X-Git-Url: https://oss.titaniummirror.com/gitweb/?a=blobdiff_plain;f=gcc%2Fada%2Fs-taprop.ads;fp=gcc%2Fada%2Fs-taprop.ads;h=0000000000000000000000000000000000000000;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=5006371e3c1f7bf21600ccca6ecaaac28fdb229f;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/gcc/ada/s-taprop.ads b/gcc/ada/s-taprop.ads deleted file mode 100644 index 5006371e..00000000 --- a/gcc/ada/s-taprop.ads +++ /dev/null @@ -1,475 +0,0 @@ ------------------------------------------------------------------------------- --- -- --- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- --- -- --- S Y S T E M . T A S K _ P R I M I T I V E S .O P E R A T I O N S -- --- -- --- S p e c -- --- -- --- $Revision: 1.3.10.1 $ --- -- --- Copyright (C) 1992-2001, 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 2, or (at your option) any later ver- -- --- sion. GNARL 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. See the GNU General Public License -- --- for more details. You should have received a copy of the GNU General -- --- Public License distributed with GNARL; see file COPYING. If not, write -- --- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- --- MA 02111-1307, USA. -- --- -- --- As a special exception, if other files instantiate generics from this -- --- unit, or you link this unit with other files to produce an executable, -- --- this unit does not by itself cause the resulting executable to be -- --- covered by the GNU General Public License. This exception does not -- --- however invalidate any other reasons why the executable file might be -- --- covered by the GNU Public License. -- --- -- --- GNARL was developed by the GNARL team at Florida State University. -- --- Extensive contributions were provided by Ada Core Technologies Inc. -- --- -- ------------------------------------------------------------------------------- - --- This package contains all the GNULL primitives that interface directly --- with the underlying OS. - -with System.Parameters; --- used for Size_Type - -with System.Tasking; --- used for Task_ID - -with System.OS_Interface; --- used for Thread_Id - -package System.Task_Primitives.Operations is - - pragma Elaborate_Body; - package ST renames System.Tasking; - package OSI renames System.OS_Interface; - - procedure Initialize (Environment_Task : ST.Task_ID); - pragma Inline (Initialize); - -- This must be called once, before any other subprograms of this - -- package are called. - - procedure Create_Task - (T : ST.Task_ID; - Wrapper : System.Address; - Stack_Size : System.Parameters.Size_Type; - Priority : System.Any_Priority; - Succeeded : out Boolean); - pragma Inline (Create_Task); - -- Create a new low-level task with ST.Task_ID T and place other needed - -- information in the ATCB. - -- - -- A new thread of control is created, with a stack of at least Stack_Size - -- storage units, and the procedure Wrapper is called by this new thread - -- of control. If Stack_Size = Unspecified_Storage_Size, choose a default - -- stack size; this may be effectively "unbounded" on some systems. - -- - -- The newly created low-level task is associated with the ST.Task_ID T - -- such that any subsequent call to Self from within the context of the - -- low-level task returns T. - -- - -- The caller is responsible for ensuring that the storage of the Ada - -- task control block object pointed to by T persists for the lifetime - -- of the new task. - -- - -- Succeeded is set to true unless creation of the task failed, - -- as it may if there are insufficient resources to create another task. - - procedure Enter_Task (Self_ID : ST.Task_ID); - pragma Inline (Enter_Task); - -- Initialize data structures specific to the calling task. - -- Self must be the ID of the calling task. - -- It must be called (once) by the task immediately after creation, - -- while abortion is still deferred. - -- The effects of other operations defined below are not defined - -- unless the caller has previously called Initialize_Task. - - procedure Exit_Task; - pragma Inline (Exit_Task); - -- Destroy the thread of control. - -- Self must be the ID of the calling task. - -- The effects of further calls to operations defined below - -- on the task are undefined thereafter. - - function New_ATCB (Entry_Num : ST.Task_Entry_Index) return ST.Task_ID; - pragma Inline (New_ATCB); - -- Allocate a new ATCB with the specified number of entries. - - procedure Initialize_TCB (Self_ID : ST.Task_ID; Succeeded : out Boolean); - pragma Inline (Initialize_TCB); - -- Initialize all fields of the TCB - - procedure Finalize_TCB (T : ST.Task_ID); - pragma Inline (Finalize_TCB); - -- Finalizes Private_Data of ATCB, and then deallocates it. - -- This is also responsible for recovering any storage or other resources - -- that were allocated by Create_Task (the one in this package). - -- This should only be called from Free_Task. - -- After it is called there should be no further - -- reference to the ATCB that corresponds to T. - - procedure Abort_Task (T : ST.Task_ID); - pragma Inline (Abort_Task); - -- Abort the task specified by T (the target task). This causes - -- the target task to asynchronously raise Abort_Signal if - -- abort is not deferred, or if it is blocked on an interruptible - -- system call. - -- - -- precondition: - -- the calling task is holding T's lock and has abort deferred - -- - -- postcondition: - -- the calling task is holding T's lock and has abort deferred. - - -- ??? modify GNARL to skip wakeup and always call Abort_Task - - function Self return ST.Task_ID; - pragma Inline (Self); - -- Return a pointer to the Ada Task Control Block of the calling task. - - type Lock_Level is - (PO_Level, - Global_Task_Level, - All_Attrs_Level, - All_Tasks_Level, - Interrupts_Level, - ATCB_Level); - -- Type used to describe kind of lock for second form of Initialize_Lock - -- call specified below. - -- See locking rules in System.Tasking (spec) for more details. - - procedure Initialize_Lock (Prio : System.Any_Priority; L : access Lock); - procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level); - pragma Inline (Initialize_Lock); - -- Initialize a lock object. - -- - -- For Lock, Prio is the ceiling priority associated with the lock. - -- For RTS_Lock, the ceiling is implicitly Priority'Last. - -- - -- If the underlying system does not support priority ceiling - -- locking, the Prio parameter is ignored. - -- - -- The effect of either initialize operation is undefined unless L - -- is a lock object that has not been initialized, or which has been - -- finalized since it was last initialized. - -- - -- The effects of the other operations on lock objects - -- are undefined unless the lock object has been initialized - -- and has not since been finalized. - -- - -- Initialization of the per-task lock is implicit in Create_Task. - -- - -- These operations raise Storage_Error if a lack of storage is detected. - - procedure Finalize_Lock (L : access Lock); - procedure Finalize_Lock (L : access RTS_Lock); - pragma Inline (Finalize_Lock); - -- Finalize a lock object, freeing any resources allocated by the - -- corresponding Initialize_Lock operation. - - procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean); - procedure Write_Lock (L : access RTS_Lock); - procedure Write_Lock (T : ST.Task_ID); - pragma Inline (Write_Lock); - -- Lock a lock object for write access. After this operation returns, - -- the calling task holds write permission for the lock object. No other - -- Write_Lock or Read_Lock operation on the same lock object will return - -- until this task executes an Unlock operation on the same object. The - -- effect is undefined if the calling task already holds read or write - -- permission for the lock object L. - -- - -- For the operation on Lock, Ceiling_Violation is set to true iff the - -- operation failed, which will happen if there is a priority ceiling - -- violation. - -- - -- For the operation on ST.Task_ID, the lock is the special lock object - -- associated with that task's ATCB. This lock has effective ceiling - -- priority high enough that it is safe to call by a task with any - -- priority in the range System.Priority. It is implicitly initialized - -- by task creation. The effect is undefined if the calling task already - -- holds T's lock, or has interrupt-level priority. Finalization of the - -- per-task lock is implicit in Exit_Task. - - procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean); - pragma Inline (Read_Lock); - -- Lock a lock object for read access. After this operation returns, - -- the calling task has non-exclusive read permission for the logical - -- resources that are protected by the lock. No other Write_Lock operation - -- on the same object will return until this task and any other tasks with - -- read permission for this lock have executed Unlock operation(s) on the - -- lock object. A Read_Lock for a lock object may return immediately while - -- there are tasks holding read permission, provided there are no tasks - -- holding write permission for the object. The effect is undefined if - -- the calling task already holds read or write permission for L. - -- - -- Alternatively: An implementation may treat Read_Lock identically to - -- Write_Lock. This simplifies the implementation, but reduces the level - -- of concurrency that can be achieved. - -- - -- Note that Read_Lock is not defined for RT_Lock and ST.Task_ID. - -- That is because (1) so far Read_Lock has always been implemented - -- the same as Write_Lock, (2) most lock usage inside the RTS involves - -- potential write access, and (3) implementations of priority ceiling - -- locking that make a reader-writer distinction have higher overhead. - - procedure Unlock (L : access Lock); - procedure Unlock (L : access RTS_Lock); - procedure Unlock (T : ST.Task_ID); - pragma Inline (Unlock); - -- Unlock a locked lock object. - -- - -- The effect is undefined unless the calling task holds read or write - -- permission for the lock L, and L is the lock object most recently - -- locked by the calling task for which the calling task still holds - -- read or write permission. (That is, matching pairs of Lock and Unlock - -- operations on each lock object must be properly nested.) - - -- Note that Write_Lock for RTS_Lock does not have an out-parameter. - -- RTS_Locks are used in situations where we have not made provision - -- for recovery from ceiling violations. We do not expect them to - -- occur inside the runtime system, because all RTS locks have ceiling - -- Priority'Last. - - -- There is one way there can be a ceiling violation. - -- That is if the runtime system is called from a task that is - -- executing in the Interrupt_Priority range. - - -- It is not clear what to do about ceiling violations due - -- to RTS calls done at interrupt priority. In general, it - -- is not acceptable to give all RTS locks interrupt priority, - -- since that whould give terrible performance on systems where - -- this has the effect of masking hardware interrupts, though we - -- could get away with allowing Interrupt_Priority'last where we - -- are layered on an OS that does not allow us to mask interrupts. - -- Ideally, we would like to raise Program_Error back at the - -- original point of the RTS call, but this would require a lot of - -- detailed analysis and recoding, with almost certain performance - -- penalties. - - -- For POSIX systems, we considered just skipping setting a - -- priority ceiling on RTS locks. This would mean there is no - -- ceiling violation, but we would end up with priority inversions - -- inside the runtime system, resulting in failure to satisfy the - -- Ada priority rules, and possible missed validation tests. - -- This could be compensated-for by explicit priority-change calls - -- to raise the caller to Priority'Last whenever it first enters - -- the runtime system, but the expected overhead seems high, though - -- it might be lower than using locks with ceilings if the underlying - -- implementation of ceiling locks is an inefficient one. - - -- This issue should be reconsidered whenever we get around to - -- checking for calls to potentially blocking operations from - -- within protected operations. If we check for such calls and - -- catch them on entry to the OS, it may be that we can eliminate - -- the possibility of ceiling violations inside the RTS. For this - -- to work, we would have to forbid explicitly setting the priority - -- of a task to anything in the Interrupt_Priority range, at least. - -- We would also have to check that there are no RTS-lock operations - -- done inside any operations that are not treated as potentially - -- blocking. - - -- The latter approach seems to be the best, i.e. to check on entry - -- to RTS calls that may need to use locks that the priority is not - -- in the interrupt range. If there are RTS operations that NEED to - -- be called from interrupt handlers, those few RTS locks should then - -- be converted to PO-type locks, with ceiling Interrupt_Priority'Last. - - -- For now, we will just shut down the system if there is a - -- ceiling violation. - - procedure Yield (Do_Yield : Boolean := True); - pragma Inline (Yield); - -- Yield the processor. Add the calling task to the tail of the - -- ready queue for its active_priority. - -- The Do_Yield argument is only used in some very rare cases very - -- a yield should have an effect on a specific target and not on regular - -- ones. - - procedure Set_Priority - (T : ST.Task_ID; - Prio : System.Any_Priority; - Loss_Of_Inheritance : Boolean := False); - pragma Inline (Set_Priority); - -- Set the priority of the task specified by T to T.Current_Priority. - -- The priority set is what would correspond to the Ada concept of - -- "base priority" in the terms of the lower layer system, but - -- the operation may be used by the upper layer to implement - -- changes in "active priority" that are not due to lock effects. - -- The effect should be consistent with the Ada Reference Manual. - -- In particular, when a task lowers its priority due to the loss of - -- inherited priority, it goes at the head of the queue for its new - -- priority (RM D.2.2 par 9). - -- Loss_Of_Inheritance helps the underlying implementation to do it - -- right when the OS doesn't. - - function Get_Priority (T : ST.Task_ID) return System.Any_Priority; - pragma Inline (Get_Priority); - -- Returns the priority last set by Set_Priority for this task. - - function Monotonic_Clock return Duration; - pragma Inline (Monotonic_Clock); - -- Returns "absolute" time, represented as an offset - -- relative to "the Epoch", which is Jan 1, 1970. - -- This clock implementation is immune to the system's clock changes. - - function RT_Resolution return Duration; - pragma Inline (RT_Resolution); - -- Returns the resolution of the underlying clock used to implement - -- RT_Clock. - - ------------------ - -- Extensions -- - ------------------ - - -- Whoever calls either of the Sleep routines is responsible - -- for checking for pending aborts before the call. - -- Pending priority changes are handled internally. - - procedure Sleep - (Self_ID : ST.Task_ID; - Reason : System.Tasking.Task_States); - pragma Inline (Sleep); - -- Wait until the current task, T, is signaled to wake up. - -- - -- precondition: - -- The calling task is holding its own ATCB lock - -- and has abort deferred - -- - -- postcondition: - -- The calling task is holding its own ATCB lock - -- and has abort deferred. - - -- The effect is to atomically unlock T's lock and wait, so that another - -- task that is able to lock T's lock can be assured that the wait has - -- actually commenced, and that a Wakeup operation will cause the waiting - -- task to become ready for execution once again. When Sleep returns, - -- the waiting task will again hold its own ATCB lock. The waiting task - -- may become ready for execution at any time (that is, spurious wakeups - -- are permitted), but it will definitely become ready for execution when - -- a Wakeup operation is performed for the same task. - - procedure Timed_Sleep - (Self_ID : ST.Task_ID; - Time : Duration; - Mode : ST.Delay_Modes; - Reason : System.Tasking.Task_States; - Timedout : out Boolean; - Yielded : out Boolean); - -- Combination of Sleep (above) and Timed_Delay - - procedure Timed_Delay - (Self_ID : ST.Task_ID; - Time : Duration; - Mode : ST.Delay_Modes); - -- Implements the semantics of the delay statement. It is assumed that - -- the caller is not abort-deferred and does not hold any locks. - - procedure Wakeup - (T : ST.Task_ID; - Reason : System.Tasking.Task_States); - pragma Inline (Wakeup); - -- Wake up task T if it is waiting on a Sleep call (of ordinary - -- or timed variety), making it ready for execution once again. - -- If the task T is not waiting on a Sleep, the operation has no effect. - - function Environment_Task return ST.Task_ID; - pragma Inline (Environment_Task); - -- returns the task ID of the environment task - -- Consider putting this into a variable visible directly - -- by the rest of the runtime system. ??? - - function Get_Thread_Id (T : ST.Task_ID) return OSI.Thread_Id; - -- returns the thread id of the specified task. - - -------------------- - -- Stack Checking -- - -------------------- - - -- Stack checking in GNAT is done using the concept of stack probes. A - -- stack probe is an operation that will generate a storage error if - -- an insufficient amount of stack space remains in the current task. - - -- The exact mechanism for a stack probe is target dependent. Typical - -- possibilities are to use a load from a non-existent page, a store - -- to a read-only page, or a comparison with some stack limit constant. - -- Where possible we prefer to use a trap on a bad page access, since - -- this has less overhead. The generation of stack probes is either - -- automatic if the ABI requires it (as on for example DEC Unix), or - -- is controlled by the gcc parameter -fstack-check. - - -- When we are using bad-page accesses, we need a bad page, called a - -- guard page, at the end of each task stack. On some systems, this - -- is provided automatically, but on other systems, we need to create - -- the guard page ourselves, and the procedure Stack_Guard is provided - -- for this purpose. - - procedure Stack_Guard (T : ST.Task_ID; On : Boolean); - -- Ensure guard page is set if one is needed and the underlying thread - -- system does not provide it. The procedure is as follows: - -- - -- 1. When we create a task adjust its size so a guard page can - -- safely be set at the bottom of the stack - -- - -- 2. When the thread is created (and its stack allocated by the - -- underlying thread system), get the stack base (and size, depending - -- how the stack is growing), and create the guard page taking care of - -- page boundaries issues. - -- - -- 3. When the task is destroyed, remove the guard page. - -- - -- If On is true then protect the stack bottom (i.e make it read only) - -- else unprotect it (i.e. On is True for the call when creating a task, - -- and False when a task is destroyed). - -- - -- The call to Stack_Guard has no effect if guard pages are not used on - -- the target, or if guard pages are automatically provided by the system. - - ----------------------------------------- - -- Runtime System Debugging Interfaces -- - ----------------------------------------- - - -- These interfaces have been added to assist in debugging the - -- tasking runtime system. - - function Check_Exit (Self_ID : ST.Task_ID) return Boolean; - pragma Inline (Check_Exit); - -- Check that the current task is holding only Global_Task_Lock. - - function Check_No_Locks (Self_ID : ST.Task_ID) return Boolean; - pragma Inline (Check_No_Locks); - -- Check that current task is holding no locks. - - function Suspend_Task - (T : ST.Task_ID; - Thread_Self : OSI.Thread_Id) - return Boolean; - -- Suspend a specific task when the underlying thread library provides - -- such functionality, unless the thread associated with T is Thread_Self. - -- Such functionality is needed by gdb on some targets (e.g VxWorks) - -- Return True is the operation is successful - - function Resume_Task - (T : ST.Task_ID; - Thread_Self : OSI.Thread_Id) - return Boolean; - -- Resume a specific task when the underlying thread library provides - -- such functionality, unless the thread associated with T is Thread_Self. - -- Such functionality is needed by gdb on some targets (e.g VxWorks) - -- Return True is the operation is successful - - procedure Lock_All_Tasks_List; - procedure Unlock_All_Tasks_List; - -- Lock/Unlock the All_Tasks_L lock which protects - -- System.Initialization.All_Tasks_List and Known_Tasks - -- ??? These routines were previousely in System.Tasking.Initialization - -- but were moved here to avoid dependency problems. That would be - -- nice to look at it some day and put it back in Initialization. - -end System.Task_Primitives.Operations;