Wsrep TLS service

This commit defines a TLS service interface. If the implementation is
provided by the application when the provider is loaded, appropriate
hooks are probed from the provider and the provider side hooks are
initialized after the provider is loaded.

A sample implementation to demostrate the use of TLS interface
is provided in dbsim/db_tls.cpp.

Also contains a change to thread service interface: The
thread exit virtual method was changed to function pointer
to allow thread exit path which does not involve C++.

Author: temeo

dbsim/CMakeLists.txt

@@ -13,6 +13,7 @@ add_executable(dbsim
   db_simulator.cpp
   db_storage_engine.cpp
   db_threads.cpp
+  db_tls.cpp
   dbsim.cpp
 )
 

dbsim/db_params.cpp

@@ -87,6 +87,11 @@ db::params db::parse_args(int argc, char** argv)
          po::value<bool>(&params.cond_checks),
          "Enable checks for correct condition variable use. "
          " Effective only if thread-instrumentation is enabled")
+        ("tls-service",
+         po::value<int>(&params.tls_service),
+         "Configure TLS service stubs.\n0 default disabled\n1 enabled\n"
+         "2 enabled with short read/write and renegotiation simulation\n"
+         "3 enabled with error simulation.")
         ;
     try
     {

dbsim/db_params.hpp

@@ -42,6 +42,7 @@ namespace db
         int fast_exit;
         int thread_instrumentation;
         bool cond_checks;
+        int tls_service;
         params()
             : n_servers(0)
             , n_clients(0)
@@ -58,6 +59,7 @@ namespace db
             , fast_exit(0)
             , thread_instrumentation()
             , cond_checks()
+            , tls_service()
         { }
     };
 

dbsim/db_simulator.cpp

@@ -20,13 +20,15 @@
 #include "db_simulator.hpp"
 #include "db_client.hpp"
 #include "db_threads.hpp"
+#include "db_tls.hpp"
 
 #include "wsrep/logger.hpp"
 
 #include <boost/filesystem.hpp>
 #include <sstream>
 
 static db::ti thread_instrumentation;
+static db::tls tls_service;
 
 void db::simulator::run()
 {
@@ -36,6 +38,7 @@ void db::simulator::run()
     std::cout << "Results:\n";
     std::cout << stats() << std::endl;
     std::cout << db::ti::stats() << std::endl;
+    std::cout << db::tls::stats() << std::endl;
 }
 
 void db::simulator::sst(db::server& server,
@@ -114,6 +117,7 @@ void db::simulator::start()
 {
     thread_instrumentation.level(params_.thread_instrumentation);
     thread_instrumentation.cond_checks(params_.cond_checks);
+    tls_service.init(params_.tls_service);
     wsrep::log_info() << "Provider: " << params_.wsrep_provider;
 
     std::string cluster_address(build_cluster_address());
@@ -149,6 +153,9 @@ void db::simulator::start()
         services.thread_service = params_.thread_instrumentation
                                       ? &thread_instrumentation
                                       : nullptr;
+        services.tls_service = params_.tls_service
+            ? &tls_service
+            : nullptr;
         if (server.server_state().load_provider(params_.wsrep_provider,
                                                 server_options, services))
         {

dbsim/db_threads.cpp

@@ -35,6 +35,7 @@
 #include <unordered_map>
 #include <vector>
 
+extern "C" { static void* start_thread(void* args_ptr); }
 namespace
 {
     struct ti_obj
@@ -186,7 +187,6 @@ namespace
         }
     };
 
-    void* thread_start_fn(void* args_ptr);
 
     class ti_thread : public ti_obj
     {
@@ -209,7 +209,7 @@ namespace
         int run(void* (*fn)(void *), void* args)
         {
             auto ta(new thread_args{this, fn, args});
-            return pthread_create(&th_, nullptr, thread_start_fn, ta);
+            return pthread_create(&th_, nullptr, start_thread, ta);
         }
 
         int detach()
@@ -254,24 +254,6 @@ namespace
         bool detached_;
     };
 
-    void* thread_start_fn(void* args_ptr)
-    {
-        thread_args* ta(reinterpret_cast<thread_args*>(args_ptr));
-        ti_thread* thread = reinterpret_cast<ti_thread*>(ta->this_thread);
-        pthread_setspecific(this_thread_key, thread);
-        void* (*fn)(void*) = ta->fn;
-        void* args = ta->args;
-        delete ta;
-        void* ret((*fn)(args));
-        pthread_setspecific(this_thread_key, nullptr);
-
-        // If we end here the thread returned instead of calling
-        // pthread_exit()
-        if (thread->detached())
-            delete thread;
-        return ret;
-    }
-
     class ti_mutex : public ti_obj
     {
     public:
@@ -482,6 +464,42 @@ int db::ti::after_init()
 //                               Thread                                     //
 //////////////////////////////////////////////////////////////////////////////
 
+extern "C"
+{
+static void* start_thread(void* args_ptr)
+{
+    thread_args* ta(reinterpret_cast<thread_args*>(args_ptr));
+    ti_thread* thread = reinterpret_cast<ti_thread*>(ta->this_thread);
+    pthread_setspecific(this_thread_key, thread);
+    void* (*fn)(void*) = ta->fn;
+    void* args = ta->args;
+    delete ta;
+    void* ret = (*fn)(args);
+    pthread_setspecific(this_thread_key, nullptr);
+    // If we end here the thread returned instead of calling
+    // pthread_exit()
+    if (thread->detached())
+        delete thread;
+    return ret;
+}
+
+WSREP_NORETURN
+static void exit_thread(wsrep::thread_service::thread* thread, void* retval)
+{
+    pthread_setspecific(this_thread_key, nullptr);
+    ti_thread* th(reinterpret_cast<ti_thread*>(thread));
+    th->retval(retval);
+    if (th->detached())
+        delete th;
+    pthread_exit(retval);
+}
+} // extern "C"
+
+db::ti::ti()
+{
+    thread_service::exit = exit_thread;
+}
+
 const wsrep::thread_service::thread_key*
 db::ti::create_thread_key(const char* name) WSREP_NOEXCEPT
 {
@@ -513,15 +531,6 @@ int db::ti::detach(wsrep::thread_service::thread* thread) WSREP_NOEXCEPT
     return reinterpret_cast<ti_thread*>(thread)->detach();
 }
 
-void db::ti::exit(wsrep::thread_service::thread* thread, void* retval) WSREP_NOEXCEPT
-{
-    ti_thread* th(reinterpret_cast<ti_thread*>(thread));
-    th->retval(retval);
-    if (th->detached())
-        delete th;
-    pthread_exit(retval);
-}
-
 int db::ti::equal(wsrep::thread_service::thread* thread_1,
                    wsrep::thread_service::thread* thread_2) WSREP_NOEXCEPT
 {

dbsim/db_threads.hpp

@@ -28,7 +28,7 @@ namespace db
     class ti : public wsrep::thread_service
     {
     public:
-        ti() { }
+        ti();
         int before_init() override;
         int after_init() override;
 
@@ -41,7 +41,6 @@ namespace db
         int detach(wsrep::thread_service::thread*) WSREP_NOEXCEPT override;
         int equal(wsrep::thread_service::thread*,
                   wsrep::thread_service::thread*) WSREP_NOEXCEPT override;
-        void exit(wsrep::thread_service::thread*, void*) WSREP_NOEXCEPT override;
         int join(wsrep::thread_service::thread*, void**) WSREP_NOEXCEPT override;
         wsrep::thread_service::thread* self() WSREP_NOEXCEPT override;
         int setschedparam(wsrep::thread_service::thread*, int,