[Ada] Implementation of pragma CPU

This patch adds the support of "pragma CPU" for controlling task affinity.
This pragma can appear in the task definition or in the declarative part of
the main subprogram. It uses the support of the underlying operating system,
and it is implemented (so far) on top of Linux, Windows and Solaris.

Tested on x86_64-pc-linux-gnu, committed on trunk

2010-10-18  Jose Ruiz  <ruiz@adacore.com>

	* exp_ch9.adb (Expand_N_Task_Type_Declaration): Add field corresponding
	to the affinity when expanding the task declaration.
	(Make_Task_Create_Call): Add the affinity parameter to the call to
	create task.
	* sem_prag.adb (Analyze_Pragma): Add the analysis for pragma CPU,
	taking into account the case when it applies to a subprogram (only for
	main and with static expression) or to a task.
	* par_prag.adb:(Prag): Make pragma CPU a valid one.
	* snames.ads-tmpl (Name_uCPU, Name_CPU): Add these new name identifiers
	used by the expander for handling the affinity parameter when creating
	a task.
	(Pragma_Id): Add Pragma_CPU as a valid one.
	* rtsfind.ads (RTU_Id): Make System_Multiprocessors accesible.
	(RE_Id, RE_Unit_Table): Make the entities RE_CPU_Range and
	RE_Unspecified_CPU visible.
	* sinfo.ads, sinfo.adb (Has_Pragma_CPU, Set_Has_Pragma_CPU): Add these
	two subprograms to set/get the flag indicating whether there is a
	pragma CPU which applies to the entity.
	* lib.ads, lib.adb (Unit_Record, Default_Main_CPU, Main_CPU,
	Set_Main_CPU): Add the field Main_CPU to Unit_Record to store the value
	of the affinity associated to the main subprogram (if any).
	Default_Main_CPU is used when no affinity is set. Subprograms
	Set_Main_CPU and Main_CPU are added to set/get the affinity of the main
	subprogram.
	* ali.ads, ali.adb (ALIs_Record): Add field Main_CPU to contain the
	value of the affinity of the main subprogram.
	(Scan_ALI): Get the affinity of the main subprogram (encoded as C=XX in
	the M line).
	* lib-writ.ads, lib-writ.adb (M_Parameters): Encode the affinity of the
	main subprogram in the M (main) line using C=XX.
	* lib-load.adb (Create_Dummy_Package_Unit, Load_Main_Source,
	Load_Unit): Add new field Main_CPU.
	* bindgen.adb (Gen_Adainit_Ada, Gen_Adainit_C): Add the code to pass
	the affinity of the main subprogram to the run time.
	* s-taskin.ads (Common_ATCB): Add the field Base_CPU to store the
	affinity.
	(Unspecified_CPU): Add this constant to identify the case when no
	affinity is set for tasks.
	* s-taskin.adb (Initialize_ATCB): Store the value coming from pragma
	CPU in the common part of the ATCB.
	(Initialize): Store the value coming from pragma CPU (for the
	environment task) in the common part of the ATCB.
	* s-tassta.ads, s-tassta.adb (Create_Task): Add the affinity specified
	by pragma CPU to the ATCB.
	* s-tarest.ads, s-tarest.adb (Create_Restricted_Task): Add the affinity
	specified by pragma CPU to the ATCB.
	* s-tporft.adb (Register_Foreign_Thread): Add the new affinity
	parameter to the call to Initialize_ATCB.
	* s-taprop-linux.adb (Create_Task): Change the attributes of the thread
	to include the task affinity before creation. Additionally, the
	affinity selected with Task_Info is also enforced changing the
	attributes at task creation time, instead of changing it after creation.
	(Initialize): Change the affinity of the environment task if required
	by a pragma CPU.
	* s-osinte-linux.ads (pthread_setaffinity_np): Instead of using a
	wrapper to check whether the function is available or not, use a weak
	symbol.
	(pthread_attr_setaffinity_np): Add the import of this function which is
	used to change the affinity in the attributes used to create a thread.
	* adaint.c (__gnat_pthread_attr_setaffinity_np): Remove this wrapper.
	It was used to check whether the pthread function was available or not,
	but the use of a weak symbol handles this situation in a cleaner way.
	* s-taprop-mingw.adb (Create_Task, Initialize): Change the affinity of
	tasks (including the environment task) if required by a pragma CPU.
	* s-taprop-solaris.adb (Enter_Task): Change the affinity of tasks
	(including the environment task) if required by a pragma CPU.
	* s-taprop-vxworks.adb (Create_Task, Initialize): Change the affinity
	of tasks (including the environment task) if required by a pragma CPU.
	* init.c (__gl_main_cpu): Make this value visible to the run time. It
	will pass the affinity of the environment task.

[Ada] Implementation of pragma CPU

Commit Message

Patch