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#ifndef CYGONCE_KERNEL_THREAD_HXX

#define CYGONCE_KERNEL_THREAD_HXX

//==========================================================================

//

//      thread.hxx

//

//      Thread class declarations

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

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// for more details.

//

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// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

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// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

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// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   nickg

// Contributors:        nickg

// Date:        1997-09-09

// Purpose:     Define Thread class interfaces

// Description: The classes defined here collectively implement the

//              internal API used to create, configure and manage threads.

// Usage:       #include 

//

//####DESCRIPTIONEND####

//

//==========================================================================

#include 

#include          // assertion macros

#include 

#include 

#include 

#include 

// -------------------------------------------------------------------------

// Miscellaneous types

typedef void cyg_thread_entry(CYG_ADDRWORD data);// Thread entry point function

// -------------------------------------------------------------------------

// Hardware thread interface.

// The implementation of this class is provided by the HAL.

class Cyg_HardwareThread

{

    friend class Cyg_Scheduler;

protected:

    CYG_ADDRESS         stack_base;     // pointer to base of stack area

    cyg_uint32          stack_size;     // size of stack area in bytes

#ifdef CYGFUN_KERNEL_THREADS_STACK_LIMIT

    CYG_ADDRESS         stack_limit;    // movable stack limit

#endif

    CYG_ADDRESS         stack_ptr;      // pointer to saved state on stack

    cyg_thread_entry    *entry_point;   // main entry point (code pointer!)

    CYG_ADDRWORD        entry_data;     // entry point argument

#ifdef CYGDBG_KERNEL_DEBUG_GDB_THREAD_SUPPORT

    HAL_SavedRegisters  *saved_context; // If non-zero, this points at a more

                                        // interesting context than stack_ptr.

#endif

    Cyg_HardwareThread(

        cyg_thread_entry        *entry_point,   // entry point function

        CYG_ADDRWORD            entry_data,     // entry data

        cyg_ucount32            stack_size = 0, // stack size, 0 = use default

        CYG_ADDRESS             stack_base = 0  // stack base, NULL = allocate

    );

    // Thread entry point. This is where all threads begin execution.

    // This routine does a little housekeeping and then call the main

    // entry_point specified above.

    static void thread_entry(Cyg_Thread *thread);

    // Initialize the context of the thread to start execution at thread_entry

    void    init_context( Cyg_Thread *thread );

    // Save current thread's context and load that of the given next thread.

    void    switch_context(Cyg_HardwareThread *next);

    // attach a stack to this thread

    void    attach_stack(CYG_ADDRESS stack, cyg_uint32 stack_size);

    // detach the stack from this thread

    CYG_ADDRESS detach_stack();

    // Adjust the thread's saved state to call the exception

    // handler when next executed.

    void    prepare_exception (

        cyg_exception_handler   *exception_handler,

        CYG_ADDRWORD            exception_data,

        cyg_code                exception_number,

        CYG_ADDRWORD            exception_info

        );

public:

    CYGDBG_DEFINE_CHECK_THIS

    // Get and set entry_data.

    void set_entry_data( CYG_ADDRWORD data );

    CYG_ADDRWORD get_entry_data();

#ifdef CYGDBG_KERNEL_DEBUG_GDB_THREAD_SUPPORT

    // Return the current saved state for this thread.

    HAL_SavedRegisters *get_saved_context();

    // Set the saved context pointer.

    void set_saved_context(HAL_SavedRegisters *ctx);

#endif

    // get the size/base of this thread's stack

    CYG_ADDRESS get_stack_base();

    cyg_uint32 get_stack_size();

#ifdef CYGFUN_KERNEL_THREADS_STACK_LIMIT

    // Allocate some memory at the lower end of the stack

    // by moving the stack limit pointer.

    void *increment_stack_limit( cyg_ucount32 size);

    CYG_ADDRESS get_stack_limit();

#endif

#ifdef CYGFUN_KERNEL_THREADS_STACK_CHECKING

    inline void check_stack(void);

#endif

#ifdef CYGFUN_KERNEL_THREADS_STACK_MEASUREMENT

    inline cyg_uint32 measure_stack_usage(void);

#endif

};

// -------------------------------------------------------------------------

// Per-thread timer support class.

// This is only included when required.

#ifdef CYGFUN_KERNEL_THREADS_TIMER

class Cyg_ThreadTimer

    : public Cyg_Alarm

{

    friend class Cyg_Thread;

    // Pointer to current thread

    Cyg_Thread          *thread;

    // Constructor

    Cyg_ThreadTimer(

        Cyg_Thread      *thread

        );

    // Alarm function

    static void alarm( Cyg_Alarm *alarm, CYG_ADDRWORD data);

    CYGDBG_DEFINE_CHECK_THIS

};

#endif

// -------------------------------------------------------------------------

// Main Thread class.

// This provides the public API for controlling threads.

class Cyg_Thread

    : public Cyg_HardwareThread,       // provides hardware abstractions

      public Cyg_SchedThread           // provides scheduling abstractions

{

    friend class Cyg_Scheduler;

    friend void deliver_exception( CYG_WORD code, CYG_ADDRWORD data );

    // The following definitions are used by all variants of the

    // basic thread object.

public:

    enum {                       // Thread state values

        RUNNING    = 0,          // Thread is runnable or running

        SLEEPING   = 1,          // Thread is waiting for something to happen

        COUNTSLEEP = 2,          // Sleep in counted manner

        SUSPENDED  = 4,          // Suspend count is non-zero

        CREATING   = 8,          // Thread is being created

        EXITED     = 16,         // Thread has exited

        // This is the set of bits that must be cleared by a generic

        // wake() or release().

        SLEEPSET   = (SLEEPING | COUNTSLEEP)

    };

private:

    // Current thread state, a logical OR of the above values.

    // Only if this word is zero can the thread execute.

    cyg_uint32                  state;

    // Suspension counter, if > 0, the thread is suspended

    cyg_ucount32                suspend_count;

    // Wakeup counter, if > 0, sleep will not sleep, just decrement

    cyg_ucount32                wakeup_count;

    // A word of data used in syncronization object to communicate

    // information between sleepers and wakers.

    CYG_ADDRWORD                wait_info;

    // Unique thread id assigned on creation

    cyg_uint16                  unique_id;

#ifdef CYGPKG_KERNEL_EXCEPTIONS

    // If exceptions are supported, define an exception control

    // object that will be used to manage and deliver them. If

    // exceptions are global there is a single static instance

    // of this object, if they are per-thread then there is one

    // for each thread.

private:

#ifdef CYGSEM_KERNEL_EXCEPTIONS_GLOBAL

    static

#endif

    Cyg_Exception_Control       exception_control;

public:

    static void register_exception(

        cyg_code                exception_number,       // exception number

        cyg_exception_handler   handler,                // handler function

        CYG_ADDRWORD            data,                   // data argument

        cyg_exception_handler   **old_handler,          // handler function

        CYG_ADDRWORD            *old_data               // data argument

        );

    static void deregister_exception(

        cyg_code                exception_number        // exception number

        );

    void deliver_exception(

        cyg_code            exception_number,       // exception being raised

        CYG_ADDRWORD        exception_info          // exception specific info

        );

#endif

public:

    CYGDBG_DEFINE_CHECK_THIS

    // Constructor, Initialize the thread structure. The thread is

    // created in suspended state, and needs to be resumed to execute.

    // It is also started at some (configurable) default priority, which

    // may need to be changed before calling resume.

    Cyg_Thread (

        cyg_thread_entry        *entry,         // entry point function

        CYG_ADDRWORD            entry_data,     // entry data

        cyg_ucount32            stack_size = 0, // stack size, 0 = use default

        CYG_ADDRESS             stack_base = 0  // stack base, NULL = allocate

        );

    Cyg_Thread (

        CYG_ADDRWORD            sched_info,     // Scheduling parameter(s)

        cyg_thread_entry        *entry,         // entry point function

        CYG_ADDRWORD            entry_data,     // entry data

        char                    *name,          // thread name

        CYG_ADDRESS             stack_base = 0, // stack base, NULL = allocate

        cyg_ucount32            stack_size = 0  // stack size, 0 = use default

        );

    // Re-initialize the thread back to it's initial state.

    void Cyg_Thread::reinitialize();

    ~Cyg_Thread();

    // The following are invoked implicitly on the current thread,

    // hence they are static member functions.

    static void         sleep();        // Put thread to sleep

    static void         counted_sleep();// Decrement counter or put

                                        // thread to sleep

#ifdef CYGFUN_KERNEL_THREADS_TIMER

    static void         counted_sleep( cyg_tick_count delay );

                                        // ...for delay ticks

#endif

    static void         exit();         // Terminate thread

    static void         yield();        // Yield CPU to another thread

    static void         rotate_queue( cyg_priority pri );

                                        // Rotate that run queue

    void                to_queue_head( void );

                                        // Move to the head of its queue

                                        // (not necessarily a scheduler q)

    static Cyg_Thread   *self();        // Return current thread

    // The following are called on threads other than the current one.

    void                wake();         // Wake this thread from sleep.

    void                counted_wake(); // Increment counter or wake thread

    cyg_uint32          cancel_counted_wake();

                                        // Cancel counted wakeups for this

                                        // thread and return how many were

                                        // pending

    void                suspend();      // Suspend this thread: increment counter and

                                        // deschedule.

    void                resume();       // Resume this thread: decrement counter and

                                        // reschedule if counter is zero.

    void                release();      // Release thread from sleep with BREAK

                                        // wake_reason.

    void                kill();         // Kill this thread

    void                force_resume(); // Resume this thread: set counter to zero.

    cyg_uint32          get_state();    // Return current thread state.

    // Accessor functions to set and get wait_info.

    void                set_wait_info(CYG_ADDRWORD data);

    CYG_ADDRWORD        get_wait_info();

    // This part of the API is used if we have a clock and want

    // per-thread timers for doing delays and timeouts.

    // delay the given number of ticks

    void delay( cyg_tick_count delay );

    enum cyg_reason                     // sleep/wakeup reason codes

    {

        NONE,                           // No recorded reason

        WAIT,                           // Wait with no timeout

        DELAY,                          // Simple time delay

        TIMEOUT,                        // Wait with timeout/timeout expired

        BREAK,                          // forced break out of sleep

        DESTRUCT,                       // wait object destroyed[note]

        EXIT,                           // forced termination

        DONE                            // Wait/delay complete

    };

    // [note] NOT the thread, some object it was waiting on.

    //        Thread destruction would first involve EXITing it.

private:

#ifdef CYGFUN_KERNEL_THREADS_TIMER

    Cyg_ThreadTimer     timer;          // per-thread timer

#endif

    cyg_reason          sleep_reason;   // reason for sleeping

    cyg_reason          wake_reason;    // reason for waking

#ifdef CYGIMP_THREAD_PRIORITY

public:

    // If the scheduler implements priorities, provide

    // functions to set and get it.

    void set_priority( cyg_priority pri );

    cyg_priority get_priority();

    // This returns the current dispatching priority of the

    // thread. This may differ from the result of get_priority()

    // in the presence of priority inheritance or certain

    // scheduling algorithms.

    cyg_priority get_current_priority();

#endif

#ifdef CYGVAR_KERNEL_THREADS_DATA

private:

    // Array of single word entries for each index.

    CYG_ADDRWORD        thread_data[CYGNUM_KERNEL_THREADS_DATA_MAX];

    // Map of free thread_data indexes. Each bit represents an index

    // and is 1 if that index is free, and 0 if it is in use.

    static cyg_ucount32        thread_data_map;

public:

    typedef cyg_count32 cyg_data_index;

    static CYG_ADDRWORD get_data( cyg_data_index index );

    static CYG_ADDRWORD *get_data_ptr( cyg_data_index index );

    void                set_data( cyg_data_index index, CYG_ADDRWORD data );

    // returns -1 if no more indexes available

    static cyg_data_index new_data_index();

    static void         free_data_index( cyg_data_index index );

#endif

#ifdef CYGPKG_KERNEL_THREADS_DESTRUCTORS

    // thread destructors, called on thread exit.

private:

    typedef void (*destructor_fn)(CYG_ADDRWORD);

    struct Cyg_Destructor_Entry {

        destructor_fn fn;

        CYG_ADDRWORD data;

    };

#ifndef CYGSEM_KERNEL_THREADS_DESTRUCTORS_PER_THREAD

    static

#endif

    Cyg_Destructor_Entry destructors[ CYGNUM_KERNEL_THREADS_DESTRUCTORS ];

public:

    // Add and remove destructors. Returns true on success, false on failure.

#ifndef CYGSEM_KERNEL_THREADS_DESTRUCTORS_PER_THREAD

    static

#endif

    cyg_bool     add_destructor( destructor_fn fn, CYG_ADDRWORD data );

#ifndef CYGSEM_KERNEL_THREADS_DESTRUCTORS_PER_THREAD

    static

#endif

    cyg_bool     rem_destructor( destructor_fn fn, CYG_ADDRWORD data );

#endif

#ifdef CYGVAR_KERNEL_THREADS_NAME

private:

    // An optional thread name string, for humans to read

    char                        *name;

public:

    // function to get the name string

    char                        *get_name();

#endif

#ifdef CYGVAR_KERNEL_THREADS_LIST

        // Housekeeping list that tracks all threads

private:

    Cyg_Thread                  *list_next;

    static Cyg_Thread           *thread_list;

    void                        add_to_list(      void );

    void                        remove_from_list( void );

public:

    static Cyg_Thread           *get_list_head();

    Cyg_Thread                  *get_list_next();

#endif

public:

    // Set sleep reason to reason and wake reason to NONE

    static void set_sleep_reason( cyg_reason reason = WAIT);

    cyg_reason get_sleep_reason();

    // Set the wakeup reason to the given value

    void set_wake_reason( cyg_reason reason = DONE);

    // Get current wake reason

    cyg_reason get_wake_reason();

    static void set_timer(              // Set timeout and sleep reason

        cyg_tick_count  trigger,        // Absolute wakeup time

        cyg_reason      sleep_reason    // reason for sleeping

        );

    static void clear_timer();          // disable thread timer

    // Get a 16 bit unique id for this thread. This is

    // used in tracing and instrumentation to identify the

    // current thread.

    cyg_uint16 get_unique_id();

};

// -------------------------------------------------------------------------

// Thread Queue class.

// This defines the main API for manipulating queues of threads.

class Cyg_ThreadQueue

    : public Cyg_ThreadQueue_Implementation

{

public:

    CYGDBG_DEFINE_CHECK_THIS

    // API used by rest of kernel.

                        // Add thread to queue

    void                enqueue(Cyg_Thread *thread);

                        // return first thread on queue

    Cyg_Thread          *highpri();

                        // remove first thread on queue

    Cyg_Thread          *dequeue();

                        // remove specified thread from queue

    void                remove(Cyg_Thread *thread);

                        // test if queue is empty

    cyg_bool            empty();

};

// -------------------------------------------------------------------------

// Thread inlines

// Return current thread state.

inline cyg_uint32 Cyg_Thread::get_state()

{

    return state;

}

inline void Cyg_Thread::set_wait_info(CYG_ADDRWORD data)

{

    wait_info = data;

}

inline CYG_ADDRWORD Cyg_Thread::get_wait_info()

{

    return wait_info;

}

// -------------------------------------------------------------------------

#endif // ifndef CYGONCE_KERNEL_THREAD_HXX

// EOF thread.hxx