Reimplement input functions on top of libuv

The functions `mch_inchar`, `mch_breakcheck`, `mch_char_avail` were
reimplemented on top of libuv. Here's how it works:

- When Neovim needs to wait for characters, it will transfer control to libuv
  event loop.
- When the libuv event loop gets user input, it will transfer control back to
  Neovim
- Neovim uses the `input_read` function to get the actual data read by libuv.

With this scheme its possible to keep Neovim single-threaded while enjoying the
benefits provided by libuv.

This commit leaves SIGWINCH broken for now

1 files changed, 4 insertions, 125 deletions

diff --git a/src/os_unix.c b/src/os_unix.c
index 4b38cea807..f24e7ccff4 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -31,7 +31,6 @@
 
 #include "vim.h"
 #include "os_unix.h"
-#include "os/time.h"
 #include "buffer.h"
 #include "charset.h"
 #include "eval.h"
@@ -51,6 +50,8 @@
 #include "ui.h"
 #include "os/os.h"
 #include "os/time.h"
+#include "os/event.h"
+#include "os/input.h"
 
 #include "os_unixx.h"       /* unix includes for os_unix.c only */
 
@@ -108,7 +109,6 @@ typedef int waitstatus;
 #endif
 static pid_t wait4pid(pid_t, waitstatus *);
 
-static int WaitForChar(long);
 static int RealWaitForChar(int, long, int *);
 
 
@@ -248,98 +248,12 @@ void mch_write(char_u *s, int len)
     RealWaitForChar(read_cmd_fd, p_wd, NULL);
 }
 
-/*
- * mch_inchar(): low level input function.
- * Get a characters from the keyboard.
- * Return the number of characters that are available.
- * If wtime == 0 do not wait for characters.
- * If wtime == n wait a short time for characters.
- * If wtime == -1 wait forever for characters.
- */
-int mch_inchar(
-        char_u      *buf,
-        int maxlen,
-        long wtime,                 /* don't use "time", MIPS cannot handle it */
-        int tb_change_cnt
-        )
-{
-    int len;
-
-
-    /* Check if window changed size while we were busy, perhaps the ":set
-     * columns=99" command was used. */
-    while (do_resize)
-        handle_resize();
-
-    if (wtime >= 0) {
-        while (WaitForChar(wtime) == 0) {           /* no character available */
-            if (!do_resize)           /* return if not interrupted by resize */
-                return 0;
-            handle_resize();
-        }
-    } else {    /* wtime == -1 */
-        /*
-         * If there is no character available within 'updatetime' seconds
-         * flush all the swap files to disk.
-         * Also done when interrupted by SIGWINCH.
-         */
-        if (WaitForChar(p_ut) == 0) {
-            if (trigger_cursorhold() && maxlen >= 3
-                    && !typebuf_changed(tb_change_cnt)) {
-                buf[0] = K_SPECIAL;
-                buf[1] = KS_EXTRA;
-                buf[2] = (int)KE_CURSORHOLD;
-                return 3;
-            }
-            before_blocking();
-        }
-    }
-
-    for (;; ) {   /* repeat until we got a character */
-        while (do_resize)        /* window changed size */
-            handle_resize();
-
-        /*
-         * We want to be interrupted by the winch signal
-         * or by an event on the monitored file descriptors.
-         */
-        if (WaitForChar(-1L) == 0) {
-            if (do_resize)                /* interrupted by SIGWINCH signal */
-                handle_resize();
-            return 0;
-        }
-
-        /* If input was put directly in typeahead buffer bail out here. */
-        if (typebuf_changed(tb_change_cnt))
-            return 0;
-
-        /*
-         * For some terminals we only get one character at a time.
-         * We want the get all available characters, so we could keep on
-         * trying until none is available
-         * For some other terminals this is quite slow, that's why we don't do
-         * it.
-         */
-        len = read_from_input_buf(buf, (long)maxlen);
-        if (len > 0) {
-            return len;
-        }
-    }
-}
-
 static void handle_resize()
 {
   do_resize = FALSE;
   shell_resized();
 }
 
-/*
- * return non-zero if a character is available
- */
-int mch_char_avail()
-{
-  return WaitForChar(0L);
-}
 
 #if defined(HAVE_SIGALTSTACK) || defined(HAVE_SIGSTACK)
 /*
@@ -682,6 +596,8 @@ void mch_init()
 #ifdef MACOS_CONVERT
   mac_conv_init();
 #endif
+
+  event_init();
 }
 
 static void set_signals()
@@ -2461,43 +2377,6 @@ error:
 }
 
 /*
- * Check for CTRL-C typed by reading all available characters.
- * In cooked mode we should get SIGINT, no need to check.
- */
-void mch_breakcheck()
-{
-  if (curr_tmode == TMODE_RAW && RealWaitForChar(read_cmd_fd, 0L, NULL))
-    fill_input_buf(FALSE);
-}
-
-/*
- * Wait "msec" msec until a character is available from the keyboard or from
- * inbuf[]. msec == -1 will block forever.
- * When a GUI is being used, this will never get called -- webb
- */
-static int WaitForChar(msec)
-long msec;
-{
-  int avail;
-
-  if (input_available())            /* something in inbuf[] */
-    return 1;
-
-  /* May need to query the mouse position. */
-  if (WantQueryMouse) {
-    WantQueryMouse = FALSE;
-    mch_write((char_u *)IF_EB("\033[1'|", ESC_STR "[1'|"), 5);
-  }
-
-  /*
-   * For FEAT_MOUSE_GPM and FEAT_XCLIPBOARD we loop here to process mouse
-   * events.  This is a bit complicated, because they might both be defined.
-   */
-  avail = RealWaitForChar(read_cmd_fd, msec, NULL);
-  return avail;
-}
-
-/*
  * Wait "msec" msec until a character is available from file descriptor "fd".
  * "msec" == 0 will check for characters once.
  * "msec" == -1 will block until a character is available.