cvs commit: apachen/src/test test-writev.c

[dg...@hyperreal.org]

dgaudet     97/11/09 18:03:40

  Added:       src/test test-writev.c
  Log:
  Another little ditty from my box of test programs.
  
  Revision  Changes    Path
  1.1                  apachen/src/test/test-writev.c
  
  Index: test-writev.c
  ===================================================================
  /*
      test-writev: use this to figure out if your writev() does intelligent
      things on the network.  Some writev()s when given multiple buffers
      will break them up into multiple packets, which is a waste.
  
      Linux prior to 2.0.31 has this problem.
  
      Solaris 2.5, 2.5.1 doesn't appear to, 2.6 hasn't been tested.
  
      IRIX 5.3 doesn't have this problem.
  
      To use this you want to snoop the wire with tcpdump, and then run
      "test-writev a.b.c.d port#" ... against some TCP service on another
      box.  For example you can run it against port 80 on another server.
      You want to look to see how many data packets are sent, you're hoping
      only one of size 300 is sent.
  */
  
  #include <stdio.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <arpa/inet.h>
  #include <sys/uio.h>
  #include <errno.h>
  
  #ifndef INADDR_NONE
  #define INADDR_NONE (-1ul)
  #endif
  
  void main( int argc, char **argv )
  {
      struct sockaddr_in server_addr;
      int s;
      struct iovec vector[3];
      char buf[100];
      int i;
      const int just_say_no = 1;
  
      if( argc != 3 ) {
  usage:
  	fprintf( stderr, "usage: test-writev a.b.c.d port#\n" );
  	exit( 1 );
      }
      server_addr.sin_family = AF_INET;
      server_addr.sin_addr.s_addr = inet_addr( argv[1] );
      if( server_addr.sin_addr.s_addr == INADDR_NONE ) {
  	fprintf( stderr, "bogus address\n" );
  	goto usage;
      }
      server_addr.sin_port = htons( atoi( argv[2] ) );
  
      s = socket( AF_INET, SOCK_STREAM, 0 );
      if( s < 0 ) {
  	perror("socket");
  	exit(1);
      }
      if( connect( s, (struct sockaddr *)&server_addr, sizeof( server_addr ) )
  	!= 0 ) {
  	perror("connect");
  	exit(1);
      }
  
      if( setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (char*)&just_say_no,
  	sizeof(just_say_no)) != 0 ) {
  	perror( "TCP_NODELAY" );
  	exit(1);
      }
      /* now build up a two part writev and write it out */
      for( i = 0; i < sizeof( buf ); ++i ) {
  	buf[i] = 'x';
      }
      vector[0].iov_base = buf;
      vector[0].iov_len = sizeof(buf);
      vector[1].iov_base = buf;
      vector[1].iov_len = sizeof(buf);
      vector[2].iov_base = buf;
      vector[2].iov_len = sizeof(buf);
  
      i = writev( s, &vector[0], 3 );
      fprintf( stdout, "i=%d, errno=%d\n", i, errno );
      exit(0);
  }