PROJECTS

   1 Open jobs for finishing GNU libc:
   2 ---------------------------------
   3 Status: December 1998
   4
   5 If you have time and talent to take over any of the jobs below please
   6 contact <bug-glibc@gnu.org>.
   7
   8 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9 \f
  10 [ 1] Port to new platforms or test current version on formerly supported
  11      platforms.
  12
  13 **** See http://www.gnu.org/software/libc/porting.html for more details.
  14
  15
  16 [ 2] Test compliance with standards.  If you have access to recent
  17      standards (IEEE, ISO, ANSI, X/Open, ...) and/or test suites you
  18      could do some checks as the goal is to be compliant with all
  19      standards if they do not contradict each other.
  20
  21
  22 [ 3] The IMHO opinion most important task is to write a more complete
  23      test suite.  We cannot get too many people working on this.  It is
  24      not difficult to write a test, find a definition of the function
  25      which I normally can provide, if necessary, and start writing tests
  26      to test for compliance.  Beside this, take a look at the sources
  27      and write tests which in total test as many paths of execution as
  28      possible.
  29
  30
  31 [ 4] Write translations for the GNU libc message for the so far
  32      unsupported languages.  GNU libc is fully internationalized and
  33      users can immediately benefit from this.
  34
  35      Take a look at the matrix in
  36         ftp://ftp.gnu.org/pub/gnu/ABOUT-NLS
  37      for the current status (of course better use a mirror of ftp.gnu.org).
  38
  39
  40 [ 6] Write `long double' versions of the math functions.  This should be
  41      done in collaboration with the NetBSD and FreeBSD people.
  42
  43      The libm is in fact fdlibm (not the same as in Linux libc 5).
  44
  45 **** Partly done.  But we need someone with numerical experiences for
  46      the rest.
  47
  48
  49 [ 7] Several math functions have to be written:
  50
  51      - exp2
  52
  53      with long double arguments.
  54
  55      Beside this most of the complex math functions which are new in
  56      ISO C 9X should be improved.  Writing some of them in assembler is
  57      useful to exploit the parallelism which often is available.
  58
  59
  60 [ 8] If you enjoy assembler programming (as I do --drepper :-) you might
  61      be interested in writing optimized versions for some functions.
  62      Especially the string handling functions can be optimized a lot.
  63
  64      Take a look at
  65
  66         Faster String Functions
  67         Henry Spencer, University of Toronto
  68         Usenix Winter '92, pp. 419--428
  69
  70      or just ask.  Currently mostly i?86 and Alpha optimized versions
  71      exist.  Please ask before working on this to avoid duplicate
  72      work.
  73
  74
  75 [10] Extend regex and/or rx to work with wide characters and complete
  76      implementation of character class and collation class handling.
  77
  78      It is planned to do a complete rewrite.
  79
  80
  81 [11] Write access function for netmasks, bootparams, and automount
  82      databases for nss_files and nss_db module.
  83      The functions should be embedded in the nss scheme.  This is not
  84      hard and not all services must be supported at once.
  85
  86
  87 [14] We need to write a library for on-the-fly transformation of streams
  88      of text.  In fact, this would be a recode-library (you know, GNU recode).
  89      This is needed in several places in the GNU libc and I already have
  90      rather concrete plans but so far no possibility to start this.
  91
  92 ***  The library is available, now it remains to be used in the streams.
  93
  94
  95 [15] Cleaning up the header files.  Ideally, each header style should
  96      follow the "good examples".  Each variable and function should have
  97      a short description of the function and its parameters.  The prototypes
  98      should always contain variable names which can help to identify their
  99      meaning; better than
 100
 101                 int foo __P ((int, int, int, int));
 102
 103      Blargh!
 104
 105
 106 [16] The libio stream file functions should be extended in a way to use
 107      mmap to map the file and use it as the buffer to user sees.  For
 108      read-only streams this should be rather easy and it avoids all read()
 109      calls.
 110
 111      A more sophisticated solution would use mmap also for writing.  The
 112      standards do not demand that the file on the disk is always in the
 113      correct form so it would be possible to enlarge it always according
 114      to the page size and install the correct length only for fclose() and
 115      fflush() calls.
 116
 117
 118 [18] Based on the sprof program we need tools to analyze the output.  The
 119      result should be a link map which specifies in which order the .o
 120      files are placed in the shared object.  This should help to improve
 121      code locality and result in a smaller foorprint (in code and data
 122      memory) since less pages are only used in small parts.
 123
 124
 125 [19] A user-level STREAMS implementation should be available if the
 126      kernel does not provide the support.
 127
 128
 129 [20] More conversion modules for iconv(3).  Existing modules should be
 130      extended to do things like transliteration if this is wanted.
 131      For often used conversion a direct conversion function should be
 132      available.
 133
 134
 135 [21] The nscd program and the stubs in the libc should be changed so
 136      that each program uses only one socket connect.  Take a look at
 137         http://www.cygnus.com/~drepper/nscd.html
 138
 139      An alternative approach is to use an mmap()ed file.  The idea is
 140      the following:
 141      - the nscd creates the hash tables and the information it stores
 142        in it in a mmap()ed region.  This means no pointers must be
 143        used, only offsets.
 144      - each program using NSS functionality tries to open the file
 145        with the data.
 146      - by checking some timestamp (which the nscd renew frequently)
 147        the programs can test whether the file is still valid
 148      - if the file is valid look through the nscd and locate the
 149        appropriate hash table for the database and lookup the data.
 150        If it is included we are set.
 151      - if the data is not yet in the database we contact the nscd using
 152        the currently implemented methods.
 153
 154
 155 [22] It should be possible to have the information gconv-modules in
 156      a simple database which is faster to access.  Using libdb is probably
 157      overkill and loading it would probably be slower than reading the
 158      plain text file.  But a file format with a simple hash table and
 159      some data it points to should be fine.  Probably it should be
 160      two tables, one for the aliases, one for the mappings.  The code
 161      should start similar to this:
 162
 163         if (stat ("gconv-modules", &stp) == 0
 164             && stat ("gconv-modules.db", &std) == 0
 165             && stp.st_mtime < std.st_mtime)
 166           {
 167             ... use the database ...
 168           {
 169         else
 170           {
 171             ... use the plain file if it exists, otherwise the db ...
 172           }
 173
 174
 175 [23] The `strptime' function needs to be completed.  This includes among
 176      other things that it must get teached about timezones.  The solution
 177      envisioned is to extract the timezones from the ADO timezone
 178      specifications.  Special care must be given names which are used
 179      multiple times.  Here the precedence should (probably) be according
 180      to the geograhical distance.  E.g., the timezone EST should be
 181      treated as the `Eastern Australia Time' instead of the US `Eastern
 182      Standard Time' if the current TZ variable is set to, say,
 183      Australia/Canberra or if the current locale is en_AU.
 184
 185
 186 [25] Sun's nscd version implements a feature where the nscd keeps N entries
 187      for each database current.  I.e., if an entries lifespan is over and
 188      it is one of the N entries to be kept the nscd updates the information
 189      instead of removing the entry.
 190
 191      How to decide about which N entries to keep has to be examined.
 192      Factors should be number of uses (of course), influenced by aging.
 193      Just imagine a computer used by several people.  The IDs of the current
 194      user should be preferred even if the last user spent more time.
 195
 196
 197 [26] Improve the AIO implementation so that threads do not immediately
 198      terminate if no more requests are available.  Let them sleep for a
 199      while and wake them up on demand.  If after a while no request arrived
 200      they really can die.