Attachment 296546 Details for Bug 435662 – reproducer

reproducer

repro-oom.C (text/plain), 1.61 KB, created by Qian Cai on 2008-03-03 05:15:35 UTC

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Creator: Qian Cai

Created: 2008-03-03 05:15:35 UTC

Size: 1.61 KB

patch

obsolete

>#include <sys/types.h>
>#include <sys/stat.h>
>#include <fcntl.h>
>#include <stdlib.h>
>#include <unistd.h>
>#include <pthread.h>
>
>#include <iostream>
>
>#define BUFSIZE 10485760
>#define BUFFERS 1700
>
>char *buffers[BUFFERS];
>int child_num=0;
>
>void *copy_block(void *);
>
>int main(int argc, char **argv){
>  int order=0;
>
>  // make 8 procs
>  while(order<7)
>    switch(fork()){
>    case -1:
>      break;
>    default:
>      order++;
>      break;
>    case 0:
>      child_num=order;
>      order=8;
>      break;
>    }
>
>  int random_fd=open("/dev/urandom",O_RDONLY);
>  if(random_fd==-1)
>    exit(1);
>
>  int i;
>  int retval=0;
>  try{
>    /* Why lots of buffers rather than one big buffer. It is my 
>       expectation that this is the way that OpenMPI does it when
>       it allocates its set of queue pair destinations. */
>  
>    for(i=0;i<BUFFERS;i++){
>      buffers[i]=new char[BUFSIZE];
>    }
>    
>    pthread_t copy_thread;
>    pthread_create(&copy_thread,NULL,copy_block,NULL);
>
>    /* Bang on them in a random order */
>    for(i=0;i<BUFFERS;i++){
>      int cur;
>      while(buffers[cur=random()%BUFFERS][random()%BUFSIZE]==0)
>	read(random_fd,buffers[cur],BUFSIZE);
>      std::cout << 'a'+ child_num;
>    }
>  }
>  catch(std::bad_alloc &e){
>    std::cout << "failed allocating " << i << '\t'; 
>    retval=2;
>  }
>  
>  std::cout << getpid() <<'\n';
>  exit(retval);
>}
>
>void *copy_block(void *){
>  for(int i=0;i<BUFFERS/2;i++){
>    int src;
>    while(buffers[src=random()%BUFFERS][random()%BUFSIZE]==0);
>
>    int dst;
>    while(buffers[dst=random()%BUFFERS][random()%BUFSIZE]==0)
>      memcpy(buffers[dst],buffers[src],BUFSIZE);
>    std::cout << 'A'+ child_num;
>  }
>}

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Attachments on bug 435662: 296546