2005-03-17 Jose Ruiz <ruiz@adacore.com>

	* s-taprob.adb (Initialize_Protection): Initialize the protected
	object's owner to Null_Task.
	(Lock): If pragma Detect_Blocking is in effect and the caller of this
	procedure is already the protected object's owner then Program_Error
	is raised. In addition the protected object's owner is updated.
	(Lock_Read_Only): If pragma Detect_Blocking is in effect and the caller
	of this procedure is already the protected object's owner then
	Program_Error is raised.
	In addition the protected object's owner is updated.
	(Unlock): Remove the ownership of the protected object.

	* s-taprob.ads (Protection): Add the field Owner, used to store the
	protected object's owner.
	This component is needed for detecting one type of potentially blocking
	operations (external calls on a protected subprogram with the same
	target object as that of the protected action). Document the rest of
	the components.

	* s-tposen.adb, s-tpoben.adb (Initialize_Protection_Entries):
	Initialize the protected object's owner to Null_Task.
	(Lock_Read_Only_Entries): If pragma Detect_Blocking is in effect and the
	caller of this procedure is already the protected object's owner then
	Program_Error is raised.
	Do not raise Program_Error when this procedure is called from a
	protected action.
	(Unlock_Entries): Remove the ownership of the protected object.
	(Lock_Entries): If pragma Detect_Blocking is in effect and the caller
	of this procedure is already the protected object's owner then
	Program_Error is raised.
	Do not raise Program_Error when this procedure is called from
	a protected action.

	* s-tposen.ads, s-tpoben.ads (Protection_Entries): Add the field Owner,
	used to store the protected object's owner.

	* s-tpobop.adb (Protected_Entry_Call): If pragma Detect_Blocking is in
	effect and this procedure (a potentially blocking operation) is called
	from whithin a protected action, Program_Error is raised.
	(Timed_Protected_Entry_Call): If pragma Detect_Blocking is in effect
	and this procedure (a potentially blocking operation) is called from
	whithin a protected action, Program_Error is raised.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@96675 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 28 insertions, 7 deletions

diff --git a/gcc/ada/s-tposen.ads b/gcc/ada/s-tposen.ads
index 148098f4cae..8ad0cb43085 100644
--- a/gcc/ada/s-tposen.ads
+++ b/gcc/ada/s-tposen.ads
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                  S p e c                                 --
 --                                                                          --
---          Copyright (C) 1992-2004 Free Software Foundation, Inc.          --
+--          Copyright (C) 1992-2005 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- --
@@ -277,12 +277,33 @@ package System.Tasking.Protected_Objects.Single_Entry is
 
 private
    type Protection_Entry is record
-      L                 : aliased Task_Primitives.Lock;
-      Compiler_Info     : System.Address;
-      Call_In_Progress  : Entry_Call_Link;
-      Ceiling           : System.Any_Priority;
-      Entry_Body        : Entry_Body_Access;
-      Entry_Queue       : Entry_Call_Link;
+      L : aliased Task_Primitives.Lock;
+      --  The underlying lock associated with a Protection_Entries. Note that
+      --  you should never (un)lock Object.L directly, but instead use
+      --  Lock_Entry/Unlock_Entry.
+
+      Compiler_Info : System.Address;
+      --  Pointer to compiler-generated record representing protected object
+
+      Call_In_Progress : Entry_Call_Link;
+      --  Pointer to the entry call being executed (if any)
+
+      Ceiling : System.Any_Priority;
+      --  Ceiling priority associated to the protected object
+
+      Owner : Task_Id;
+      --  This field contains the protected object's owner. Null_Task
+      --  indicates that the protected object is not currently being used.
+      --  This information is used for detecting the type of potentially
+      --  blocking operations described in the ARM 9.5.1, par. 15 (external
+      --  calls on a protected subprogram with the same target object as that
+      --  of the protected action).
+
+      Entry_Body : Entry_Body_Access;
+      --  Pointer to executable code for the entry body of the protected type
+
+      Entry_Queue : Entry_Call_Link;
+      --  Place to store the waiting entry call (if any)
    end record;
 
 end System.Tasking.Protected_Objects.Single_Entry;