1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- SYSTEM.TASK_PRIMITIVES.OPERATIONS.REGISTER_FOREIGN_THREAD -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 2002-2020, 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 32with System.Multiprocessors; 33with System.Soft_Links; 34with System.Task_Info; 35 36separate (System.Task_Primitives.Operations) 37function Register_Foreign_Thread 38 (Thread : Thread_Id; 39 Sec_Stack_Size : Size_Type := Unspecified_Size) 40 return Task_Id 41is 42 Local_ATCB : aliased Ada_Task_Control_Block (0); 43 Self_Id : Task_Id; 44 Succeeded : Boolean; 45 46begin 47 -- This section is tricky. We must not call anything that might require 48 -- an ATCB, until the new ATCB is in place. In order to get an ATCB 49 -- immediately, we fake one, so that it is then possible to e.g allocate 50 -- memory (which might require accessing self). 51 52 -- Record this as the Task_Id for the thread 53 54 Local_ATCB.Common.LL.Thread := Thread; 55 Local_ATCB.Common.Current_Priority := System.Priority'First; 56 Local_ATCB.Common.Global_Task_Lock_Nesting := 0; 57 Specific.Set (Local_ATCB'Unchecked_Access); 58 59 -- It is now safe to use an allocator 60 61 Self_Id := new Ada_Task_Control_Block (0); 62 63 -- Finish initialization 64 65 Lock_RTS; 66 System.Tasking.Initialize_ATCB 67 (Self_Id, null, Null_Address, Null_Task, 68 Foreign_Task_Elaborated'Access, 69 System.Priority'First, System.Multiprocessors.Not_A_Specific_CPU, null, 70 Task_Info.Unspecified_Task_Info, 0, Self_Id, Succeeded); 71 Unlock_RTS; 72 pragma Assert (Succeeded); 73 74 Self_Id.Master_Of_Task := 0; 75 Self_Id.Master_Within := Self_Id.Master_Of_Task + 1; 76 77 for L in Self_Id.Entry_Calls'Range loop 78 Self_Id.Entry_Calls (L).Self := Self_Id; 79 Self_Id.Entry_Calls (L).Level := L; 80 end loop; 81 82 Self_Id.Common.State := Runnable; 83 Self_Id.Awake_Count := 1; 84 85 Self_Id.Common.Task_Image (1 .. 14) := "foreign thread"; 86 Self_Id.Common.Task_Image_Len := 14; 87 88 -- Since this is not an ordinary Ada task, we will start out undeferred 89 90 Self_Id.Deferral_Level := 0; 91 92 -- We do not provide an alternate stack for foreign threads 93 94 Self_Id.Common.Task_Alternate_Stack := Null_Address; 95 96 -- Create the TSD for the task 97 98 System.Soft_Links.Create_TSD 99 (Self_Id.Common.Compiler_Data, null, Sec_Stack_Size); 100 101 Enter_Task (Self_Id); 102 103 return Self_Id; 104end Register_Foreign_Thread; 105