SC22/WG15 N696
								PASC-SEC  N636

 To:		 PASC-SEC, WG15
 Subject:	 1003.1g Problem statement
 Date:		 1996-10-22 (final version)

 Two problems with the additions to IEEE 1003.1/ISO 9945-1 that have
 been developed by IEEE project P1003.1g have come to light as a result of
 work that has been done within X/Open on the introduction of 64-bit
 architectures into computer systems that support the programming interface
 defined by IEEE 1003.1/ISO 9945-1.  These problems impact on implementations
 and applications of that interface.

 1. POSIX.1g mandates the use of size_t in a number of interfaces
 and structures where such use is unwarranted and contrary to
 existing industry practice (BSD, Winsock, etc.) which use int's.

 This issue has assumed increased importance as the major UNIX
 vendors move from 32-bit ILP32 platforms to 64-bit LP64 platforms.
 On ILP32 platforms size_t is the same size as an int so there is
 no major problems with the use of size_t.  However on LP64 platforms
 size_t is 64 bits whilst int remains at 32 bits.

 In particular, the use of size_t instead of int for the specified
 parameter in the following interfaces

	 - accept	 addresslen
	 - bind 	 addresslen
	 - connect	 addresslen
	 - getpeername	 addresslen
	 - getsockname	 addresslen
	 - getsockopt	 optlen
	 - recvfrom	 fromlen
	 - sendto	 tolen
	 - setsockopt	 optlen

 and for the specified members of the following structures
	 - msghdr	 msg_namelen
	 - msghdr	 msg_controllen
	 - cmsghdr	 cmsg_len

 is unnecessary and adds no value.

 The unnecessary use of size_t in these interfaces and structures
 presents significant porting and source management issues for
 application developers.  It also adds to the development costs for
 those UNIX vendors who wish to support 32-bit binaries on LP64
 platforms.

 We propose that specification of the above listed interface
 parameters and structure members revert to using ints.

 2. Use of long in XTI interfaces creates a binary compatibility issue
 in 64-bit environments.  Since long in 64-bit environments is
 64-bit and 32-bit in 32-bit environments,  XTI providers
 will have to provide two sets of XTI libraries and expensive
 conversion modules to convert structures of one form to another.
 XTI performance will consequently suffer significant degradation.

 Redefining long to a 32-bit integral type is not an answer either
 since it should be possible to implement and conform to the XTI
 specification only in a 64-bit environment.  Therefore, it is
 proposed that all instances of signed and unsigned
 longs be respectively changed to an opaque unsigned integral type,
 t_uscalar_t, and an opaque signed integral type, t_scalar_t.
 t_scalar_t and t_uscalar_t are equal in length and occupy at least
 32-bits.

____________________________________________________________________________
	    Dr Petr Janecek			    Apex Plaza, Forbury Road
   T H E    Manager, CAE Development Business Unit  Reading, Berkshire
  O P E N   E-Mail: p.janecek@opengroup.org	    RG1 1AX
 G R O U P  WWW:    www.opengroup.org		    United Kingdom
	    Tel:    +44 118 950 8311 x2239	    Fax: +44 118 950 0110
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