UNIX PORTABILITY CHANGES IN V8.4 Rupesh Shantamurty OpenVMS Engineering 1 © Copyright 2010 Hewlett-Packard Development Company, L.P. AGENDA –Overview of Unix Portability Initiative –Semaphores –UTF-8 support –GNV Update –Q & A 2 © Copyright 2010 Hewlett-Packard Development Company, L.P. UNIX PORTABILITY - OVERVIEW 3 © Copyright 2010 Hewlett-Packard Development Company, L.P. UNIX PORTABILITY INITIATIVE OBJECTIVE GOAL BENEFIT • Ease Porting of • OpenVMS will be • Less OpenVMS applications from like any other development UNIX, LINUX “UNIX flavor” for cost and Open easy application • Enhanced Source to portability application OpenVMS • Cost of porting portfolio on from UNIX to OpenVMS, OpenVMS is including Open comparable to Source porting one applications "flavor" of UNIX • Familiar UNIX- to another style development environment 4 © Copyright 2010 Hewlett-Packard Development Company, L.P. RECENT DEVELOPMENTS & V8.4 Byte Range File Lock APIs Standard Stat Locking Structure SEMAPHORES Symbolic Links POSIX style GNV Updates pathnames statvfs/fstatvfs Pthreads Encryption UTF-8 Routines Shared Objects SUPPORT 5 © Copyright 2010 Hewlett-Packard Development Company, L.P. SEMAPHORES 6 © Copyright 2010 Hewlett-Packard Development Company, L.P. INTRODUCTION - SEMAPHORES Semaphores - Inter Process Communication mechanism for synchronization across multiple processes. –System V Semaphores –POSIX Semaphores 7 © Copyright 2010 Hewlett-Packard Development Company, L.P. NEED FOR SEMAPHORES ON OPENVMS PRE V8.4 SOLUTION IN IMPACT V8.4 • Semaphore API Implements Reduces porting implementation was Semaphore APIs time Reduces cost of not available Applications using porting • Implement emulator semaphores can be Facilitates porting solutions ported without code of other Open Source • Performance issues change applications to due to layered OpenVMS emulator solutions 8 © Copyright 2010 Hewlett-Packard Development Company, L.P. SYSTEM V SEMAPHORE API Generates a standard inter process f t ok () communication key s e m ge t () Gets a set of semaphores Performs operations on semaphores in a s e mop () semaphore set s e m c tl() Semaphore control operations 9 © Copyright 2010 Hewlett-Packard Development Company, L.P. POSIX SEMAPHORE API Opens/creates a named semaphore for use by a s e m _ o p e n () process. s e m _ i n i t () Initializes an unnamed semaphore sem_getvalue () Gets the value of a specified semaphore. s e m _ w a i t () Performs a semaphore lock. sem_trywait () Conditionally performs a semaphore lock Performs a semaphore lock by waiting for a sem_timedwait () specified time. s e m _ p o s t () Unlocks a semaphore. s e m _ u n l i n k () Removes the specified named semaphore. sem_destroy () Destroys an unnamed semaphore. s e m _ c l o s e () De-allocates the specified named semaphore. 10 © Copyright 2010 Hewlett-Packard Development Company, L.P. USING SEMAPHORE API Application programs need to include the following header files • POSIX SEMAPHORE: #include<semaphore.h> • System V SEMAPHORE: #include <sys/ipc.h> #include <sys/sem.h> 11 © Copyright 2010 Hewlett-Packard Development Company, L.P. CONSIDERATIONS – System V Semaphores: • Maximum number of semaphore sets allowed on a system is 1024 • Maximum value of a semaphore is 32767 • Maximum number of SEM_UNDO operations allowed for a process is 1024. • No support for IPC_PRIVATE – POSIX Semaphores: • Unnamed semaphores not supported across processes 12 © Copyright 2010 Hewlett-Packard Development Company, L.P. UTF-8 SUPPORT 13 © Copyright 2010 Hewlett-Packard Development Company, L.P. INTRODUCTION –UTF-8 . UTF-8 (8-bit Unicode Transformation Format) is a variable-length character encoding for Unicode. UTF-8 can represent any character in the Unicode standard. UTF-8 is becoming the preferred encoding for e- mail, web pages. 14 © Copyright 2010 Hewlett-Packard Development Company, L.P. CRTL APIS SUPPORTING UTF-8 mkdir() stat() opendir() chdir() rmdir() chmod() creat() chown() open() readdir() rename() fopen() link() 15 © Copyright 2010 Hewlett-Packard Development Company, L.P. NEED FOR UTF-8 SUPPORT PRE V8.4 SOLUTION IN IMPACT V8.4 • UTF-8 character-set Support UTF-8 CRTL APIs support support was not character-set with UTF-8 file format available CRTL APIs specification E.g. CIFS support Applications with Japanese requiring this OpenVMS feature can be ported without code changes 16 © Copyright 2010 Hewlett-Packard Development Company, L.P. USING UTF-8 SUPPORT • $DEFINE / SYSTEM - $_ DECC$FILENAME_ENCODING_UTF8 “ENABLE” • $DEFINE / SYSTEM DECC$EFS_CHARSET “ENABLE” • Requirement: ODS-5 disk 17 © Copyright 2010 Hewlett-Packard Development Company, L.P. EXAMPLE USAGE OF UTF-8 SUPPORT 18 © Copyright 2010 Hewlett-Packard Development Company, L.P. GNV 19 © Copyright 2010 Hewlett-Packard Development Company, L.P. GNV V2.1-3 –Available @ Sourceforge –Changes : Support for Symlink Capability –> ln -s Installation changes Stability in setting up Mount Point Mixed Architecture Environments – Configuration files Bash – Command recall Improvements in cc wrapper mnt – improvement in record keeping 20 © Copyright 2010 Hewlett-Packard Development Company, L.P. GNV V2.1-3 – CALL TO ACTION –Community Participation is key –Want to contribute to GNV Project •Subscribe to the mailing list: https://lists.sourceforge.net/lists/listinfo/gnv-develop – Want to be part of GNV Developer Team •send a mail to -> [email protected] 21 © Copyright 2010 Hewlett-Packard Development Company, L.P. Q&A 22 © Copyright 2010 Hewlett-Packard Development Company, L.P..