Add tsan_decr() API, counterpart of tsan_counter()

The existing tsan_counter() API increments a reference counter.
Provide a new API, tsan_decr(), to decrement such a reference counter.
This can be used, for example, when a reference is added to the session_ctx's
sess_accept stats but should more properly be tracked in the regular ctx's
statistics.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7464)

(cherry picked from commit 95658c32436017aeeef3d8598957071baf6769a9)

diff --git a/include/internal/tsan_assist.h b/include/internal/tsan_assist.h
index 2c7638344a0038a446521511b6c13483d855e3e2..f30ffe398ac7d262614f265c94ef84212fd53d22 100644 (file)
--- a/include/internal/tsan_assist.h
+++ b/include/internal/tsan_assist.h
@@ -57,6 +57,7 @@
 #  define tsan_load(ptr) atomic_load_explicit((ptr), memory_order_relaxed)
 #  define tsan_store(ptr, val) atomic_store_explicit((ptr), (val), memory_order_relaxed)
 #  define tsan_counter(ptr) atomic_fetch_add_explicit((ptr), 1, memory_order_relaxed)
+#  define tsan_decr(ptr) atomic_fetch_add_explicit((ptr), -1, memory_order_relaxed)
 #  define tsan_ld_acq(ptr) atomic_load_explicit((ptr), memory_order_acquire)
 #  define tsan_st_rel(ptr, val) atomic_store_explicit((ptr), (val), memory_order_release)
 # endif
@@ -69,6 +70,7 @@
 #  define tsan_load(ptr) __atomic_load_n((ptr), __ATOMIC_RELAXED)
 #  define tsan_store(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_RELAXED)
 #  define tsan_counter(ptr) __atomic_fetch_add((ptr), 1, __ATOMIC_RELAXED)
+#  define tsan_decr(ptr) __atomic_fetch_add((ptr), -1, __ATOMIC_RELAXED)
 #  define tsan_ld_acq(ptr) __atomic_load_n((ptr), __ATOMIC_ACQUIRE)
 #  define tsan_st_rel(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_RELEASE)
 # endif
@@ -113,8 +115,11 @@
 #  pragma intrinsic(_InterlockedExchangeAdd64)
 #  define tsan_counter(ptr) (sizeof(*(ptr)) == 8 ? _InterlockedExchangeAdd64((ptr), 1) \
                                                  : _InterlockedExchangeAdd((ptr), 1))
+#  define tsan_decr(ptr) (sizeof(*(ptr)) == 8 ? _InterlockedExchangeAdd64((ptr), -1) \
+                                                 : _InterlockedExchangeAdd((ptr), -1))
 # else
 #  define tsan_counter(ptr) _InterlockedExchangeAdd((ptr), 1)
+#  define tsan_decr(ptr) _InterlockedExchangeAdd((ptr), -1)
 # endif
 # if !defined(_ISO_VOLATILE)
 #  define tsan_ld_acq(ptr) (*(ptr))
@@ -129,6 +134,7 @@
 # define tsan_load(ptr) (*(ptr))
 # define tsan_store(ptr, val) (*(ptr) = (val))
 # define tsan_counter(ptr) ((*(ptr))++)
+# define tsan_decr(ptr) ((*(ptr))--)
 /*
  * Lack of tsan_ld_acq and tsan_ld_rel means that compiler support is not
  * sophisticated enough to support them. Code that relies on them should be