7 files changed, 329 insertions, 365 deletions

diff --git a/src/nvim/msgpack_rpc/channel.c b/src/nvim/msgpack_rpc/channel.c
index de6167c7fc..32781cf4d9 100644
--- a/src/nvim/msgpack_rpc/channel.c
+++ b/src/nvim/msgpack_rpc/channel.c
@@ -1,3 +1,6 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
 #include <stdbool.h>
 #include <string.h>
 #include <inttypes.h>
@@ -8,6 +11,7 @@
 #include "nvim/api/private/helpers.h"
 #include "nvim/api/vim.h"
 #include "nvim/api/ui.h"
+#include "nvim/channel.h"
 #include "nvim/msgpack_rpc/channel.h"
 #include "nvim/event/loop.h"
 #include "nvim/event/libuv_process.h"
@@ -26,56 +30,13 @@
 #include "nvim/log.h"
 #include "nvim/misc1.h"
 #include "nvim/lib/kvec.h"
-
-#define CHANNEL_BUFFER_SIZE 0xffff
+#include "nvim/os/input.h"
 
 #if MIN_LOG_LEVEL > DEBUG_LOG_LEVEL
 #define log_client_msg(...)
 #define log_server_msg(...)
 #endif
 
-typedef enum {
-  kChannelTypeSocket,
-  kChannelTypeProc,
-  kChannelTypeStdio
-} ChannelType;
-
-typedef struct {
-  uint64_t request_id;
-  bool returned, errored;
-  Object result;
-} ChannelCallFrame;
-
-typedef struct {
-  uint64_t id;
-  size_t refcount;
-  size_t pending_requests;
-  PMap(cstr_t) *subscribed_events;
-  bool closed;
-  ChannelType type;
-  msgpack_unpacker *unpacker;
-  union {
-    Stream stream;
-    Process *proc;
-    struct {
-      Stream in;
-      Stream out;
-    } std;
-  } data;
-  uint64_t next_request_id;
-  kvec_t(ChannelCallFrame *) call_stack;
-  kvec_t(WBuffer *) delayed_notifications;
-  MultiQueue *events;
-} Channel;
-
-typedef struct {
-  Channel *channel;
-  MsgpackRpcRequestHandler handler;
-  Array args;
-  uint64_t request_id;
-} RequestEvent;
-
-static PMap(uint64_t) *channels = NULL;
 static PMap(cstr_t) *event_strings = NULL;
 static msgpack_sbuffer out_buffer;
 
@@ -83,91 +44,64 @@ static msgpack_sbuffer out_buffer;
 # include "msgpack_rpc/channel.c.generated.h"
 #endif
 
-/// Initializes the module
-void channel_init(void)
+void rpc_init(void)
 {
-  channels = pmap_new(uint64_t)();
+  ch_before_blocking_events = multiqueue_new_child(main_loop.events);
   event_strings = pmap_new(cstr_t)();
   msgpack_sbuffer_init(&out_buffer);
-  remote_ui_init();
 }
 
-/// Teardown the module
-void channel_teardown(void)
-{
-  if (!channels) {
-    return;
-  }
-
-  Channel *channel;
-
-  map_foreach_value(channels, channel, {
-    close_channel(channel);
-  });
-}
 
-/// Creates an API channel by starting a process and connecting to its
-/// stdin/stdout. stderr is handled by the job infrastructure.
-///
-/// @param argv The argument vector for the process. [consumed]
-/// @return The channel id (> 0), on success.
-///         0, on error.
-uint64_t channel_from_process(Process *proc, uint64_t id)
+void rpc_start(Channel *channel)
 {
-  Channel *channel = register_channel(kChannelTypeProc, id, proc->events);
-  incref(channel);  // process channels are only closed by the exit_cb
-  channel->data.proc = proc;
+  channel_incref(channel);
+  channel->is_rpc = true;
+  RpcState *rpc = &channel->rpc;
+  rpc->closed = false;
+  rpc->unpacker = msgpack_unpacker_new(MSGPACK_UNPACKER_INIT_BUFFER_SIZE);
+  rpc->subscribed_events = pmap_new(cstr_t)();
+  rpc->next_request_id = 1;
+  kv_init(rpc->call_stack);
 
-  wstream_init(proc->in, 0);
-  rstream_init(proc->out, 0);
-  rstream_start(proc->out, parse_msgpack, channel);
+  if (channel->streamtype != kChannelStreamInternal) {
+    Stream *out = channel_outstream(channel);
+#if MIN_LOG_LEVEL <= DEBUG_LOG_LEVEL
+    Stream *in = channel_instream(channel);
+    DLOG("rpc ch %" PRIu64 " in-stream=%p out-stream=%p", channel->id, in, out);
+#endif
 
-  return channel->id;
+    rstream_start(out, receive_msgpack, channel);
+  }
 }
 
-/// Creates an API channel from a tcp/pipe socket connection
-///
-/// @param watcher The SocketWatcher ready to accept the connection
-void channel_from_connection(SocketWatcher *watcher)
+
+static Channel *find_rpc_channel(uint64_t id)
 {
-  Channel *channel = register_channel(kChannelTypeSocket, 0, NULL);
-  socket_watcher_accept(watcher, &channel->data.stream);
-  incref(channel);  // close channel only after the stream is closed
-  channel->data.stream.internal_close_cb = close_cb;
-  channel->data.stream.internal_data = channel;
-  wstream_init(&channel->data.stream, 0);
-  rstream_init(&channel->data.stream, CHANNEL_BUFFER_SIZE);
-  rstream_start(&channel->data.stream, parse_msgpack, channel);
+  Channel *chan = find_channel(id);
+  if (!chan || !chan->is_rpc || chan->rpc.closed) {
+    return NULL;
+  }
+  return chan;
 }
 
-/// Sends event/arguments to channel
+/// Publishes an event to a channel.
 ///
-/// @param id The channel id. If 0, the event will be sent to all
-///        channels that have subscribed to the event type
-/// @param name The event name, an arbitrary string
-/// @param args Array with event arguments
+/// @param id Channel id. 0 means "broadcast to all subscribed channels"
+/// @param name Event name (application-defined)
+/// @param args Array of event arguments
 /// @return True if the event was sent successfully, false otherwise.
-bool channel_send_event(uint64_t id, char *name, Array args)
+bool rpc_send_event(uint64_t id, const char *name, Array args)
 {
   Channel *channel = NULL;
 
-  if (id && (!(channel = pmap_get(uint64_t)(channels, id))
-            || channel->closed)) {
+  if (id && (!(channel = find_rpc_channel(id)))) {
     api_free_array(args);
     return false;
   }
 
   if (channel) {
-    if (channel->pending_requests) {
-      // Pending request, queue the notification for later sending.
-      String method = cstr_as_string(name);
-      WBuffer *buffer = serialize_request(id, 0, method, args, &out_buffer, 1);
-      kv_push(channel->delayed_notifications, buffer);
-    } else {
-      send_event(channel, name, args);
-    }
+    send_event(channel, name, args);
   }  else {
-    // TODO(tarruda): Implement event broadcasting in vimscript
     broadcast_event(name, args);
   }
 
@@ -181,35 +115,35 @@ bool channel_send_event(uint64_t id, char *name, Array args)
 /// @param args Array with method arguments
 /// @param[out] error True if the return value is an error
 /// @return Whatever the remote method returned
-Object channel_send_call(uint64_t id,
-                         char *method_name,
-                         Array args,
-                         Error *err)
+Object rpc_send_call(uint64_t id,
+                     const char *method_name,
+                     Array args,
+                     Error *err)
 {
   Channel *channel = NULL;
 
-  if (!(channel = pmap_get(uint64_t)(channels, id)) || channel->closed) {
-    api_set_error(err, Exception, _("Invalid channel \"%" PRIu64 "\""), id);
+  if (!(channel = find_rpc_channel(id))) {
+    api_set_error(err, kErrorTypeException, "Invalid channel: %" PRIu64, id);
     api_free_array(args);
     return NIL;
   }
 
-  incref(channel);
-  uint64_t request_id = channel->next_request_id++;
+  channel_incref(channel);
+  RpcState *rpc = &channel->rpc;
+  uint64_t request_id = rpc->next_request_id++;
   // Send the msgpack-rpc request
   send_request(channel, request_id, method_name, args);
 
   // Push the frame
   ChannelCallFrame frame = { request_id, false, false, NIL };
-  kv_push(channel->call_stack, &frame);
-  channel->pending_requests++;
+  kv_push(rpc->call_stack, &frame);
   LOOP_PROCESS_EVENTS_UNTIL(&main_loop, channel->events, -1, frame.returned);
-  (void)kv_pop(channel->call_stack);
-  channel->pending_requests--;
+  (void)kv_pop(rpc->call_stack);
 
   if (frame.errored) {
     if (frame.result.type == kObjectTypeString) {
-      api_set_error(err, Exception, "%s", frame.result.data.string.data);
+      api_set_error(err, kErrorTypeException, "%s",
+                    frame.result.data.string.data);
     } else if (frame.result.type == kObjectTypeArray) {
       // Should be an error in the form [type, message]
       Array array = frame.result.data.array;
@@ -217,24 +151,19 @@ Object channel_send_call(uint64_t id,
           && (array.items[0].data.integer == kErrorTypeException
               || array.items[0].data.integer == kErrorTypeValidation)
           && array.items[1].type == kObjectTypeString) {
-        err->type = (ErrorType) array.items[0].data.integer;
-        xstrlcpy(err->msg, array.items[1].data.string.data, sizeof(err->msg));
-        err->set = true;
+        api_set_error(err, (ErrorType)array.items[0].data.integer, "%s",
+                      array.items[1].data.string.data);
       } else {
-        api_set_error(err, Exception, "%s", "unknown error");
+        api_set_error(err, kErrorTypeException, "%s", "unknown error");
       }
     } else {
-      api_set_error(err, Exception, "%s", "unknown error");
+      api_set_error(err, kErrorTypeException, "%s", "unknown error");
     }
 
     api_free_object(frame.result);
   }
 
-  if (!channel->pending_requests) {
-    send_delayed_notifications(channel);
-  }
-
-  decref(channel);
+  channel_decref(channel);
 
   return frame.errored ? NIL : frame.result;
 }
@@ -243,11 +172,11 @@ Object channel_send_call(uint64_t id,
 ///
 /// @param id The channel id
 /// @param event The event type string
-void channel_subscribe(uint64_t id, char *event)
+void rpc_subscribe(uint64_t id, char *event)
 {
   Channel *channel;
 
-  if (!(channel = pmap_get(uint64_t)(channels, id)) || channel->closed) {
+  if (!(channel = find_rpc_channel(id))) {
     abort();
   }
 
@@ -258,91 +187,63 @@ void channel_subscribe(uint64_t id, char *event)
     pmap_put(cstr_t)(event_strings, event_string, event_string);
   }
 
-  pmap_put(cstr_t)(channel->subscribed_events, event_string, event_string);
+  pmap_put(cstr_t)(channel->rpc.subscribed_events, event_string, event_string);
 }
 
 /// Unsubscribes to event broadcasts
 ///
 /// @param id The channel id
 /// @param event The event type string
-void channel_unsubscribe(uint64_t id, char *event)
+void rpc_unsubscribe(uint64_t id, char *event)
 {
   Channel *channel;
 
-  if (!(channel = pmap_get(uint64_t)(channels, id)) || channel->closed) {
+  if (!(channel = find_rpc_channel(id))) {
     abort();
   }
 
   unsubscribe(channel, event);
 }
 
-/// Closes a channel
-///
-/// @param id The channel id
-/// @return true if successful, false otherwise
-bool channel_close(uint64_t id)
-{
-  Channel *channel;
-
-  if (!(channel = pmap_get(uint64_t)(channels, id)) || channel->closed) {
-    return false;
-  }
-
-  close_channel(channel);
-  return true;
-}
-
-/// Creates an API channel from stdin/stdout. This is used when embedding
-/// Neovim
-void channel_from_stdio(void)
-{
-  Channel *channel = register_channel(kChannelTypeStdio, 0, NULL);
-  incref(channel);  // stdio channels are only closed on exit
-  // read stream
-  rstream_init_fd(&main_loop, &channel->data.std.in, 0, CHANNEL_BUFFER_SIZE);
-  rstream_start(&channel->data.std.in, parse_msgpack, channel);
-  // write stream
-  wstream_init_fd(&main_loop, &channel->data.std.out, 1, 0);
-}
-
-void channel_process_exit(uint64_t id, int status)
-{
-  Channel *channel = pmap_get(uint64_t)(channels, id);
-
-  channel->closed = true;
-  decref(channel);
-}
-
-static void parse_msgpack(Stream *stream, RBuffer *rbuf, size_t c, void *data,
-    bool eof)
+static void receive_msgpack(Stream *stream, RBuffer *rbuf, size_t c,
+                            void *data, bool eof)
 {
   Channel *channel = data;
-  incref(channel);
+  channel_incref(channel);
 
   if (eof) {
-    close_channel(channel);
+    channel_close(channel->id, kChannelPartRpc, NULL);
     char buf[256];
     snprintf(buf, sizeof(buf), "ch %" PRIu64 " was closed by the client",
              channel->id);
-    call_set_error(channel, buf);
+    call_set_error(channel, buf, WARN_LOG_LEVEL);
     goto end;
   }
 
   size_t count = rbuffer_size(rbuf);
-  DLOG("parsing %u bytes of msgpack data from Stream(%p)", count, stream);
+  DLOG("ch %" PRIu64 ": parsing %zu bytes from msgpack Stream: %p",
+       channel->id, count, stream);
 
   // Feed the unpacker with data
-  msgpack_unpacker_reserve_buffer(channel->unpacker, count);
-  rbuffer_read(rbuf, msgpack_unpacker_buffer(channel->unpacker), count);
-  msgpack_unpacker_buffer_consumed(channel->unpacker, count);
+  msgpack_unpacker_reserve_buffer(channel->rpc.unpacker, count);
+  rbuffer_read(rbuf, msgpack_unpacker_buffer(channel->rpc.unpacker), count);
+  msgpack_unpacker_buffer_consumed(channel->rpc.unpacker, count);
 
+  parse_msgpack(channel);
+
+end:
+  channel_decref(channel);
+}
+
+static void parse_msgpack(Channel *channel)
+{
   msgpack_unpacked unpacked;
   msgpack_unpacked_init(&unpacked);
   msgpack_unpack_return result;
 
   // Deserialize everything we can.
-  while ((result = msgpack_unpacker_next(channel->unpacker, &unpacked)) ==
-      MSGPACK_UNPACK_SUCCESS) {
+  while ((result = msgpack_unpacker_next(channel->rpc.unpacker, &unpacked)) ==
+         MSGPACK_UNPACK_SUCCESS) {
     bool is_response = is_rpc_response(&unpacked.data);
     log_client_msg(channel->id, !is_response, unpacked.data);
 
@@ -355,11 +256,11 @@ static void parse_msgpack(Stream *stream, RBuffer *rbuf, size_t c, void *data,
                  "ch %" PRIu64 " returned a response with an unknown request "
                  "id. Ensure the client is properly synchronized",
                  channel->id);
-        call_set_error(channel, buf);
+        call_set_error(channel, buf, ERROR_LOG_LEVEL);
       }
       msgpack_unpacked_destroy(&unpacked);
       // Bail out from this event loop iteration
-      goto end;
+      return;
     }
 
     handle_request(channel, &unpacked.data);
@@ -368,7 +269,7 @@ static void parse_msgpack(Stream *stream, RBuffer *rbuf, size_t c, void *data,
   if (result == MSGPACK_UNPACK_NOMEM_ERROR) {
     mch_errmsg(e_outofmem);
     mch_errmsg("\n");
-    decref(channel);
+    channel_decref(channel);
     preserve_exit();
   }
 
@@ -377,17 +278,15 @@ static void parse_msgpack(Stream *stream, RBuffer *rbuf, size_t c, void *data,
     // causes for this error(search for 'goto _failed')
     //
     // A not so uncommon cause for this might be deserializing objects with
-    // a high nesting level: msgpack will break when it's internal parse stack
-    // size exceeds MSGPACK_EMBED_STACK_SIZE(defined as 32 by default)
+    // a high nesting level: msgpack will break when its internal parse stack
+    // size exceeds MSGPACK_EMBED_STACK_SIZE (defined as 32 by default)
     send_error(channel, 0, "Invalid msgpack payload. "
                            "This error can also happen when deserializing "
                            "an object with high level of nesting");
   }
-
-end:
-  decref(channel);
 }
 
+
 static void handle_request(Channel *channel, msgpack_object *request)
   FUNC_ATTR_NONNULL_ALL
 {
@@ -395,7 +294,7 @@ static void handle_request(Channel *channel, msgpack_object *request)
   Error error = ERROR_INIT;
   msgpack_rpc_validate(&request_id, request, &error);
 
-  if (error.set) {
+  if (ERROR_SET(&error)) {
     // Validation failed, send response with error
     if (channel_write(channel,
                       serialize_response(channel->id,
@@ -407,11 +306,11 @@ static void handle_request(Channel *channel, msgpack_object *request)
       snprintf(buf, sizeof(buf),
                "ch %" PRIu64 " sent an invalid message, closed.",
                channel->id);
-      call_set_error(channel, buf);
+      call_set_error(channel, buf, ERROR_LOG_LEVEL);
     }
+    api_clear_error(&error);
     return;
   }
-
   // Retrieve the request handler
   MsgpackRpcRequestHandler handler;
   msgpack_object *method = msgpack_rpc_method(request);
@@ -430,16 +329,24 @@ static void handle_request(Channel *channel, msgpack_object *request)
     handler.async = true;
   }
 
-  RequestEvent *event_data = xmalloc(sizeof(RequestEvent));
-  event_data->channel = channel;
-  event_data->handler = handler;
-  event_data->args = args;
-  event_data->request_id = request_id;
-  incref(channel);
+  RequestEvent *evdata = xmalloc(sizeof(RequestEvent));
+  evdata->channel = channel;
+  evdata->handler = handler;
+  evdata->args = args;
+  evdata->request_id = request_id;
+  channel_incref(channel);
   if (handler.async) {
-    on_request_event((void **)&event_data);
+    bool is_get_mode = handler.fn == handle_nvim_get_mode;
+
+    if (is_get_mode && !input_blocking()) {
+      // Defer the event to a special queue used by os/input.c. #6247
+      multiqueue_put(ch_before_blocking_events, on_request_event, 1, evdata);
+    } else {
+      // Invoke immediately.
+      on_request_event((void **)&evdata);
+    }
   } else {
-    multiqueue_put(channel->events, on_request_event, 1, event_data);
+    multiqueue_put(channel->events, on_request_event, 1, evdata);
   }
 }
 
@@ -465,64 +372,78 @@ static void on_request_event(void **argv)
     api_free_object(result);
   }
   api_free_array(args);
-  decref(channel);
+  channel_decref(channel);
   xfree(e);
+  api_clear_error(&error);
 }
 
 static bool channel_write(Channel *channel, WBuffer *buffer)
 {
   bool success;
 
-  if (channel->closed) {
+  if (channel->rpc.closed) {
     wstream_release_wbuffer(buffer);
     return false;
   }
 
-  switch (channel->type) {
-    case kChannelTypeSocket:
-      success = wstream_write(&channel->data.stream, buffer);
-      break;
-    case kChannelTypeProc:
-      success = wstream_write(channel->data.proc->in, buffer);
-      break;
-    case kChannelTypeStdio:
-      success = wstream_write(&channel->data.std.out, buffer);
-      break;
-    default:
-      abort();
+  if (channel->streamtype == kChannelStreamInternal) {
+    channel_incref(channel);
+    CREATE_EVENT(channel->events, internal_read_event, 2, channel, buffer);
+    success = true;
+  } else {
+    Stream *in = channel_instream(channel);
+    success = wstream_write(in, buffer);
   }
 
+
   if (!success) {
     // If the write failed for any reason, close the channel
     char buf[256];
     snprintf(buf,
              sizeof(buf),
-             "Before returning from a RPC call, ch %" PRIu64 " was "
-             "closed due to a failed write",
+             "ch %" PRIu64 ": stream write failed. "
+             "RPC canceled; closing channel",
              channel->id);
-    call_set_error(channel, buf);
+    call_set_error(channel, buf, ERROR_LOG_LEVEL);
   }
 
   return success;
 }
 
+static void internal_read_event(void **argv)
+{
+  Channel *channel = argv[0];
+  WBuffer *buffer = argv[1];
+
+  msgpack_unpacker_reserve_buffer(channel->rpc.unpacker, buffer->size);
+  memcpy(msgpack_unpacker_buffer(channel->rpc.unpacker),
+         buffer->data, buffer->size);
+  msgpack_unpacker_buffer_consumed(channel->rpc.unpacker, buffer->size);
+
+  parse_msgpack(channel);
+
+  channel_decref(channel);
+  wstream_release_wbuffer(buffer);
+}
+
 static void send_error(Channel *channel, uint64_t id, char *err)
 {
   Error e = ERROR_INIT;
-  api_set_error(&e, Exception, "%s", err);
+  api_set_error(&e, kErrorTypeException, "%s", err);
   channel_write(channel, serialize_response(channel->id,
                                             id,
                                             &e,
                                             NIL,
                                             &out_buffer));
+  api_clear_error(&e);
 }
 
 static void send_request(Channel *channel,
                          uint64_t id,
-                         char *name,
+                         const char *name,
                          Array args)
 {
-  String method = {.size = strlen(name), .data = name};
+  const String method = cstr_as_string((char *)name);
   channel_write(channel, serialize_request(channel->id,
                                            id,
                                            method,
@@ -532,10 +453,10 @@ static void send_request(Channel *channel,
 }
 
 static void send_event(Channel *channel,
-                       char *name,
+                       const char *name,
                        Array args)
 {
-  String method = {.size = strlen(name), .data = name};
+  const String method = cstr_as_string((char *)name);
   channel_write(channel, serialize_request(channel->id,
                                            0,
                                            method,
@@ -544,13 +465,14 @@ static void send_event(Channel *channel,
                                            1));
 }
 
-static void broadcast_event(char *name, Array args)
+static void broadcast_event(const char *name, Array args)
 {
   kvec_t(Channel *) subscribed = KV_INITIAL_VALUE;
   Channel *channel;
 
   map_foreach_value(channels, channel, {
-    if (pmap_has(cstr_t)(channel->subscribed_events, name)) {
+    if (channel->is_rpc
+        && pmap_has(cstr_t)(channel->rpc.subscribed_events, name)) {
       kv_push(subscribed, channel);
     }
   });
@@ -560,7 +482,7 @@ static void broadcast_event(char *name, Array args)
     goto end;
   }
 
-  String method = {.size = strlen(name), .data = name};
+  const String method = cstr_as_string((char *)name);
   WBuffer *buffer = serialize_request(0,
                                       0,
                                       method,
@@ -570,11 +492,7 @@ static void broadcast_event(char *name, Array args)
 
   for (size_t i = 0; i < kv_size(subscribed); i++) {
     Channel *channel = kv_A(subscribed, i);
-    if (channel->pending_requests) {
-      kv_push(channel->delayed_notifications, buffer);
-    } else {
-      channel_write(channel, buffer);
-    }
+    channel_write(channel, buffer);
   }
 
 end:
@@ -584,10 +502,11 @@ end:
 static void unsubscribe(Channel *channel, char *event)
 {
   char *event_string = pmap_get(cstr_t)(event_strings, event);
-  pmap_del(cstr_t)(channel->subscribed_events, event_string);
+  pmap_del(cstr_t)(channel->rpc.subscribed_events, event_string);
 
   map_foreach_value(channels, channel, {
-    if (pmap_has(cstr_t)(channel->subscribed_events, event_string)) {
+    if (channel->is_rpc
+        && pmap_has(cstr_t)(channel->rpc.subscribed_events, event_string)) {
       return;
     }
   });
@@ -597,89 +516,43 @@ static void unsubscribe(Channel *channel, char *event)
   xfree(event_string);
 }
 
-/// Close the channel streams/process and free the channel resources.
-static void close_channel(Channel *channel)
+
+/// Mark rpc state as closed, and release its reference to the channel.
+/// Don't call this directly, call channel_close(id, kChannelPartRpc, &error)
+void rpc_close(Channel *channel)
 {
-  if (channel->closed) {
+  if (channel->rpc.closed) {
     return;
   }
 
-  channel->closed = true;
+  channel->rpc.closed = true;
+  channel_decref(channel);
 
-  switch (channel->type) {
-    case kChannelTypeSocket:
-      stream_close(&channel->data.stream, NULL, NULL);
-      break;
-    case kChannelTypeProc:
-      // Only close the rpc channel part,
-      // there could be an error message on the stderr stream
-      process_close_in(channel->data.proc);
-      process_close_out(channel->data.proc);
-      break;
-    case kChannelTypeStdio:
-      stream_close(&channel->data.std.in, NULL, NULL);
-      stream_close(&channel->data.std.out, NULL, NULL);
-      multiqueue_put(main_loop.fast_events, exit_event, 1, channel);
-      return;
-    default:
-      abort();
+  if (channel->streamtype == kChannelStreamStdio) {
+    multiqueue_put(main_loop.fast_events, exit_event, 0);
   }
-
-  decref(channel);
 }
 
 static void exit_event(void **argv)
 {
-  decref(argv[0]);
-
   if (!exiting) {
     mch_exit(0);
   }
 }
 
-static void free_channel(Channel *channel)
+void rpc_free(Channel *channel)
 {
   remote_ui_disconnect(channel->id);
-  pmap_del(uint64_t)(channels, channel->id);
-  msgpack_unpacker_free(channel->unpacker);
+  msgpack_unpacker_free(channel->rpc.unpacker);
 
   // Unsubscribe from all events
   char *event_string;
-  map_foreach_value(channel->subscribed_events, event_string, {
+  map_foreach_value(channel->rpc.subscribed_events, event_string, {
     unsubscribe(channel, event_string);
   });
 
-  pmap_free(cstr_t)(channel->subscribed_events);
-  kv_destroy(channel->call_stack);
-  kv_destroy(channel->delayed_notifications);
-  if (channel->type != kChannelTypeProc) {
-    multiqueue_free(channel->events);
-  }
-  xfree(channel);
-}
-
-static void close_cb(Stream *stream, void *data)
-{
-  decref(data);
-}
-
-static Channel *register_channel(ChannelType type, uint64_t id,
-                                 MultiQueue *events)
-{
-  Channel *rv = xmalloc(sizeof(Channel));
-  rv->events = events ? events : multiqueue_new_child(main_loop.events);
-  rv->type = type;
-  rv->refcount = 1;
-  rv->closed = false;
-  rv->unpacker = msgpack_unpacker_new(MSGPACK_UNPACKER_INIT_BUFFER_SIZE);
-  rv->id = id > 0 ? id : next_chan_id++;
-  rv->pending_requests = 0;
-  rv->subscribed_events = pmap_new(cstr_t)();
-  rv->next_request_id = 1;
-  kv_init(rv->call_stack);
-  kv_init(rv->delayed_notifications);
-  pmap_put(uint64_t)(channels, rv->id, rv);
-  return rv;
+  pmap_free(cstr_t)(channel->rpc.subscribed_events);
+  kv_destroy(channel->rpc.call_stack);
 }
 
 static bool is_rpc_response(msgpack_object *obj)
@@ -694,15 +567,18 @@ static bool is_rpc_response(msgpack_object *obj)
 static bool is_valid_rpc_response(msgpack_object *obj, Channel *channel)
 {
   uint64_t response_id = obj->via.array.ptr[1].via.u64;
+  if (kv_size(channel->rpc.call_stack) == 0) {
+    return false;
+  }
+
   // Must be equal to the frame at the stack's bottom
-  return kv_size(channel->call_stack) && response_id
-    == kv_A(channel->call_stack, kv_size(channel->call_stack) - 1)->request_id;
+  ChannelCallFrame *frame = kv_last(channel->rpc.call_stack);
+  return response_id == frame->request_id;
 }
 
 static void complete_call(msgpack_object *obj, Channel *channel)
 {
-  ChannelCallFrame *frame = kv_A(channel->call_stack,
-                             kv_size(channel->call_stack) - 1);
+  ChannelCallFrame *frame = kv_last(channel->rpc.call_stack);
   frame->returned = true;
   frame->errored = obj->via.array.ptr[2].type != MSGPACK_OBJECT_NIL;
 
@@ -713,22 +589,23 @@ static void complete_call(msgpack_object *obj, Channel *channel)
   }
 }
 
-static void call_set_error(Channel *channel, char *msg)
+static void call_set_error(Channel *channel, char *msg, int loglevel)
 {
-  ELOG("RPC: %s", msg);
-  for (size_t i = 0; i < kv_size(channel->call_stack); i++) {
-    ChannelCallFrame *frame = kv_A(channel->call_stack, i);
+  LOG(loglevel, "RPC: %s", msg);
+  for (size_t i = 0; i < kv_size(channel->rpc.call_stack); i++) {
+    ChannelCallFrame *frame = kv_A(channel->rpc.call_stack, i);
     frame->returned = true;
     frame->errored = true;
+    api_free_object(frame->result);
     frame->result = STRING_OBJ(cstr_to_string(msg));
   }
 
-  close_channel(channel);
+  channel_close(channel->id, kChannelPartRpc, NULL);
 }
 
 static WBuffer *serialize_request(uint64_t channel_id,
                                   uint64_t request_id,
-                                  String method,
+                                  const String method,
                                   Array args,
                                   msgpack_sbuffer *sbuffer,
                                   size_t refcount)
@@ -765,28 +642,6 @@ static WBuffer *serialize_response(uint64_t channel_id,
   return rv;
 }
 
-static void send_delayed_notifications(Channel* channel)
-{
-  for (size_t i = 0; i < kv_size(channel->delayed_notifications); i++) {
-    WBuffer *buffer = kv_A(channel->delayed_notifications, i);
-    channel_write(channel, buffer);
-  }
-
-  kv_size(channel->delayed_notifications) = 0;
-}
-
-static void incref(Channel *channel)
-{
-  channel->refcount++;
-}
-
-static void decref(Channel *channel)
-{
-  if (!(--channel->refcount)) {
-    free_channel(channel);
-  }
-}
-
 #if MIN_LOG_LEVEL <= DEBUG_LOG_LEVEL
 #define REQ "[request]  "
 #define RES "[response] "
diff --git a/src/nvim/msgpack_rpc/channel.h b/src/nvim/msgpack_rpc/channel.h
index 0d92976d02..9ff5abdc5f 100644
--- a/src/nvim/msgpack_rpc/channel.h
+++ b/src/nvim/msgpack_rpc/channel.h
@@ -8,9 +8,16 @@
 #include "nvim/event/socket.h"
 #include "nvim/event/process.h"
 #include "nvim/vim.h"
+#include "nvim/channel.h"
 
 #define METHOD_MAXLEN 512
 
+/// HACK: os/input.c drains this queue immediately before blocking for input.
+///       Events on this queue are async-safe, but they need the resolved state
+///       of os_inchar(), so they are processed "just-in-time".
+MultiQueue *ch_before_blocking_events;
+
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "msgpack_rpc/channel.h.generated.h"
 #endif
diff --git a/src/nvim/msgpack_rpc/channel_defs.h b/src/nvim/msgpack_rpc/channel_defs.h
new file mode 100644
index 0000000000..6d8362e8b7
--- /dev/null
+++ b/src/nvim/msgpack_rpc/channel_defs.h
@@ -0,0 +1,36 @@
+#ifndef NVIM_MSGPACK_RPC_CHANNEL_DEFS_H
+#define NVIM_MSGPACK_RPC_CHANNEL_DEFS_H
+
+#include <stdbool.h>
+#include <uv.h>
+#include <msgpack.h>
+
+#include "nvim/api/private/defs.h"
+#include "nvim/event/socket.h"
+#include "nvim/event/process.h"
+#include "nvim/vim.h"
+
+typedef struct Channel Channel;
+
+typedef struct {
+  uint64_t request_id;
+  bool returned, errored;
+  Object result;
+} ChannelCallFrame;
+
+typedef struct {
+  Channel *channel;
+  MsgpackRpcRequestHandler handler;
+  Array args;
+  uint64_t request_id;
+} RequestEvent;
+
+typedef struct {
+  PMap(cstr_t) *subscribed_events;
+  bool closed;
+  msgpack_unpacker *unpacker;
+  uint64_t next_request_id;
+  kvec_t(ChannelCallFrame *) call_stack;
+} RpcState;
+
+#endif  // NVIM_MSGPACK_RPC_CHANNEL_DEFS_H
diff --git a/src/nvim/msgpack_rpc/helpers.c b/src/nvim/msgpack_rpc/helpers.c
index 5137b375f0..fecae11d45 100644
--- a/src/nvim/msgpack_rpc/helpers.c
+++ b/src/nvim/msgpack_rpc/helpers.c
@@ -1,3 +1,6 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
 #include <stdint.h>
 #include <stdbool.h>
 #include <inttypes.h>
@@ -21,12 +24,12 @@ static msgpack_zone zone;
 static msgpack_sbuffer sbuffer;
 
 #define HANDLE_TYPE_CONVERSION_IMPL(t, lt) \
-  bool msgpack_rpc_to_##lt(const msgpack_object *const obj, \
-                           Integer *const arg) \
-    FUNC_ATTR_NONNULL_ALL \
+  static bool msgpack_rpc_to_##lt(const msgpack_object *const obj, \
+                                  Integer *const arg) \
+    FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT \
   { \
     if (obj->type != MSGPACK_OBJECT_EXT \
-        || obj->via.ext.type != kObjectType##t) { \
+        || obj->via.ext.type + EXT_OBJECT_TYPE_SHIFT != kObjectType##t) { \
       return false; \
     } \
     \
@@ -45,13 +48,14 @@ static msgpack_sbuffer sbuffer;
     return true; \
   } \
   \
-  void msgpack_rpc_from_##lt(Integer o, msgpack_packer *res) \
+  static void msgpack_rpc_from_##lt(Integer o, msgpack_packer *res) \
     FUNC_ATTR_NONNULL_ARG(2) \
   { \
     msgpack_packer pac; \
     msgpack_packer_init(&pac, &sbuffer, msgpack_sbuffer_write); \
     msgpack_pack_int64(&pac, (handle_T)o); \
-    msgpack_pack_ext(res, sbuffer.size, kObjectType##t); \
+    msgpack_pack_ext(res, sbuffer.size, \
+                     kObjectType##t - EXT_OBJECT_TYPE_SHIFT); \
     msgpack_pack_ext_body(res, sbuffer.data, sbuffer.size); \
     msgpack_sbuffer_clear(&sbuffer); \
   }
@@ -73,7 +77,7 @@ typedef struct {
   size_t idx;
 } MPToAPIObjectStackItem;
 
-/// Convert type used by msgpack parser to Neovim own API type
+/// Convert type used by msgpack parser to Nvim API type.
 ///
 /// @param[in]  obj  Msgpack value to convert.
 /// @param[out]  arg  Location where result of conversion will be saved.
@@ -84,7 +88,12 @@ bool msgpack_rpc_to_object(const msgpack_object *const obj, Object *const arg)
 {
   bool ret = true;
   kvec_t(MPToAPIObjectStackItem) stack = KV_INITIAL_VALUE;
-  kv_push(stack, ((MPToAPIObjectStackItem) { obj, arg, false, 0 }));
+  kv_push(stack, ((MPToAPIObjectStackItem) {
+    .mobj = obj,
+    .aobj = arg,
+    .container = false,
+    .idx = 0,
+  }));
   while (ret && kv_size(stack)) {
     MPToAPIObjectStackItem cur = kv_last(stack);
     if (!cur.container) {
@@ -114,10 +123,16 @@ bool msgpack_rpc_to_object(const msgpack_object *const obj, Object *const arg)
         }
         break;
       }
-      case MSGPACK_OBJECT_FLOAT: {
+#ifdef NVIM_MSGPACK_HAS_FLOAT32
+      case MSGPACK_OBJECT_FLOAT32:
+      case MSGPACK_OBJECT_FLOAT64:
+#else
+      case MSGPACK_OBJECT_FLOAT:
+#endif
+      {
         STATIC_ASSERT(sizeof(Float) == sizeof(cur.mobj->via.f64),
                       "Msgpack floating-point size does not match API integer");
-        *cur.aobj = FLOATING_OBJ(cur.mobj->via.f64);
+        *cur.aobj = FLOAT_OBJ(cur.mobj->via.f64);
         break;
       }
 #define STR_CASE(type, attr, obj, dest, conv) \
@@ -181,7 +196,12 @@ bool msgpack_rpc_to_object(const msgpack_object *const obj, Object *const arg)
               case MSGPACK_OBJECT_BOOLEAN:
               case MSGPACK_OBJECT_POSITIVE_INTEGER:
               case MSGPACK_OBJECT_NEGATIVE_INTEGER:
+#ifdef NVIM_MSGPACK_HAS_FLOAT32
+              case MSGPACK_OBJECT_FLOAT32:
+              case MSGPACK_OBJECT_FLOAT64:
+#else
               case MSGPACK_OBJECT_FLOAT:
+#endif
               case MSGPACK_OBJECT_EXT:
               case MSGPACK_OBJECT_MAP:
               case MSGPACK_OBJECT_ARRAY: {
@@ -211,7 +231,7 @@ bool msgpack_rpc_to_object(const msgpack_object *const obj, Object *const arg)
         break;
       }
       case MSGPACK_OBJECT_EXT: {
-        switch (cur.mobj->via.ext.type) {
+        switch ((ObjectType)(cur.mobj->via.ext.type + EXT_OBJECT_TYPE_SHIFT)) {
           case kObjectTypeBuffer: {
             cur.aobj->type = kObjectTypeBuffer;
             ret = msgpack_rpc_to_buffer(cur.mobj, &cur.aobj->data.integer);
@@ -227,6 +247,15 @@ bool msgpack_rpc_to_object(const msgpack_object *const obj, Object *const arg)
             ret = msgpack_rpc_to_tabpage(cur.mobj, &cur.aobj->data.integer);
             break;
           }
+          case kObjectTypeNil:
+          case kObjectTypeBoolean:
+          case kObjectTypeInteger:
+          case kObjectTypeFloat:
+          case kObjectTypeString:
+          case kObjectTypeArray:
+          case kObjectTypeDictionary: {
+            break;
+          }
         }
         break;
       }
@@ -322,7 +351,7 @@ void msgpack_rpc_from_float(Float result, msgpack_packer *res)
   msgpack_pack_double(res, result);
 }
 
-void msgpack_rpc_from_string(String result, msgpack_packer *res)
+void msgpack_rpc_from_string(const String result, msgpack_packer *res)
   FUNC_ATTR_NONNULL_ARG(2)
 {
   msgpack_pack_str(res, result.size);
@@ -337,7 +366,7 @@ typedef struct {
   size_t idx;
 } APIToMPObjectStackItem;
 
-/// Convert type used by Neovim API to msgpack
+/// Convert type used by Nvim API to msgpack type.
 ///
 /// @param[in]  result  Object to convert.
 /// @param[out]  res  Structure that defines where conversion results are saved.
@@ -350,6 +379,9 @@ void msgpack_rpc_from_object(const Object result, msgpack_packer *const res)
   kv_push(stack, ((APIToMPObjectStackItem) { &result, false, 0 }));
   while (kv_size(stack)) {
     APIToMPObjectStackItem cur = kv_last(stack);
+    STATIC_ASSERT(kObjectTypeWindow == kObjectTypeBuffer + 1
+                  && kObjectTypeTabpage == kObjectTypeWindow + 1,
+                  "Buffer, window and tabpage enum items are in order");
     switch (cur.aobj->type) {
       case kObjectTypeNil: {
         msgpack_pack_nil(res);
@@ -461,8 +493,7 @@ Object msgpack_rpc_handle_missing_method(uint64_t channel_id,
                                          Array args,
                                          Error *error)
 {
-  snprintf(error->msg, sizeof(error->msg), "Invalid method name");
-  error->set = true;
+  api_set_error(error, kErrorTypeException, "Invalid method name");
   return NIL;
 }
 
@@ -471,14 +502,13 @@ Object msgpack_rpc_handle_invalid_arguments(uint64_t channel_id,
                                             Array args,
                                             Error *error)
 {
-  snprintf(error->msg, sizeof(error->msg), "Invalid method arguments");
-  error->set = true;
+  api_set_error(error, kErrorTypeException, "Invalid method arguments");
   return NIL;
 }
 
 /// Serializes a msgpack-rpc request or notification(id == 0)
 void msgpack_rpc_serialize_request(uint64_t request_id,
-                                   String method,
+                                   const String method,
                                    Array args,
                                    msgpack_packer *pac)
   FUNC_ATTR_NONNULL_ARG(4)
@@ -505,7 +535,7 @@ void msgpack_rpc_serialize_response(uint64_t response_id,
   msgpack_pack_int(pac, 1);
   msgpack_pack_uint64(pac, response_id);
 
-  if (err->set) {
+  if (ERROR_SET(err)) {
     // error represented by a [type, message] array
     msgpack_pack_array(pac, 2);
     msgpack_rpc_from_integer(err->type, pac);
@@ -558,49 +588,49 @@ void msgpack_rpc_validate(uint64_t *response_id,
   *response_id = NO_RESPONSE;
   // Validate the basic structure of the msgpack-rpc payload
   if (req->type != MSGPACK_OBJECT_ARRAY) {
-    api_set_error(err, Validation, _("Message is not an array"));
+    api_set_error(err, kErrorTypeValidation, "Message is not an array");
     return;
   }
 
   if (req->via.array.size == 0) {
-    api_set_error(err, Validation, _("Message is empty"));
+    api_set_error(err, kErrorTypeValidation, "Message is empty");
     return;
   }
 
   if (req->via.array.ptr[0].type != MSGPACK_OBJECT_POSITIVE_INTEGER) {
-    api_set_error(err, Validation, _("Message type must be an integer"));
+    api_set_error(err, kErrorTypeValidation, "Message type must be an integer");
     return;
   }
 
   uint64_t type = req->via.array.ptr[0].via.u64;
   if (type != kMessageTypeRequest && type != kMessageTypeNotification) {
-    api_set_error(err, Validation, _("Unknown message type"));
+    api_set_error(err, kErrorTypeValidation, "Unknown message type");
     return;
   }
 
   if ((type == kMessageTypeRequest && req->via.array.size != 4)
       || (type == kMessageTypeNotification && req->via.array.size != 3)) {
-    api_set_error(err, Validation, _("Request array size should be 4 (request) "
-                                     "or 3 (notification)"));
+    api_set_error(err, kErrorTypeValidation,
+                  "Request array size must be 4 (request) or 3 (notification)");
     return;
   }
 
   if (type == kMessageTypeRequest) {
     msgpack_object *id_obj = msgpack_rpc_msg_id(req);
     if (!id_obj) {
-      api_set_error(err, Validation, _("ID must be a positive integer"));
+      api_set_error(err, kErrorTypeValidation, "ID must be a positive integer");
       return;
     }
     *response_id = id_obj->via.u64;
   }
 
   if (!msgpack_rpc_method(req)) {
-    api_set_error(err, Validation, _("Method must be a string"));
+    api_set_error(err, kErrorTypeValidation, "Method must be a string");
     return;
   }
 
   if (!msgpack_rpc_args(req)) {
-    api_set_error(err, Validation, _("Parameters must be an array"));
+    api_set_error(err, kErrorTypeValidation, "Parameters must be an array");
     return;
   }
 }
diff --git a/src/nvim/msgpack_rpc/helpers.h b/src/nvim/msgpack_rpc/helpers.h
index 7d9f114140..0e4cd1be6d 100644
--- a/src/nvim/msgpack_rpc/helpers.h
+++ b/src/nvim/msgpack_rpc/helpers.h
@@ -9,6 +9,13 @@
 #include "nvim/event/wstream.h"
 #include "nvim/api/private/defs.h"
 
+/// Value by which objects represented as EXT type are shifted
+///
+/// Subtracted when packing, added when unpacking. Used to allow moving
+/// buffer/window/tabpage block inside ObjectType enum. This block yet cannot be
+/// split or reordered.
+#define EXT_OBJECT_TYPE_SHIFT kObjectTypeBuffer
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "msgpack_rpc/helpers.h.generated.h"
 #endif
diff --git a/src/nvim/msgpack_rpc/server.c b/src/nvim/msgpack_rpc/server.c
index d7c2926a0f..9bf122f4db 100644
--- a/src/nvim/msgpack_rpc/server.c
+++ b/src/nvim/msgpack_rpc/server.c
@@ -1,3 +1,6 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
@@ -94,39 +97,61 @@ char *server_address_new(void)
 #endif
 }
 
-/// Starts listening for API calls on the TCP address or pipe path `endpoint`.
+/// Check if this instance owns a pipe address.
+/// The argument must already be resolved to an absolute path!
+bool server_owns_pipe_address(const char *path)
+{
+  for (int i = 0; i < watchers.ga_len; i++) {
+    if (!strcmp(path, ((SocketWatcher **)watchers.ga_data)[i]->addr)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/// Starts listening for API calls.
+///
 /// The socket type is determined by parsing `endpoint`: If it's a valid IPv4
-/// address in 'ip[:port]' format, then it will be TCP socket. The port is
-/// optional and if omitted defaults to NVIM_DEFAULT_TCP_PORT. Otherwise it
-/// will be a unix socket or named pipe.
+/// or IPv6 address in 'ip:[port]' format, then it will be a TCP socket.
+/// Otherwise it will be a Unix socket or named pipe (Windows).
+///
+/// If no port is given, a random one will be assigned.
 ///
-/// @param endpoint Address of the server. Either a 'ip[:port]' string or an
-///        arbitrary identifier (trimmed to 256 bytes) for the unix socket or
-///        named pipe.
+/// @param endpoint Address of the server. Either a 'ip:[port]' string or an
+///                 arbitrary identifier (trimmed to 256 bytes) for the Unix
+///                 socket or named pipe.
 /// @returns 0 on success, 1 on a regular error, and negative errno
-///          on failure to bind or connect.
+///          on failure to bind or listen.
 int server_start(const char *endpoint)
 {
-  if (endpoint == NULL) {
-    ELOG("Attempting to start server on NULL endpoint");
+  if (endpoint == NULL || endpoint[0] == '\0') {
+    WLOG("Empty or NULL endpoint");
     return 1;
   }
 
   SocketWatcher *watcher = xmalloc(sizeof(SocketWatcher));
-  socket_watcher_init(&main_loop, watcher, endpoint, NULL);
+
+  int result = socket_watcher_init(&main_loop, watcher, endpoint);
+  if (result < 0) {
+    xfree(watcher);
+    return result;
+  }
 
   // Check if a watcher for the endpoint already exists
   for (int i = 0; i < watchers.ga_len; i++) {
     if (!strcmp(watcher->addr, ((SocketWatcher **)watchers.ga_data)[i]->addr)) {
       ELOG("Already listening on %s", watcher->addr);
+      if (watcher->stream->type == UV_TCP) {
+        uv_freeaddrinfo(watcher->uv.tcp.addrinfo);
+      }
       socket_watcher_close(watcher, free_server);
       return 1;
     }
   }
 
-  int result = socket_watcher_start(watcher, MAX_CONNECTIONS, connection_cb);
+  result = socket_watcher_start(watcher, MAX_CONNECTIONS, connection_cb);
   if (result < 0) {
-    ELOG("Failed to start server: %s", uv_strerror(result));
+    WLOG("Failed to start server: %s", uv_strerror(result));
     socket_watcher_close(watcher, free_server);
     return result;
   }
@@ -155,6 +180,7 @@ int server_start(const char *endpoint)
 void server_stop(char *endpoint)
 {
   SocketWatcher *watcher;
+  bool watcher_found = false;
   char addr[ADDRESS_MAX_SIZE];
 
   // Trim to `ADDRESS_MAX_SIZE`
@@ -164,11 +190,12 @@ void server_stop(char *endpoint)
   for (; i < watchers.ga_len; i++) {
     watcher = ((SocketWatcher **)watchers.ga_data)[i];
     if (strcmp(addr, watcher->addr) == 0) {
+      watcher_found = true;
       break;
     }
   }
 
-  if (i >= watchers.ga_len) {
+  if (!watcher_found) {
     ELOG("Not listening on %s", addr);
     return;
   }
diff --git a/src/nvim/msgpack_rpc/server.h b/src/nvim/msgpack_rpc/server.h
index f1a6703938..5446e40e0b 100644
--- a/src/nvim/msgpack_rpc/server.h
+++ b/src/nvim/msgpack_rpc/server.h
@@ -1,6 +1,8 @@
 #ifndef NVIM_MSGPACK_RPC_SERVER_H
 #define NVIM_MSGPACK_RPC_SERVER_H
 
+#include <stdio.h>
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "msgpack_rpc/server.h.generated.h"
 #endif