gdb/testsuite/gdb.hp/more-steps.c

   1 /* BeginSourceFile more_steps.c
   2
   3   This file creates a lot of threads which then execute
   4   in parallel, so that wdb can be tested on handling
   5   simultaneous thread events.
   6
   7   To compile:
   8
   9       cc -Ae +DA1.0 -g -o more_steps -lpthread more_steps.c
  10
  11   To run:
  12
  13      more_threads
  14 */
  15
  16 #include <unistd.h>
  17 #include <stdlib.h>
  18 #include <stdio.h>
  19 #include <assert.h>
  20 #include <pthread.h>
  21
  22 #define TRUE 1
  23 #define FALSE 0
  24 #define N_THREADS 3
  25 #define PHASES 3
  26
  27 typedef enum {
  28   ZERO,
  29   ONE,
  30   TWO,
  31   THREE
  32 } phase_t;
  33
  34 /* Uncomment to turn on debugging output */
  35 /* #define DEBUG  */
  36
  37 /* Locks.
  38  */
  39 int lock_one; /* Main W, others R */
  40 int lock_two; /* ditto */
  41 int lock_end[ N_THREADS ]; /* Main R, others R[i] */
  42 int phase[ N_THREADS ];
  43
  44 /* Routine for each thread to run.
  45  */
  46 void *spin( vp )
  47     void * vp;
  48 {
  49     int me = (int) vp;
  50     int i;
  51
  52     lock_end[ me ] = TRUE;
  53
  54     phase[ me ] = ONE;
  55
  56     while( lock_one );
  57
  58     phase[ me ] = TWO;
  59
  60     while( lock_two );
  61
  62     phase[ me ] = THREE;
  63
  64     lock_end[ me ] = FALSE;
  65 }
  66
  67 void
  68 do_pass()
  69 {
  70     int i;
  71     pthread_t t[ N_THREADS ];
  72     int err;
  73     int done;
  74
  75     /* Start N_THREADS threads, then join them so
  76      * that they are terminated.
  77      */
  78     for( i = 0; i < N_THREADS; i++ ) {
  79         err = pthread_create( &t[i], NULL, spin, (void *)i );
  80         if( err != 0 ) {
  81             printf( "== Start/stop, error in thread %d create\n", i );
  82         }
  83     }
  84
  85     /* Do phase 1.
  86      */
  87     lock_one = FALSE;
  88
  89     /* Do phase 2.
  90      */
  91     lock_two = FALSE;
  92
  93     /* Be done.
  94      */
  95     done = 0;
  96     while( !done ) {
  97
  98        /* Be optimistic.
  99         */
 100        done = 1;
 101        for( i = 0; i < N_THREADS; i++ ) {
 102            if( lock_end[i] ) {
 103                /* Thread "i" is not ready yet.
 104                 */
 105                done = 0;
 106                break;
 107            }
 108        }
 109     }
 110
 111     /* Finish up
 112      */
 113     for( i = 0; i < N_THREADS; i++ ) {
 114         err = pthread_join(t[i], NULL );    /* Line 105 */
 115         if( err != 0 ) {                    /* Line 106 */
 116             printf( "== Start/stop, error in thread %d join\n", i );
 117         }
 118     }
 119
 120     i = 10;  /* Line 109.  Null line for setting bpts on. */
 121 }
 122
 123 main( argc, argv )
 124 int    argc;
 125 char **argv;
 126 {
 127     int i;
 128
 129     /* Init
 130      */
 131     lock_one = TRUE;
 132     lock_two = TRUE;
 133     for( i = 0; i < N_THREADS; i++ ) {
 134         lock_end[i] = TRUE;
 135         phase[i]    = ZERO;
 136     }
 137
 138     do_pass();
 139     return(0);
 140 }