1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME COMPONENTS -- 4-- -- 5-- S Y S T E M . M E M O R Y -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 2001-2003 Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 2, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING. If not, write -- 19-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- 20-- MA 02111-1307, USA. -- 21-- -- 22-- As a special exception, if other files instantiate generics from this -- 23-- unit, or you link this unit with other files to produce an executable, -- 24-- this unit does not by itself cause the resulting executable to be -- 25-- covered by the GNU General Public License. This exception does not -- 26-- however invalidate any other reasons why the executable file might be -- 27-- covered by the GNU Public License. -- 28-- -- 29-- GNAT was originally developed by the GNAT team at New York University. -- 30-- Extensive contributions were provided by Ada Core Technologies Inc. -- 31-- -- 32------------------------------------------------------------------------------ 33 34-- This is the default implementation of this package. 35 36-- This implementation assumes that the underlying malloc/free/realloc 37-- implementation is thread safe, and thus, no additional lock is required. 38-- Note that we still need to defer abortion because on most systems, 39-- an asynchronous signal (as used for implementing asynchronous abortion 40-- of task) cannot safely be handled while malloc is executing. 41 42-- If you are not using Ada constructs containing the "abort" keyword, 43-- then you can remove the calls to Abort_Defer.all and Abort_Undefer.all 44-- from this unit. 45 46with Ada.Exceptions; 47with System.Soft_Links; 48with System.Parameters; 49with System.CRTL; 50 51package body System.Memory is 52 53 use Ada.Exceptions; 54 use System.Soft_Links; 55 56 function c_malloc (Size : System.CRTL.size_t) return System.Address 57 renames System.CRTL.malloc; 58 59 procedure c_free (Ptr : System.Address) 60 renames System.CRTL.free; 61 62 function c_realloc 63 (Ptr : System.Address; Size : System.CRTL.size_t) return System.Address 64 renames System.CRTL.realloc; 65 66 ----------- 67 -- Alloc -- 68 ----------- 69 70 function Alloc (Size : size_t) return System.Address is 71 Result : System.Address; 72 Actual_Size : size_t := Size; 73 74 begin 75 if Size = size_t'Last then 76 Raise_Exception (Storage_Error'Identity, "object too large"); 77 end if; 78 79 -- Change size from zero to non-zero. We still want a proper pointer 80 -- for the zero case because pointers to zero length objects have to 81 -- be distinct, but we can't just go ahead and allocate zero bytes, 82 -- since some malloc's return zero for a zero argument. 83 84 if Size = 0 then 85 Actual_Size := 1; 86 end if; 87 88 if Parameters.No_Abort then 89 Result := c_malloc (System.CRTL.size_t (Actual_Size)); 90 else 91 Abort_Defer.all; 92 Result := c_malloc (System.CRTL.size_t (Actual_Size)); 93 Abort_Undefer.all; 94 end if; 95 96 if Result = System.Null_Address then 97 Raise_Exception (Storage_Error'Identity, "heap exhausted"); 98 end if; 99 100 return Result; 101 end Alloc; 102 103 ---------- 104 -- Free -- 105 ---------- 106 107 procedure Free (Ptr : System.Address) is 108 begin 109 if Parameters.No_Abort then 110 c_free (Ptr); 111 else 112 Abort_Defer.all; 113 c_free (Ptr); 114 Abort_Undefer.all; 115 end if; 116 end Free; 117 118 ------------- 119 -- Realloc -- 120 ------------- 121 122 function Realloc 123 (Ptr : System.Address; 124 Size : size_t) 125 return System.Address 126 is 127 Result : System.Address; 128 Actual_Size : constant size_t := Size; 129 130 begin 131 if Size = size_t'Last then 132 Raise_Exception (Storage_Error'Identity, "object too large"); 133 end if; 134 135 if Parameters.No_Abort then 136 Result := c_realloc (Ptr, System.CRTL.size_t (Actual_Size)); 137 else 138 Abort_Defer.all; 139 Result := c_realloc (Ptr, System.CRTL.size_t (Actual_Size)); 140 Abort_Undefer.all; 141 end if; 142 143 if Result = System.Null_Address then 144 Raise_Exception (Storage_Error'Identity, "heap exhausted"); 145 end if; 146 147 return Result; 148 end Realloc; 149 150end System.Memory; 151