Merge #6247 'api: nvim_get_mode()'

3 files changed, 24 insertions, 8 deletions

diff --git a/src/nvim/msgpack_rpc/channel.c b/src/nvim/msgpack_rpc/channel.c
index 59594357de..911f2a6fa4 100644
--- a/src/nvim/msgpack_rpc/channel.c
+++ b/src/nvim/msgpack_rpc/channel.c
@@ -29,6 +29,7 @@
 #include "nvim/log.h"
 #include "nvim/misc1.h"
 #include "nvim/lib/kvec.h"
+#include "nvim/os/input.h"
 
 #define CHANNEL_BUFFER_SIZE 0xffff
 
@@ -89,6 +90,7 @@ static msgpack_sbuffer out_buffer;
 /// Initializes the module
 void channel_init(void)
 {
+  ch_before_blocking_events = multiqueue_new_child(main_loop.events);
   channels = pmap_new(uint64_t)();
   event_strings = pmap_new(cstr_t)();
   msgpack_sbuffer_init(&out_buffer);
@@ -433,16 +435,25 @@ 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;
+  RequestEvent *evdata = xmalloc(sizeof(RequestEvent));
+  evdata->channel = channel;
+  evdata->handler = handler;
+  evdata->args = args;
+  evdata->request_id = request_id;
   incref(channel);
   if (handler.async) {
-    on_request_event((void **)&event_data);
+    bool is_get_mode = sizeof("nvim_get_mode") - 1 == method->via.bin.size
+      && !strncmp("nvim_get_mode", method->via.bin.ptr, method->via.bin.size);
+
+    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);
   }
 }
 
diff --git a/src/nvim/msgpack_rpc/channel.h b/src/nvim/msgpack_rpc/channel.h
index 0d92976d02..f8fe6f129b 100644
--- a/src/nvim/msgpack_rpc/channel.h
+++ b/src/nvim/msgpack_rpc/channel.h
@@ -11,6 +11,11 @@
 
 #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/helpers.c b/src/nvim/msgpack_rpc/helpers.c
index 0228582d37..91ef5524ea 100644
--- a/src/nvim/msgpack_rpc/helpers.c
+++ b/src/nvim/msgpack_rpc/helpers.c
@@ -76,7 +76,7 @@ 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.