After even more studying of the sys/types.h header, I could see a MAJOR problem with the way fd_set is defined. It appears that this structure is defined as a wrapper around an array of bytes, the number of which determined by the FD_SETSIZE macro. The length of this is computed at COMPILE TIME.
What's worse, the various macros like FD_ZERO, and friends do not do any sort of bounds checking. This means that when I called FD_SET() with a descriptor value greater than FD_SETSIZE, I was actually over-running a buffer. Talk about subtle!!! To fix this, I could simply #define my own value of FD_SETSIZE so that the size of the array is computed large enough to handle all the descriptors I need. (Adding a -D to my makefile). Caveat programmer... -----Original Message----- From: Geoff Thorpe <[EMAIL PROTECTED]> Sent: Jul 29, 2004 12:34 PM To: [EMAIL PROTECTED] Subject: Re: max sessions On July 29, 2004 02:20 pm, Joseph Bruni wrote: > The other thing I noticed was that (according to the man page for > select()) the results of the FD_ macros are undefined if the descriptor > value is greater than FD_SETSIZE, which is 1024 on my system. I find > this odd since the hard limit of the number of files any given process > can have open is kern.maxfilesperproc = 10240. Is this a limitation of > the POSIX API or could the man page for select() be wrong? Does anyone > have any insight into the proper use of select() if the descriptor > values are larger than FD_SETSIZE? Or maybe some other function that > replaces select() for programs with LOTS of descriptors? I don't know which system you're runing, but perhaps you might have more luck with poll(2)? Cheers, Geoff -- Geoff Thorpe [EMAIL PROTECTED] http://www.geoffthorpe.net/ ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED] ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]
