   ____  _   _
  |  _ \| |_| |__                  ``A good magician never reveals
  | |_) | __| '_ \                   his secret; the unbelievable trick
  |  __/| |_| | | |                  becomes simple and obvious once it is
  |_|    \__|_| |_|                  explained. So too with UNIX.''

  GNU Pth - The GNU Portable Threads

  PORTING
  =======

  SUCCESSFULLY TESTED PLATFORMS

  The Pth package was successfully tested on the following platforms
  (and should automatically adjust to other platforms, of course):

  __PLATFORM_ID_________________________ __MACHINE_CONTEXT__ _STACK_ _VERSION_
  i386-unknown-freebsd6.1               | mcsc/sc/mc        | down  | 2.0.6
  i386-unknown-freebsd5.3               | mcsc/sc/mc        | down  | 2.0.3
  i386-unknown-freebsd4.10              | sjlj/ssjlj/sas    | down  | 2.0.1
  i386-unknown-freebsd4.7               | sjlj/ssjlj/sas    | down  | 2.0b0
  i386-pc-solaris2.8                    | mcsc/sc/mc        | down  | 1.4.1
  i686-gnu-linux-gnu2.2glibc2.2         | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-pc-sysv4.2uw2.1.2                | mcsc/sc/mc        | down  | 1.4.1
  alpha-portbld-freebsd4.6.2            | sjlj/ssjlj/sas    | down  | 1.4.1
  i586-pc-freebsd4.6                    | sjlj/ssjlj/sas    | down  | 1.4.1
  m68k--netbsdelf                       | sjlj/ssjlj/sas    | down  | 1.4.1
  alpha-unknown-freebsd4.6              | sjlj/ssjlj/sas    | down  | 1.4.1
  powerpc-apple-darwin6.1               | sjlj/ssjlj/sas    | down  | 1.4.1
  powerpc-apple-netbsd1.5.2             | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-pclocal-interix                  | sjlj/sjljisc/none | down  | 1.4.1
  powerpc-ibm-aix4.3.1.0                | mcsc/sc/mc        | down  | 1.4.1
  alpha-unknown-netbsd1.5.3.            | sjlj/ssjlj/sas    | down  | 1.4.1
  alphaev56-dec-osf4.0a                 | mcsc/sc/mc        | down  | 1.4.1
  i686-redhat-linux-gnu2.2glibc1        | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-portbld-freebsd4.4               | sjlj/ssjlj/sas    | down  | 1.4.1
  i686-pc-sco3.2v5.0.6                  | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-portbld-freebsd4.5               | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-portbld-freebsd4.6               | sjlj/ssjlj/sas    | down  | 1.4.1
  i686-pc-freebsd4.6                    | sjlj/ssjlj/sas    | down  | 1.4.1
  i686-pc-freebsd4.5                    | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-portbld-freebsd4.7               | sjlj/ssjlj/sas    | down  | 1.4.1
  rs6000-ibm-aix5.1.0.0                 | mcsc/sc/mc        | down  | 1.4.1
  i386-unknown-gnu0.2                   | sjlj/sjljlx/none  | down  | 1.4.1
  sparc--netbsdelf                      | sjlj/ssjlj/sas    | down  | 1.4.1
  sparc-sun-solaris2.9                  | mcsc/sc/mc        | down  | 1.4.1
  sparc-unknown-netbsd1.5.2             | sjlj/ssjlj/sas    | down  | 1.4.1
  sparc-unknown-netbsd1.6               | sjlj/ssjlj/sas    | down  | 1.4.1
  i586-pc-freebsd4.5                    | sjlj/ssjlj/sas    | down  | 1.4.1
  vax--netbsdelf                        | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-unknown-netbsd1.5.2              | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-unknown-netbsd1.5ZA              | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-unknown-netbsd1.6                | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-unknown-netbsd1.6.               | sjlj/ssjlj/sas    | down  | 1.4.1
  i386--netbsdelf                       | sjlj/ssjlj/sas    | down  | 1.4.1
  i686-debian-linux-gnu2.4glibc2.1      | sjlj/ssjlj/sas    | down  | 1.4.1
  i586-debian-linux-gnu2.2glibs2.2      | mcsc/sc/mc        | down  | 1.4.1
  i586-gnu-linux-gnu2.4glibc2.2         | mcsc/sc/mc        | down  | 1.4.1
  i586-sco-sysv5                        | mcsc/sc/mc        | down  | 1.4.1
  i586-redhat-linux-gnu2.4glibc2.3      | mcsc/sc/mc        | down  | 1.4.1
  i386-pc-freebsd4.0-gnu                | mcsc/sc/mc        | down  | 1.4.1
  i386-pc-freebsd4.3                    | sjlj/ssjlj/sas    | down  | 1.4.1
  i386-pc-freebsd4.5                    | sjlj/ssjlj/sas    | down  | 1.4.1
  i686-suse-linux-gnu2.4glibc2.2        | mcsc/sc/mc        | down  | 1.4.1
  m68k--netbsd                          | sjlj/ssjlj/sas    | down  | 1.4.1
  i686-gnu-linux-gnu2.4glibc2.2         | mcsc/sc/mc        | down  | 1.4.1
  i386-pc-sco3.2v5.0.6                  | sjlj/ssjlj/sas    | down  | 1.4.1
  i386--freebsd4.4                      | sjlj/ssjlj/sas    | down  | 1.4.0
  i386--freebsd4.5                      | sjlj/ssjlj/sas    | down  | 1.4.0
  powerpc-yellowdog-linux-gnu2.4glibc2. | sjlj/ssjlj/sas    | down  | 1.4.0
  i586-pc-cygwin                        | sjlj/sjljw32/none | down  | 1.4.0
  i586-redhat-linux-gnu2.4glibc2.2      | mcsc/sc/mc        | down  | 1.4.0
  mips-debian-linux-gnu2.4glibc2.2      | sjlj/ssjlj/sas    | down  | 1.4.0
  i386-portbld-freebsd4.3               | sjlj/ssjlj/sas    | down  | 1.4.0
  powerpc-yellowdog-linux-gnu2.4glibc2. | sjlj/ssjlj/sas    | down  | 1.4.0
  powerpc-apple-darwin6.0               | sjlj/ssjlj/sas    | down  | 1.4.0
  i686-debian-linux-gnu2.2glibc2.2      | mcsc/sc/mc        | down  | 1.4.0
  i386-unknown-openbsd3.0               | sjlj/ssjlj/sas    | down  | 1.4.0
  sparc-unknown-openbsd2.9              | sjlj/ssjlj/sas    | down  | 1.4.0
  arm-redhat-linux-gnu2.2glibc2.1       | sjlj/ssjlj/sas    | down  | 1.4.0
  i686-debian-linux-gnu2.4glibc2.2      | mcsc/sc/mc        | down  | 1.4.0
  i586-debian-linux-gnu2.2glibc2.2      | sjlj/ssjlj/sas    | down  | 1.4.0
  i686-pc-freebsd4.3                    | sjlj/ssjlj/sas    | down  | 1.4a4
  i686-pc-freebsd4.1                    | sjlj/ssjlj/sas    | down  | 1.4a3
  i386-unknown-netbsd1.4.2              | sjlj/ssjlj/sas    | down  | 1.4a2
  i686-pc-freebsd3.5                    | sjlj/ssjlj/sas    | down  | 1.4a2
  alpha-unknown-netbsd1.5.1             | sjlj/ssjlj/sas    | down  | 1.4a2
  hppa2.0w-hp-hpux11.00                 | mcsc/sc/mc        | up    | 1.4a1
  i586-redhat-linux-gnu2.2glibc1        | sjlj/ssjlj/sas    | down  | 1.3.7
  i686-redhat-linux-gnu2.4glibc2.2      | sjlj/ssjlj/sas    | down  | 1.3.7
  i686-redhat-linux-gnu2.2glibc2.2      | sjlj/ssjlj/sas    | down  | 1.3.7
  i586-gnu-linux-gnu2.4glibc2.1         | sjlj/ssjlj/sas    | down  | 1.3.7
  i386-unknown-openbsd2.7               | sjlj/ssjlj/sas    | down  | 1.3.7
  i586-suse-linux-gnu2.2glibc2.0        | sjlj/sjljlx/none  | down  | 1.3.7
  i386-unknown-openbsd2.8               | sjlj/ssjlj/sas    | down  | 1.3.7
  i486-gnu-linux-gnu2.0glibc1           | sjlj/sjljlx/none  | down  | 1.3.7
  m68k-apple-netbsd1.3.3                | sjlj/ssjlj/sas    | down  | 1.3.7
  mips-compaq-nonstopux                 | sjlj/ssjlj/sas    | down  | 1.3.7
  mips-dec-netbsd1.5                    | sjlj/ssjlj/sas    | down  | 1.3.7
  hppa1.1-hp-hpux10.10                  | sjlj/ssjlj/sas    | up    | 1.3.7
  i586-pc-freebsd4.1                    | sjlj/ssjlj/sas    | down  | 1.3.7
  i686-pc-freebsd4.2                    | sjlj/ssjlj/sas    | down  | 1.3.7
  mips-sgi-irix6.3                      | mcsc/sc/mc        | down  | 1.3.7
  i686-pc-freebsd4.1.1                  | sjlj/ssjlj/sas    | down  | 1.3.7
  powerpc-redhat-linux-gnu2.2glibc2.1   | sjlj/ssjlj/sas    | down  | 1.3.7
  i386-pc-bsdi4.1                       | sjlj/ssjlj/sas    | down  | 1.3.7
  i386-pc-freebsd3.2                    | sjlj/ssjlj/sas    | down  | 1.3.7
  rs6000-ibm-aix4.2.0.0                 | mcsc/sc/mc        | down  | 1.3.7
  sparc--netbsd                         | sjlj/ssjlj/sas    | down  | 1.3.7
  i586-redhat-linux-gnu2.2glibc2.2      | sjlj/ssjlj/sas    | down  | 1.3.7
  i686-pc-cygwin                        | sjlj/sjljw32/none | down  | 1.3.6
  i586-debian-linux-gnu2.4glibc2.1      | sjlj/ssjlj/sas    | down  | 1.3.6
  powerpc-apple-netbsd1.4.2             | sjlj/ssjlj/sas    | down  | 1.3.5
  alpha-redhat-linux-gnu2.2glibc2.1     | sjlj/ssjlj/sas    | down  | 1.3.5
  alpha-unknown-freebsd5.0              | sjlj/ssjlj/sas    | down  | 1.3.5
  i486-redhat-linux-gnu2.2glibc2.1      | sjlj/ssjlj/sas    | down  | 1.3.5
  powerpc-debian-linux-gnu2.2glibc2.1   | sjlj/ssjlj/sas    | down  | 1.3.5
  powerpc-ibm-aix4.3.3.0                | mcsc/sc/mc        | down  | 1.3.5
  i686-pc-sco3.2v5.0.4                  | sjlj/ssjlj/sas    | down  | 1.3.5
  alphaev6-dec-osf4.0f                  | mcsc/sc/mc        | down  | 1.3.5
  i686-gnu-linux-gnu2.2glibc2.1         | sjlj/ssjlj/sas    | down  | 1.3.5
  rs6000-ibm-aix4.1.5.0                 | sjlj/ssjlj/ss     | down  | 1.3.5
  rs6000-ibm-aix4.3.3.0                 | mcsc/sc/mc        | down  | 1.3.5
  i686-pc-freebsd3.2                    | sjlj/ssjlj/sas    | down  | 1.3.5
  i386-pc-interix                       | sjlj/sjljisc/none | down  | 1.3.5
  i386-unknown-netbsd1.4T               | sjlj/ssjlj/sas    | down  | 1.3.5
  i386-pc-sysv5uw7.1.0                  | mcsc/sc/mc        | down  | 1.3.5
  m68k-cbm-amigaos                      | sjlj/ssjlj/ss     | down  | 1.3.5
  i686-gnu-linux-gnu2.0glibc1           | sjlj/sjljlx/none  | down  | 1.3.5
  sparc64-redhat-linux-gnu2.2glibc2.1   | sjlj/ssjlj/sas    | down  | 1.3.5
  mipsel-unknown-netbsd1.4.2            | sjlj/ssjlj/sas    | down  | 1.3.5
  i686-gnu-linux-gnu2.2glibc1           | sjlj/sjljlx/none  | down  | 1.3.5
  i686-debian-linux-gnu2.2glibc2.1      | sjlj/ssjlj/sas    | down  | 1.3.5
  alphaev56-dec-osf4.0e                 | mcsc/sc/mc        | down  | 1.3.4
  i586-pc-freebsd5.0                    | sjlj/ssjlj/sas    | down  | 1.3.4
  i686-redhat-linux-gnu2.2glibc2.1      | sjlj/ssjlj/sas    | down  | 1.3.3
  i686-va-linux-gnu2.2glibc2.1          | sjlj/ssjlj/sas    | down  | 1.3.3
  hppa1.1-hp-hpux10.01                  | sjlj/ssjlj/ss     | up    | 1.3.3
  sparc-redhat-linux-gnu2.2glibc2.1     | sjlj/ssjlj/sas    | down  | 1.3.3
  i386-pc-bsdi4.0                       | sjlj/ssjlj/sas    | down  | 1.3.3
  i586-pc-freebsd3.1                    | sjlj/ssjlj/sas    | down  | 1.3.3
  i586-gnu-linux-gnu2.2glibc2.0         | sjlj/sjljlx/none  | down  | 1.3.3
  alpha-dec-osf4.0e                     | mcsc/sc/mc        | down  | 1.3.3
  i386-pc-sysv5uw7.1.1                  | mcsc/sc/mc        | down  | 1.3.3
  i586-debian-linux-gnu2.3glibc2.1      | sjlj/ssjlj/sas    | down  | 1.3.3
  powerpc-ibm-aix4.1.3.0                | sjlj/ssjlj/ss     | down  | 1.3.3
  powerpc-apple-macosX                  | sjlj/ssjlj/sas    | down  | 1.3.2
  i586-suse-linux-gnu2.2glibc2.1        | sjlj/ssjlj/sas    | down  | 1.3.2
  powerpc-unknown-netbsd                | sjlj/ssjlj/sas    | down  | 1.3.2
  sparc-sun-solaris2.8                  | mcsc/sc/mc        | down  | 1.3.2
  alpha-unknown-netbsd1.4.1             | sjlj/ssjlj/sas    | down  | 1.3.2
  i686-suse-linux-gnu2.2glibc2.1        | sjlj/ssjlj/sas    | down  | 1.3.2
  i586-pc-sco3.2v5.0.2                  | sjlj/ssjlj/sas    | down  | 1.3.2
  i586-redhat-linux-gnu2.2glibc2.1      | sjlj/ssjlj/sas    | down  | 1.3.1
  i586-gnu-linux-gnu2.0glibc1           | sjlj/sjljlx/none  | down  | 1.3.1
  i686-suse-linux-gnu2.2glibc2.0        | sjlj/sjljlx/none  | down  | 1.3.1
  hppa1.1-stratus-sysv4                 | mcsc/sc/mc        | up    | 1.3.1
  i586-gnu-linux-gnu2.2glibc1           | sjlj/sjljlx/none  | down  | 1.3.1
  i686-pc-freebsd4.0                    | sjlj/ssjlj/sas    | down  | 1.3.0
  i686-slackware-linux-gnu              | sjlj/ssjlj/sas    | down  | 1.3.0
  alpha-unknown-freebsd4.0              | sjlj/ssjlj/sas    | down  | 1.3.0
  hppa1.1-hp-hpux10.20                  | sjlj/ssjlj/sas    | up    | 1.3.0
  hppa2.0-hp-hpux10.20                  | sjlj/ssjlj/sas    | up    | 1.3.0
  i386-pc-sysv4.2uw2.1.3                | mcsc/sc/mc        | down  | 1.3.0
  i386-pc-sysv5uw7                      | mcsc/sc/mc        | down  | 1.3.0
  sparc-sun-solaris2.6                  | mcsc/sc/mc        | down  | 1.3.0
  i386-unknown-netbsd1.4                | sjlj/ssjlj/sas    | down  | 1.3.0
  i386-unknown-netbsd1.4.1              | sjlj/ssjlj/sas    | down  | 1.3.0
  i586-debian-linux-gnu2.2glibc2.0      | sjlj/sjljlx/none  | down  | 1.3.0
  i586-gnu-linux-gnu2.2glibc2.1         | sjlj/ssjlj/sas    | down  | 1.3.0
  i586-redhat-linux-gnu2.0glibc2.0      | sjlj/sjljlx/none  | down  | 1.3.0
  i686-pc-freebsd3.1                    | sjlj/ssjlj/sas    | down  | 1.3.0
  i686-pc-freebsd3.4                    | sjlj/ssjlj/sas    | down  | 1.3.0
  i586-pc-freebsd4.0                    | sjlj/ssjlj/sas    | down  | 1.3b2
  i586-pc-freebsd3.3                    | sjlj/ssjlj/sas    | down  | 1.3a5
  m68k-cbm-netbsd1.4.1                  | sjlj/ssjlj/sas    | down  | 1.3a5
  i686-redhat-linux-gnu2.3glibc2.0      | sjlj/sjljlx/none  | down  | 1.3a4
  i386--netbsd                          | sjlj/ssjlj/sas    | down  | 1.3a2
  i386-pc-freebsd3.4                    | sjlj/ssjlj/sas    | down  | 1.3a2
  i586-redhat-linux-gnu2.2glibc2.0      | sjlj/sjljlx/none  | down  | 1.3a2
  i686-redhat-linux-gnu2.2glibc2.0      | sjlj/sjljlx/none  | down  | 1.3a1
  i386-redhat-linux-gnu                 | sjlj/sjljlx/none  | down  | 1.3a1
  sparc-unknown-linux-gnu               | sjlj/ssjlj/sas    | down  | 1.2.3
  hppa1.1-hp-hpux11.00                  | mcsc/sc/mc        | up    | 1.2.3
  mips-sni-sysv4                        | mcsc/sc/mc        | down  | 1.2.3
  i586-pc-freebsd3.4                    | sjlj/ssjlj/sas    | down  | 1.2.2
  mips-sgi-irix5.3                      | sjlj/ssjlj/sas    | down  | 1.2.2
  i386-pc-sco3.2v5.0.5                  | sjlj/ssjlj/sas    | down  | 1.2.2
  powerpc-apple-netbsd1.4.1             | sjlj/ssjlj/sas    | down  | 1.2.1
  i586-ncr-sysv4.3.03                   | mcsc/sc/mc        | down  | 1.2.1
  i486-pc-linux-gnulibc1                | sjlj/sjljlx/none  | down  | 1.2.1
  i486-pc-linux-gnu                     | sjlj/sjljlx/none  | down  | 1.2.1
  i386-pc-freebsd3.3                    | sjlj/ssjlj/sas    | down  | 1.2.1
  i486-pc-freebsd3.3                    | sjlj/ssjlj/sas    | down  | 1.2.1
  powerpc-ibm-aix4.3.2.0                | mcsc/sc/mc        | down  | 1.2.1
  m68k-unknown-amigaos                  | sjlj/ssjlj/ss     | down  | 1.2.1
  i386-unknown-openbsd2.6               | sjlj/ssjlj/sas    | down  | 1.2.1
  hppa2.0n-hp-hpux11.00                 | mcsc/sc/mc        | up    | 1.2.1
  i686-pc-sco3.2v5.0.5                  | sjlj/ssjlj/sas    | down  | 1.2.1
  alpha-dec-osf5.0                      | mcsc/sc/mc        | down  | 1.2.1
  alpha-dec-osf4.0f                     | mcsc/sc/mc        | down  | 1.2.1
  i586-pc-linux-gnu                     | sjlj/sjljlx/none  | down  | 1.2.1
  i586-pc-freebsd3.2                    | sjlj/ssjlj/sas    | down  | 1.2.0
  i586-pc-linux-gnulibc1                | sjlj/sjljlx/none  | down  | 1.2.0
  m68k-hp-hpux9.10                      | sjlj/ssjlj/ss     | down  | 1.2.0
  alphaev56-dec-osf4.0f                 | mcsc/sc/mc        | down  | 1.2.0
  sparc-sun-solaris2.5.1                | mcsc/sc/mc        | down  | 1.2.0
  sparc-sun-solaris2.7                  | mcsc/sc/mc        | down  | 1.2.0
  powerpc-unknown-linux-gnu             | sjls/ssjlj/sas    | down  | 1.2.0
  sparc-unknown-openbsd2.6              | sjlj/ssjlj/sas    | down  | 1.2.0
  alphaev6-unknown-linux-gnu            | sjlj/ssjlj/sas    | down  | 1.2.0
  alphaev6-dec-osf5.0                   | mcsc/sc/mc        | down  | 1.2.0
  i686-pc-linux-gnu                     | sjlj/sjljlx/none  | down  | 1.2.0
  i686-pc-freebsd3.3                    | sjlj/ssjlj/sas    | down  | 1.2.0
  i586-pc-sco3.2v5.0.4                  | sjlj/ssjlj/sas    | down  | 1.2.0
  i686-pc-linux-gnulibc1                | sjlj/sjljlx/none  | down  | 1.2.0
  alphaev56-unknown-linux-gnu           | sjlj/ssjlj/sas    | down  | 1.2.0
  armv4l-unknown-linux-gnu              | sjlj/ssjlj/sas    | down  | 1.2b8
  sparc-unknown-netbsd1.4.1             | sjlj/ssjlj/sas    | down  | 1.2b8
  alphaev56-dec-osf4.0d                 | mcsc/sc/mc        | down  | 1.2b6
  m68k-apple-netbsd1.4.1                | sjlj/ssjlj/sas    | down  | 1.2b5
  i386-unknown-openbsd2.5               | sjlj/ssjlj/sas    | down  | 1.2b5
  powerpc-apple-rhapsody5.5             | sjlj/ssjlj/sas    | down  | 1.2b3
  i386-pc-isc4.0                        | sjlj/sjljisc/none | down  | 1.2b2
  mips-sgi-irix6.5                      | mcsc/sc/mc        | down  | 1.2b1
  i386-pc-sysv4.2uw2.1                  | mcsc/sc/mc        | down  | 1.1.6
  sparc-sun-sunos4.1.4                  | sjlj/ssjlj/ss     | down  | 1.1.6
  powerpc-ibm-aix4.1.4.0                | mcsc/sc/mc        | down  | 1.1.6
  powerpc-ibm-aix4.2.1.0                | mcsc/sc/mc        | down  | 1.1.6
  rs6000-ibm-aix4.3.2.0                 | mcsc/sc/mc        | down  | 1.1.5
  rs6000-ibm-aix4.2.1.0                 | mcsc/sc/mc        | down  | 1.1.5
  i386-unknown-netbsd1.3.3              | sjlj/ssjlj/sas    | down  | 1.1.5
  powerpc-ibm-aix4.1.5.0                | mcsc/sc/mc        | down  | 1.1.5
  sparc-sun-sunos4.1.3_U1               | sjlj/ssjlj/ss     | down  | 1.1.4
  sparc-sun-solaris2.5                  | mcsc/sc/mc        | down  | 1.1.4
  alpha-unknown-netbsd1.3.3             | sjlj/ssjlj/sas    | down  | 1.1.4

  HINTS FOR PORTING TO NEW PLATFORMS

  In case you're not able to use Pth on a new and esoteric platform,
  here are a few hints.

  Pth has only one part which perhaps has to be ported to new platforms: the
  machine context initialization, i.e. the function pth_mctx_set() in
  pth_mctx.c.  The exercise is to write a pth_mctx_set() function which
  initializes a `jmp_buf' (see setjmp(3)) with a given function and stack, so
  when the next longjmp(3) is done on this `jmp_buf', the function starts
  executing on the given stack.

  By default, Pth uses a very tricky sigstack/sigaltstack() based approach for
  establishing this `jmp_buf' which is mostly portable to all major Unix
  platforms which support the involved POSIX functions (see rse-pmt.ps for a
  detailed description of the trick). So the chance is very high that this
  approach also works for forthcoming platforms and no real porting is
  required.

  When this approach should not work (for instance brain-dead achient
  GNU/Linux versions have a dummy sigstack/sigaltstack(), so we've no chance
  this way), then you've to provide an alternative implementation. This
  usually is done be fiddling around with the ingredients of a `jmp_buf'
  structure. For this look inside your /usr/include/setjmp.h (plus files it
  includes) and there especially for things like _pc or JB_PC (the program
  counter) and _sp or JB_SP (the stack pointer). Then write an alternative
  pth_mctx_set() function in pth_mctx.c.

  Currently, as mentioned, Pth requires such an alternative only under
  GNU/Linux where sigstack/sigaltstack() are dummy functions. Look at the
  GNU/Linux pth_mctx_set() variant in pth_mctx.c to get an impression what
  type of `jmp_buf' fiddling you perhaps have to do for esoteric platforms.
  Don't be confused by the fact that such specialized pth_mctx_set() functions
  are just a few lines long while the standard function is very large. That's
  all just needed for maximum portability.  The goal nevertheless only is to
  initialize a `jmp_buf' with PC and SP. That's all...

  Additionally see the INSTALL document for the --enable-mctx-XXX options.
  These can be used to easily try out mctx combinations on a platform, too.

