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请教TCP Socket的编程问题

时间:2010-12-27

来源:互联网

下面这段代码是一个TCP socket编写的网络服务器程序,请问,为什么它在接收并处理完第一个request后就退出了?
  1. #!/usr/bin/perl

  2. use Socket;
  3. use POSIX qw(:sys_wait_h);

  4. sub REAPER {
  5.   1 until -1 == waitpid(-1, WNOHANG);
  6.   $SIG{CHLD} = \&REAPER;
  7. }

  8. $SIG{CHLD} = \&REAPER;

  9. socket(SERVER, PF_INET, SOCK_STREAM, getprotobyname('tcp'));
  10. setsockopt(SERVER, SOL_SOCKET, SO_REUSEADDR, 1);
  11. $my_addr = sockaddr_in(8080, INADDR_ANY);
  12. bind SERVER, $my_addr;
  13. listen(SERVER, 1000);
  14. REQUEST:
  15. while (accept(CLIENT, SERVER)) {
  16.   if ($pid = fork) {
  17.     close CLIENT;
  18.     next REQUEST;
  19.   }
  20.   die "$!" unless defined $pid;
  21.   close SERVER;
  22.   print CLIENT "hello\n";
  23.   close CLIENT;
  24.   exit;
  25. }
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作者: lululau   发布时间: 2010-12-27

StackOverflow上有哥们给了个解答,说accept会被SIGCHLD中断,下面是他给出的代码
  1. #!/usr/bin/perl

  2. use strict;
  3. use warnings;
  4. use Socket;
  5. use POSIX qw(:sys_wait_h);

  6. sub REAPER {
  7.   local $!;                    # Don't let signal handler mess with $!
  8.   1 until -1 == waitpid(-1, WNOHANG);
  9.   $SIG{CHLD} = \&REAPER;
  10. }

  11. $SIG{CHLD} = \&REAPER;
  12. socket(SERVER, PF_INET, SOCK_STREAM, getprotobyname('tcp'));
  13. setsockopt(SERVER, SOL_SOCKET, SO_REUSEADDR, 1);
  14. my $my_addr = sockaddr_in(8080, INADDR_ANY);
  15. bind SERVER, $my_addr;
  16. listen(SERVER, 1000);
  17. REQUEST:
  18. while (1) {
  19.   my $paddr = accept(CLIENT, SERVER) || do {
  20.     # try again if accept() returned because a signal was received
  21.     next REQUEST if $!{EINTR};
  22.     die "accept: $!";
  23.   };

  24.   my $pid;
  25.   if ($pid = fork) {
  26.     close CLIENT;
  27.     next REQUEST;
  28.   }
  29.   die "$!" unless defined $pid;
  30.   close SERVER;
  31.   print CLIENT "hello\n";
  32.   close CLIENT;
  33.   exit;
  34. }
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作者: lululau   发布时间: 2010-12-27