1 files changed, 14 insertions, 0 deletions
diff --git a/src/common/compat_threads.h b/src/common/compat_threads.h
index 2943573b23..9fa3d0d0b7 100644
--- a/src/common/compat_threads.h
+++ b/src/common/compat_threads.h
@@ -147,5 +147,19 @@ void *tor_threadlocal_get(tor_threadlocal_t *threadlocal);
  */
 void tor_threadlocal_set(tor_threadlocal_t *threadlocal, void *value);
 
+/**
+ * Atomic counter type; holds a size_t value.
+ */
+typedef struct atomic_counter_t {
+  tor_mutex_t mutex;
+  size_t val;
+} atomic_counter_t;
+
+void atomic_counter_init(atomic_counter_t *counter);
+void atomic_counter_destroy(atomic_counter_t *counter);
+void atomic_counter_add(atomic_counter_t *counter, size_t add);
+void atomic_counter_sub(atomic_counter_t *counter, size_t sub);
+size_t atomic_counter_get(atomic_counter_t *counter);
+
 #endif