Remove ROCKSDB_SUPPORT_THREAD_LOCAL define because it's a part of C++11 (#10015)

Summary:
ROCKSDB_SUPPORT_THREAD_LOCAL definition has been removed.
`__thread`(#define) has been replaced with `thread_local`(C++ keyword) across the code base.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10015

Reviewed By: siying

Differential Revision: D36485491

Pulled By: pdillinger

fbshipit-source-id: 6522d212514ee190b90b4e2750c80c7e34013c78

CMakeLists.txt

@@ -337,9 +337,6 @@ endif()
 # Reset the required flags
 set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
 
-# thread_local is part of C++11 and later (TODO: clean up this define)
-add_definitions(-DROCKSDB_SUPPORT_THREAD_LOCAL)
-
 option(WITH_IOSTATS_CONTEXT "Enable IO stats context" ON)
 if (NOT WITH_IOSTATS_CONTEXT)
   add_definitions(-DNIOSTATS_CONTEXT)

build_tools/build_detect_platform

@@ -800,9 +800,6 @@ if [ "$?" = 0 ]; then
   COMMON_FLAGS="$COMMON_FLAGS -DHAVE_UINT128_EXTENSION"
 fi
 
-# thread_local is part of C++11 and later (TODO: clean up this define)
-COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SUPPORT_THREAD_LOCAL"
-
 if [ "$FBCODE_BUILD" != "true" -a "$PLATFORM" = OS_LINUX ]; then
   $CXX $COMMON_FLAGS $PLATFORM_SHARED_CFLAGS -x c++ -c - -o test_dl.o 2>/dev/null <<EOF
   void dummy_func() {}

build_tools/fbcode_config.sh

@@ -147,7 +147,7 @@ else
 fi
 
 CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42"
+CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DHAVE_SSE42"
 CXXFLAGS+=" $CFLAGS"
 
 EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS"

build_tools/fbcode_config_platform009.sh

@@ -144,7 +144,7 @@ else
 fi
 
 CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42 -DROCKSDB_IOURING_PRESENT"
+CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DHAVE_SSE42 -DROCKSDB_IOURING_PRESENT"
 CXXFLAGS+=" $CFLAGS"
 
 EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS $LIBURING_LIBS $BENCHMARK_LIBS"

build_tools/fbcode_config_platform010.sh

@@ -154,7 +154,7 @@ CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE/linux "
 CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE "
 
 CFLAGS+=" $DEPS_INCLUDE"
-CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DROCKSDB_SUPPORT_THREAD_LOCAL -DHAVE_SSE42 -DROCKSDB_IOURING_PRESENT"
+CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_LIB_IO_POSIX -DROCKSDB_FALLOCATE_PRESENT -DROCKSDB_MALLOC_USABLE_SIZE -DROCKSDB_RANGESYNC_PRESENT -DROCKSDB_SCHED_GETCPU_PRESENT -DHAVE_SSE42 -DROCKSDB_IOURING_PRESENT"
 CXXFLAGS+=" $CFLAGS"
 
 EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $ZSTD_LIBS $GFLAGS_LIBS $NUMA_LIB $TBB_LIBS $LIBURING_LIBS $BENCHMARK_LIBS"

db_stress_tool/db_stress_shared_state.cc

@@ -12,14 +12,6 @@
 #include "db_stress_tool/db_stress_shared_state.h"
 
 namespace ROCKSDB_NAMESPACE {
-#if defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
-#if defined(OS_SOLARIS)
-__thread bool SharedState::ignore_read_error;
-#else
 thread_local bool SharedState::ignore_read_error;
-#endif // OS_SOLARIS
-#else
-bool SharedState::ignore_read_error;
-#endif // ROCKSDB_SUPPORT_THREAD_LOCAL
 }  // namespace ROCKSDB_NAMESPACE
 #endif  // GFLAGS

db_stress_tool/db_stress_shared_state.h

@@ -53,15 +53,7 @@ class SharedState {
   // local variable updated via sync points to keep track of errors injected
   // while reading filter blocks in order to ignore the Get/MultiGet result
   // for those calls
-#if defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
-#if defined(OS_SOLARIS)
-  static __thread bool ignore_read_error;
-#else
   static thread_local bool ignore_read_error;
-#endif // OS_SOLARIS
-#else
-  static bool ignore_read_error;
-#endif // ROCKSDB_SUPPORT_THREAD_LOCAL
 
   SharedState(Env* /*env*/, StressTest* stress_test)
       : cv_(&mu_),

include/rocksdb/iostats_context.h

@@ -81,10 +81,8 @@ struct IOStatsContext {
 // If RocksDB is compiled with -DNIOSTATS_CONTEXT, then a pointer to a global,
 // non-thread-local IOStatsContext object will be returned. Attempts to update
 // this object will be ignored, and reading from it will also be no-op.
-// Otherwise,
-// a) if thread-local is supported on the platform, then a pointer to
-//    a thread-local IOStatsContext object will be returned.
-// b) if thread-local is NOT supported, then compilation will fail.
+// Otherwise, a pointer to a thread-local IOStatsContext object will be
+// returned.
 //
 // This function never returns nullptr.
 IOStatsContext* get_iostats_context();

include/rocksdb/thread_status.h

@@ -22,8 +22,7 @@
 
 #include "rocksdb/rocksdb_namespace.h"
 
-#if !defined(ROCKSDB_LITE) && !defined(NROCKSDB_THREAD_STATUS) && \
-    defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
+#if !defined(ROCKSDB_LITE) && !defined(NROCKSDB_THREAD_STATUS)
 #define ROCKSDB_USING_THREAD_STATUS
 #endif
 

memory/concurrent_arena.cc

@@ -14,9 +14,7 @@
 
 namespace ROCKSDB_NAMESPACE {
 
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
-__thread size_t ConcurrentArena::tls_cpuid = 0;
-#endif
+thread_local size_t ConcurrentArena::tls_cpuid = 0;
 
 namespace {
 // If the shard block size is too large, in the worst case, every core
@@ -36,11 +34,9 @@ ConcurrentArena::ConcurrentArena(size_t block_size, AllocTracker* tracker,
 
 ConcurrentArena::Shard* ConcurrentArena::Repick() {
   auto shard_and_index = shards_.AccessElementAndIndex();
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
   // even if we are cpu 0, use a non-zero tls_cpuid so we can tell we
   // have repicked
   tls_cpuid = shard_and_index.second | shards_.Size();
-#endif
   return shard_and_index.first;
 }
 

memory/concurrent_arena.h

@@ -97,11 +97,7 @@ class ConcurrentArena : public Allocator {
     Shard() : free_begin_(nullptr), allocated_and_unused_(0) {}
   };
 
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
-  static __thread size_t tls_cpuid;
-#else
-  enum ZeroFirstEnum : size_t { tls_cpuid = 0 };
-#endif
+  static thread_local size_t tls_cpuid;
 
   char padding0[56] ROCKSDB_FIELD_UNUSED;
 

monitoring/iostats_context.cc

@@ -13,11 +13,8 @@ namespace ROCKSDB_NAMESPACE {
 // Should not be used because the counters are not thread-safe.
 // Put here just to make get_iostats_context() simple without ifdef.
 static IOStatsContext iostats_context;
-#elif defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
-__thread IOStatsContext iostats_context;
 #else
-#error \
-    "No thread-local support. Disable iostats context with -DNIOSTATS_CONTEXT."
+thread_local IOStatsContext iostats_context;
 #endif
 
 IOStatsContext* get_iostats_context() {

monitoring/iostats_context_imp.h

@@ -7,9 +7,9 @@
 #include "monitoring/perf_step_timer.h"
 #include "rocksdb/iostats_context.h"
 
-#if defined(ROCKSDB_SUPPORT_THREAD_LOCAL) && !defined(NIOSTATS_CONTEXT)
+#if !defined(NIOSTATS_CONTEXT)
 namespace ROCKSDB_NAMESPACE {
-extern __thread IOStatsContext iostats_context;
+extern thread_local IOStatsContext iostats_context;
 }  // namespace ROCKSDB_NAMESPACE
 
 // increment a specific counter by the specified value
@@ -40,7 +40,7 @@ extern __thread IOStatsContext iostats_context;
       PerfLevel::kEnableTimeAndCPUTimeExceptForMutex); \
   iostats_step_timer_##metric.Start();
 
-#else  // ROCKSDB_SUPPORT_THREAD_LOCAL && !NIOSTATS_CONTEXT
+#else  // !NIOSTATS_CONTEXT
 
 #define IOSTATS_ADD(metric, value)
 #define IOSTATS_ADD_IF_POSITIVE(metric, value)
@@ -53,4 +53,4 @@ extern __thread IOStatsContext iostats_context;
 #define IOSTATS_TIMER_GUARD(metric)
 #define IOSTATS_CPU_TIMER_GUARD(metric, clock) static_cast<void>(clock)
 
-#endif  // ROCKSDB_SUPPORT_THREAD_LOCAL && !NIOSTATS_CONTEXT
+#endif  // !NIOSTATS_CONTEXT

monitoring/perf_context.cc

@@ -13,14 +13,8 @@ namespace ROCKSDB_NAMESPACE {
 // Should not be used because the counters are not thread-safe.
 // Put here just to make get_perf_context() simple without ifdef.
 PerfContext perf_context;
-#elif defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
-#if defined(OS_SOLARIS)
-__thread PerfContext perf_context;
-#else   // OS_SOLARIS
-thread_local PerfContext perf_context;
-#endif  // OS_SOLARIS
 #else
-#error "No thread-local support. Disable perf context with -DNPERF_CONTEXT."
+thread_local PerfContext perf_context;
 #endif
 
 PerfContext* get_perf_context() {
@@ -28,7 +22,7 @@ PerfContext* get_perf_context() {
 }
 
 PerfContext::~PerfContext() {
-#if !defined(NPERF_CONTEXT) && defined(ROCKSDB_SUPPORT_THREAD_LOCAL) && !defined(OS_SOLARIS)
+#if !defined(NPERF_CONTEXT) && !defined(OS_SOLARIS)
   ClearPerLevelPerfContext();
 #endif
 }

monitoring/perf_context_imp.h

@@ -9,11 +9,11 @@
 #include "util/stop_watch.h"
 
 namespace ROCKSDB_NAMESPACE {
-#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
+#if defined(NPERF_CONTEXT)
 extern PerfContext perf_context;
 #else
 #if defined(OS_SOLARIS)
-extern __thread PerfContext perf_context_;
+extern thread_local PerfContext perf_context_;
 #define perf_context (*get_perf_context())
 #else
 extern thread_local PerfContext perf_context;

monitoring/perf_level.cc

@@ -9,11 +9,7 @@
 
 namespace ROCKSDB_NAMESPACE {
 
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
-__thread PerfLevel perf_level = kEnableCount;
-#else
-PerfLevel perf_level = kEnableCount;
-#endif
+thread_local PerfLevel perf_level = kEnableCount;
 
 void SetPerfLevel(PerfLevel level) {
   assert(level > kUninitialized);

monitoring/perf_level_imp.h

@@ -9,10 +9,6 @@
 
 namespace ROCKSDB_NAMESPACE {
 
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
-extern __thread PerfLevel perf_level;
-#else
-extern PerfLevel perf_level;
-#endif
+extern thread_local PerfLevel perf_level;
 
 }  // namespace ROCKSDB_NAMESPACE

monitoring/thread_status_updater.cc

@@ -16,7 +16,8 @@ namespace ROCKSDB_NAMESPACE {
 
 #ifdef ROCKSDB_USING_THREAD_STATUS
 
-__thread ThreadStatusData* ThreadStatusUpdater::thread_status_data_ = nullptr;
+thread_local ThreadStatusData* ThreadStatusUpdater::thread_status_data_ =
+    nullptr;
 
 void ThreadStatusUpdater::RegisterThread(ThreadStatus::ThreadType ttype,
                                          uint64_t thread_id) {

monitoring/thread_status_updater.h

@@ -196,7 +196,7 @@ class ThreadStatusUpdater {
  protected:
 #ifdef ROCKSDB_USING_THREAD_STATUS
   // The thread-local variable for storing thread status.
-  static __thread ThreadStatusData* thread_status_data_;
+  static thread_local ThreadStatusData* thread_status_data_;
 
   // Returns the pointer to the thread status data only when the
   // thread status data is non-null and has enable_tracking == true.

monitoring/thread_status_util.cc

@@ -12,9 +12,9 @@
 namespace ROCKSDB_NAMESPACE {
 
 #ifdef ROCKSDB_USING_THREAD_STATUS
-__thread ThreadStatusUpdater* ThreadStatusUtil::thread_updater_local_cache_ =
-    nullptr;
-__thread bool ThreadStatusUtil::thread_updater_initialized_ = false;
+thread_local ThreadStatusUpdater*
+    ThreadStatusUtil::thread_updater_local_cache_ = nullptr;
+thread_local bool ThreadStatusUtil::thread_updater_initialized_ = false;
 
 void ThreadStatusUtil::RegisterThread(const Env* env,
                                       ThreadStatus::ThreadType thread_type) {

monitoring/thread_status_util.h

@@ -94,7 +94,7 @@ class ThreadStatusUtil {
   // When this variable is set to true, thread_updater_local_cache_
   // will not be updated until this variable is again set to false
   // in UnregisterThread().
-  static  __thread bool thread_updater_initialized_;
+  static thread_local bool thread_updater_initialized_;
 
   // The thread-local cached ThreadStatusUpdater that caches the
   // thread_status_updater_ of the first Env that uses any ThreadStatusUtil
@@ -109,7 +109,7 @@ class ThreadStatusUtil {
   // When thread_updater_initialized_ is set to true, this variable
   // will not be updated until this thread_updater_initialized_ is
   // again set to false in UnregisterThread().
-  static __thread ThreadStatusUpdater* thread_updater_local_cache_;
+  static thread_local ThreadStatusUpdater* thread_updater_local_cache_;
 #else
   static bool thread_updater_initialized_;
   static ThreadStatusUpdater* thread_updater_local_cache_;

port/port_posix.h

@@ -25,11 +25,6 @@
 
 #define ROCKSDB_NOEXCEPT noexcept
 
-// thread_local is part of C++11 and later (TODO: clean up this define)
-#ifndef __thread
-#define __thread thread_local
-#endif
-
 #undef PLATFORM_IS_LITTLE_ENDIAN
 #if defined(OS_MACOSX)
   #include <machine/endian.h>

port/win/port_win.h

@@ -60,11 +60,6 @@ using ssize_t = SSIZE_T;
 #ifdef _MSC_VER
 #define __attribute__(A)
 
-// thread_local is part of C++11 and later (TODO: clean up this define)
-#ifndef __thread
-#define __thread thread_local
-#endif
-
 #endif
 
 namespace ROCKSDB_NAMESPACE {

util/random.cc

@@ -14,11 +14,7 @@
 #include "port/likely.h"
 #include "util/thread_local.h"
 
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
-#define STORAGE_DECL static __thread
-#else
-#define STORAGE_DECL static
-#endif
+#define STORAGE_DECL static thread_local
 
 namespace ROCKSDB_NAMESPACE {
 

util/thread_local.cc

@@ -140,20 +140,15 @@ private:
   // The private mutex.  Developers should always use Mutex() instead of
   // using this variable directly.
   port::Mutex mutex_;
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
   // Thread local storage
-  static __thread ThreadData* tls_;
-#endif
+  static thread_local ThreadData* tls_;
 
   // Used to make thread exit trigger possible if !defined(OS_MACOSX).
   // Otherwise, used to retrieve thread data.
   pthread_key_t pthread_key_;
 };
 
-
-#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
-__thread ThreadData* ThreadLocalPtr::StaticMeta::tls_ = nullptr;
-#endif
+thread_local ThreadData* ThreadLocalPtr::StaticMeta::tls_ = nullptr;
 
 // Windows doesn't support a per-thread destructor with its
 // TLS primitives.  So, we build it manually by inserting a
@@ -263,13 +258,10 @@ ThreadLocalPtr::StaticMeta* ThreadLocalPtr::Instance() {
   // the following variable will go first, then OnThreadExit, therefore causing
   // invalid access.
   //
-  // The above problem can be solved by using thread_local to store tls_ instead
-  // of using __thread.  The major difference between thread_local and __thread
-  // is that thread_local supports dynamic construction and destruction of
+  // The above problem can be solved by using thread_local to store tls_.
+  // thread_local supports dynamic construction and destruction of
   // non-primitive typed variables.  As a result, we can guarantee the
   // destruction order even when the main thread dies before any child threads.
-  // However, thread_local is not supported in all compilers that accept -std=c++11
-  // (e.g., eg Mac with XCode < 8. XCode 8+ supports thread_local).
   static ThreadLocalPtr::StaticMeta* inst = new ThreadLocalPtr::StaticMeta();
   return inst;
 }
@@ -328,10 +320,6 @@ ThreadLocalPtr::StaticMeta::StaticMeta()
 #if !defined(OS_WIN)
   static struct A {
     ~A() {
-#ifndef ROCKSDB_SUPPORT_THREAD_LOCAL
-      ThreadData* tls_ =
-        static_cast<ThreadData*>(pthread_getspecific(Instance()->pthread_key_));
-#endif
       if (tls_) {
         OnThreadExit(tls_);
       }
@@ -366,13 +354,6 @@ void ThreadLocalPtr::StaticMeta::RemoveThreadData(
 }
 
 ThreadData* ThreadLocalPtr::StaticMeta::GetThreadLocal() {
-#ifndef ROCKSDB_SUPPORT_THREAD_LOCAL
-  // Make this local variable name look like a member variable so that we
-  // can share all the code below
-  ThreadData* tls_ =
-      static_cast<ThreadData*>(pthread_getspecific(Instance()->pthread_key_));
-#endif
-
   if (UNLIKELY(tls_ == nullptr)) {
     auto* inst = Instance();
     tls_ = new ThreadData(inst);