golang.org/x/exp@v0.0.0-20240506185415-9bf2ced13842/shootout/threadring.c (about)

     1  // +build ignore
     2  
     3  /*
     4  Redistribution and use in source and binary forms, with or without
     5  modification, are permitted provided that the following conditions are met:
     6  
     7      * Redistributions of source code must retain the above copyright
     8      notice, this list of conditions and the following disclaimer.
     9  
    10      * Redistributions in binary form must reproduce the above copyright
    11      notice, this list of conditions and the following disclaimer in the
    12      documentation and/or other materials provided with the distribution.
    13  
    14      * Neither the name of "The Computer Language Benchmarks Game" nor the
    15      name of "The Computer Language Shootout Benchmarks" nor the names of
    16      its contributors may be used to endorse or promote products derived
    17      from this software without specific prior written permission.
    18  
    19  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    20  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    21  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    22  ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    23  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    24  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    25  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    26  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    27  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    28  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    29  POSSIBILITY OF SUCH DAMAGE.
    30  */
    31  
    32  /*
    33  * The Computer Language Benchmarks Game
    34  * http://shootout.alioth.debian.org/
    35  
    36  * contributed by Premysl Hruby
    37  */
    38  
    39  #include <stdint.h>
    40  #include <stdio.h>
    41  #include <stdlib.h>
    42  #include <pthread.h>
    43  #include <string.h>
    44  #include <limits.h>
    45  
    46  // PTHREAD_STACK_MIN undeclared on mingw
    47  #ifndef PTHREAD_STACK_MIN
    48  #define PTHREAD_STACK_MIN 65535
    49  #endif
    50  
    51  #define THREADS (503)
    52  
    53  struct stack {
    54     char x[PTHREAD_STACK_MIN];
    55  };
    56  
    57  
    58  /* staticaly initialize mutex[0] mutex */
    59  static pthread_mutex_t mutex[THREADS];
    60  static int data[THREADS];
    61  static struct stack stacks[THREADS];
    62  /* stacks must be defined staticaly, or my i386 box run of virtual memory for this
    63   * process while creating thread +- #400 */
    64  
    65  static void* thread(void *num)
    66  {
    67     int l = (int)(uintptr_t)num;
    68     int r = (l+1) % THREADS;
    69     int token;
    70  
    71     while(1) {
    72        pthread_mutex_lock(mutex + l);
    73        token = data[l];
    74        if (token) {
    75           data[r] = token - 1;
    76           pthread_mutex_unlock(mutex + r);
    77        }
    78        else {
    79           printf("%i\n", l+1);
    80           exit(0);
    81        }
    82     }
    83  }
    84  
    85  
    86  
    87  int main(int argc, char **argv)
    88  {
    89     int i;
    90     pthread_t cthread;
    91     pthread_attr_t stack_attr;
    92  
    93     if (argc != 2)
    94        exit(255);
    95     data[0] = atoi(argv[1]);
    96  
    97     pthread_attr_init(&stack_attr);
    98  
    99     for (i = 0; i < THREADS; i++) {
   100        pthread_mutex_init(mutex + i, NULL);
   101        pthread_mutex_lock(mutex + i);
   102  
   103  #if defined(__MINGW32__) || defined(__MINGW64__)
   104        pthread_attr_setstackaddr(&stack_attr, &stacks[i]);
   105        pthread_attr_setstacksize(&stack_attr, sizeof(struct stack));
   106  #else
   107        pthread_attr_setstack(&stack_attr, &stacks[i], sizeof(struct stack));
   108  #endif
   109  
   110        pthread_create(&cthread, &stack_attr, thread, (void*)(uintptr_t)i);
   111     }
   112  
   113     pthread_mutex_unlock(mutex + 0);
   114     pthread_join(cthread, NULL);
   115  }