Fixing Solaris Sparc crash due to cached TLS

Summary:
Workaround for Solaris gcc binary. Program is crashing, because when TLS of perf context that is used twice on same frame, it is damaged thus Segmentation fault.

Issue: #2153
Closes https://github.com/facebook/rocksdb/pull/2187

Differential Revision: D4922274

Pulled By: siying

fbshipit-source-id: 549105ebce9a8ce08a737f4d6b9f2312ebcde9a8

include/rocksdb/perf_context.h

@@ -155,7 +155,12 @@ extern PerfContext perf_context;
 #elif defined(_MSC_VER)
 extern __declspec(thread) PerfContext perf_context;
 #else
-extern __thread PerfContext perf_context;
+  #if defined(OS_SOLARIS)
+    PerfContext *getPerfContext();
+    #define perf_context (*getPerfContext())
+  #else
+    extern __thread PerfContext perf_context;
+  #endif
 #endif
 
 }

monitoring/perf_context.cc

@@ -14,7 +14,11 @@ namespace rocksdb {
 #elif defined(_MSC_VER)
   __declspec(thread) PerfContext perf_context;
 #else
-  __thread PerfContext perf_context;
+  #if defined(OS_SOLARIS)
+    __thread PerfContext perf_context_;
+  #else
+    __thread PerfContext perf_context;
+  #endif
 #endif
 
 void PerfContext::Reset() {
@@ -162,4 +166,10 @@ std::string PerfContext::ToString(bool exclude_zero_counters) const {
 #endif
 }
 
+#if defined(OS_SOLARIS)
+PerfContext *getPerfContext() {
+  return &perf_context_;
+}
+#endif
+
 }