add simple Windows lock implementation

crypto/crypto_lock_win.c

@@ -0,0 +1,53 @@
+/* $OpenBSD: crypto_lock.c,v 1.1 2018/11/11 06:41:28 bcook Exp $ */
+/*
+ * Copyright (c) 2018 Brent Cook <bcook@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <windows.h>
+
+static HANDLE locks[CRYPTO_NUM_LOCKS];
+
+void
+crypto_init_locks(void)
+{
+	int i;
+
+	for (i = 0; i < CRYPTO_NUM_LOCKS; i++)
+		locks[i] = CreateMutex(NULL, FALSE, NULL);
+}
+
+void
+CRYPTO_lock(int mode, int type, const char *file, int line)
+{
+	if (type < 0 || type >= CRYPTO_NUM_LOCKS)
+		return;
+
+	if (mode & CRYPTO_LOCK)
+		WaitForSingleObject(locks[type], INFINITE);
+	else
+		ReleaseMutex(locks[type]);
+}
+
+int
+CRYPTO_add_lock(int *pointer, int amount, int type, const char *file,
+    int line)
+{
+	int ret = 0;
+	CRYPTO_lock(CRYPTO_LOCK|CRYPTO_WRITE, type, file, line);
+	ret = *pointer + amount;
+	*pointer = ret;
+	CRYPTO_lock(CRYPTO_UNLOCK|CRYPTO_WRITE, type, file, line);
+	return (ret);
+}