Download M4 Source | Macro History | Category Index |
AX_HAVE_POLL([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
AX_HAVE_PPOLL([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
This macro determines whether the system supports the poll I/O event interface. A neat usage example would be:
AX_HAVE_POLL( [AX_CONFIG_FEATURE_ENABLE(poll)], [AX_CONFIG_FEATURE_DISABLE(poll)]) AX_CONFIG_FEATURE( [poll], [This platform supports poll(7)], [HAVE_POLL], [This platform supports poll(7).])
Some systems -- most notably Linux kernel 2.6.16 and later -- also have the variant ppoll(). The availability of that function can be tested with the second macro. Generally speaking, it is safe to assume that AX_HAVE_POLL would succeed if AX_HAVE_PPOLL has, but not the other way round.
Peter Simons <simons@cryp.to>
2008-05-01
AC_DEFUN([AX_HAVE_POLL], [dnl AC_MSG_CHECKING([for poll(2)]) AC_CACHE_VAL([ax_cv_have_poll], [dnl AC_LINK_IFELSE([dnl AC_LANG_PROGRAM( [#include <poll.h>], [int rc; rc = poll((struct pollfd *)(0), 0, 0);])], [ax_cv_have_poll=yes], [ax_cv_have_poll=no])]) AS_IF([test "${ax_cv_have_poll}" = "yes"], [AC_MSG_RESULT([yes]) $1],[AC_MSG_RESULT([no]) $2]) ])dnl AC_DEFUN([AX_HAVE_PPOLL], [dnl AC_MSG_CHECKING([for ppoll(2)]) AC_CACHE_VAL([ax_cv_have_ppoll], [dnl AC_LINK_IFELSE([dnl AC_LANG_PROGRAM( [dnl #include <poll.h> #include <signal.h>], [dnl int rc; rc = poll((struct pollfd *)(0), 0, 0); rc = ppoll((struct pollfd *)(0), 0, (struct timespec const *)(0), (sigset_t const *)(0));])], [ax_cv_have_ppoll=yes], [ax_cv_have_ppoll=no])]) AS_IF([test "${ax_cv_have_ppoll}" = "yes"], [AC_MSG_RESULT([yes]) $1],[AC_MSG_RESULT([no]) $2]) ])
Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.