Add a CRYPTO_atomic_read call which allows an int variable to be read

in an atomic fashion.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4414)

1 files changed, 6 insertions, 0 deletions

diff --git a/crypto/threads_win.c b/crypto/threads_win.c
index 512e19f5f3..6f9c7b1bd3 100644
--- a/crypto/threads_win.c
+++ b/crypto/threads_win.c
@@ -133,6 +133,12 @@ int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
     return 1;
 }
 
+int CRYPTO_atomic_read(int *val, int *ret, CRYPTO_RWLOCK *lock)
+{
+    InterlockedCompareExchange(val, 0, 0);
+    return 1;
+}
+
 int openssl_init_fork_handlers(void)
 {
     return 0;