| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- S Y S T E M . M E M O R Y -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.2 $ |
| -- -- |
| -- Copyright (C) 2001 Free Software Foundation, Inc. -- |
| -- -- |
| -- This specification is derived from the Ada Reference Manual for use with -- |
| -- GNAT. The copyright notice above, and the license provisions that follow -- |
| -- apply solely to the contents of the part following the private keyword. -- |
| -- -- |
| -- GNAT 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 2, 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. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This is the default implementation of this package. |
| |
| -- This implementation assumes that the underlying malloc/free/realloc |
| -- implementation is thread safe, and thus, no additional lock is required. |
| -- Note that we still need to defer abortion because on most systems, |
| -- an asynchronous signal (as used for implementing asynchronous abortion |
| -- of task) cannot safely be handled while malloc is executing. |
| |
| -- If you are not using Ada constructs containing the "abort" keyword, |
| -- then you can remove the calls to Abort_Defer.all and Abort_Undefer.all |
| -- from this unit. |
| |
| with Ada.Exceptions; |
| with System.Soft_Links; |
| |
| package body System.Memory is |
| |
| use Ada.Exceptions; |
| use System.Soft_Links; |
| |
| function c_malloc (Size : size_t) return System.Address; |
| pragma Import (C, c_malloc, "malloc"); |
| |
| procedure c_free (Ptr : System.Address); |
| pragma Import (C, c_free, "free"); |
| |
| function c_realloc |
| (Ptr : System.Address; Size : size_t) return System.Address; |
| pragma Import (C, c_realloc, "realloc"); |
| |
| ----------- |
| -- Alloc -- |
| ----------- |
| |
| function Alloc (Size : size_t) return System.Address is |
| Result : System.Address; |
| Actual_Size : size_t := Size; |
| |
| begin |
| if Size = size_t'Last then |
| Raise_Exception (Storage_Error'Identity, "object too large"); |
| end if; |
| |
| -- Change size from zero to non-zero. We still want a proper pointer |
| -- for the zero case because pointers to zero length objects have to |
| -- be distinct, but we can't just go ahead and allocate zero bytes, |
| -- since some malloc's return zero for a zero argument. |
| |
| if Size = 0 then |
| Actual_Size := 1; |
| end if; |
| |
| Abort_Defer.all; |
| Result := c_malloc (Actual_Size); |
| Abort_Undefer.all; |
| |
| if Result = System.Null_Address then |
| Raise_Exception (Storage_Error'Identity, "heap exhausted"); |
| end if; |
| |
| return Result; |
| end Alloc; |
| |
| ---------- |
| -- Free -- |
| ---------- |
| |
| procedure Free (Ptr : System.Address) is |
| begin |
| Abort_Defer.all; |
| c_free (Ptr); |
| Abort_Undefer.all; |
| end Free; |
| |
| ------------- |
| -- Realloc -- |
| ------------- |
| |
| function Realloc |
| (Ptr : System.Address; |
| Size : size_t) |
| return System.Address |
| is |
| Result : System.Address; |
| Actual_Size : size_t := Size; |
| |
| begin |
| if Size = size_t'Last then |
| Raise_Exception (Storage_Error'Identity, "object too large"); |
| end if; |
| |
| Abort_Defer.all; |
| Result := c_realloc (Ptr, Actual_Size); |
| Abort_Undefer.all; |
| |
| if Result = System.Null_Address then |
| Raise_Exception (Storage_Error'Identity, "heap exhausted"); |
| end if; |
| |
| return Result; |
| end Realloc; |
| |
| end System.Memory; |
