[其它] Arduino多线程ProtoThread测试

/**

* This is a very small example that shows how to use

* protothreads. The program consists of two protothreads that wait

* for each other to toggle a variable.

*/



/* We must always include pt.h in our protothreads code. */

#include "pt.h"



/* Two flags that the two protothread functions use. */

static int protothread1_flag, protothread2_flag;



/* protothread state variables, one for each ptorothread. */

static struct pt pt1, pt2;



// constants won't change. Used here to set a pin number :

const int ledPin =  13;      // the number of the LED pin



/**

* The first protothread function. A protothread function must always

* return an integer, but must never explicitly return - returning is

* performed inside the protothread statements.

*

* The protothread function is driven by the main loop further down in

* the code.

*/

static int protothread1(struct pt *pt)

{

  /* A protothread function must begin with PT_BEGIN() which takes a

     pointer to a struct pt. */

  PT_BEGIN(pt);



  /* We loop forever here. */

  while(1) {

    /* Wait until the other protothread has set its flag. */

    PT_WAIT_UNTIL(pt, protothread2_flag != 0);

    Serial.println("Protothread 1 running");

    

    digitalWrite(ledPin,LOW);

   

    /* We then reset the other protothread's flag, and set our own

       flag so that the other protothread can run. */

    protothread2_flag = 0;

    protothread1_flag = 1;



    /* And we loop. */

  }



  /* All protothread functions must end with PT_END() which takes a

     pointer to a struct pt. */

  PT_END(pt);

}



/**

* The second protothread function.

* This one is almost the same as the first one.

*/

static int protothread2(struct pt *pt)

{

  PT_BEGIN(pt);



  while(1) {

    /* Let the other protothread run. */

    protothread2_flag = 1;



    /* Wait until the other protothread has set its flag. */

    PT_WAIT_UNTIL(pt, protothread1_flag != 0);

    Serial.println("Protothread 2 running");

    

    digitalWrite(ledPin,HIGH);

    

    /* We then reset the other protothread's flag. */

    protothread1_flag = 0;



    /* And we loop. */

  }

  PT_END(pt);

}



/**

* setup() is where the protothreads are initialized.

* The state variables pt1 and pt2 holdthe state of the two protothreads.

*/

void setup() 

{ 

  /* Initialize the protothread state variables with PT_INIT(). */

  PT_INIT(&pt1);

  PT_INIT(&pt2);



  Serial.begin(9600);

  

  // set the digital pin as output:

  pinMode(ledPin, OUTPUT);

} 



/**

* Finally, we have the main loop.

* This is where the protothreads are scheduled. 

*/

void loop() 

{ 

  /*

   * We schedule the two protothreads by repeatedly calling their

   * protothread functions and passing a pointer to the protothread

   * state variables as arguments.

   */

  protothread1(&pt1);

  protothread2(&pt2);

}