revert perf_context and io_stats to __thread

Summary:
https://github.com/facebook/rocksdb/pull/2380 introduces a regression by replacing __thread with ThreadLocalPtr. Revert the thread local implementation back.
Closes https://github.com/facebook/rocksdb/pull/2485

Differential Revision: D5308050

Pulled By: lightmark

fbshipit-source-id: 2676e9c22edf76e8133d3f4c50e2711e11a95480

include/rocksdb/perf_context.h

@@ -154,7 +154,6 @@ struct PerfContext {
 // if defined(NPERF_CONTEXT), then the pointer is not thread-local
 PerfContext* get_perf_context();
 
-
 }
 
 #endif

monitoring/iostats_context.cc

@@ -10,16 +10,16 @@
 
 namespace rocksdb {
 
-ThreadLocalPtr iostats_context([](void* ptr) {
-    auto* p = static_cast<IOStatsContext*>(ptr);
-    delete p;
-  });
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
+__thread IOStatsContext iostats_context;
+#endif
 
 IOStatsContext* get_iostats_context() {
-  if (iostats_context.Get() == nullptr) {
-    iostats_context.Reset(static_cast<void*>(new IOStatsContext()));
-  }
-  return static_cast<IOStatsContext*>(iostats_context.Get());
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
+  return &iostats_context;
+#else
+  return nullptr;
+#endif
 }
 
 void IOStatsContext::Reset() {

monitoring/perf_context.cc

@@ -8,27 +8,28 @@
 
 #include <sstream>
 #include "monitoring/perf_context_imp.h"
-#include "util/thread_local.h"
 
 namespace rocksdb {
 
-#ifdef NPERF_CONTEXT
+#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
 PerfContext perf_context;
 #else
-ThreadLocalPtr perf_context([](void* ptr) {
-    auto* p = static_cast<PerfContext*>(ptr);
-    delete p;
-  });
+#if defined(OS_SOLARIS)
+__thread PerfContext perf_context_;
+#else
+__thread PerfContext perf_context;
+#endif
 #endif
 
 PerfContext* get_perf_context() {
-#ifdef NPERF_CONTEXT
+#if defined(NPERF_CONTEXT) || !defined(ROCKSDB_SUPPORT_THREAD_LOCAL)
   return &perf_context;
 #else
-  if (perf_context.Get() == nullptr) {
-    perf_context.Reset(static_cast<void*>(new PerfContext()));
-  }
-  return static_cast<PerfContext*>(perf_context.Get());
+#if defined(OS_SOLARIS)
+  return &perf_context_;
+#else
+  return &perf_context;
+#endif
 #endif
 }
 

monitoring/perf_context_imp.h

@@ -44,7 +44,10 @@ namespace rocksdb {
 #define PERF_TIMER_MEASURE(metric) perf_step_timer_##metric.Measure();
 
 // Increase metric value
-#define PERF_COUNTER_ADD(metric, value) get_perf_context()->metric += value;
+#define PERF_COUNTER_ADD(metric, value)        \
+  if (perf_level >= PerfLevel::kEnableCount) { \
+    get_perf_context()->metric += value;       \
+  }
 
 #endif
 

util/thread_local_test.cc

@@ -67,54 +67,53 @@ TEST_F(ThreadLocalTest, UniqueIdTest) {
   port::Mutex mu;
   port::CondVar cv(&mu);
 
-  // perf_context and iostats_context take 2 ids
-  ASSERT_EQ(IDChecker::PeekId(), 2u);
+  ASSERT_EQ(IDChecker::PeekId(), 0u);
   // New ThreadLocal instance bumps id by 1
   {
-    // Id used 2
+    // Id used 0
     Params p1(&mu, &cv, nullptr, 1u);
-    ASSERT_EQ(IDChecker::PeekId(), 3u);
-    // Id used 3
+    ASSERT_EQ(IDChecker::PeekId(), 1u);
+    // Id used 1
     Params p2(&mu, &cv, nullptr, 1u);
-    ASSERT_EQ(IDChecker::PeekId(), 4u);
-    // Id used 4
+    ASSERT_EQ(IDChecker::PeekId(), 2u);
+    // Id used 2
     Params p3(&mu, &cv, nullptr, 1u);
-    ASSERT_EQ(IDChecker::PeekId(), 5u);
-    // Id used 5
+    ASSERT_EQ(IDChecker::PeekId(), 3u);
+    // Id used 3
     Params p4(&mu, &cv, nullptr, 1u);
-    ASSERT_EQ(IDChecker::PeekId(), 6u);
+    ASSERT_EQ(IDChecker::PeekId(), 4u);
   }
-  // id 5, 4, 3, 2 are in the free queue in order
-  ASSERT_EQ(IDChecker::PeekId(), 2u);
+  // id 3, 2, 1, 0 are in the free queue in order
+  ASSERT_EQ(IDChecker::PeekId(), 0u);
 
-  // pick up 2
+  // pick up 0
   Params p1(&mu, &cv, nullptr, 1u);
-  ASSERT_EQ(IDChecker::PeekId(), 3u);
-  // pick up 3
+  ASSERT_EQ(IDChecker::PeekId(), 1u);
+  // pick up 1
   Params* p2 = new Params(&mu, &cv, nullptr, 1u);
-  ASSERT_EQ(IDChecker::PeekId(), 4u);
-  // pick up 4
+  ASSERT_EQ(IDChecker::PeekId(), 2u);
+  // pick up 2
   Params p3(&mu, &cv, nullptr, 1u);
-  ASSERT_EQ(IDChecker::PeekId(), 5u);
-  // return up 3
+  ASSERT_EQ(IDChecker::PeekId(), 3u);
+  // return up 1
   delete p2;
+  ASSERT_EQ(IDChecker::PeekId(), 1u);
+  // Now we have 3, 1 in queue
+  // pick up 1
+  Params p4(&mu, &cv, nullptr, 1u);
   ASSERT_EQ(IDChecker::PeekId(), 3u);
-  // Now we have 4, 2 in queue
   // pick up 3
-  Params p4(&mu, &cv, nullptr, 1u);
-  ASSERT_EQ(IDChecker::PeekId(), 5u);
-  // pick up 5
   Params p5(&mu, &cv, nullptr, 1u);
   // next new id
-  ASSERT_EQ(IDChecker::PeekId(), 6u);
+  ASSERT_EQ(IDChecker::PeekId(), 4u);
   // After exit, id sequence in queue:
-  // 5, 4, 3, 2(, 1, 0)
+  // 3, 1, 2, 0
 }
 #endif  // __clang_analyzer__
 
 TEST_F(ThreadLocalTest, SequentialReadWriteTest) {
-  // global id list carries over 5, 4, 3, 2
-  ASSERT_EQ(IDChecker::PeekId(), 2u);
+  // global id list carries over 3, 1, 2, 0
+  ASSERT_EQ(IDChecker::PeekId(), 0u);
 
   port::Mutex mu;
   port::CondVar cv(&mu);
@@ -144,7 +143,7 @@ TEST_F(ThreadLocalTest, SequentialReadWriteTest) {
   };
 
   for (int iter = 0; iter < 1024; ++iter) {
-    ASSERT_EQ(IDChecker::PeekId(), 3u);
+    ASSERT_EQ(IDChecker::PeekId(), 1u);
     // Another new thread, read/write should not see value from previous thread
     env_->StartThread(func, static_cast<void*>(&p));
     mu.Lock();
@@ -152,13 +151,13 @@ TEST_F(ThreadLocalTest, SequentialReadWriteTest) {
       cv.Wait();
     }
     mu.Unlock();
-    ASSERT_EQ(IDChecker::PeekId(), 3u);
+    ASSERT_EQ(IDChecker::PeekId(), 1u);
   }
 }
 
 TEST_F(ThreadLocalTest, ConcurrentReadWriteTest) {
-  // global id list carries over 5, 4, 3, 2
-  ASSERT_EQ(IDChecker::PeekId(), 2u);
+  // global id list carries over 3, 1, 2, 0
+  ASSERT_EQ(IDChecker::PeekId(), 0u);
 
   ThreadLocalPtr tls2;
   port::Mutex mu1;
@@ -239,11 +238,11 @@ TEST_F(ThreadLocalTest, ConcurrentReadWriteTest) {
   }
   mu2.Unlock();
 
-  ASSERT_EQ(IDChecker::PeekId(), 5u);
+  ASSERT_EQ(IDChecker::PeekId(), 3u);
 }
 
 TEST_F(ThreadLocalTest, Unref) {
-  ASSERT_EQ(IDChecker::PeekId(), 2u);
+  ASSERT_EQ(IDChecker::PeekId(), 0u);
 
   auto unref = [](void* ptr) {
     auto& p = *static_cast<Params*>(ptr);