thread.hxx

ecos为实时嵌入式操作系统

    
    // 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:
    
    static CYG_ADDRWORD get_data( cyg_ucount32 index );

    static CYG_ADDRWORD *get_data_ptr( cyg_ucount32 index );

    void                set_data( cyg_ucount32 index, CYG_ADDRWORD data );

    static cyg_ucount32 new_data_index();

    static void         free_data_index( cyg_ucount32 index );

#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