* src/igc.c (process_one_message): Use "GC end:" instead of "GC:"

A comment in mps/code/traceanc.c says:

 * (Note: this should properly be called "trace end", but it's much
 * too late to change it now!)

lisp/emacs-lisp/igc.el

@@ -468,7 +468,7 @@ This function is called from a timer;  see `igc-start-collecting-stats'."
 ;;; Opportunistic GC
 
 (defvar igc--idle-timer nil
-  "Idle timer to trigger oppurtunistic GC.")
+  "Idle timer to trigger opportunistic GC.")
 
 (defvar igc--idle-delay 1.0
   "Time, in seconds, to wait for `igc--idle-timer'.")
@@ -490,14 +490,18 @@ This function is called from a timer;  see `igc-start-collecting-stats'."
                              #'igc--on-idle (vector nil) 0)))
 
 (defun igc--current-idle-time ()
+  "Time since the last command finished, in seconds as a float.
+See `igc--on-idle'."
   (let ((idle-time (current-idle-time)))
     (if idle-time (float-time idle-time) 0)))
 
 (defun igc--predict-idle-time ()
+  "Predict available time until the next command starts.
+See `igc--on-idle'."
   (* (igc--current-idle-time) 0.80))
 
 ;; The igc-idle-timer works a bit like the blink-cursor-timer.  It can
-;; call 'gc--on-idle' multiple times per idle cycle either until some GC
+;; call 'igc--on-idle' multiple times per idle cycle either until some GC
 ;; work is done or until `igc--idle-repetitions' is reached.  We do this
 ;; because our idle time prediction primarily depends on the
 ;; `current-idle-time', i.e. our predicted idle time gets larger the
@@ -509,6 +513,9 @@ This function is called from a timer;  see `igc-start-collecting-stats'."
 ;; calling 'igc--arena-step' again.
 
 (defun igc--on-idle (state repetition)
+  "Timer function to do GC in idle Emacs state.
+Calls igc--arena-step, wrapper for mps_arena_step for this very purpose.
+See `igc-start-idle-timer."
   (let ((timer2 (aref state 0)))
     (when timer2
       (cancel-timer timer2)))

src/igc.c

@@ -4137,7 +4137,7 @@ process_one_message (struct igc *gc)
 	    = mps_message_gc_not_condemned_size (gc->arena, msg);
 	  mps_clock_t clock = mps_message_clock (gc->arena, msg);
 	  double secs = (double) clock / mps_clocks_per_sec ();
-	  message ("[%f] GC: condemned: %" pD "u live: %" pD "u "
+	  message ("[%f] GC end: condemned: %" pD "u live: %" pD "u "
 		   "not_condemned: %" pD "u",
 		   secs, condemned, live, not_condemned);
 	}

src/igc.h

@@ -182,9 +182,6 @@ void *igc_alloc_dump (size_t nbytes);
 bool igc_busy_p (void);
 Lisp_Object igc_discard_killed_buffers (Lisp_Object list);
 
-ptrdiff_t igc_pin (void *obj);
-void igc_unpin (void *obj, ptrdiff_t idx);
-
 # define eassert_not_mps() eassert (false)
 
 # define eassert_not_mps() eassert (false)
@@ -204,9 +201,6 @@ void w32_remove_non_lisp_thread (void *);
 extern void igc_assert_not_an_mps_object (void *ptr);
 # define eassert_not_mps() eassert (false)
 
-ptrdiff_t igc_pin (void *obj);
-void igc_unpin (void *obj, ptrdiff_t idx);
-
 #else
 # define igc_break() (void) 0
 # define eassert_not_mps() (void) 0