[PATCH] PR ada/81070 * s-interr-hwint.adb: Reinstate. * gcc-interface/Makefile.in (RTEMS): Use it again.

Sebastian Huber sebastian.huber at embedded-brains.de
Mon Jun 12 11:22:25 UTC 2017


From: ebotcazou <ebotcazou at 138bc75d-0d04-0410-961f-82ee72b054a4>

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-7-branch@249116 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ada/ChangeLog                 |    6 +
 gcc/ada/gcc-interface/Makefile.in |    2 +-
 gcc/ada/s-interr-hwint.adb        | 1110 +++++++++++++++++++++++++++++++++++++
 3 files changed, 1117 insertions(+), 1 deletion(-)
 create mode 100644 gcc/ada/s-interr-hwint.adb

diff --git a/gcc/ada/gcc-interface/Makefile.in b/gcc/ada/gcc-interface/Makefile.in
index 2dff5ab36e6..95221cdbe73 100644
--- a/gcc/ada/gcc-interface/Makefile.in
+++ b/gcc/ada/gcc-interface/Makefile.in
@@ -1736,7 +1736,7 @@ ifeq ($(strip $(filter-out rtems%,$(target_os))),)
   s-taspri.ads<s-taspri-posix.ads \
   s-tpopsp.adb<s-tpopsp-tls.adb \
   s-stchop.adb<s-stchop-rtems.adb \
-  s-interr.adb<s-interr-vxworks.adb
+  s-interr.adb<s-interr-hwint.adb
 endif
 
 # PikeOS
diff --git a/gcc/ada/s-interr-hwint.adb b/gcc/ada/s-interr-hwint.adb
new file mode 100644
index 00000000000..8e2950f30fb
--- /dev/null
+++ b/gcc/ada/s-interr-hwint.adb
@@ -0,0 +1,1110 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
+--                                                                          --
+--                     S Y S T E M . I N T E R R U P T S                    --
+--                                                                          --
+--                                  B o d y                                 --
+--                                                                          --
+--         Copyright (C) 1992-2014, 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.     --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  Invariants:
+
+--  All user-handlable signals are masked at all times in all tasks/threads
+--  except possibly for the Interrupt_Manager task.
+
+--  When a user task wants to have the effect of masking/unmasking an signal,
+--  it must call Block_Interrupt/Unblock_Interrupt, which will have the effect
+--  of unmasking/masking the signal in the Interrupt_Manager task. These
+--  comments do not apply to vectored hardware interrupts, which may be masked
+--  or unmasked using routined interfaced to the relevant embedded RTOS system
+--  calls.
+
+--  Once we associate a Signal_Server_Task with an signal, the task never goes
+--  away, and we never remove the association. On the other hand, it is more
+--  convenient to terminate an associated Interrupt_Server_Task for a vectored
+--  hardware interrupt (since we use a binary semaphore for synchronization
+--  with the umbrella handler).
+
+--  There is no more than one signal per Signal_Server_Task and no more than
+--  one Signal_Server_Task per signal. The same relation holds for hardware
+--  interrupts and Interrupt_Server_Task's at any given time. That is, only
+--  one non-terminated Interrupt_Server_Task exists for a give interrupt at
+--  any time.
+
+--  Within this package, the lock L is used to protect the various status
+--  tables. If there is a Server_Task associated with a signal or interrupt,
+--  we use the per-task lock of the Server_Task instead so that we protect the
+--  status between Interrupt_Manager and Server_Task. Protection among service
+--  requests are ensured via user calls to the Interrupt_Manager entries.
+
+--  This is reasonably generic version of this package, supporting vectored
+--  hardware interrupts using non-RTOS specific adapter routines which should
+--  easily implemented on any RTOS capable of supporting GNAT.
+
+with Ada.Unchecked_Conversion;
+with Ada.Task_Identification;
+
+with Interfaces.C; use Interfaces.C;
+with System.OS_Interface; use System.OS_Interface;
+with System.Interrupt_Management;
+with System.Task_Primitives.Operations;
+with System.Storage_Elements;
+with System.Tasking.Utilities;
+
+with System.Tasking.Rendezvous;
+pragma Elaborate_All (System.Tasking.Rendezvous);
+
+package body System.Interrupts is
+
+   use Tasking;
+
+   package POP renames System.Task_Primitives.Operations;
+
+   function To_Ada is new Ada.Unchecked_Conversion
+     (System.Tasking.Task_Id, Ada.Task_Identification.Task_Id);
+
+   function To_System is new Ada.Unchecked_Conversion
+     (Ada.Task_Identification.Task_Id, Task_Id);
+
+   -----------------
+   -- Local Tasks --
+   -----------------
+
+   --  WARNING: System.Tasking.Stages performs calls to this task with low-
+   --  level constructs. Do not change this spec without synchronizing it.
+
+   task Interrupt_Manager is
+      entry Detach_Interrupt_Entries (T : Task_Id);
+
+      entry Attach_Handler
+        (New_Handler : Parameterless_Handler;
+         Interrupt   : Interrupt_ID;
+         Static      : Boolean;
+         Restoration : Boolean := False);
+
+      entry Exchange_Handler
+        (Old_Handler : out Parameterless_Handler;
+         New_Handler : Parameterless_Handler;
+         Interrupt   : Interrupt_ID;
+         Static      : Boolean);
+
+      entry Detach_Handler
+        (Interrupt : Interrupt_ID;
+         Static    : Boolean);
+
+      entry Bind_Interrupt_To_Entry
+        (T         : Task_Id;
+         E         : Task_Entry_Index;
+         Interrupt : Interrupt_ID);
+
+      pragma Interrupt_Priority (System.Interrupt_Priority'First);
+   end Interrupt_Manager;
+
+   task type Interrupt_Server_Task
+     (Interrupt : Interrupt_ID;
+      Int_Sema  : Binary_Semaphore_Id)
+   is
+      --  Server task for vectored hardware interrupt handling
+
+      pragma Interrupt_Priority (System.Interrupt_Priority'First + 2);
+   end Interrupt_Server_Task;
+
+   type Interrupt_Task_Access is access Interrupt_Server_Task;
+
+   -------------------------------
+   -- Local Types and Variables --
+   -------------------------------
+
+   type Entry_Assoc is record
+      T : Task_Id;
+      E : Task_Entry_Index;
+   end record;
+
+   type Handler_Assoc is record
+      H      : Parameterless_Handler;
+      Static : Boolean;   --  Indicates static binding;
+   end record;
+
+   User_Handler : array (Interrupt_ID) of Handler_Assoc :=
+     (others => (null, Static => False));
+   pragma Volatile_Components (User_Handler);
+   --  Holds the protected procedure handler (if any) and its Static
+   --  information for each interrupt or signal. A handler is static iff it
+   --  is specified through the pragma Attach_Handler.
+
+   User_Entry : array (Interrupt_ID) of Entry_Assoc :=
+                  (others => (T => Null_Task, E => Null_Task_Entry));
+   pragma Volatile_Components (User_Entry);
+   --  Holds the task and entry index (if any) for each interrupt / signal
+
+   --  Type and Head, Tail of the list containing Registered Interrupt
+   --  Handlers. These definitions are used to register the handlers
+   --  specified by the pragma Interrupt_Handler.
+
+   type Registered_Handler;
+   type R_Link is access all Registered_Handler;
+
+   type Registered_Handler is record
+      H    : System.Address := System.Null_Address;
+      Next : R_Link := null;
+   end record;
+
+   Registered_Handler_Head : R_Link := null;
+   Registered_Handler_Tail : R_Link := null;
+
+   Server_ID : array (Interrupt_ID) of System.Tasking.Task_Id :=
+                 (others => System.Tasking.Null_Task);
+   pragma Atomic_Components (Server_ID);
+   --  Holds the Task_Id of the Server_Task for each interrupt / signal.
+   --  Task_Id is needed to accomplish locking per interrupt base. Also
+   --  is needed to determine whether to create a new Server_Task.
+
+   Semaphore_ID_Map : array
+     (Interrupt_ID range 0 .. System.OS_Interface.Max_HW_Interrupt) of
+        Binary_Semaphore_Id := (others => 0);
+   --  Array of binary semaphores associated with vectored interrupts. Note
+   --  that the last bound should be Max_HW_Interrupt, but this will raise
+   --  Storage_Error if Num_HW_Interrupts is null so use extra 4 bytes instead.
+
+   Interrupt_Access_Hold : Interrupt_Task_Access;
+   --  Variable for allocating an Interrupt_Server_Task
+
+   Handler_Installed : array (HW_Interrupt) of Boolean := (others => False);
+   --  True if Notify_Interrupt was connected to the interrupt. Handlers can
+   --  be connected but disconnection is not possible on VxWorks. Therefore
+   --  we ensure Notify_Installed is connected at most once.
+
+   -----------------------
+   -- Local Subprograms --
+   -----------------------
+
+   procedure Check_Reserved_Interrupt (Interrupt : Interrupt_ID);
+   --  Check if Id is a reserved interrupt, and if so raise Program_Error
+   --  with an appropriate message, otherwise return.
+
+   procedure Finalize_Interrupt_Servers;
+   --  Unbind the handlers for hardware interrupt server tasks at program
+   --  termination.
+
+   function Is_Registered (Handler : Parameterless_Handler) return Boolean;
+   --  See if Handler has been "pragma"ed using Interrupt_Handler.
+   --  Always consider a null handler as registered.
+
+   procedure Notify_Interrupt (Param : System.Address);
+   pragma Convention (C, Notify_Interrupt);
+   --  Umbrella handler for vectored interrupts (not signals)
+
+   procedure Install_Umbrella_Handler
+     (Interrupt : HW_Interrupt;
+      Handler   : System.OS_Interface.Interrupt_Handler);
+   --  Install the runtime umbrella handler for a vectored hardware
+   --  interrupt
+
+   procedure Unimplemented (Feature : String);
+   pragma No_Return (Unimplemented);
+   --  Used to mark a call to an unimplemented function. Raises Program_Error
+   --  with an appropriate message noting that Feature is unimplemented.
+
+   --------------------
+   -- Attach_Handler --
+   --------------------
+
+   --  Calling this procedure with New_Handler = null and Static = True
+   --  means we want to detach the current handler regardless of the previous
+   --  handler's binding status (i.e. do not care if it is a dynamic or static
+   --  handler).
+
+   --  This option is needed so that during the finalization of a PO, we can
+   --  detach handlers attached through pragma Attach_Handler.
+
+   procedure Attach_Handler
+     (New_Handler : Parameterless_Handler;
+      Interrupt   : Interrupt_ID;
+      Static      : Boolean := False) is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      Interrupt_Manager.Attach_Handler (New_Handler, Interrupt, Static);
+   end Attach_Handler;
+
+   -----------------------------
+   -- Bind_Interrupt_To_Entry --
+   -----------------------------
+
+   --  This procedure raises a Program_Error if it tries to
+   --  bind an interrupt to which an Entry or a Procedure is
+   --  already bound.
+
+   procedure Bind_Interrupt_To_Entry
+     (T       : Task_Id;
+      E       : Task_Entry_Index;
+      Int_Ref : System.Address)
+   is
+      Interrupt : constant Interrupt_ID :=
+                    Interrupt_ID (Storage_Elements.To_Integer (Int_Ref));
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt);
+   end Bind_Interrupt_To_Entry;
+
+   ---------------------
+   -- Block_Interrupt --
+   ---------------------
+
+   procedure Block_Interrupt (Interrupt : Interrupt_ID) is
+   begin
+      Unimplemented ("Block_Interrupt");
+   end Block_Interrupt;
+
+   ------------------------------
+   -- Check_Reserved_Interrupt --
+   ------------------------------
+
+   procedure Check_Reserved_Interrupt (Interrupt : Interrupt_ID) is
+   begin
+      if Is_Reserved (Interrupt) then
+         raise Program_Error with
+           "interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
+      else
+         return;
+      end if;
+   end Check_Reserved_Interrupt;
+
+   ---------------------
+   -- Current_Handler --
+   ---------------------
+
+   function Current_Handler
+     (Interrupt : Interrupt_ID) return Parameterless_Handler
+   is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+
+      --  ??? Since Parameterless_Handler is not Atomic, the current
+      --  implementation is wrong. We need a new service in Interrupt_Manager
+      --  to ensure atomicity.
+
+      return User_Handler (Interrupt).H;
+   end Current_Handler;
+
+   --------------------
+   -- Detach_Handler --
+   --------------------
+
+   --  Calling this procedure with Static = True means we want to Detach the
+   --  current handler regardless of the previous handler's binding status
+   --  (i.e. do not care if it is a dynamic or static handler).
+
+   --  This option is needed so that during the finalization of a PO, we can
+   --  detach handlers attached through pragma Attach_Handler.
+
+   procedure Detach_Handler
+     (Interrupt : Interrupt_ID;
+      Static    : Boolean := False)
+   is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      Interrupt_Manager.Detach_Handler (Interrupt, Static);
+   end Detach_Handler;
+
+   ------------------------------
+   -- Detach_Interrupt_Entries --
+   ------------------------------
+
+   procedure Detach_Interrupt_Entries (T : Task_Id) is
+   begin
+      Interrupt_Manager.Detach_Interrupt_Entries (T);
+   end Detach_Interrupt_Entries;
+
+   ----------------------
+   -- Exchange_Handler --
+   ----------------------
+
+   --  Calling this procedure with New_Handler = null and Static = True
+   --  means we want to detach the current handler regardless of the previous
+   --  handler's binding status (i.e. we do not care if it is a dynamic or
+   --  static handler).
+
+   --  This option is needed so that during the finalization of a PO, we can
+   --  detach handlers attached through pragma Attach_Handler.
+
+   procedure Exchange_Handler
+     (Old_Handler : out Parameterless_Handler;
+      New_Handler : Parameterless_Handler;
+      Interrupt   : Interrupt_ID;
+      Static      : Boolean := False)
+   is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      Interrupt_Manager.Exchange_Handler
+        (Old_Handler, New_Handler, Interrupt, Static);
+   end Exchange_Handler;
+
+   --------------
+   -- Finalize --
+   --------------
+
+   procedure Finalize (Object : in out Static_Interrupt_Protection) is
+   begin
+      --  ??? loop to be executed only when we're not doing library level
+      --  finalization, since in this case all interrupt / signal tasks are
+      --  gone.
+
+      if not Interrupt_Manager'Terminated then
+         for N in reverse Object.Previous_Handlers'Range loop
+            Interrupt_Manager.Attach_Handler
+              (New_Handler => Object.Previous_Handlers (N).Handler,
+               Interrupt   => Object.Previous_Handlers (N).Interrupt,
+               Static      => Object.Previous_Handlers (N).Static,
+               Restoration => True);
+         end loop;
+      end if;
+
+      Tasking.Protected_Objects.Entries.Finalize
+        (Tasking.Protected_Objects.Entries.Protection_Entries (Object));
+   end Finalize;
+
+   --------------------------------
+   -- Finalize_Interrupt_Servers --
+   --------------------------------
+
+   --  Restore default handlers for interrupt servers
+
+   --  This is called by the Interrupt_Manager task when it receives the abort
+   --  signal during program finalization.
+
+   procedure Finalize_Interrupt_Servers is
+      HW_Interrupts : constant Boolean := HW_Interrupt'Last >= 0;
+   begin
+      if HW_Interrupts then
+         for Int in HW_Interrupt loop
+            if Server_ID (Interrupt_ID (Int)) /= null
+              and then
+                not Ada.Task_Identification.Is_Terminated
+                 (To_Ada (Server_ID (Interrupt_ID (Int))))
+            then
+               Interrupt_Manager.Attach_Handler
+                 (New_Handler => null,
+                  Interrupt   => Interrupt_ID (Int),
+                  Static      => True,
+                  Restoration => True);
+            end if;
+         end loop;
+      end if;
+   end Finalize_Interrupt_Servers;
+
+   -------------------------------------
+   -- Has_Interrupt_Or_Attach_Handler --
+   -------------------------------------
+
+   function Has_Interrupt_Or_Attach_Handler
+     (Object : access Dynamic_Interrupt_Protection)
+      return   Boolean
+   is
+      pragma Unreferenced (Object);
+   begin
+      return True;
+   end Has_Interrupt_Or_Attach_Handler;
+
+   function Has_Interrupt_Or_Attach_Handler
+     (Object : access Static_Interrupt_Protection)
+      return   Boolean
+   is
+      pragma Unreferenced (Object);
+   begin
+      return True;
+   end Has_Interrupt_Or_Attach_Handler;
+
+   ----------------------
+   -- Ignore_Interrupt --
+   ----------------------
+
+   procedure Ignore_Interrupt (Interrupt : Interrupt_ID) is
+   begin
+      Unimplemented ("Ignore_Interrupt");
+   end Ignore_Interrupt;
+
+   ----------------------
+   -- Install_Handlers --
+   ----------------------
+
+   procedure Install_Handlers
+     (Object       : access Static_Interrupt_Protection;
+      New_Handlers : New_Handler_Array)
+   is
+   begin
+      for N in New_Handlers'Range loop
+
+         --  We need a lock around this ???
+
+         Object.Previous_Handlers (N).Interrupt := New_Handlers (N).Interrupt;
+         Object.Previous_Handlers (N).Static    := User_Handler
+           (New_Handlers (N).Interrupt).Static;
+
+         --  We call Exchange_Handler and not directly Interrupt_Manager.
+         --  Exchange_Handler so we get the Is_Reserved check.
+
+         Exchange_Handler
+           (Old_Handler => Object.Previous_Handlers (N).Handler,
+            New_Handler => New_Handlers (N).Handler,
+            Interrupt   => New_Handlers (N).Interrupt,
+            Static      => True);
+      end loop;
+   end Install_Handlers;
+
+   ---------------------------------
+   -- Install_Restricted_Handlers --
+   ---------------------------------
+
+   procedure Install_Restricted_Handlers
+      (Prio     : Any_Priority;
+       Handlers : New_Handler_Array)
+   is
+      pragma Unreferenced (Prio);
+   begin
+      for N in Handlers'Range loop
+         Attach_Handler (Handlers (N).Handler, Handlers (N).Interrupt, True);
+      end loop;
+   end Install_Restricted_Handlers;
+
+   ------------------------------
+   -- Install_Umbrella_Handler --
+   ------------------------------
+
+   procedure Install_Umbrella_Handler
+     (Interrupt : HW_Interrupt;
+      Handler   : System.OS_Interface.Interrupt_Handler)
+   is
+      Vec : constant Interrupt_Vector :=
+              Interrupt_Number_To_Vector (int (Interrupt));
+
+      Status : int;
+
+   begin
+      --  Only install umbrella handler when no Ada handler has already been
+      --  installed. Note that the interrupt number is passed as a parameter
+      --  when an interrupt occurs, so the umbrella handler has a different
+      --  wrapper generated by intConnect for each interrupt number.
+
+      if not Handler_Installed (Interrupt) then
+         Status :=
+            Interrupt_Connect (Vec, Handler, System.Address (Interrupt));
+         pragma Assert (Status = 0);
+
+         Handler_Installed (Interrupt) := True;
+      end if;
+   end Install_Umbrella_Handler;
+
+   ----------------
+   -- Is_Blocked --
+   ----------------
+
+   function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
+   begin
+      Unimplemented ("Is_Blocked");
+      return False;
+   end Is_Blocked;
+
+   -----------------------
+   -- Is_Entry_Attached --
+   -----------------------
+
+   function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      return User_Entry (Interrupt).T /= Null_Task;
+   end Is_Entry_Attached;
+
+   -------------------------
+   -- Is_Handler_Attached --
+   -------------------------
+
+   function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      return User_Handler (Interrupt).H /= null;
+   end Is_Handler_Attached;
+
+   ----------------
+   -- Is_Ignored --
+   ----------------
+
+   function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
+   begin
+      Unimplemented ("Is_Ignored");
+      return False;
+   end Is_Ignored;
+
+   -------------------
+   -- Is_Registered --
+   -------------------
+
+   function Is_Registered (Handler : Parameterless_Handler) return Boolean is
+      type Fat_Ptr is record
+         Object_Addr  : System.Address;
+         Handler_Addr : System.Address;
+      end record;
+
+      function To_Fat_Ptr is new Ada.Unchecked_Conversion
+        (Parameterless_Handler, Fat_Ptr);
+
+      Ptr : R_Link;
+      Fat : Fat_Ptr;
+
+   begin
+      if Handler = null then
+         return True;
+      end if;
+
+      Fat := To_Fat_Ptr (Handler);
+
+      Ptr := Registered_Handler_Head;
+      while Ptr /= null loop
+         if Ptr.H = Fat.Handler_Addr then
+            return True;
+         end if;
+
+         Ptr := Ptr.Next;
+      end loop;
+
+      return False;
+   end Is_Registered;
+
+   -----------------
+   -- Is_Reserved --
+   -----------------
+
+   function Is_Reserved (Interrupt : Interrupt_ID) return Boolean is
+      use System.Interrupt_Management;
+   begin
+      return Reserve (System.Interrupt_Management.Interrupt_ID (Interrupt));
+   end Is_Reserved;
+
+   ----------------------
+   -- Notify_Interrupt --
+   ----------------------
+
+   --  Umbrella handler for vectored hardware interrupts (as opposed to signals
+   --  and exceptions). As opposed to the signal implementation, this handler
+   --  is installed in the vector table when the first Ada handler is attached
+   --  to the interrupt. However because VxWorks don't support disconnecting
+   --  handlers, this subprogram always test whether or not an Ada handler is
+   --  effectively attached.
+
+   --  Otherwise, the handler that existed prior to program startup is in the
+   --  vector table. This ensures that handlers installed by the BSP are active
+   --  unless explicitly replaced in the program text.
+
+   --  Each Interrupt_Server_Task has an associated binary semaphore on which
+   --  it pends once it's been started. This routine determines The appropriate
+   --  semaphore and issues a semGive call, waking the server task. When
+   --  a handler is unbound, System.Interrupts.Unbind_Handler issues a
+   --  Binary_Semaphore_Flush, and the server task deletes its semaphore
+   --  and terminates.
+
+   procedure Notify_Interrupt (Param : System.Address) is
+      Interrupt : constant Interrupt_ID := Interrupt_ID (Param);
+      Id        : constant Binary_Semaphore_Id := Semaphore_ID_Map (Interrupt);
+      Status    : int;
+   begin
+      if Id /= 0 then
+         Status := Binary_Semaphore_Release (Id);
+         pragma Assert (Status = 0);
+      end if;
+   end Notify_Interrupt;
+
+   ---------------
+   -- Reference --
+   ---------------
+
+   function Reference (Interrupt : Interrupt_ID) return System.Address is
+   begin
+      Check_Reserved_Interrupt (Interrupt);
+      return Storage_Elements.To_Address
+               (Storage_Elements.Integer_Address (Interrupt));
+   end Reference;
+
+   --------------------------------
+   -- Register_Interrupt_Handler --
+   --------------------------------
+
+   procedure Register_Interrupt_Handler (Handler_Addr : System.Address) is
+      New_Node_Ptr : R_Link;
+
+   begin
+      --  This routine registers a handler as usable for dynamic interrupt
+      --  handler association. Routines attaching and detaching handlers
+      --  dynamically should determine whether the handler is registered.
+      --  Program_Error should be raised if it is not registered.
+
+      --  Pragma Interrupt_Handler can only appear in a library level PO
+      --  definition and instantiation. Therefore, we do not need to implement
+      --  an unregister operation. Nor do we need to protect the queue
+      --  structure with a lock.
+
+      pragma Assert (Handler_Addr /= System.Null_Address);
+
+      New_Node_Ptr := new Registered_Handler;
+      New_Node_Ptr.H := Handler_Addr;
+
+      if Registered_Handler_Head = null then
+         Registered_Handler_Head := New_Node_Ptr;
+         Registered_Handler_Tail := New_Node_Ptr;
+      else
+         Registered_Handler_Tail.Next := New_Node_Ptr;
+         Registered_Handler_Tail := New_Node_Ptr;
+      end if;
+   end Register_Interrupt_Handler;
+
+   -----------------------
+   -- Unblock_Interrupt --
+   -----------------------
+
+   procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is
+   begin
+      Unimplemented ("Unblock_Interrupt");
+   end Unblock_Interrupt;
+
+   ------------------
+   -- Unblocked_By --
+   ------------------
+
+   function Unblocked_By
+     (Interrupt : Interrupt_ID) return System.Tasking.Task_Id
+   is
+   begin
+      Unimplemented ("Unblocked_By");
+      return Null_Task;
+   end Unblocked_By;
+
+   ------------------------
+   -- Unignore_Interrupt --
+   ------------------------
+
+   procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
+   begin
+      Unimplemented ("Unignore_Interrupt");
+   end Unignore_Interrupt;
+
+   -------------------
+   -- Unimplemented --
+   -------------------
+
+   procedure Unimplemented (Feature : String) is
+   begin
+      raise Program_Error with Feature & " not implemented on VxWorks";
+   end Unimplemented;
+
+   -----------------------
+   -- Interrupt_Manager --
+   -----------------------
+
+   task body Interrupt_Manager is
+      --  By making this task independent of any master, when the process goes
+      --  away, the Interrupt_Manager will terminate gracefully.
+
+      Ignore : constant Boolean := System.Tasking.Utilities.Make_Independent;
+      pragma Unreferenced (Ignore);
+
+      --------------------
+      -- Local Routines --
+      --------------------
+
+      procedure Bind_Handler (Interrupt : Interrupt_ID);
+      --  This procedure does not do anything if a signal is blocked.
+      --  Otherwise, we have to interrupt Server_Task for status change
+      --  through a wakeup signal.
+
+      procedure Unbind_Handler (Interrupt : Interrupt_ID);
+      --  This procedure does not do anything if a signal is blocked.
+      --  Otherwise, we have to interrupt Server_Task for status change
+      --  through an abort signal.
+
+      procedure Unprotected_Exchange_Handler
+        (Old_Handler : out Parameterless_Handler;
+         New_Handler : Parameterless_Handler;
+         Interrupt   : Interrupt_ID;
+         Static      : Boolean;
+         Restoration : Boolean := False);
+
+      procedure Unprotected_Detach_Handler
+        (Interrupt : Interrupt_ID;
+         Static    : Boolean);
+
+      ------------------
+      -- Bind_Handler --
+      ------------------
+
+      procedure Bind_Handler (Interrupt : Interrupt_ID) is
+      begin
+         Install_Umbrella_Handler
+           (HW_Interrupt (Interrupt), Notify_Interrupt'Access);
+      end Bind_Handler;
+
+      --------------------
+      -- Unbind_Handler --
+      --------------------
+
+      procedure Unbind_Handler (Interrupt : Interrupt_ID) is
+         Status : int;
+
+      begin
+         --  Flush server task off semaphore, allowing it to terminate
+
+         Status := Binary_Semaphore_Flush (Semaphore_ID_Map (Interrupt));
+         pragma Assert (Status = 0);
+      end Unbind_Handler;
+
+      --------------------------------
+      -- Unprotected_Detach_Handler --
+      --------------------------------
+
+      procedure Unprotected_Detach_Handler
+        (Interrupt : Interrupt_ID;
+         Static    : Boolean)
+      is
+         Old_Handler : Parameterless_Handler;
+      begin
+         if User_Entry (Interrupt).T /= Null_Task then
+
+            --  If an interrupt entry is installed raise Program_Error
+            --  (propagate it to the caller).
+
+            raise Program_Error with
+              "an interrupt entry is already installed";
+         end if;
+
+         --  Note : Static = True will pass the following check. This is the
+         --  case when we want to detach a handler regardless of the static
+         --  status of the Current_Handler.
+
+         if not Static and then User_Handler (Interrupt).Static then
+
+            --  Trying to detach a static Interrupt Handler, raise
+            --  Program_Error.
+
+            raise Program_Error with
+              "trying to detach a static Interrupt Handler";
+         end if;
+
+         Old_Handler := User_Handler (Interrupt).H;
+
+         --  The new handler
+
+         User_Handler (Interrupt).H := null;
+         User_Handler (Interrupt).Static := False;
+
+         if Old_Handler /= null then
+            Unbind_Handler (Interrupt);
+         end if;
+      end Unprotected_Detach_Handler;
+
+      ----------------------------------
+      -- Unprotected_Exchange_Handler --
+      ----------------------------------
+
+      procedure Unprotected_Exchange_Handler
+        (Old_Handler : out Parameterless_Handler;
+         New_Handler : Parameterless_Handler;
+         Interrupt   : Interrupt_ID;
+         Static      : Boolean;
+         Restoration : Boolean := False)
+      is
+      begin
+         if User_Entry (Interrupt).T /= Null_Task then
+
+            --  If an interrupt entry is already installed, raise
+            --  Program_Error (propagate it to the caller).
+
+            raise Program_Error with "an interrupt is already installed";
+         end if;
+
+         --  Note : A null handler with Static = True will pass the following
+         --  check. This is the case when we want to detach a handler
+         --  regardless of the Static status of Current_Handler.
+
+         --  We don't check anything if Restoration is True, since we may be
+         --  detaching a static handler to restore a dynamic one.
+
+         if not Restoration and then not Static
+           and then (User_Handler (Interrupt).Static
+
+            --  Trying to overwrite a static Interrupt Handler with a dynamic
+            --  Handler
+
+            --  The new handler is not specified as an Interrupt Handler by a
+            --  pragma.
+
+           or else not Is_Registered (New_Handler))
+         then
+            raise Program_Error with
+               "trying to overwrite a static interrupt handler with a "
+               & "dynamic handler";
+         end if;
+
+         --  Save the old handler
+
+         Old_Handler := User_Handler (Interrupt).H;
+
+         --  The new handler
+
+         User_Handler (Interrupt).H := New_Handler;
+
+         if New_Handler = null then
+
+            --  The null handler means we are detaching the handler
+
+            User_Handler (Interrupt).Static := False;
+
+         else
+            User_Handler (Interrupt).Static := Static;
+         end if;
+
+         --  Invoke a corresponding Server_Task if not yet created. Place
+         --  Task_Id info in Server_ID array.
+
+         if New_Handler /= null
+           and then
+            (Server_ID (Interrupt) = Null_Task
+              or else
+                Ada.Task_Identification.Is_Terminated
+                  (To_Ada (Server_ID (Interrupt))))
+         then
+            Interrupt_Access_Hold :=
+              new Interrupt_Server_Task (Interrupt, Binary_Semaphore_Create);
+            Server_ID (Interrupt) :=
+              To_System (Interrupt_Access_Hold.all'Identity);
+         end if;
+
+         if (New_Handler = null) and then Old_Handler /= null then
+
+            --  Restore default handler
+
+            Unbind_Handler (Interrupt);
+
+         elsif Old_Handler = null then
+
+            --  Save default handler
+
+            Bind_Handler (Interrupt);
+         end if;
+      end Unprotected_Exchange_Handler;
+
+   --  Start of processing for Interrupt_Manager
+
+   begin
+      loop
+         --  A block is needed to absorb Program_Error exception
+
+         declare
+            Old_Handler : Parameterless_Handler;
+
+         begin
+            select
+               accept Attach_Handler
+                 (New_Handler : Parameterless_Handler;
+                  Interrupt   : Interrupt_ID;
+                  Static      : Boolean;
+                  Restoration : Boolean := False)
+               do
+                  Unprotected_Exchange_Handler
+                    (Old_Handler, New_Handler, Interrupt, Static, Restoration);
+               end Attach_Handler;
+
+            or
+               accept Exchange_Handler
+                 (Old_Handler : out Parameterless_Handler;
+                  New_Handler : Parameterless_Handler;
+                  Interrupt   : Interrupt_ID;
+                  Static      : Boolean)
+               do
+                  Unprotected_Exchange_Handler
+                    (Old_Handler, New_Handler, Interrupt, Static);
+               end Exchange_Handler;
+
+            or
+               accept Detach_Handler
+                  (Interrupt : Interrupt_ID;
+                   Static    : Boolean)
+               do
+                  Unprotected_Detach_Handler (Interrupt, Static);
+               end Detach_Handler;
+
+            or
+               accept Bind_Interrupt_To_Entry
+                 (T         : Task_Id;
+                  E         : Task_Entry_Index;
+                  Interrupt : Interrupt_ID)
+               do
+                  --  If there is a binding already (either a procedure or an
+                  --  entry), raise Program_Error (propagate it to the caller).
+
+                  if User_Handler (Interrupt).H /= null
+                    or else User_Entry (Interrupt).T /= Null_Task
+                  then
+                     raise Program_Error with
+                       "a binding for this interrupt is already present";
+                  end if;
+
+                  User_Entry (Interrupt) := Entry_Assoc'(T => T, E => E);
+
+                  --  Indicate the attachment of interrupt entry in the ATCB.
+                  --  This is needed so when an interrupt entry task terminates
+                  --  the binding can be cleaned. The call to unbinding must be
+                  --  make by the task before it terminates.
+
+                  T.Interrupt_Entry := True;
+
+                  --  Invoke a corresponding Server_Task if not yet created.
+                  --  Place Task_Id info in Server_ID array.
+
+                  if Server_ID (Interrupt) = Null_Task
+                    or else
+                      Ada.Task_Identification.Is_Terminated
+                        (To_Ada (Server_ID (Interrupt)))
+                  then
+                     Interrupt_Access_Hold := new Interrupt_Server_Task
+                       (Interrupt, Binary_Semaphore_Create);
+                     Server_ID (Interrupt) :=
+                       To_System (Interrupt_Access_Hold.all'Identity);
+                  end if;
+
+                  Bind_Handler (Interrupt);
+               end Bind_Interrupt_To_Entry;
+
+            or
+               accept Detach_Interrupt_Entries (T : Task_Id) do
+                  for Int in Interrupt_ID'Range loop
+                     if not Is_Reserved (Int) then
+                        if User_Entry (Int).T = T then
+                           User_Entry (Int) :=
+                             Entry_Assoc'
+                               (T => Null_Task, E => Null_Task_Entry);
+                           Unbind_Handler (Int);
+                        end if;
+                     end if;
+                  end loop;
+
+                  --  Indicate in ATCB that no interrupt entries are attached
+
+                  T.Interrupt_Entry := False;
+               end Detach_Interrupt_Entries;
+            end select;
+
+         exception
+            --  If there is a Program_Error we just want to propagate it to
+            --  the caller and do not want to stop this task.
+
+            when Program_Error =>
+               null;
+
+            when others =>
+               pragma Assert (False);
+               null;
+         end;
+      end loop;
+
+   exception
+      when Standard'Abort_Signal =>
+
+         --  Flush interrupt server semaphores, so they can terminate
+
+         Finalize_Interrupt_Servers;
+         raise;
+   end Interrupt_Manager;
+
+   ---------------------------
+   -- Interrupt_Server_Task --
+   ---------------------------
+
+   --  Server task for vectored hardware interrupt handling
+
+   task body Interrupt_Server_Task is
+      Ignore : constant Boolean := System.Tasking.Utilities.Make_Independent;
+
+      Self_Id         : constant Task_Id := Self;
+      Tmp_Handler     : Parameterless_Handler;
+      Tmp_ID          : Task_Id;
+      Tmp_Entry_Index : Task_Entry_Index;
+      Status          : int;
+
+   begin
+      Semaphore_ID_Map (Interrupt) := Int_Sema;
+
+      loop
+         --  Pend on semaphore that will be triggered by the umbrella handler
+         --  when the associated interrupt comes in.
+
+         Status := Binary_Semaphore_Obtain (Int_Sema);
+         pragma Assert (Status = 0);
+
+         if User_Handler (Interrupt).H /= null then
+
+            --  Protected procedure handler
+
+            Tmp_Handler := User_Handler (Interrupt).H;
+            Tmp_Handler.all;
+
+         elsif User_Entry (Interrupt).T /= Null_Task then
+
+            --  Interrupt entry handler
+
+            Tmp_ID := User_Entry (Interrupt).T;
+            Tmp_Entry_Index := User_Entry (Interrupt).E;
+            System.Tasking.Rendezvous.Call_Simple
+              (Tmp_ID, Tmp_Entry_Index, System.Null_Address);
+
+         else
+            --  Semaphore has been flushed by an unbind operation in the
+            --  Interrupt_Manager. Terminate the server task.
+
+            --  Wait for the Interrupt_Manager to complete its work
+
+            POP.Write_Lock (Self_Id);
+
+            --  Unassociate the interrupt handler
+
+            Semaphore_ID_Map (Interrupt) := 0;
+
+            --  Delete the associated semaphore
+
+            Status := Binary_Semaphore_Delete (Int_Sema);
+
+            pragma Assert (Status = 0);
+
+            --  Set status for the Interrupt_Manager
+
+            Server_ID (Interrupt) := Null_Task;
+            POP.Unlock (Self_Id);
+
+            exit;
+         end if;
+      end loop;
+   end Interrupt_Server_Task;
+
+begin
+   --  Get Interrupt_Manager's ID so that Abort_Interrupt can be sent
+
+   Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity);
+end System.Interrupts;
-- 
2.12.3





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