DrivenEngine channels are now shared_ptr

luprex/core/cpp/drivenengine.hpp

@@ -148,16 +148,18 @@ public:
     //
     void set_prompt(const std::string &prompt);
 
-    // You may delete any channel except for stdio.  This closes
-    // the channel.
+    // Do not construct your own Channels.  Instead,
+    // use methods of class DrivenEngine like new_outgoing_channel.
+    // Channels are referenced by shared_ptr.  You can
+    // release your shared_ptr at any time.
     //
-    ~Channel();
+    Channel(DrivenEngine *de, int chid, int port, const std::string &target, bool stop);
+    ~Channel() {};
     
 private:
     // Constructor is deliberately private.  Use
     // DrivenEngine::new_outgoing_channel to create outgoing socket channels.
     //
-    Channel(DrivenEngine *de, int chid, int port, const std::string &target);
 
     void feed_readline(int nbytes, const char *bytes);
     void peek_outgoing(int *nbytes, const char **bytes);
@@ -166,7 +168,6 @@ private:
 
 private:
     static const int READLINE_MAX=512;
-    DrivenEngine *driven_;
     int chid_;
     std::unique_ptr<StreamBuffer> sb_in_;
     std::unique_ptr<StreamBuffer> sb_out_;
@@ -174,6 +175,7 @@ private:
     bool closed_;
     std::string error_;
     std::string target_;
+    bool stop_driver_;
 
     // Readline stuff.
     std::string desired_command_;
@@ -187,7 +189,7 @@ private:
     friend class DrivenEngine;
 };
 
-using UniqueChannel = std::unique_ptr<Channel>;
+using SharedChannel = std::shared_ptr<Channel>;
 
 class DrivenEngine {
 public:
@@ -229,7 +231,7 @@ public:
     // actually opening the connection and relaying data into the channel using
     // drv_get_target, drv_peek_outgoing, drv_sent_outgoing, drv_recv_incoming.
     //
-    UniqueChannel new_outgoing_channel(const std::string &target);
+    SharedChannel new_outgoing_channel(const std::string &target);
 
     // Create a new channel from any pending incoming connection. If there is no
     // incoming connection, returns nullptr.
@@ -242,17 +244,16 @@ public:
     // using drv_get_target, drv_peek_outgoing, drv_sent_outgoing,
     // drv_recv_incoming.
     //
-    UniqueChannel new_incoming_channel();
+    SharedChannel new_incoming_channel();
 
-    // Obtain the stdio channel. There is only one stdio channel.  It is owned
-    // by the DrivenEngine. It is an error to delete the stdio channel.
+    // Obtain the stdio channel. There is only one stdio channel.
     //
     // DRIVER: the stdio channel is created automatically when the DrivenEngine
     // is created.  The driver is responsible for relaying data into the channel
     // using drv_get_target, drv_peek_outgoing, drv_sent_outgoing,
     // drv_recv_incoming.
     //
-    Channel *get_stdio_channel();
+    SharedChannel get_stdio_channel();
 
     // Obtain the output buffer of the stdio channel as an ostream.
     //
@@ -292,13 +293,6 @@ public:
     //
     void drv_get_listen_ports(std::set<int> &ports);
 
-    // Get a list of all recently-closed channels.  The driver should
-    // discard all socket information associated with these channels.
-    // Caution: this may contain channels that the driver has never
-    // heard of.  In that case, just ignore the close-request.
-    //
-    void drv_get_new_closed(std::set<int> &opened);
-
     // Get a list of all recently-opened channels that were created using
     // drv_new_outgoing_channel.  The driver should initiate outgoing
     // connections for these channels.
@@ -316,6 +310,12 @@ public:
     //
     bool drv_outgoing_empty(int chid);
 
+    // Return true if the user has released all references to this channel.
+    // In this case, the driver should initiate shutdown of the channel,
+    // and the driver should eventually call drv_notify_close.
+    //
+    bool drv_get_channel_released(int chid);
+
     // Get a pointer to the bytes in the outgoing buffer.  The pointer returned
     // here is naturally only valid until the buffer is changed.  This function
     // is used for all channels, including sockets and stdio.
@@ -415,11 +415,10 @@ private:
     Channel *get_chid(int chid);
     
 private:
-    Channel *channels_[MAX_CHAN];
+    SharedChannel channels_[MAX_CHAN];
     int next_unused_chid_;
-    UniqueChannel stdio_channel_;
-    std::vector<UniqueChannel> accepted_channels_;
-    std::set<int> new_closed_;
+    SharedChannel stdio_channel_;
+    std::vector<SharedChannel> accepted_channels_;
     std::set<int> new_outgoing_;
     util::LuaSourcePtr lua_source_;
     std::set<int> listen_ports_;