    oldsize = atomic_exchange_explicit(&mt->size, size, memory_order_relaxed);
+  if (oldsize != 0 && oldsize != size && oldsize != SIZE_VAR)
+    atomic_store_explicit(&mt->size, SIZE_VAR, memory_order_relaxed);
 }
 
 static inline void
 mt_count_free (struct memtype *mt)
 {
   assert(mt->n_alloc);
-  mt->n_alloc--;
+  atomic_fetch_sub_explicit(&mt->n_alloc, 1, memory_order_relaxed);
 }
 
 static inline void *
diff --git a/lib/memory.h b/lib/memory.h
index 477a6162dc..284a1b13c5 100644
--- a/lib/memory.h
+++ b/lib/memory.h
@@ -18,6 +18,7 @@
 #define _QUAGGA_MEMORY_H
 
 #include <stdlib.h>
+#include <frratomic.h>
 
 #define array_size(ar) (sizeof(ar) / sizeof(ar[0]))
 
@@ -26,8 +27,8 @@ struct memtype
 {
   struct memtype *next, **ref;
   const char *name;
-  size_t n_alloc;
-  size_t size;
+  _Atomic size_t n_alloc;
+  _Atomic size_t size;
 };
 
 struct memgroup