Support higher-resolution time stamps.

Fixes: debbugs:9000

1 files changed, 169 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a5e10fe9473..65424205f34 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,172 @@
+2012-06-22  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Support higher-resolution time stamps (Bug#9000).
+        The time stamps are only nanosecond-resolution at the C level,
+        since that's the best that any real-world system supports now.
+        But they are picosecond-resolution at the Lisp level, as that's
+        easy, and leaves room for future OS improvements.
+
+        * Makefile.in (LIB_CLOCK_GETTIME): New macro.
+        (LIBES): Use it.
+
+        * alloc.c (Fgarbage_collect): Port to higher-res time stamps.
+        Don't get current time unless it's needed.
+
+        * atimer.c: Include <sys/time.h> unconditionally, since gnulib
+        now provides it if it's absent.
+        (start_atimer): Port to higher-res time stamps.
+        Check for time stamp overflow.  Don't get current time more
+        often than is needed.
+
+        * buffer.h (struct buffer): Buffer modtime now has high resolution.
+        Include systime.h, not time.h.
+        (NONEXISTENT_MODTIME_NSECS, UNKNOWN_MODTIME_NSECS): New macros.
+
+        * dired.c: Include stat-time.h.
+        (Ffile-attributes): File times now have higher resolution.
+
+        * dispextern.h [HAVE_WINDOW_SYSTEM]: Include systime.h.
+        (struct image): Timestamp now has higher resolution.
+
+        * dispnew.c (PERIODIC_PREEMPTION_CHECKING): Remove, as Emacs always
+        has at least microseconds now.  All uses removed.
+        (update_frame, update_single_window, update_window, update_frame_1)
+        (Fsleep_for, sit_for): Port to higher-resolution time stamps.
+
+        * editfns.c (time_overflow): Now extern.
+        (Fcurrent_time, Fget_internal_run_time, make_time, lisp_time_argument)
+        (float-time, Fformat_time_string, Fcurrent_time_string)
+        (Fcurrent_time_zone): Accept and generate higher-resolution
+        time stamps.
+        (make_time_tail, make_lisp_time, dissassemble_lisp_time)
+        (decode_time_components, lisp_seconds_argument): New functions.
+        (make_time): Now static.
+        (lisp_time_argument): Now returns EMACS_TIME.  New arg ppsec.
+        Report an error if the time is invalid, rather than having the caller
+        do that.
+
+        * fileio.c: Include <stat-time.h>
+        (Fcopy_file): Copy higher-resolution time stamps.
+        Prefer to set the time stamp via a file descriptor if that works.
+        (Fset_file_times, Finsert_file_contents, Fwrite_region)
+        (Fverify_visited_file_modtime, Fclear_visited_file_modtime)
+        (Fvisited_file_modtime, Fset_visited_file_modtime):
+        Support higher-resolution time stamps.
+
+        * fns.c (Frandom): Use nanoseconds, not microseconds, for seed.
+
+        * gtkutil.c (xg_maybe_add_timer): Port to higher-res time stamps.
+
+        * image.c (prepare_image_for_display, clear_image_cache)
+        (lookup_image): Port to higer-resolution time stamps.
+
+        * keyboard.c (start_polling, bind_polling_period):
+        Check for time stamp overflow.
+        (read_char, kbd_buffer_get_event, timer_start_idle)
+        (timer_stop_idle, timer_resume_idle, timer_check_2, timer_check)
+        (Fcurrent_idle_time, init_keyboard, set_waiting_for_input):
+        Port to higher-resolution time stamps.  Do not assume time_t is signed.
+        (decode_timer): New function.  Timers are now vectors of length 9,
+        not 8, to accommodate the picosecond component.
+        (timer_check_2): Use it.
+
+        * nsterm.m (select_timeout, timeval_subtract): Remove.
+        (ns_timeout): Use Emacs's facilities for time stamp arithmetic,
+        as they're a bit more accurate and handle overflow better.
+        (ns_select): Change prototype to be compatible with pselect.
+        (ns_select, ns_term_shutdown): Port to ns-resolution time stamps.
+        * nsterm.h (ns_select): Adjust prototype.
+
+        * msdos.c (EMACS_TIME_ZERO_OR_NEG_P): Remove, as it assumes
+        us-resolution time stamps.
+        (sys_select): Use the new EMACS_TIME_SIGN macro instead.
+
+        * lread.c (read_filtered_event): Port to ns-resolution time stamps.
+
+        * lisp.h (time_overflow): New decl.
+        (wait_reading_process_output): First arg is now intmax_t, not int,
+        to accommodate larger waits.
+
+        * process.h (struct Lisp_Process.read_output_delay):
+        Now counts nanoseconds, not microseconds.
+        * process.c (ADAPTIVE_READ_BUFFERING): Don't worry about
+        EMACS_HAS_USECS.
+        (READ_OUTPUT_DELAY_INCREMENT, Faccept_process_output)
+        (wait_reading_process_output):
+        Port to ns-resolution time stamps.
+        (Faccept_process_output, wait_reading_process_output):
+        Check for time stamp overflow.  Do not assume time_t is signed.
+        (select_wrapper): Remove; we now use pselect.
+        (Fprocess_attributes): Now generates ns-resolution time stamps.
+
+        * sysdep.c: Include utimens.h.  Don't include utime.h
+        or worry about struct utimbuf; gnulib does that for us now.
+        (gettimeofday): Remove; gnulib provides a substitute.
+        (make_timeval): New function.
+        (set_file_times): Now sets ns-resolution time stamps.
+        New arg FD; all uses changed.
+        (time_from_jiffies, ltime_from_jiffies, get_up_time)
+        (system_process_attributes):
+        Now returns ns-resolution time stamp.  All uses changed.
+        Check for time stamp overflow.
+
+        * sysselect.h: Don't depend on HAVE_SYS_SELECT_H; gnulib
+        provides a substitute now.
+
+        * systime.h: Include timespec.h rather than sys/time.h and time.h,
+        since it guarantees struct timespec.
+        (EMACS_TIME): Now struct timespec, so that we can support
+        ns-resolution time stamps.
+        (EMACS_TIME_RESOLUTION, LOG10_EMACS_TIME_RESOLUTION): New macros.
+        (EMACS_HAS_USECS): Remove; Emacs always has sub-second time stamps now.
+        (EMACS_USECS): Remove.
+        (EMACS_SET_USECS): The underlying time stamp now has ns resolution,
+        so multiply the arg by 1000 before storing it.
+        (EMACS_NSECS, EMACS_SECS_ADDR, EMACS_SET_NSECS, EMACS_SET_SECS_NSECS):
+        New macros.
+        (EMACS_GET_TIME, EMACS_ADD_TIME, EMACS_SUB_TIME):
+        Port to ns-resolution time stamps.
+        (EMACS_TIME_NEG_P): Remove; replaced by....
+        (EMACS_TIME_SIGN): New macro.
+        (EMACS_SET_INVALID_TIME, EMACS_TIME_VALID_P)
+        (EMACS_TIME_FROM_DOUBLE, EMACS_TIME_TO_DOUBLE): New macros.
+        (set_file_times, make_time, lisp_time_argument): Adjust signature.
+        (make_timeval, make_lisp_time, decode_time_components): New decls.
+        (EMACS_TIME_CMP): Remove; no longer used.  Plus, it was buggy, in
+        that it mishandled time_t overflow.  You can't compare by subtracting!
+        (EMACS_TIME_EQ, EMACS_TIME_NE, EMACS_TIME_GT, EMACS_TIME_GE)
+        (EMACS_TIME_LT, EMACS_TIME_LE): Rewrite in terms of timespec_cmp.
+
+        * term.c: Include <sys/time.h>.
+        (timeval_to_Time): New function, for proper overflow wraparound.
+        (term_mouse_position, term_mouse_click): Use it.
+
+        * undo.c (record_first_change): Support higher-resolution time stamps
+        in the undo buffer.
+        (Fprimitive_undo): Use them when restoring time stamps.
+
+        * w32.c (ltime, U64_TO_LISP_TIME, process_times, emacs_gnutls_pull)
+        (w32_get_internal_run_time):
+        Port to higher-resolution Emacs time stamps.
+        (ltime): Now accepts single 64-bit integer, as that's more convenient
+        for callers.
+
+        * xdisp.c (start_hourglass): Port to ns-resolution time stamps.
+
+        * xgselect.c, xgselect.h (xg_select): Add sigmask argument,
+        for compatibility with pselect.  Support ns-resolution time stamps.
+
+        * xmenu.c (x_menu_wait_for_event): Support ns-resolution time stamps.
+
+        * xselect.c (wait_for_property_change, x_get_foreign_selection):
+        Check for time stamp overflow, and support ns-resolution time stamps.
+
+        * xterm.c: Don't include sys/time.h; gnulib does that for us now.
+        Don't worry about whether HAVE_TIMEVAL and HAVE_SELECT are set.
+        (timeval_subtract): Remove; no longer needed.
+        (XTflash, XTring_bell, x_wait_for_event):
+        Port to ns-resolution time stamps.  Don't assume time_t is signed.
+
 2012-06-22  Chong Yidong  <cyd@gnu.org>
 
         * xdisp.c (x_consider_frame_title): Revert last change.