--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnarl/s-tpopmo.adb	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,283 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
+--                                                                          --
+--               SYSTEM.TASK_PRIMITIVES.OPERATIONS.MONOTONIC                --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--         Copyright (C) 1992-2017, Free Software Foundation, Inc.          --
+--                                                                          --
+-- GNARL is free software; you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNARL was developed by the GNARL team at Florida State University.       --
+-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This is the Monotonic version of this package for Posix and Linux targets.
+
+separate (System.Task_Primitives.Operations)
+package body Monotonic is
+
+   -----------------------
+   -- Local Subprograms --
+   -----------------------
+
+   procedure Compute_Deadline
+     (Time       : Duration;
+      Mode       : ST.Delay_Modes;
+      Check_Time : out Duration;
+      Abs_Time   : out Duration;
+      Rel_Time   : out Duration);
+   --  Helper for Timed_Sleep and Timed_Delay: given a deadline specified by
+   --  Time and Mode, compute the current clock reading (Check_Time), and the
+   --  target absolute and relative clock readings (Abs_Time, Rel_Time). The
+   --  epoch for Time depends on Mode; the epoch for Check_Time and Abs_Time
+   --  is always that of CLOCK_RT_Ada.
+
+   ---------------------
+   -- Monotonic_Clock --
+   ---------------------
+
+   function Monotonic_Clock return Duration is
+      TS     : aliased timespec;
+      Result : Interfaces.C.int;
+   begin
+      Result := clock_gettime
+        (clock_id => OSC.CLOCK_RT_Ada, tp => TS'Unchecked_Access);
+      pragma Assert (Result = 0);
+
+      return To_Duration (TS);
+   end Monotonic_Clock;
+
+   -------------------
+   -- RT_Resolution --
+   -------------------
+
+   function RT_Resolution return Duration is
+      TS     : aliased timespec;
+      Result : Interfaces.C.int;
+
+   begin
+      Result := clock_getres (OSC.CLOCK_REALTIME, TS'Unchecked_Access);
+      pragma Assert (Result = 0);
+
+      return To_Duration (TS);
+   end RT_Resolution;
+
+   ----------------------
+   -- Compute_Deadline --
+   ----------------------
+
+   procedure Compute_Deadline
+     (Time       : Duration;
+      Mode       : ST.Delay_Modes;
+      Check_Time : out Duration;
+      Abs_Time   : out Duration;
+      Rel_Time   : out Duration)
+   is
+   begin
+      Check_Time := Monotonic_Clock;
+
+      --  Relative deadline
+
+      if Mode = Relative then
+         Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
+
+         if Relative_Timed_Wait then
+            Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
+         end if;
+
+         pragma Warnings (Off);
+         --  Comparison "OSC.CLOCK_RT_Ada = OSC.CLOCK_REALTIME" is compile
+         --  time known.
+
+      --  Absolute deadline specified using the tasking clock (CLOCK_RT_Ada)
+
+      elsif Mode = Absolute_RT
+        or else OSC.CLOCK_RT_Ada = OSC.CLOCK_REALTIME
+      then
+         pragma Warnings (On);
+         Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
+
+         if Relative_Timed_Wait then
+            Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
+         end if;
+
+      --  Absolute deadline specified using the calendar clock, in the
+      --  case where it is not the same as the tasking clock: compensate for
+      --  difference between clock epochs (Base_Time - Base_Cal_Time).
+
+      else
+         declare
+            Cal_Check_Time : constant Duration := OS_Primitives.Clock;
+            RT_Time        : constant Duration :=
+                               Time + Check_Time - Cal_Check_Time;
+
+         begin
+            Abs_Time :=
+              Duration'Min (Check_Time + Max_Sensible_Delay, RT_Time);
+
+            if Relative_Timed_Wait then
+               Rel_Time :=
+                 Duration'Min (Max_Sensible_Delay, RT_Time - Check_Time);
+            end if;
+         end;
+      end if;
+   end Compute_Deadline;
+
+   -----------------
+   -- Timed_Sleep --
+   -----------------
+
+   --  This is for use within the run-time system, so abort is
+   --  assumed to be already deferred, and the caller should be
+   --  holding its own ATCB lock.
+
+   procedure Timed_Sleep
+     (Self_ID  : ST.Task_Id;
+      Time     : Duration;
+      Mode     : ST.Delay_Modes;
+      Reason   : System.Tasking.Task_States;
+      Timedout : out Boolean;
+      Yielded  : out Boolean)
+   is
+      pragma Unreferenced (Reason);
+
+      Base_Time  : Duration;
+      Check_Time : Duration;
+      Abs_Time   : Duration;
+      Rel_Time   : Duration;
+
+      Request    : aliased timespec;
+      Result     : Interfaces.C.int;
+
+   begin
+      Timedout := True;
+      Yielded := False;
+
+      Compute_Deadline
+        (Time       => Time,
+         Mode       => Mode,
+         Check_Time => Check_Time,
+         Abs_Time   => Abs_Time,
+         Rel_Time   => Rel_Time);
+      Base_Time := Check_Time;
+
+      if Abs_Time > Check_Time then
+         Request :=
+           To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
+
+         loop
+            exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
+
+            Result :=
+              pthread_cond_timedwait
+                (cond    => Self_ID.Common.LL.CV'Access,
+                 mutex   => (if Single_Lock
+                             then Single_RTS_Lock'Access
+                             else Self_ID.Common.LL.L'Access),
+                 abstime => Request'Access);
+
+            Check_Time := Monotonic_Clock;
+            exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
+
+            if Result in 0 | EINTR then
+
+               --  Somebody may have called Wakeup for us
+
+               Timedout := False;
+               exit;
+            end if;
+
+            pragma Assert (Result = ETIMEDOUT);
+         end loop;
+      end if;
+   end Timed_Sleep;
+
+   -----------------
+   -- Timed_Delay --
+   -----------------
+
+   --  This is for use in implementing delay statements, so we assume the
+   --  caller is abort-deferred but is holding no locks.
+
+   procedure Timed_Delay
+     (Self_ID : ST.Task_Id;
+      Time    : Duration;
+      Mode    : ST.Delay_Modes)
+   is
+      Base_Time  : Duration;
+      Check_Time : Duration;
+      Abs_Time   : Duration;
+      Rel_Time   : Duration;
+      Request    : aliased timespec;
+
+      Result : Interfaces.C.int;
+      pragma Warnings (Off, Result);
+
+   begin
+      if Single_Lock then
+         Lock_RTS;
+      end if;
+
+      Write_Lock (Self_ID);
+
+      Compute_Deadline
+        (Time       => Time,
+         Mode       => Mode,
+         Check_Time => Check_Time,
+         Abs_Time   => Abs_Time,
+         Rel_Time   => Rel_Time);
+      Base_Time := Check_Time;
+
+      if Abs_Time > Check_Time then
+         Request :=
+           To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
+         Self_ID.Common.State := Delay_Sleep;
+
+         loop
+            exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
+
+            Result :=
+              pthread_cond_timedwait
+                (cond    => Self_ID.Common.LL.CV'Access,
+                 mutex   => (if Single_Lock
+                             then Single_RTS_Lock'Access
+                             else Self_ID.Common.LL.L'Access),
+                 abstime => Request'Access);
+
+            Check_Time := Monotonic_Clock;
+            exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
+
+            pragma Assert (Result in 0 | ETIMEDOUT | EINTR);
+         end loop;
+
+         Self_ID.Common.State := Runnable;
+      end if;
+
+      Unlock (Self_ID);
+
+      if Single_Lock then
+         Unlock_RTS;
+      end if;
+
+      Result := sched_yield;
+   end Timed_Delay;
+
+end Monotonic;