eval: implement timers. vim-patch: 7.4.1578, 7.4.1831

For the moment, timers are triggered during sleep,
but not in wait-for-input modes, like press-RETURN or f_getchar()

10 files changed, 318 insertions, 13 deletions

diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index eebdabd154..8b23d2ff5f 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2114,9 +2114,12 @@ tabpagewinnr({tabarg}[, {arg}])
 				Number	number of current window in tab page
 taglist({expr})		List	list of tags matching {expr}
 tagfiles()			List	tags files used
-tempname()			String	name for a temporary file
 tan({expr})			Float	tangent of {expr}
 tanh({expr})			Float	hyperbolic tangent of {expr}
+tempname()			String	name for a temporary file
+timer_start({time}, {callback} [, {options}])
+				Number	create a timer
+timer_stop({timer})		none	stop a timer
 tolower({expr})		String	the String {expr} switched to lowercase
 toupper({expr})		String	the String {expr} switched to uppercase
 tr({src}, {fromstr}, {tostr})	String	translate chars of {src} in {fromstr}
@@ -6840,6 +6843,37 @@ tanh({expr})						*tanh()*
 <			-0.761594
 
 
+							*timer_start()*
+timer_start({time}, {callback} [, {options}])
+		Create a timer and return the timer ID.
+
+		{time} is the waiting time in milliseconds. This is the
+		minimum time before invoking the callback.  When the system is
+		busy or Vim is not waiting for input the time will be longer.
+
+		{callback} is the function to call.  It can be the name of a
+		function or a Funcref.  It is called with one argument, which
+		is the timer ID.  The callback is only invoked when Vim is
+		waiting for input.
+
+		{options} is a dictionary.  Supported entries:
+		   "repeat"	Number of times to repeat calling the
+		   		callback.  -1 means forever.
+
+		Example: >
+			func MyHandler(timer)
+			  echo 'Handler called'
+			endfunc
+			let timer = timer_start(500, 'MyHandler',
+				\ {'repeat': 3})
+<		This will invoke MyHandler() three times at 500 msec
+		intervals.
+		{only available when compiled with the |+timers| feature}
+
+timer_stop({timer})					*timer_stop()*
+		Stop a timer.  {timer} is an ID returned by timer_start().
+		The timer callback will no longer be invoked.
+
 tolower({expr})						*tolower()*
 		The result is a copy of the String given, with all uppercase
 		characters turned into lowercase (just like applying |gu| to
@@ -7323,6 +7357,7 @@ termresponse		Compiled with support for |t_RV| and |v:termresponse|.
 textobjects		Compiled with support for |text-objects|.
 tgetent			Compiled with tgetent support, able to use a termcap
 			or terminfo file.
+timers			Compiled with |timer_start()| support.
 title			Compiled with window title support |'title'|.
 toolbar			Compiled with support for |gui-toolbar|.
 unix			Unix version of Vim.
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 96c008b0e0..6ae5081550 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -79,6 +79,7 @@
 #include "nvim/event/pty_process.h"
 #include "nvim/event/rstream.h"
 #include "nvim/event/wstream.h"
+#include "nvim/event/time.h"
 #include "nvim/os/time.h"
 #include "nvim/msgpack_rpc/channel.h"
 #include "nvim/msgpack_rpc/server.h"
@@ -428,6 +429,14 @@ typedef struct {
   int status;
 } JobEvent;
 
+typedef struct {
+  TimeWatcher tw;
+  int timer_id;
+  int repeat_count;
+  bool stopped;
+  ufunc_T *callback;
+} timer_T;
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "eval.c.generated.h"
 #endif
@@ -438,6 +447,9 @@ typedef struct {
 static uint64_t current_job_id = 1;
 static PMap(uint64_t) *jobs = NULL; 
 
+static uint64_t last_timer_id = 0;
+static PMap(uint64_t) *timers = NULL;
+
 static const char *const msgpack_type_names[] = {
   [kMPNil] = "nil",
   [kMPBoolean] = "boolean",
@@ -469,6 +481,7 @@ void eval_init(void)
   vimvars[VV_VERSION].vv_nr = VIM_VERSION_100;
 
   jobs = pmap_new(uint64_t)();
+  timers = pmap_new(uint64_t)();
   struct vimvar   *p;
 
   init_var_dict(&globvardict, &globvars_var, VAR_DEF_SCOPE);
@@ -6930,6 +6943,8 @@ static struct fst {
   { "tempname",          0, 0, f_tempname },
   { "termopen",          1, 2, f_termopen },
   { "test",              1, 1, f_test },
+  { "timer_start",       2, 3, f_timer_start },
+  { "timer_stop",        1, 1, f_timer_stop },
   { "tolower",           1, 1, f_tolower },
   { "toupper",           1, 1, f_toupper },
   { "tr",                3, 3, f_tr },
@@ -10688,6 +10703,7 @@ static void f_has(typval_T *argvars, typval_T *rettv)
     "termguicolors",
     "termresponse",
     "textobjects",
+    "timers",
     "title",
     "user-commands",        /* was accidentally included in 5.4 */
     "user_commands",
@@ -16441,6 +16457,116 @@ static void f_tanh(typval_T *argvars, typval_T *rettv)
   float_op_wrapper(argvars, rettv, &tanh);
 }
 
+
+/// "timer_start(timeout, callback, opts)" function
+static void f_timer_start(typval_T *argvars, typval_T *rettv)
+{
+  long timeout = get_tv_number(&argvars[0]);
+  timer_T *timer;
+  int repeat = 1;
+  dict_T *dict;
+
+  rettv->vval.v_number = -1;
+
+  if (argvars[2].v_type != VAR_UNKNOWN) {
+    if (argvars[2].v_type != VAR_DICT
+        || (dict = argvars[2].vval.v_dict) == NULL) {
+      EMSG2(_(e_invarg2), get_tv_string(&argvars[2]));
+      return;
+    }
+    if (dict_find(dict, (char_u *)"repeat", -1) != NULL) {
+      repeat = get_dict_number(dict, (char_u *)"repeat");
+    }
+  }
+
+  if (argvars[1].v_type != VAR_FUNC && argvars[1].v_type != VAR_STRING) {
+    EMSG2(e_invarg2, "funcref");
+    return;
+  }
+  ufunc_T *func = find_ufunc(argvars[1].vval.v_string);
+  if (!func) {
+    // Invalid function name. Error already reported by `find_ufunc`.
+    return;
+  }
+  func->uf_refcount++;
+
+  timer = xmalloc(sizeof *timer);
+  timer->stopped = false;
+  timer->repeat_count = repeat;
+  timer->timer_id = last_timer_id++;
+  timer->callback = func;
+
+  time_watcher_init(&loop, &timer->tw, timer);
+  timer->tw.events = queue_new_child(loop.events);
+  // if main loop is blocked, don't queue up multiple events
+  timer->tw.blockable = true;
+  time_watcher_start(&timer->tw, timer_due_cb, timeout,
+                     timeout * (repeat != 1));
+
+  pmap_put(uint64_t)(timers, timer->timer_id, timer);
+  rettv->vval.v_number = timer->timer_id;
+}
+
+
+// "timer_stop(timerid)" function
+static void f_timer_stop(typval_T *argvars, typval_T *rettv)
+{
+    if (argvars[0].v_type != VAR_NUMBER) {
+        EMSG(_(e_number_exp));
+        return;
+    }
+
+    timer_T *timer = pmap_get(uint64_t)(timers, get_tv_number(&argvars[0]));
+
+    if (timer == NULL) {
+      return;
+    }
+
+    timer_stop(timer);
+}
+
+// invoked on the main loop
+static void timer_due_cb(TimeWatcher *tw, void *data)
+{
+  timer_T *timer = (timer_T *)data;
+  // if repeat was negative repeat forever
+  if (timer->repeat_count >= 0 && --timer->repeat_count == 0) {
+    timer_stop(timer);
+  }
+
+  typval_T argv[1];
+  init_tv(argv);
+  argv[0].v_type = VAR_NUMBER;
+  argv[0].vval.v_number = timer->timer_id;
+  typval_T rettv;
+
+  init_tv(&rettv);
+  call_user_func(timer->callback, ARRAY_SIZE(argv), argv, &rettv,
+                 curwin->w_cursor.lnum, curwin->w_cursor.lnum, NULL);
+  clear_tv(&rettv);
+}
+
+static void timer_stop(timer_T *timer)
+{
+  if (timer->stopped) {
+    // avoid double free
+    return;
+  }
+  timer->stopped = true;
+  time_watcher_stop(&timer->tw);
+  time_watcher_close(&timer->tw, timer_free_cb);
+}
+
+// invoked on next event loop tick, so queue is empty
+static void timer_free_cb(TimeWatcher *tw, void *data)
+{
+  timer_T *timer = (timer_T *)data;
+  queue_free(timer->tw.events);
+  user_func_unref(timer->callback);
+  pmap_del(uint64_t)(timers, timer->timer_id);
+  xfree(timer);
+}
+
 /*
  * "tolower(string)" function
  */
diff --git a/src/nvim/event/time.c b/src/nvim/event/time.c
index 7bf333bcea..f68a66345f 100644
--- a/src/nvim/event/time.c
+++ b/src/nvim/event/time.c
@@ -17,6 +17,7 @@ void time_watcher_init(Loop *loop, TimeWatcher *watcher, void *data)
   watcher->uv.data = watcher;
   watcher->data = data;
   watcher->events = loop->fast_events;
+  watcher->blockable = false;
 }
 
 void time_watcher_start(TimeWatcher *watcher, time_cb cb, uint64_t timeout,
@@ -50,6 +51,10 @@ static void time_watcher_cb(uv_timer_t *handle)
   FUNC_ATTR_NONNULL_ALL
 {
   TimeWatcher *watcher = handle->data;
+  if (watcher->blockable && !queue_empty(watcher->events)) {
+    // the timer blocked and there already is an unprocessed event waiting
+    return;
+  }
   CREATE_EVENT(watcher->events, time_event, 1, watcher);
 }
 
diff --git a/src/nvim/event/time.h b/src/nvim/event/time.h
index 7882b2b627..14df176ea3 100644
--- a/src/nvim/event/time.h
+++ b/src/nvim/event/time.h
@@ -13,6 +13,7 @@ struct time_watcher {
   void *data;
   time_cb cb, close_cb;
   Queue *events;
+  bool blockable;
 };
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 870284a0f7..59962c153b 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -6989,10 +6989,10 @@ static void ex_sleep(exarg_T *eap)
  */
 void do_sleep(long msec)
 {
-  long done;
   ui_flush();  // flush before waiting
-  for (done = 0; !got_int && done < msec; done += 1000L) {
-    os_delay(msec - done > 1000L ? 1000L : msec - done, true);
+  for (long left = msec; !got_int && left > 0; left -= 1000L) {
+    int next = left > 1000l ? 1000 : (int)left;
+    LOOP_PROCESS_EVENTS_UNTIL(&loop, loop.events, (int)next, got_int);
     os_breakcheck();
   }
 }
diff --git a/src/nvim/testdir/Makefile b/src/nvim/testdir/Makefile
index 2fba6dd563..3e17117db0 100644
--- a/src/nvim/testdir/Makefile
+++ b/src/nvim/testdir/Makefile
@@ -40,6 +40,7 @@ NEW_TESTS = \
 	    test_cursor_func.res \
 	    test_help_tagjump.res \
 	    test_menu.res \
+	    test_timers.res \
 	    test_viml.res \
 	    test_alot.res
 
diff --git a/src/nvim/testdir/test_timers.vim b/src/nvim/testdir/test_timers.vim
new file mode 100644
index 0000000000..9f58a35909
--- /dev/null
+++ b/src/nvim/testdir/test_timers.vim
@@ -0,0 +1,32 @@
+" Test for timers
+
+if !has('timers')
+  finish
+endif
+
+func MyHandler(timer)
+  let s:val += 1
+endfunc
+
+func Test_oneshot()
+  let s:val = 0
+  let timer = timer_start(50, 'MyHandler')
+  sleep 200m
+  call assert_equal(1, s:val)
+endfunc
+
+func Test_repeat_three()
+  let s:val = 0
+  let timer = timer_start(50, 'MyHandler', {'repeat': 3})
+  sleep 500m
+  call assert_equal(3, s:val)
+endfunc
+
+func Test_repeat_many()
+  let s:val = 0
+  let timer = timer_start(50, 'MyHandler', {'repeat': -1})
+  sleep 200m
+  call timer_stop(timer)
+  call assert_true(s:val > 1)
+  call assert_true(s:val < 5)
+endfunc
diff --git a/src/nvim/version.c b/src/nvim/version.c
index 23bfca6221..820c878998 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -70,6 +70,7 @@ static char *features[] = {
 // clang-format off
 static int included_patches[] = {
   1832,
+  1831,
   1809,
   1808,
   1806,
@@ -82,6 +83,7 @@ static int included_patches[] = {
   1652,
   1643,
   1641,
+  // 1624 NA
 
   // 1600 NA
   // 1599 NA
@@ -106,7 +108,7 @@ static int included_patches[] = {
   // 1581,
   // 1580,
   // 1579,
-  // 1578,
+  1578,
   // 1577,
   1576,
   // 1575 NA
diff --git a/test/functional/eval/timer_spec.lua b/test/functional/eval/timer_spec.lua
new file mode 100644
index 0000000000..df0a55e462
--- /dev/null
+++ b/test/functional/eval/timer_spec.lua
@@ -0,0 +1,106 @@
+local helpers = require('test.functional.helpers')
+local ok, feed, eq, eval = helpers.ok, helpers.feed, helpers.eq, helpers.eval
+local source, nvim_async, run = helpers.source, helpers.nvim_async, helpers.run
+local clear, execute, funcs = helpers.clear, helpers.execute, helpers.funcs
+
+describe('timers', function()
+  before_each(function()
+    clear()
+    source([[
+      let g:val = 0
+      func MyHandler(timer)
+        let g:val += 1
+      endfunc
+    ]])
+  end)
+
+  it('works one-shot', function()
+    execute("call timer_start(50, 'MyHandler')")
+    eq(0,eval("g:val"))
+    run(nil, nil, nil, 200)
+    eq(1,eval("g:val"))
+  end)
+
+  it('works with repeat two', function()
+    execute("call timer_start(50, 'MyHandler', {'repeat': 2})")
+    eq(0,eval("g:val"))
+    run(nil, nil, nil, 300)
+    eq(2,eval("g:val"))
+  end)
+
+  it('are triggered during sleep', function()
+    execute("call timer_start(50, 'MyHandler', {'repeat': 2})")
+    nvim_async("command", "sleep 10")
+    eq(0,eval("g:val"))
+    run(nil, nil, nil, 300)
+    eq(2,eval("g:val"))
+  end)
+
+  it('can be started during sleep', function()
+    nvim_async("command", "sleep 10")
+    -- this also tests that remote requests works during sleep
+    eval("timer_start(50, 'MyHandler', {'repeat': 2})")
+    eq(0,eval("g:val"))
+    run(nil, nil, nil, 300)
+    eq(2,eval("g:val"))
+  end)
+
+  it('are paused when event processing is disabled', function()
+    -- this is not the intended behavior, but at least there will
+    -- not be a burst of queued up callbacks
+    execute("call timer_start(50, 'MyHandler', {'repeat': 2})")
+    run(nil, nil, nil, 100)
+    local count = eval("g:val")
+    nvim_async("command", "let g:c = getchar()")
+    run(nil, nil, nil, 300)
+    feed("c")
+    local diff = eval("g:val") - count
+    ok(0 <= diff and diff <= 2)
+    eq(99, eval("g:c"))
+  end)
+
+  it('can be stopped', function()
+    local t = eval("timer_start(50, 'MyHandler', {'repeat': -1})")
+    eq(0,eval("g:val"))
+    run(nil, nil, nil, 300)
+    funcs.timer_stop(t)
+    local count = eval("g:val")
+    run(nil, nil, nil, 300)
+    local count2 = eval("g:val")
+    ok(4 <= count and count <= 7)
+    -- when count is eval:ed after timer_stop this should be non-racy
+    eq(count, count2)
+  end)
+
+  it('can be stopped from the handler', function()
+    source([[
+      func! MyHandler(timer)
+        let g:val += 1
+        if g:val == 3
+          call timer_stop(a:timer)
+          " check double stop is ignored
+          call timer_stop(a:timer)
+        endif
+      endfunc
+    ]])
+    execute("call timer_start(50, 'MyHandler', {'repeat': -1})")
+    eq(0,eval("g:val"))
+    run(nil, nil, nil, 300)
+    eq(3,eval("g:val"))
+  end)
+
+  it('can have two timers', function()
+    source([[
+      let g:val2 = 0
+      func! MyHandler2(timer)
+        let g:val2 += 1
+      endfunc
+    ]])
+    execute("call timer_start(50,  'MyHandler', {'repeat': 3})")
+    execute("call timer_start(100, 'MyHandler2', {'repeat': 2})")
+    run(nil, nil, nil, 300)
+    eq(3,eval("g:val"))
+    eq(2,eval("g:val2"))
+  end)
+
+end)
diff --git a/test/functional/legacy/061_undo_tree_spec.lua b/test/functional/legacy/061_undo_tree_spec.lua
index 6db37bf1ff..350a77b2c5 100644
--- a/test/functional/legacy/061_undo_tree_spec.lua
+++ b/test/functional/legacy/061_undo_tree_spec.lua
@@ -1,10 +1,9 @@
 -- Tests for undo tree and :earlier and :later.
 
 local helpers = require('test.functional.helpers')
-local feed, source, eq, eval, clear, execute, expect, wait, write_file =
-  helpers.feed, helpers.source, helpers.eq, helpers.eval,
-  helpers.clear, helpers.execute, helpers.expect, helpers.wait,
-  helpers.write_file
+local expect, feed, source = helpers.expect, helpers.feed, helpers.source
+local eval, clear, execute = helpers.eval, helpers.clear, helpers.execute
+local write_file, command, eq = helpers.write_file, helpers.command, helpers.eq
 
 local function expect_empty_buffer()
   -- The space will be removed by helpers.dedent but is needed because dedent
@@ -57,8 +56,7 @@ describe('undo tree:', function()
         -- Delete three other characters and go back in time step by step.
         feed('$xxx')
         expect_line('123456')
-        execute('sleep 1')
-        wait()
+        command('sleep 1')
         feed('g-')
         expect_line('1234567')
         feed('g-')
@@ -79,8 +77,7 @@ describe('undo tree:', function()
         expect_line('123456')
 
         -- Delay for two seconds and go some seconds forward and backward.
-        execute('sleep 2')
-        wait()
+        command('sleep 2')
         feed('Aa<esc>')
         feed('Ab<esc>')
         feed('Ac<esc>')