core: envoy engine

library/common/BUILD

@@ -9,6 +9,8 @@ envoy_cc_library(
     srcs = [
         "certificates.inc",
         "config_template.cc",
+        "engine.cc",
+        "engine.h",
         "main_interface.cc",
     ],
     hdrs = ["main_interface.h"],

library/common/engine.cc

@@ -0,0 +1,101 @@
+#include "library/common/engine.h"
+
+#include "common/common/lock_guard.h"
+
+namespace Envoy {
+
+// As a server, Envoy's static factory registration happens when main is run. However, when compiled
+// as a library, there is no guarantee that such registration will happen before the names are
+// needed. The following calls ensure that registration happens before the entities are needed. Note
+// that as more registrations are needed, explicit initialization calls will need to be added here.
+static void registerFactories() {
+  Envoy::Extensions::Clusters::DynamicForwardProxy::forceRegisterClusterFactory();
+  Envoy::Extensions::HttpFilters::DynamicForwardProxy::
+      forceRegisterDynamicForwardProxyFilterFactory();
+  Envoy::Extensions::HttpFilters::RouterFilter::forceRegisterRouterFilterConfig();
+  Envoy::Extensions::NetworkFilters::HttpConnectionManager::
+      forceRegisterHttpConnectionManagerFilterConfigFactory();
+  Envoy::Extensions::TransportSockets::RawBuffer::forceRegisterDownstreamRawBufferSocketFactory();
+  Envoy::Extensions::TransportSockets::RawBuffer::forceRegisterUpstreamRawBufferSocketFactory();
+  Envoy::Extensions::TransportSockets::Tls::forceRegisterUpstreamSslSocketFactory();
+  Envoy::Upstream::forceRegisterLogicalDnsClusterFactory();
+}
+
+Engine::Engine(const char* config, const char* log_level,
+               std::atomic<envoy_network_t>& preferred_network) {
+  // Ensure static factory registration occurs on time.
+  // TODO: ensure this is only called one time once multiple Engine objects can be allocated.
+  registerFactories();
+
+  // Create the Http::Dispatcher first since it contains initial queueing logic.
+  // TODO: consider centralizing initial queueing in this class.
+  http_dispatcher_ = std::make_unique<Http::Dispatcher>(preferred_network);
+
+  // Start the Envoy on a dedicated thread.
+  main_thread_ = std::thread(&Engine::run, this, std::string(config), std::string(log_level));
+}
+
+envoy_status_t Engine::run(std::string config, std::string log_level) {
+  {
+    Thread::LockGuard lock(mutex_);
+    try {
+      char* envoy_argv[] = {strdup("envoy"), strdup("--config-yaml"),   strdup(config.c_str()),
+                            strdup("-l"),    strdup(log_level.c_str()), nullptr};
+
+      main_common_ = std::make_unique<Envoy::MainCommon>(5, envoy_argv);
+      event_dispatcher_ = &main_common_->server()->dispatcher();
+      cv_.notifyOne();
+    } catch (const Envoy::NoServingException& e) {
+      return ENVOY_FAILURE;
+    } catch (const Envoy::MalformedArgvException& e) {
+      std::cerr << e.what() << std::endl;
+      return ENVOY_FAILURE;
+    } catch (const Envoy::EnvoyException& e) {
+      std::cerr << e.what() << std::endl;
+      return ENVOY_FAILURE;
+    }
+
+    // Note: We're waiting longer than we might otherwise to drain to the main thread's dispatcher.
+    // This is because we're not simply waiting for its availability and for it to have started, but
+    // also because we're waiting for clusters to have done their first attempt at DNS resolution.
+    // When we improve synchronous failure handling and/or move to dynamic forwarding, we only need
+    // to wait until the dispatcher is running (and can drain by enqueueing a drain callback on it,
+    // as we did previously).
+    auto server = main_common_->server();
+    postinit_callback_handler_ = main_common_->server()->lifecycleNotifier().registerCallback(
+        Envoy::Server::ServerLifecycleNotifier::Stage::PostInit, [this, server]() -> void {
+          http_dispatcher_->ready(server->dispatcher(), server->clusterManager());
+        });
+  } // mutex_
+
+  // The main run loop must run without holding the mutex, so that the destructor can acquire it.
+  return TS_UNCHECKED_READ(main_common_)->run() ? ENVOY_SUCCESS : ENVOY_FAILURE;
+}
+
+Engine::~Engine() {
+  // If we're already on the main thread, it should be safe to simply destruct.
+  if (!main_thread_.joinable()) {
+    return;
+  }
+
+  // If we're not on the main thread, we need to be sure that MainCommon is finished being
+  // constructed so we can dispatch shutdown.
+  {
+    Thread::LockGuard lock(mutex_);
+    if (!main_common_) {
+      cv_.wait(mutex_);
+    }
+    ASSERT(main_common_);
+    // Gracefully shutdown the running envoy instance by resetting the main_common_ unique_ptr.
+    // Destroying MainCommon's member variables shutsdown things in the correct order and
+    // gracefully.
+    event_dispatcher_->post([this]() -> void { TS_UNCHECKED_READ(main_common_).reset(); });
+  } // _mutex
+
+  // Now we wait for the main thread to wrap things up.
+  main_thread_.join();
+}
+
+Http::Dispatcher& Engine::httpDispatcher() { return *http_dispatcher_; }
+
+} // namespace Envoy

library/common/engine.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "envoy/server/lifecycle_notifier.h"
+
+#include "common/upstream/logical_dns_cluster.h"
+
+#include "exe/main_common.h"
+
+#include "extensions/clusters/dynamic_forward_proxy/cluster.h"
+#include "extensions/filters/http/dynamic_forward_proxy/config.h"
+#include "extensions/filters/http/router/config.h"
+#include "extensions/filters/network/http_connection_manager/config.h"
+#include "extensions/transport_sockets/raw_buffer/config.h"
+#include "extensions/transport_sockets/tls/config.h"
+
+#include "absl/base/call_once.h"
+#include "library/common/http/dispatcher.h"
+#include "library/common/types/c_types.h"
+
+namespace Envoy {
+
+class Engine {
+public:
+  Engine(const char* config, const char* log_level,
+         std::atomic<envoy_network_t>& preferred_network);
+
+  ~Engine();
+
+  envoy_status_t run(std::string config, std::string log_level);
+
+  Http::Dispatcher& httpDispatcher();
+
+private:
+  Thread::MutexBasicLockable mutex_;
+  Thread::CondVar cv_;
+  std::thread main_thread_;
+  std::unique_ptr<Envoy::Http::Dispatcher> http_dispatcher_;
+  std::unique_ptr<Envoy::MainCommon> main_common_ GUARDED_BY(mutex_);
+  Envoy::Server::ServerLifecycleNotifier::HandlePtr postinit_callback_handler_;
+  Event::Dispatcher* event_dispatcher_;
+};
+
+} // namespace Envoy

library/common/jni_interface.cc

@@ -30,11 +30,9 @@ extern "C" JNIEXPORT jlong JNICALL Java_io_envoyproxy_envoymobile_engine_JniLibr
   return init_engine();
 }
 
-extern "C" JNIEXPORT jint JNICALL
-Java_io_envoyproxy_envoymobile_engine_JniLibrary_runEngine(JNIEnv* env,
-                                                           jclass, // class
-                                                           jstring config, jstring log_level) {
-  return run_engine(env->GetStringUTFChars(config, nullptr),
+extern "C" JNIEXPORT jint JNICALL Java_io_envoyproxy_envoymobile_engine_JniLibrary_runEngine(
+    JNIEnv* env, jclass, jlong engine, jstring config, jstring log_level) {
+  return run_engine(engine, env->GetStringUTFChars(config, nullptr),
                     env->GetStringUTFChars(log_level, nullptr));
 }
 
@@ -121,6 +119,11 @@ static JNIEnv* get_env() {
   int get_env_res = static_jvm->GetEnv((void**)&env, JNI_VERSION);
   if (get_env_res == JNI_EDETACHED) {
     __android_log_write(ANDROID_LOG_ERROR, "jni_lib", "equals JNI_EDETACHED");
+    // Note: the only thread that should need to be attached is Envoy's engine std::thread.
+    // TODO: harden this piece of code to make sure that we are only needing to attach Envoy
+    // engine's std::thread, and that we detach it successfully.
+    static_jvm->AttachCurrentThread(&env, NULL);
+    static_jvm->GetEnv((void**)&env, JNI_VERSION);
   }
   return env;
 }

library/common/main_interface.cc

@@ -1,59 +1,43 @@
 #include "library/common/main_interface.h"
 
 #include <atomic>
-#include <unordered_map>
 
-#include "envoy/server/lifecycle_notifier.h"
-
-#include "common/upstream/logical_dns_cluster.h"
-
-#include "exe/main_common.h"
-
-#include "extensions/clusters/dynamic_forward_proxy/cluster.h"
-#include "extensions/filters/http/dynamic_forward_proxy/config.h"
-#include "extensions/filters/http/router/config.h"
-#include "extensions/filters/network/http_connection_manager/config.h"
-#include "extensions/transport_sockets/raw_buffer/config.h"
-#include "extensions/transport_sockets/tls/config.h"
-
-#include "library/common/buffer/utility.h"
+#include "library/common/engine.h"
 #include "library/common/http/dispatcher.h"
-#include "library/common/http/header_utility.h"
 
 // NOLINT(namespace-envoy)
 
-static std::unique_ptr<Envoy::MainCommon> main_common_;
-static std::unique_ptr<Envoy::Http::Dispatcher> http_dispatcher_;
-static Envoy::Server::ServerLifecycleNotifier::HandlePtr stageone_callback_handler_;
+static std::unique_ptr<Envoy::Engine> engine_;
 static std::atomic<envoy_stream_t> current_stream_handle_{0};
 static std::atomic<envoy_network_t> preferred_network_{ENVOY_NET_GENERIC};
 
 envoy_stream_t init_stream(envoy_engine_t) { return current_stream_handle_++; }
 
 envoy_status_t start_stream(envoy_stream_t stream, envoy_http_callbacks callbacks) {
-  http_dispatcher_->startStream(stream, callbacks);
+  engine_->httpDispatcher().startStream(stream, callbacks);
   return ENVOY_SUCCESS;
 }
 
 envoy_status_t send_headers(envoy_stream_t stream, envoy_headers headers, bool end_stream) {
-  return http_dispatcher_->sendHeaders(stream, headers, end_stream);
+  return engine_->httpDispatcher().sendHeaders(stream, headers, end_stream);
 }
 
 envoy_status_t send_data(envoy_stream_t stream, envoy_data data, bool end_stream) {
-  return http_dispatcher_->sendData(stream, data, end_stream);
+  return engine_->httpDispatcher().sendData(stream, data, end_stream);
 }
 
 // TODO: implement.
 envoy_status_t send_metadata(envoy_stream_t, envoy_headers) { return ENVOY_FAILURE; }
 
 envoy_status_t send_trailers(envoy_stream_t stream, envoy_headers trailers) {
-  return http_dispatcher_->sendTrailers(stream, trailers);
+  return engine_->httpDispatcher().sendTrailers(stream, trailers);
 }
 
-envoy_status_t reset_stream(envoy_stream_t stream) { return http_dispatcher_->resetStream(stream); }
+envoy_status_t reset_stream(envoy_stream_t stream) {
+  return engine_->httpDispatcher().resetStream(stream);
+}
 
 envoy_engine_t init_engine() {
-  http_dispatcher_ = std::make_unique<Envoy::Http::Dispatcher>(preferred_network_);
   // TODO(goaway): return new handle once multiple engine support is in place.
   // https://github.com/lyft/envoy-mobile/issues/332
   return 1;
@@ -67,62 +51,9 @@ envoy_status_t set_preferred_network(envoy_network_t network) {
 /**
  * External entrypoint for library.
  */
-envoy_status_t run_engine(const char* config, const char* log_level) {
-  char* envoy_argv[] = {strdup("envoy"), strdup("--config-yaml"), strdup(config),
-                        strdup("-l"),    strdup(log_level),       nullptr};
-
-  // Ensure static factory registration occurs on time.
-  // Envoy's static factory registration happens when main is run.
-  // However, when compiled as a library, there is no guarantee that such registration will happen
-  // before the names are needed.
-  // The following calls ensure that registration happens before the entities are needed.
-  // Note that as more registrations are needed, explicit initialization calls will need to be added
-  // here.
-  Envoy::Extensions::Clusters::DynamicForwardProxy::forceRegisterClusterFactory();
-  Envoy::Extensions::HttpFilters::DynamicForwardProxy::
-      forceRegisterDynamicForwardProxyFilterFactory();
-  Envoy::Extensions::HttpFilters::RouterFilter::forceRegisterRouterFilterConfig();
-  Envoy::Extensions::NetworkFilters::HttpConnectionManager::
-      forceRegisterHttpConnectionManagerFilterConfigFactory();
-  Envoy::Extensions::TransportSockets::RawBuffer::forceRegisterDownstreamRawBufferSocketFactory();
-  Envoy::Extensions::TransportSockets::RawBuffer::forceRegisterUpstreamRawBufferSocketFactory();
-  Envoy::Extensions::TransportSockets::Tls::forceRegisterUpstreamSslSocketFactory();
-  Envoy::Upstream::forceRegisterLogicalDnsClusterFactory();
-
-  // Initialize the server's main context under a try/catch loop and simply
-  // return EXIT_FAILURE as needed. Whatever code in the initialization path
-  // that fails is expected to log an error message so the user can diagnose.
-  // Note that in the Android examples logging will not be seen.
-  // This is a known problem, and will be addressed by:
-  // https://github.com/lyft/envoy-mobile/issues/34
-  try {
-    main_common_ = std::make_unique<Envoy::MainCommon>(5, envoy_argv);
-
-    // Note: init_engine must have been called prior to calling run_engine or the creation of the
-    // envoy runner thread.
-
-    // Note: We're waiting longer than we might otherwise to drain to the main thread's dispatcher.
-    // This is because we're not simply waiting for its availability and for it to have started, but
-    // also because we're waiting for clusters to have done their first attempt at DNS resolution.
-    // When we improve synchronous failure handling and/or move to dynamic forwarding, we only need
-    // to wait until the dispatcher is running (and can drain by enqueueing a drain callback on it,
-    // as we did previously).
-    stageone_callback_handler_ = main_common_->server()->lifecycleNotifier().registerCallback(
-        Envoy::Server::ServerLifecycleNotifier::Stage::PostInit, []() -> void {
-          http_dispatcher_->ready(main_common_->server()->dispatcher(),
-                                  main_common_->server()->clusterManager());
-        });
-  } catch (const Envoy::NoServingException& e) {
-    return ENVOY_SUCCESS;
-  } catch (const Envoy::MalformedArgvException& e) {
-    std::cerr << e.what() << std::endl;
-    return ENVOY_FAILURE;
-  } catch (const Envoy::EnvoyException& e) {
-    std::cerr << e.what() << std::endl;
-    return ENVOY_FAILURE;
-  }
-
-  // Run the server listener loop outside try/catch blocks, so that unexpected
-  // exceptions show up as a core-dumps for easier diagnostics.
-  return main_common_->run() ? ENVOY_SUCCESS : ENVOY_FAILURE;
+envoy_status_t run_engine(envoy_engine_t, const char* config, const char* log_level) {
+  // This will change once multiple engine support is in place.
+  // https://github.com/lyft/envoy-mobile/issues/332
+  engine_ = std::make_unique<Envoy::Engine>(config, log_level, preferred_network_);
+  return ENVOY_SUCCESS;
 }

library/common/main_interface.h

@@ -93,11 +93,12 @@ envoy_status_t set_preferred_network(envoy_network_t network);
 
 /**
  * External entry point for library.
+ * @param engine, handle to the engine to run.
  * @param config, the configuration blob to run envoy with.
  * @param log_level, the logging level to run envoy with.
  * @return envoy_status_t, the resulting status of the operation.
  */
-envoy_status_t run_engine(const char* config, const char* log_level);
+envoy_status_t run_engine(envoy_engine_t engine, const char* config, const char* log_level);
 
 #ifdef __cplusplus
 } // functions

library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java

@@ -32,7 +32,7 @@ public EnvoyHTTPStream startStream(EnvoyHTTPCallbacks callbacks) {
   @Override
   public int runWithConfig(String configurationYAML, String logLevel) {
     try {
-      return JniLibrary.runEngine(configurationYAML, logLevel);
+      return JniLibrary.runEngine(this.engineHandle, configurationYAML, logLevel);
     } catch (Throwable throwable) {
       // TODO: Need to have a way to log the exception somewhere
       return 1;
@@ -43,7 +43,7 @@ public int runWithConfig(String configurationYAML, String logLevel) {
    * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
    * @param envoyConfiguration The EnvoyConfiguration used to start Envoy.
-   * @param logLevel The log level to use when starting Envoy.
+   * @param logLevel           The log level to use when starting Envoy.
    * @return int A status indicating if the action was successful.
    */
   @Override

library/java/src/io/envoyproxy/envoymobile/engine/JniLibrary.java

@@ -131,11 +131,12 @@ private static class JavaLoader {
   /**
    * External entry point for library.
    *
+   * @param engine,   the engine to run.
    * @param config,   the configuration blob to run envoy with.
    * @param logLevel, the logging level to run envoy with.
    * @return int, the resulting status of the operation.
    */
-  protected static native int runEngine(String config, String logLevel);
+  protected static native int runEngine(long engine, String config, String logLevel);
 
   // Other native methods
 

library/objective-c/EnvoyEngineImpl.m

@@ -32,7 +32,7 @@ - (int)runWithConfigYAML:(NSString *)configYAML logLevel:(NSString *)logLevel {
   // Envoy exceptions will only be caught here when compiled for 64-bit arches.
   // https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Exceptions/Articles/Exceptions64Bit.html
   @try {
-    return (int)run_engine(configYAML.UTF8String, logLevel.UTF8String);
+    return (int)run_engine(_engineHandle, configYAML.UTF8String, logLevel.UTF8String);
   } @catch (...) {
     NSLog(@"Envoy exception caught.");
     [NSNotificationCenter.defaultCenter postNotificationName:@"EnvoyException" object:self];

test/performance/test_binary_size.cc

@@ -5,4 +5,4 @@
 // This binary is used to perform stripped down binary size investigations of the Envoy codebase.
 // Please refer to the development docs for more information:
 // https://envoy-mobile.github.io/docs/envoy-mobile/latest/development/performance/binary_size.html
-int main() { return run_engine(nullptr, nullptr); }
+int main() { return run_engine(0, nullptr, nullptr); }