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// IBM_PROLOG_BEGIN_TAG
// This is an automatically generated prolog.
//
// $Source: src/include/kernel/taskmgr.H $
//
// IBM CONFIDENTIAL
//
// COPYRIGHT International Business Machines Corp. 2010 - 2011
//
// p1
//
// Object Code Only (OCO) source materials
// Licensed Internal Code Source Materials
// IBM HostBoot Licensed Internal Code
//
// The source code for this program is not published or other-
// wise divested of its trade secrets, irrespective of what has
// been deposited with the U.S. Copyright Office.
//
// Origin: 30
//
// IBM_PROLOG_END
#ifndef __KERNEL_TASKMGR_H
#define __KERNEL_TASKMGR_H
#include <kernel/types.h>
#include <util/lockfree/counter.H>
#include <kernel/vmmmgr.H>
#include <sys/task.h>
#include <util/locked/list.H>
#include <kernel/spinlock.H>
// Forward declaration.
struct task_tracking_t;
struct task_wait_t;
/** Typedef for a list of task_tracking_t's. */
typedef Util::Locked::List<task_tracking_t, tid_t> task_tracking_list_t;
/** @struct task_tracking_t
* Stores the parent/child relationships and join information for tasks.
*
* The task_tracking_t's become a tree so that we can create a ps-like
* debug output and so that a task can do a wait() on all of its children.
*/
struct task_tracking_t
{
typedef tid_t key_type;
/** previous pointer for list. */
task_tracking_t* prev;
/** next pointer for list. */
task_tracking_t* next;
/** pointer to parent's tracking info. */
task_tracking_t* parent;
/** list of all children. */
task_tracking_list_t children;
/** tid as a key for list. */
key_type key;
/** Pointer to task structure if it is still running. */
task_t* task;
/** Crash/clean-exit status if task has ended. */
int status;
/** Return-value to task_end2() if task has ended. */
void* retval;
/** Task-wait state object. */
task_wait_t* wait_info;
/** Record the original entry point of the thread for debug purpose. */
void* entry_point;
};
/** @struct task_wait_t
* Stores the parameters for the task_wait syscall for a task which is
* deferred due to the syscall.
*/
struct task_wait_t
{
/** Tid waiting on (or -1 for any). */
int64_t tid;
/** Address to return the child status. */
int* status;
/** Address to return the child return-value. */
void** retval;
};
/** @class TaskManager
* Kernel management class to deal with task creation / exit.
*/
class TaskManager
{
public:
/** @brief Returns a pointer to the currently running task on this
* CPU.
*
* @retval NULL - Kernel has never started running any tasks.
* @retval non-NULL - The task most recently running and/or will be
* running when kernel returns to user-space.
*/
static task_t* getCurrentTask();
/** @brief Sets the current task pointer in this CPU object.
*
* @param[in] t - The task to assign on this CPU.
*/
static void setCurrentTask(task_t* t);
/** Typedef for task entry points. */
typedef void(*task_fn_t)(void*);
/** @brief Create a new task object.
*
* @param[in] t - The entry point to start the task at.
* @param[in] p - An argument pointer to pass to the task.
* @param[in] kernelParent - Should the kernel be assigned the parent
* of the new task.
*/
static task_t* createTask(task_fn_t t, void* p,
bool kernelParent = false);
/** @brief End / destroy a task object.
*
* @param[in] t - The task to end.
* @param[in] retval - Return value from the task.
* @param[in] status - TASK_STATUS_* enumeration of how the task ended.
*
* @note This function obtains the VMM-subsystem spinlock as part of
* releasing the task stack.
*/
static void endTask(task_t* t, void* retval, int status);
/** @brief Perform the 'task_wait' for a task.
*
* Returns the child information if the requested child has already
* ended or defers the task if the child requested is still running.
*
* @param[in] t - The task requesting the wait.
* @param[in] tid - The child task requested to wait on or -1 for any.
* @param[out] status - The address to write the child status.
* @param[out] retval - The address to write the child retval.
*/
static void waitTask(task_t* t, int64_t tid,
int* status, void** retval);
friend class CpuManager;
protected:
TaskManager();
~TaskManager() {};
/** Create a new task where the entry point is idleTaskLoop. */
static task_t* createIdleTask();
private:
/** Get the next TID in the task sequence. */
tid_t getNextTid() { return iv_nextTid.next(); };
/** Run the idle task loop */
static void idleTaskLoop(void*);
// Internal implementations of non-static / non-_ functions.
task_t* _createIdleTask();
task_t* _createTask(task_fn_t, void*, bool, bool);
void _endTask(task_t*, void*, int);
void _waitTask(task_t*, int64_t, int*, void**);
/** Remove a tracker from the tracker-tree and delete it.
*
* @param[in] t - The tracker to remove.
* @note Spinlock-locking of the tracker-tree is the
* responsibility of the caller.
*/
void removeTracker(task_tracking_t* t);
/** Atomic monotonically increasing counter to use for TIDs. */
Util::Lockfree::Counter<tid_t> iv_nextTid;
/** Task-tracking tree spinlock. */
Spinlock iv_spinlock;
/** Task-tracking tree. */
task_tracking_list_t iv_taskList;
};
#endif
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