File content as of revision 0:ee91220d7bea:

/**
 * This is hw2_3 that shows the implementation of 
 * protothreads. The program consists of three protothreads that wait
 * for each other to toggle a variable.
 */

/* We must always include pt.h in our protothreads code. */
#include "pt.h"
#include "mbed.h"
#include "pre_work.h"

/* Three flags that the three protothread functions use. */
static int protothread1_flag, protothread2_flag,  protothread3_flag;

    int count=0;
    int pre_cir_pro=0;   // in case of initial trigger fault
    int judge=1;
    int shown=0;
/**
 * The first protothread function. It achieves the pc input part.
 *
 * The protothread function is driven by the main loop further down in
 * the code.
 */
static int
protothread1(struct pt *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 || pc.readable());//wait until pc inputs
    //  printf("Protothread 1 running\n");
    /* 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;
    char temp;
    if (pc.readable()) {
    temp=pc.getc();
        if (temp=='E'&& length!=0){pc.printf("Input ends");}
        else if (temp=='E'&& length==0){pc.printf("Error. No 'S' before 'E'");}
        else if (temp=='S'){pc.printf("It is a new start.");length=0;count=0;}
        else if (temp=='1'){
        str[length]='1';length++;}
        else if (temp=='0'){
        str[length]='0';length++;}
        else if (temp==' '){}
        else senderror2();
        if (length>40) {pc.printf("The allocated space is too small.");}
        for (int i=0;i<length; i++)
        { pc.putc(str[i]);}
        pc.printf("\n");
    
    }
     //   PT_WAIT_UNTIL(pt, pc.readable());  
     //   pc.printf("I am here. Start inputing.");
     //   pc.getc();
     //   length=gtchar();
    /* And we loop. */
     protothread3_flag=1;
  }

  /* All protothread functions must end with PT_END() which takes a
     pointer to a struct pt. */
  PT_END(pt);
}

/**
 * The second protothread function. This is almost the same as the
 * first one. This part helps with the sensor input.
 */
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);  //This part always usually has not trigger info
    //   printf("Protothread 2 running\n");  
    /* We then reset the other protothread's flag. */
    protothread1_flag = 0;
    if (touchSense1()&& !touchSense2()) {   //T0 happens
         myled1 = 1;
         myled2=0;
         pc.putc('a');
         shown=0;
         while(1) {if (!test1()){break;} if  (touchSense2()&& touchSense1()) {break;}}
          //  if (str[count]=='0') {judge=0;}
          //  judge=1;
          //  pc.putc(str[count]);
         if (count>=length){
            for (int i=1;i<count;i++)
             { str2[i-1]=str2[i];
               pc.putc(str2[i-1]);
              }
             str2[count-1]='1';
             pc.putc(str2[count-1]);}
            else { str2[count]='1';count++;}
          //process_char();
        } else if (touchSense2()&& !touchSense1()) {  //T1 happens
           if (pre_cir_pro>30){
            myled1 = 0;
            myled2=1;
            pc.putc('b');
            shown=0;
            while(1) {if (!test2()){break;} if  (touchSense2()&& touchSense1()) {break;} }
            // if (str[count]=='1') {judge=0;}
            // judge=0;
            // pc.putc(str[count]);
            if (count>=length){
              for (int i=1;i<count;i++)
              { str2[i-1]=str2[i];
               pc.putc(str2[i-1]);
              }
             str2[count-1]='0';
             pc.putc(str2[count-1]);}
            else { str2[count]='0';count++;}
            }
        } else if  (touchSense2()&& touchSense1()) {  //Touch error
            myled1 = 1;
            myled2=1;
            senderror();
        } else {   //anything else
            myled1=0;
            myled2=0;
        }
        pre_cir_pro++;
    /* And we loop. */
    protothread3_flag=1;
  }
  PT_END(pt);
}

static int
protothread3(struct pt *pt)
{
  /* A protothread function must begin with PT_BEGIN() which takes a
     pointer to a struct pt. Match judging and output */
  PT_BEGIN(pt);
  /* We loop forever here. */
  while(1) {
     PT_WAIT_UNTIL(pt,count>=length &&count!=0 && protothread3_flag==1 );
  //   pc.printf("here");
        for (int i=0;i<length;i++)
          { if (str[i]!=str2[i]) {judge=0;} }
          if (judge==1 && shown==0) {pc.printf("\nMATCH");shown=1;}
          judge=1;  
          protothread3_flag=0;
     //   PT_WAIT_UNTIL(pt, pc.readable()); 
     //   pc.printf("I am here. Start inputing.");
     //   pc.getc();
     //   length=gtchar();
    /* And we loop. */
  }

  /* All protothread functions must end with PT_END() which takes a
     pointer to a struct pt. */
  PT_END(pt);
}


/**
 * Finally, we have the main loop. Here is where the protothreads are
 * initialized and scheduled. Almost nothing in it.
 */
static struct pt pt1,pt2,pt3;
int
main(void)
{
  /* Initialize the protothread state variables with PT_INIT(). */
   PT_INIT(&pt1);
   PT_INIT(&pt2);
   PT_INIT(&pt3);
  /*
   * Then we schedule the three protothreads by repeatedly calling their
   * protothread functions and passing a pointer to the protothread
   * state variables as arguments.
   */while(1){ protothread2(&pt2);
    protothread1(&pt1);
    protothread3(&pt3);
   }
}