1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- SYSTEM.TASK_PRIMITIVES.OPERATIONS.SPECIFIC -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2021, Free Software Foundation, Inc. -- 10-- -- 11-- GNARL 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 3, 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. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNARL was developed by the GNARL team at Florida State University. -- 28-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This is a VxWorks version of this package where foreign threads are 33-- recognized. The implementation is based on VxWorks taskVarLib. 34 35separate (System.Task_Primitives.Operations) 36package body Specific is 37 38 ERROR : constant STATUS := System.VxWorks.Ext.ERROR; 39 40 ATCB_Key : aliased System.Address := System.Null_Address; 41 -- Key used to find the Ada Task_Id associated with a thread 42 43 ATCB_Key_Addr : System.Address := ATCB_Key'Address; 44 pragma Export (Ada, ATCB_Key_Addr, "__gnat_ATCB_key_addr"); 45 -- Exported to support the temporary AE653 task registration 46 -- implementation. This mechanism is used to minimize impact on other 47 -- targets. 48 49 Stack_Limit : aliased System.Address; 50 51 pragma Import (C, Stack_Limit, "__gnat_stack_limit"); 52 53 type Set_Stack_Limit_Proc_Acc is access procedure; 54 pragma Convention (C, Set_Stack_Limit_Proc_Acc); 55 56 Set_Stack_Limit_Hook : Set_Stack_Limit_Proc_Acc; 57 pragma Import (C, Set_Stack_Limit_Hook, "__gnat_set_stack_limit_hook"); 58 -- Procedure to be called when a task is created to set stack limit if 59 -- limit checking is used. 60 61 ---------------- 62 -- Initialize -- 63 ---------------- 64 65 procedure Initialize is 66 begin 67 null; 68 end Initialize; 69 70 ------------------- 71 -- Is_Valid_Task -- 72 ------------------- 73 74 function Is_Valid_Task return Boolean is 75 IERR : constant := -1; 76 begin 77 return taskVarGet (taskIdSelf, ATCB_Key'Access) /= IERR; 78 end Is_Valid_Task; 79 80 --------- 81 -- Set -- 82 --------- 83 84 procedure Set (Self_Id : Task_Id) is 85 Result : STATUS; 86 87 begin 88 -- If argument is null, destroy task specific data, to make API 89 -- consistent with other platforms, and thus compatible with the 90 -- shared version of s-tpoaal.adb. 91 92 if Self_Id = null then 93 Result := taskVarDelete (taskIdSelf, ATCB_Key'Access); 94 pragma Assert (Result /= ERROR); 95 return; 96 end if; 97 98 if not Is_Valid_Task then 99 Result := taskVarAdd (Self_Id.Common.LL.Thread, ATCB_Key'Access); 100 pragma Assert (Result = OK); 101 102 if Stack_Check_Limits 103 and then Result /= ERROR 104 and then Set_Stack_Limit_Hook /= null 105 then 106 -- This will be initialized from taskInfoGet() once the task is 107 -- is running. 108 109 Result := 110 taskVarAdd (Self_Id.Common.LL.Thread, Stack_Limit'Access); 111 pragma Assert (Result /= ERROR); 112 end if; 113 end if; 114 115 Result := 116 taskVarSet 117 (Self_Id.Common.LL.Thread, 118 ATCB_Key'Access, 119 To_Address (Self_Id)); 120 pragma Assert (Result /= ERROR); 121 end Set; 122 123 ---------- 124 -- Self -- 125 ---------- 126 127 -- To make Ada tasks and C threads interoperate better, we have added some 128 -- functionality to Self. Suppose a C main program (with threads) calls an 129 -- Ada procedure and the Ada procedure calls the tasking runtime system. 130 -- Eventually, a call will be made to self. Since the call is not coming 131 -- from an Ada task, there will be no corresponding ATCB. 132 133 -- What we do in Self is to catch references that do not come from 134 -- recognized Ada tasks, and create an ATCB for the calling thread. 135 136 -- The new ATCB will be "detached" from the normal Ada task master 137 -- hierarchy, much like the existing implicitly created signal-server 138 -- tasks. 139 140 function Self return Task_Id is 141 Result : constant Task_Id := To_Task_Id (ATCB_Key); 142 begin 143 if Result /= null then 144 return Result; 145 else 146 -- If the value is Null then it is a non-Ada task 147 148 return Register_Foreign_Thread; 149 end if; 150 end Self; 151 152end Specific; 153