Backport #670

Updated by usa (Usaku NAKAMURA) almost 3 years ago

  The main motivation for reporting this bug is that currently on win32 [any version] if you try to pass more than 64 sockets to select, it ignores the 65th onward.    This limit is not obeyed by Ruby currently and therefore some sockets will never select. 
  I'd first suggest raising an error if more than 64 total sockets are passed [to the most recent thread that called select?] 
  While examining it, this same aspect [too many or too high of numbered selects] is also seen to cause some problems on other platforms. 
  In the test cases attached, sometimes Mac OS X consistently crashes, sometimes Linux does.    Depends on the test. 
  I'd bet that these problems also continue for Ruby 1.9 as well. 
  How to run tests: 
  first touch file 'abc' # used for some tests 
  then run ulimit -n 2000 # if this fails, you may need to run "sudo bash" first 
  then run the files. 
  To ruby's credit, without having first run the ulimit, above, most platforms don't seg fault [though windows still has the difficulty mentioned], so this isn't life critical. 
  Note that in Linux/OS X if a file descriptor's "number" is > FD_SETSIZE then it will be ignored by select.    In Windows if the "total number of descriptors" past to select is > FD_SETSIZE then those past FD_SETSIZE will be ignored.   
  Thanks much!