RSDK-10842 - shut down cpp modules properly when viam-server is hard killed (viamrobotics#448)

Author: stuqdog

src/viam/sdk/module/service.cpp

@@ -194,7 +194,10 @@ struct ModuleService::ServiceImpl : viam::module::v1::ModuleService::Service {
         auto new_parent_addr = request->parent_address();
         if (parent.parent_addr_ != new_parent_addr) {
             parent.parent_addr_ = std::move(new_parent_addr);
-            parent.parent_ = RobotClient::at_local_socket(parent.parent_addr_, {0, boost::none});
+            Options opts{0, boost::none};
+            opts.set_check_every_interval(std::chrono::seconds{5})
+                .set_reconnect_every_interval(std::chrono::seconds{1});
+            parent.parent_ = RobotClient::at_local_socket(parent.parent_addr_, opts);
             parent.parent_->connect_logging();
         }
         response->set_ready(parent.module_->ready());

src/viam/sdk/robot/client.cpp

@@ -1,3 +1,4 @@
+#include <exception>
 #include <viam/sdk/robot/client.hpp>
 
 #include <chrono>
@@ -144,11 +145,16 @@ RobotClient::~RobotClient() {
 
 void RobotClient::close() {
     should_refresh_.store(false);
+    should_check_connection_.store(false);
 
     if (refresh_thread_.joinable()) {
         refresh_thread_.join();
     }
 
+    if (check_connection_thread_.joinable()) {
+        check_connection_thread_.join();
+    }
+
     stop_all();
 
     viam_channel_.close();
@@ -231,6 +237,62 @@ void RobotClient::refresh_every() {
     }
 };
 
+void RobotClient::check_connection() {
+    auto check_every = check_every_interval_;
+    auto reconnect_every = reconnect_every_interval_;
+    if (check_every == std::chrono::seconds{0}) {
+        check_every = reconnect_every;
+    }
+    if (check_every == std::chrono::seconds{0} && reconnect_every == std::chrono::seconds{0}) {
+        should_check_connection_.store(false);
+    }
+    bool connected(true);
+    while (should_check_connection_) {
+        std::exception_ptr connection_error;
+        std::string what;
+        for (int i = 0; i < 3; ++i) {
+            try {
+                std::this_thread::sleep_for(check_every);
+                impl::client_helper(impl_, &RobotService::Stub::ResourceNames).invoke([](auto&) {
+                    return;
+                });
+                connected = true;
+                break;
+            } catch (const std::exception& e) {
+                connected = false;
+                connection_error = std::current_exception();
+                what = e.what();
+                std::this_thread::sleep_for(std::chrono::milliseconds{100});
+            }
+        }
+        if (connected) {
+            continue;
+        }
+        const auto* uri = viam_channel_.get_channel_addr();
+        VIAM_SDK_LOG(error) << "Lost connection to machine at address " << uri << " with error "
+                            << what << ". Attempting to reconnect every " << reconnect_every.count()
+                            << "second(s)";
+
+        viam_channel_.close();
+
+        for (int i = 0; i < 3; ++i) {
+            try {
+                auto channel = ViamChannel::dial(uri, {});
+                impl_ =
+                    std::make_unique<RobotClient::impl>(RobotService::NewStub(channel.channel()));
+                refresh();
+                connected = true;
+            } catch (const std::exception& e) {
+                viam_channel_.close();
+                std::this_thread::sleep_for(reconnect_every);
+            }
+        }
+        if (!connected) {
+            close();
+        }
+    }
+}
+
 RobotClient::RobotClient(ViamChannel channel)
     : viam_channel_(std::move(channel)),
       impl_(std::make_unique<impl>(RobotService::NewStub(viam_channel_.channel()))) {}
@@ -262,8 +324,8 @@ void RobotClient::log(const std::string& name,
     ClientContext ctx;
     const auto response = impl_->stub->Log(ctx, req, &resp);
     if (is_error_response(response)) {
-        // Manually override to force this to get logged to console so we don't set off an infinite
-        // loop
+        // Manually override to force this to get logged to console so we don't set off an
+        // infinite loop
         VIAM_SDK_LOG(error) << boost::log::add_value(sdk::impl::attr_console_force_type{}, true)
                             << "Error sending log message over grpc: " << response.error_message()
                             << response.error_details();
@@ -279,6 +341,13 @@ std::shared_ptr<RobotClient> RobotClient::with_channel(ViamChannel channel,
         robot->refresh_thread_ = std::thread{&RobotClient::refresh_every, robot.get()};
     }
 
+    robot->should_check_connection_ = true;
+
+    robot->check_every_interval_ = options.check_every_interval();
+    robot->reconnect_every_interval_ = options.reconnect_every_interval();
+
+    robot->check_connection_thread_ = std::thread{&RobotClient::check_connection, robot.get()};
+
     robot->refresh();
     return robot;
 };

src/viam/sdk/robot/client.hpp

@@ -184,10 +184,15 @@ class RobotClient {
     void connect_logging();
 
     void refresh_every();
+    void check_connection();
 
     std::thread refresh_thread_;
+    std::thread check_connection_thread_;
     std::atomic<bool> should_refresh_;
+    std::atomic<bool> should_check_connection_;
     std::chrono::seconds refresh_interval_;
+    std::chrono::seconds check_every_interval_;
+    std::chrono::seconds reconnect_every_interval_;
 
     ViamChannel viam_channel_;
 

src/viam/sdk/rpc/dial.cpp

@@ -187,9 +187,12 @@ ViamChannel ViamChannel::dial(const char* uri, const boost::optional<DialOptions
     }
     address += proxy_path;
 
-    return ViamChannel(sdk::impl::create_viam_channel(address, grpc::InsecureChannelCredentials()),
-                       proxy_path,
-                       ptr);
+    auto chan =
+        ViamChannel(sdk::impl::create_viam_channel(address, grpc::InsecureChannelCredentials()),
+                    proxy_path,
+                    ptr);
+    chan.uri_ = uri;
+    return chan;
 }
 
 const std::shared_ptr<grpc::Channel>& ViamChannel::channel() const {
@@ -200,7 +203,27 @@ void ViamChannel::close() {
     pimpl_.reset();
 }
 
-unsigned int Options::refresh_interval() const {
+const char* ViamChannel::get_channel_addr() const {
+    return uri_;
+}
+Options& Options::set_check_every_interval(std::chrono::seconds interval) {
+    check_every_interval_ = interval;
+    return *this;
+}
+Options& Options::set_reconnect_every_interval(std::chrono::seconds interval) {
+    reconnect_every_interval_ = interval;
+    return *this;
+}
+
+std::chrono::seconds Options::check_every_interval() const {
+    return check_every_interval_;
+}
+
+std::chrono::seconds Options::reconnect_every_interval() const {
+    return reconnect_every_interval_;
+}
+
+std::chrono::seconds Options::refresh_interval() const {
     return refresh_interval_;
 }
 

src/viam/sdk/rpc/dial.hpp

@@ -45,7 +45,10 @@ class ViamChannel {
 
     void close();
 
+    const char* get_channel_addr() const;
+
    private:
+    const char* uri_;
     struct impl;
 
     std::shared_ptr<GrpcChannel> channel_;
@@ -116,13 +119,33 @@ class Options {
     Options(unsigned int refresh_interval, boost::optional<DialOptions> dial_options)
         : refresh_interval_(std::move(refresh_interval)), dial_options_(std::move(dial_options)) {}
 
-    unsigned int refresh_interval() const;
+    std::chrono::seconds refresh_interval() const;
+    std::chrono::seconds check_every_interval() const;
+    std::chrono::seconds reconnect_every_interval() const;
+
+    /// @brief Sets the frequency (in seconds) to verify connectivity
+    Options& set_check_every_interval(std::chrono::seconds interval);
+
+    /// @brief Sets the frequency (in seconds) to attempt to reconnect when connectivity is lost
+    Options& set_reconnect_every_interval(std::chrono::seconds interval);
     const boost::optional<DialOptions>& dial_options() const;
 
    private:
     /// @brief How often to refresh the status/parts of the robot, in seconds. If set to 0, the
     /// robot will not automatically refresh.
-    unsigned int refresh_interval_;
+    std::chrono::seconds refresh_interval_{0};
+
+    /// @brief How often to verify connectivity to the robot, in seconds. If set to 0, will not
+    /// check, will default to the `reconnect_every_interval_` value. Defaults to 0.
+    /// @note Setting to a non-zero value is useful in modules but may result in delays shutting
+    /// down client code
+    std::chrono::seconds check_every_interval_{0};
+
+    /// @brief How often to attempt to reconnect to the robot when disconnected. If set to 0,
+    /// will not attempt to reconnect. Defaults to 0.
+    /// @note Setting to a non-zero value is useful in modules but may result in delays shutting
+    /// down client code
+    std::chrono::seconds reconnect_every_interval_{0};
     boost::optional<DialOptions> dial_options_;
 };