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Diffstat (limited to 'gcc-4.8.3/gcc/ada/s-mudido-affinity.adb')
| -rw-r--r-- | gcc-4.8.3/gcc/ada/s-mudido-affinity.adb | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/ada/s-mudido-affinity.adb b/gcc-4.8.3/gcc/ada/s-mudido-affinity.adb new file mode 100644 index 000000000..35239b87c --- /dev/null +++ b/gcc-4.8.3/gcc/ada/s-mudido-affinity.adb @@ -0,0 +1,386 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- SYSTEM.MULTIPROCESSORS.DISPATCHING_DOMAINS -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2011, 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- -- +-- ware Foundation; either version 3, 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNARL was developed by the GNARL team at Florida State University. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- Body used on targets where the operating system supports setting task +-- affinities. + +with System.Tasking.Initialization; +with System.Task_Primitives.Operations; use System.Task_Primitives.Operations; + +with Ada.Unchecked_Conversion; + +package body System.Multiprocessors.Dispatching_Domains is + + package ST renames System.Tasking; + + ----------------------- + -- Local subprograms -- + ----------------------- + + function Convert_Ids is new + Ada.Unchecked_Conversion (Ada.Task_Identification.Task_Id, ST.Task_Id); + + procedure Unchecked_Set_Affinity + (Domain : ST.Dispatching_Domain_Access; + CPU : CPU_Range; + T : ST.Task_Id); + -- Internal procedure to move a task to a target domain and CPU. No checks + -- are performed about the validity of the domain and the CPU because they + -- are done by the callers of this procedure (either Assign_Task or + -- Set_CPU). + + procedure Freeze_Dispatching_Domains; + pragma Export + (Ada, Freeze_Dispatching_Domains, "__gnat_freeze_dispatching_domains"); + -- Signal the time when no new dispatching domains can be created. It + -- should be called before the environment task calls the main procedure + -- (and after the elaboration code), so the binder-generated file needs to + -- import and call this procedure. + + ----------------- + -- Assign_Task -- + ----------------- + + procedure Assign_Task + (Domain : in out Dispatching_Domain; + CPU : CPU_Range := Not_A_Specific_CPU; + T : Ada.Task_Identification.Task_Id := + Ada.Task_Identification.Current_Task) + is + Target : constant ST.Task_Id := Convert_Ids (T); + + use type System.Tasking.Dispatching_Domain_Access; + + begin + -- The exception Dispatching_Domain_Error is propagated if T is already + -- assigned to a Dispatching_Domain other than + -- System_Dispatching_Domain, or if CPU is not one of the processors of + -- Domain (and is not Not_A_Specific_CPU). + + if Target.Common.Domain /= null and then + Dispatching_Domain (Target.Common.Domain) /= System_Dispatching_Domain + then + raise Dispatching_Domain_Error with + "task already in user-defined dispatching domain"; + + elsif CPU /= Not_A_Specific_CPU and then CPU not in Domain'Range then + raise Dispatching_Domain_Error with + "processor does not belong to dispatching domain"; + end if; + + -- Assigning a task to System_Dispatching_Domain that is already + -- assigned to that domain has no effect. + + if Domain = System_Dispatching_Domain then + return; + + else + -- Set the task affinity once we know it is possible + + Unchecked_Set_Affinity + (ST.Dispatching_Domain_Access (Domain), CPU, Target); + end if; + end Assign_Task; + + ------------ + -- Create -- + ------------ + + function Create (First, Last : CPU) return Dispatching_Domain is + use type System.Tasking.Dispatching_Domain; + use type System.Tasking.Dispatching_Domain_Access; + use type System.Tasking.Array_Allocated_Tasks; + use type System.Tasking.Task_Id; + + Valid_System_Domain : constant Boolean := + (First > CPU'First + and then + not (System_Dispatching_Domain (CPU'First .. First - 1) = + (CPU'First .. First - 1 => False))) + or else (Last < Number_Of_CPUs + and then not + (System_Dispatching_Domain + (Last + 1 .. Number_Of_CPUs) = + (Last + 1 .. Number_Of_CPUs => False))); + -- Constant that indicates whether there would exist a non-empty system + -- dispatching domain after the creation of this dispatching domain. + + T : ST.Task_Id; + + New_Domain : Dispatching_Domain; + + begin + -- The range of processors for creating a dispatching domain must + -- comply with the following restrictions: + -- - Non-empty range + -- - Not exceeding the range of available processors + -- - Range from the System_Dispatching_Domain + -- - Range does not contain a processor with a task assigned to it + -- - The allocation cannot leave System_Dispatching_Domain empty + -- - The calling task must be the environment task + -- - The call to Create must take place before the call to the main + -- subprogram + + if First > Last then + raise Dispatching_Domain_Error with "empty dispatching domain"; + + elsif Last > Number_Of_CPUs then + raise Dispatching_Domain_Error with + "CPU range not supported by the target"; + + elsif + System_Dispatching_Domain (First .. Last) /= (First .. Last => True) + then + raise Dispatching_Domain_Error with + "CPU range not currently in System_Dispatching_Domain"; + + elsif + ST.Dispatching_Domain_Tasks (First .. Last) /= (First .. Last => 0) + then + raise Dispatching_Domain_Error with "CPU range has tasks assigned"; + + elsif not Valid_System_Domain then + raise Dispatching_Domain_Error with + "would leave System_Dispatching_Domain empty"; + + elsif Self /= Environment_Task then + raise Dispatching_Domain_Error with + "only the environment task can create dispatching domains"; + + elsif ST.Dispatching_Domains_Frozen then + raise Dispatching_Domain_Error with + "cannot create dispatching domain after call to main program"; + end if; + + New_Domain := new ST.Dispatching_Domain'(First .. Last => True); + + -- At this point we need to fix the processors belonging to the system + -- domain, and change the affinity of every task that has been created + -- and assigned to the system domain. + + ST.Initialization.Defer_Abort (Self); + + Lock_RTS; + + System_Dispatching_Domain (First .. Last) := (First .. Last => False); + + -- Iterate the list of tasks belonging to the default system + -- dispatching domain and set the appropriate affinity. + + T := ST.All_Tasks_List; + + while T /= null loop + if T.Common.Domain = null or else + T.Common.Domain = ST.System_Domain + then + Set_Task_Affinity (T); + end if; + + T := T.Common.All_Tasks_Link; + end loop; + + Unlock_RTS; + + ST.Initialization.Undefer_Abort (Self); + + return New_Domain; + end Create; + + ----------------------------- + -- Delay_Until_And_Set_CPU -- + ----------------------------- + + procedure Delay_Until_And_Set_CPU + (Delay_Until_Time : Ada.Real_Time.Time; + CPU : CPU_Range) + is + begin + -- Not supported atomically by the underlying operating systems. + -- Operating systems use to migrate the task immediately after the call + -- to set the affinity. + + delay until Delay_Until_Time; + Set_CPU (CPU); + end Delay_Until_And_Set_CPU; + + -------------------------------- + -- Freeze_Dispatching_Domains -- + -------------------------------- + + procedure Freeze_Dispatching_Domains is + begin + -- Signal the end of the elaboration code + + ST.Dispatching_Domains_Frozen := True; + end Freeze_Dispatching_Domains; + + ------------- + -- Get_CPU -- + ------------- + + function Get_CPU + (T : Ada.Task_Identification.Task_Id := + Ada.Task_Identification.Current_Task) return CPU_Range + is + begin + return Convert_Ids (T).Common.Base_CPU; + end Get_CPU; + + ---------------------------- + -- Get_Dispatching_Domain -- + ---------------------------- + + function Get_Dispatching_Domain + (T : Ada.Task_Identification.Task_Id := + Ada.Task_Identification.Current_Task) return Dispatching_Domain + is + begin + return Dispatching_Domain (Convert_Ids (T).Common.Domain); + end Get_Dispatching_Domain; + + ------------------- + -- Get_First_CPU -- + ------------------- + + function Get_First_CPU (Domain : Dispatching_Domain) return CPU is + begin + for Proc in Domain'Range loop + if Domain (Proc) then + return Proc; + end if; + end loop; + + -- Should never reach the following return + + return Domain'First; + end Get_First_CPU; + + ------------------ + -- Get_Last_CPU -- + ------------------ + + function Get_Last_CPU (Domain : Dispatching_Domain) return CPU is + begin + for Proc in reverse Domain'Range loop + if Domain (Proc) then + return Proc; + end if; + end loop; + + -- Should never reach the following return + + return Domain'Last; + end Get_Last_CPU; + + ------------- + -- Set_CPU -- + ------------- + + procedure Set_CPU + (CPU : CPU_Range; + T : Ada.Task_Identification.Task_Id := + Ada.Task_Identification.Current_Task) + is + Target : constant ST.Task_Id := Convert_Ids (T); + + use type ST.Dispatching_Domain_Access; + + begin + -- The exception Dispatching_Domain_Error is propagated if CPU is not + -- one of the processors of the Dispatching_Domain on which T is + -- assigned (and is not Not_A_Specific_CPU). + + if CPU /= Not_A_Specific_CPU and then + (CPU not in Target.Common.Domain'Range or else + not Target.Common.Domain (CPU)) + then + raise Dispatching_Domain_Error with + "processor does not belong to the task's dispatching domain"; + end if; + + Unchecked_Set_Affinity (Target.Common.Domain, CPU, Target); + end Set_CPU; + + ---------------------------- + -- Unchecked_Set_Affinity -- + ---------------------------- + + procedure Unchecked_Set_Affinity + (Domain : ST.Dispatching_Domain_Access; + CPU : CPU_Range; + T : ST.Task_Id) + is + Source_CPU : constant CPU_Range := T.Common.Base_CPU; + + use type System.Tasking.Dispatching_Domain_Access; + + begin + Write_Lock (T); + + -- Move to the new domain + + T.Common.Domain := Domain; + + -- Attach the CPU to the task + + T.Common.Base_CPU := CPU; + + -- Change the number of tasks attached to a given task in the system + -- domain if needed. + + if not ST.Dispatching_Domains_Frozen + and then (Domain = null or else Domain = ST.System_Domain) + then + -- Reduce the number of tasks attached to the CPU from which this + -- task is being moved, if needed. + + if Source_CPU /= Not_A_Specific_CPU then + ST.Dispatching_Domain_Tasks (Source_CPU) := + ST.Dispatching_Domain_Tasks (Source_CPU) - 1; + end if; + + -- Increase the number of tasks attached to the CPU to which this + -- task is being moved, if needed. + + if CPU /= Not_A_Specific_CPU then + ST.Dispatching_Domain_Tasks (CPU) := + ST.Dispatching_Domain_Tasks (CPU) + 1; + end if; + end if; + + -- Change the actual affinity calling the operating system level + + Set_Task_Affinity (T); + + Unlock (T); + end Unchecked_Set_Affinity; + +end System.Multiprocessors.Dispatching_Domains; |