Replumbing: New public API to load or add providers

[openssl.git] / include / internal / refcount.h

diff --git a/include/internal/refcount.h b/include/internal/refcount.h
index 591561ffeeb7e4a4ebe7ee8f1b005b7c378cf15a..b6c9f9c99096181b947a842c56442cc7ae171441 100644 (file)
--- a/include/internal/refcount.h
+++ b/include/internal/refcount.h
@@ -1,7 +1,7 @@
 /*
- * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
- * Licensed under the OpenSSL license (the "License").  You may not use
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
@@ -9,28 +9,45 @@
 #ifndef HEADER_INTERNAL_REFCOUNT_H
 # define HEADER_INTERNAL_REFCOUNT_H
 
+/* Used to checking reference counts, most while doing perl5 stuff :-) */
+# if defined(OPENSSL_NO_STDIO)
+#  if defined(REF_PRINT)
+#   error "REF_PRINT requires stdio"
+#  endif
+# endif
+
 # if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L \
      && !defined(__STDC_NO_ATOMICS__)
-# include <stdatomic.h>
-# define HAVE_C11_ATOMICS
+#  include <stdatomic.h>
+#  define HAVE_C11_ATOMICS
 # endif
 
 # if defined(HAVE_C11_ATOMICS) && defined(ATOMIC_INT_LOCK_FREE) \
      && ATOMIC_INT_LOCK_FREE > 0
 
-# define HAVE_ATOMICS 1
+#  define HAVE_ATOMICS 1
 
 typedef _Atomic int CRYPTO_REF_COUNT;
 
-static ossl_inline int CRYPTO_UP_REF(_Atomic int *val, int *ret, void *lock)
+static inline int CRYPTO_UP_REF(_Atomic int *val, int *ret, void *lock)
 {
     *ret = atomic_fetch_add_explicit(val, 1, memory_order_relaxed) + 1;
     return 1;
 }
 
-static ossl_inline int CRYPTO_DOWN_REF(_Atomic int *val, int *ret, void *lock)
+/*
+ * Changes to shared structure other than reference counter have to be
+ * serialized. And any kind of serialization implies a release fence. This
+ * means that by the time reference counter is decremented all other
+ * changes are visible on all processors. Hence decrement itself can be
+ * relaxed. In case it hits zero, object will be destructed. Since it's
+ * last use of the object, destructor programmer might reason that access
+ * to mutable members doesn't have to be serialized anymore, which would
+ * otherwise imply an acquire fence. Hence conditional acquire fence...
+ */
+static inline int CRYPTO_DOWN_REF(_Atomic int *val, int *ret, void *lock)
 {
-    *ret = atomic_fetch_sub_explicit(val, 1, memory_order_release) - 1;
+    *ret = atomic_fetch_sub_explicit(val, 1, memory_order_relaxed) - 1;
     if (*ret == 0)
         atomic_thread_fence(memory_order_acquire);
     return 1;
@@ -38,24 +55,65 @@ static ossl_inline int CRYPTO_DOWN_REF(_Atomic int *val, int *ret, void *lock)
 
 # elif defined(__GNUC__) && defined(__ATOMIC_RELAXED) && __GCC_ATOMIC_INT_LOCK_FREE > 0
 
-# define HAVE_ATOMICS 1
+#  define HAVE_ATOMICS 1
 
 typedef int CRYPTO_REF_COUNT;
 
-static ossl_inline int CRYPTO_UP_REF(int *val, int *ret, void *lock)
+static __inline__ int CRYPTO_UP_REF(int *val, int *ret, void *lock)
 {
     *ret = __atomic_fetch_add(val, 1, __ATOMIC_RELAXED) + 1;
     return 1;
 }
 
-static ossl_inline int CRYPTO_DOWN_REF(int *val, int *ret, void *lock)
+static __inline__ int CRYPTO_DOWN_REF(int *val, int *ret, void *lock)
 {
-    *ret = __atomic_fetch_sub(val, 1, __ATOMIC_RELEASE) - 1;
+    *ret = __atomic_fetch_sub(val, 1, __ATOMIC_RELAXED) - 1;
     if (*ret == 0)
         __atomic_thread_fence(__ATOMIC_ACQUIRE);
     return 1;
 }
 
+# elif defined(_MSC_VER) && _MSC_VER>=1200
+
+#  define HAVE_ATOMICS 1
+
+typedef volatile int CRYPTO_REF_COUNT;
+
+#  if (defined(_M_ARM) && _M_ARM>=7) || defined(_M_ARM64)
+#   include <intrin.h>
+#   if defined(_M_ARM64) && !defined(_ARM_BARRIER_ISH)
+#    define _ARM_BARRIER_ISH _ARM64_BARRIER_ISH
+#   endif
+
+static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, void *lock)
+{
+    *ret = _InterlockedExchangeAdd_nf(val, 1) + 1;
+    return 1;
+}
+
+static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, void *lock)
+{
+    *ret = _InterlockedExchangeAdd_nf(val, -1) - 1;
+    if (*ret == 0)
+        __dmb(_ARM_BARRIER_ISH);
+    return 1;
+}
+#  else
+#   pragma intrinsic(_InterlockedExchangeAdd)
+
+static __inline int CRYPTO_UP_REF(volatile int *val, int *ret, void *lock)
+{
+    *ret = _InterlockedExchangeAdd(val, 1) + 1;
+    return 1;
+}
+
+static __inline int CRYPTO_DOWN_REF(volatile int *val, int *ret, void *lock)
+{
+    *ret = _InterlockedExchangeAdd(val, -1) - 1;
+    return 1;
+}
+#  endif
+
 # else
 
 typedef int CRYPTO_REF_COUNT;
@@ -64,4 +122,19 @@ typedef int CRYPTO_REF_COUNT;
 # define CRYPTO_DOWN_REF(val, ret, lock) CRYPTO_atomic_add(val, -1, ret, lock)
 
 # endif
+
+# if !defined(NDEBUG) && !defined(OPENSSL_NO_STDIO)
+#  define REF_ASSERT_ISNT(test) \
+    (void)((test) ? (OPENSSL_die("refcount error", __FILE__, __LINE__), 1) : 0)
+# else
+#  define REF_ASSERT_ISNT(i)
+# endif
+
+# ifdef REF_PRINT
+#  define REF_PRINT_COUNT(a, b) \
+        fprintf(stderr, "%p:%4d:%s\n", b, b->references, a)
+# else
+#  define REF_PRINT_COUNT(a, b)
+# endif
+
 #endif