Ucoⅱ semaphore and semaphore set instance

The Code comes from the book CD, "Principles and Applications of the embedded operating system ucoⅱ"

Instance 1 semaphore

# Include "des. H"

# Define task_stk_size 512 // Task Stack Length

OS _stk starttaskstk [task_stk_size]; // defines the task stack area.
OS _stk mytaskstk [task_stk_size];
OS _stk youtaskstk [task_stk_size];
OS _stk hertaskstk [task_stk_size];

Int16s key; // The key used to exit ucos_ii
Char * S1 = "mytask ";
Char * S2 = "youtask ";

Int8u err;
Int8u y = 0;
// Character display position

OS _event * fun_semp; // defines the semaphore.

Void starttask (void * data );
Void mytask (void * data );
Void youtask (void * data );
Void fun (int8u X, int8u y );
Void quitkey (void );

/************************ Main function ************* ********************************/
Void main (void)
{
Osinit (); // initialize ucos_ii
Pc_dossavereturn (); // Save the DOS environment
Pc_vectset (UCOS, osctxsw); // ucos_ii installation interrupted

Fun_semp = ossemcreate (1); // create a semaphore
Ostaskcreate (starttask, 0, & starttaskstk [task_stk_size-1], 0 );
Osstart ();
}

// ***************************** Starttask ******** ************************************
Void starttask (void * pdata)
{
Pdata = pdata;
OS _enter_critical ();
Pc_vectset (0x08, ostickisr );
Pc_settickrate (OS _ticks_per_sec );
OS _exit_critical ();
// Osstatinit ();

Ostaskcreate (mytask, 0, & mytaskstk [task_stk_size-1], 1 );
Ostaskcreate (youtask, 0, & youtaskstk [task_stk_size-1], 2 );
Ostasksuspend (OS _prio_self );

}
// ***************************** Mytask ******** ************************************
Void mytask (void * pdata)
{
Pdata = pdata;

For (;;)
{
// Ossempend (fun_semp, 0, & ERR); // request semaphore
Pc_dispstr (0, ++ y, S1, disp_bgnd_black + disp_fgnd_white );
Fun (9, y );
// Ossempost (fun_semp); // sends a semaphore
Quitkey ();
Ostimedlyhmsm (0, 0, 1, 0 );
}
}

// ***************************** Youtask ******** ************************************
Void youtask (void * pdata)
{
Pdata = pdata;

For (;;)
{
// Ossempend (fun_semp, 0, & ERR );
Pc_dispstr (0, ++ y, S2, disp_bgnd_black + disp_fgnd_white );
Fun (10, y );
// Ossempost (fun_semp );
Quitkey ();
Ostimedlyhmsm (0, 0, 2, 0 );
}
}

// ****************************** Fun () **************************************** ****
Void fun (int8u X, int8u y)
{
Pc_dispstr (X, Y, "call fun ()", disp_bgnd_black + disp_fgnd_yellow );
}

// ****************************** Quitkey () **************************************** ****
Void quitkey (void)
{
If (pc_getkey (& Key) = true)
{
If (Key = 0x1b)
{Pc_dosreturn ();}
}
}

Instance 2 semaphores

# Include "des. H"

# Define task_stk_size 512 // Task Stack Length

OS _stk starttaskstk [task_stk_size]; // defines the task stack area.
OS _stk mytaskstk [task_stk_size];
OS _stk youtaskstk [task_stk_size];
OS _stk hertaskstk [task_stk_size];

Int16s key; // The key used to exit ucos_ii
Char * S1 = "mytask is running ";
Char * S2 = "youtask is running ";
Char * S3 = "hertask is running ";
Char * Ss = "mytask pend a SEM ";

Int8u err;
Int8u x = 0, y = 0; // character position
Int32u times = 0;

OS _event * SEMP;

Void starttask (void * data );
Void mytask (void * data );
Void youtask (void * data );
Void hertask (void * data );

Void quitkey (void );

/************************ Main function ************* ********************************/
Void main (void)
{
Osinit (); // initialize ucos_ii
Pc_dossavereturn (); // Save the DOS environment
Pc_vectset (UCOS, osctxsw); // ucos_ii installation interrupted

SEMP = ossemcreate (1 );
Ostaskcreate (starttask, 0, & starttaskstk [task_stk_size-1], 5 );
Osstart ();
}

// ***************************** Starttask ******** ************************************
Void starttask (void * pdata)
{
Pdata = pdata;
OS _enter_critical ();
Pc_vectset (0x08, ostickisr );
Pc_settickrate (OS _ticks_per_sec );
OS _exit_critical ();
Osstatinit ();

Ostaskcreate (mytask, 0, & mytaskstk [task_stk_size-1], 6 );
Ostaskcreate (youtask, 0, & youtaskstk [task_stk_size-1], 7 );
Ostaskcreate (hertask, 0, & hertaskstk [task_stk_size-1], 8 );
Ostasksuspend (OS _prio_self );
}
// ***************************** Mytask ******** ************************************
Void mytask (void * pdata)
{
Pdata = pdata;

For (;;)
{
Ostimedlyhmsm (0, 0, 1,200 );
{
Pc_dispstr (10, ++ y, SS, disp_bgnd_black + disp_fgnd_yellow );
Ossempend (SEMP, 0, & ERR );
Pc_dispstr (10, ++ y, S1, disp_bgnd_black + disp_fgnd_yellow );
Ossempost (SEMP );
Quitkey ();
}
Ostimedlyhmsm (0, 0, 0,200 );
}
}

// ***************************** Youtask ******** ************************************
Void youtask (void * pdata)
{
Pdata = pdata;

For (;;)
{
Pc_dispstr (7, ++ y, S2, disp_bgnd_black + disp_fgnd_white );
Quitkey ();
Ostimedlyhmsm (0, 0, 0,300 );
}
}

// ****************************** Hertask ******** ************************************

Void hertask (void * pdata)
{
Pdata = pdata;

For (;;)
{
Ossempend (SEMP, 0, & ERR );
Pc_dispstr (10, ++ y, S3, disp_bgnd_black + disp_fgnd_white );
For (times; Times <30000000; times ++)
{OS _sched ();}
Ossempost (SEMP );
Quitkey ();
Ostimedlyhmsm (0, 0, 1, 0 );
}
}

// ****************************** Quitkey () **************************************** ****
Void quitkey (void)
{
If (pc_getkey (& Key) = true)
{
If (Key = 0x1b)
{Pc_dosreturn ();}
}
}

Instance three semaphores

The first task is executed only after the last two tasks are executed.

# Include "des. H"

# Define task_stk_size 512 // Task Stack Length

OS _stk starttaskstk [task_stk_size]; // defines the task stack area.
OS _stk mytaskstk [task_stk_size];
OS _stk youtaskstk [task_stk_size];
OS _stk hertaskstk [task_stk_size];

Int16s key; // The key used to exit ucos_ii

Char * S1 = "mytask is running ";
Char * S2 = "youtask is running ";
Char * S3 = "hertask is running ";

Int8u err;
Int8u x = 0, y = 0;
// Character display position

OS _flag_grp * wflag;/* event flag pointer */

Void starttask (void * data );
Void mytask (void * data );
Void youtask (void * data );
Void hertask (void * data );

Void quitkey (void );

/************************ Main function ************* ********************************/
Void main (void)
{
Osinit (); // initialize ucos_ii
Pc_dossavereturn (); // Save the DOS environment
Pc_vectset (UCOS, osctxsw); // ucos_ii installation interrupted

Wflag = osflagcreate (0, & ERR );
/* Create an event flag Group */
If (ERR = OS _no_err)
/* Check whether the creation is successful */
Pc_dispstr (0, 23, "no error", disp_bgnd_black + disp_fgnd_white );
Ostaskcreate (starttask, 0, & starttaskstk [task_stk_size-1], 5 );

Osstart ();
}

// ***************************** Starttask ******** ************************************
Void starttask (void * pdata)
{
Pdata = pdata;

OS _enter_critical ();
Pc_vectset (0x08, ostickisr );
Pc_settickrate (OS _ticks_per_sec );
OS _exit_critical ();
// Osstatinit ();

Ostaskcreate (mytask, 0, & mytaskstk [task_stk_size-1], 6 );
Ostaskcreate (youtask, 0, & youtaskstk [task_stk_size-1], 7 );
Ostaskcreate (hertask, 0, & hertaskstk [task_stk_size-1], 8 );

Ostasksuspend (OS _prio_self );

}
// ***************************** Mytask ******** ************************************
Void mytask (void * pdata)
{
Pdata = pdata;

For (;;)
{
Osflagpend (wflag, (OS _flags) 3, OS _flag_wait_set_all, 0, & ERR );
Pc_dispstr (10, ++ y, S1, disp_bgnd_black + disp_fgnd_white );
Quitkey ();
Ostimedlyhmsm (0, 0, 2, 0 );
}
}

// ***************************** Youtask ******** ************************************
Void youtask (void * pdata)
{
Pdata = pdata;

For (;;)
{
Pc_dispstr (10, ++ y, S2, disp_bgnd_black + disp_fgnd_white );
Ostimedlyhmsm (0, 0, 8, 0 );
Osflagpost (wflag, (OS _flags) 2, OS _flag_set, & ERR );
Quitkey ();
Ostimedlyhmsm (0, 0, 2, 0 );
}
}

// ****************************** Hertask ******** ************************************
Void hertask (void * pdata)
{
Pdata = pdata;

For (;;)
{
Pc_dispstr (10, ++ y, S3, disp_bgnd_black + disp_fgnd_white );
Osflagpost (wflag, (OS _flags) 1, OS _flag_set, & ERR );
Quitkey ();
Ostimedlyhmsm (0, 0, 1, 0 );
}
}
// ****************************** Quitkey () **************************************** ****
Void quitkey (void)
{
If (pc_getkey (& Key) = true)
{
If (Key = 0x1b)
{Pc_dosreturn ();}
}
}