From 88f8ddd70cebd8b0e7728467ac3958ad2a4c2cf1 Mon Sep 17 00:00:00 2001 From: Peter Kasting Date: Fri, 13 May 2022 09:09:59 -0700 Subject: [PATCH] Include conceptual change from PR 2001. --- include/rapidjson/document.h | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/include/rapidjson/document.h b/include/rapidjson/document.h index 5136f98..a72a04f 100644 --- a/include/rapidjson/document.h +++ b/include/rapidjson/document.h @@ -1230,19 +1230,29 @@ public: else { RAPIDJSON_ASSERT(false); // see above note -#if defined(__cplusplus) && (__cplusplus >= 201103L) - // This will generate -Wexit-time-destructors in clang - // static GenericValue NullValue; - // return NullValue; + // Use thread-local storage to prevent races between threads. +#if defined(_MSC_VER) && _MSC_VER < 1900 +// MSVC 2013 or earlier does not support `thread_local` attribute even in C++11 +// mode. +#define RAPIDJSON_THREAD_LOCAL __declspec(thread) +#elif RAPIDJSON_HAS_CXX11 +#define RAPIDJSON_THREAD_LOCAL thread_local +#elif defined(__GNUC__) || defined(__clang__) +#define RAPIDJSON_THREAD_LOCAL __thread +#else +#define RAPIDJSON_THREAD_LOCAL +#endif - // Use static buffer and placement-new to prevent destruction - alignas(GenericValue) static char buffer[sizeof(GenericValue)]; +#if RAPIDJSON_HAS_CXX11 + // Use static buffer and placement-new to prevent destruction. + alignas(GenericValue) RAPIDJSON_THREAD_LOCAL static char buffer[sizeof(GenericValue)]; return *new (buffer) GenericValue(); #else - static GenericValue buffer; - return *new (reinterpret_cast(&buffer)) GenericValue(); + // This will generate -Wexit-time-destructors in clang. + RAPIDJSON_THREAD_LOCAL static GenericValue buffer; + return buffer; #endif - } + } } template const GenericValue& operator[](const GenericValue& name) const { return const_cast(*this)[name]; }