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dnl I don't like the standard mmap test, its broken in
dnl several ways.
AC_DEFUN(JM_FUNC_MMAP,
[AC_CACHE_CHECK(for working mmap read private, ac_cv_func_mmap,
[AC_TRY_RUN([
/* Josh's READ ONLY mmap test. This is taken from, but heavily
* modified, the autoconf 2.10 distribution. This only tests the
* features of mmap required by PRCS. It is advisable to run
* this test on an NFS filesystem if you intend to use PRCS with
* a repository on NFS. */
#include <sys/types.h>
#include <unistd.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
int
main()
{
char *buf1;
caddr_t buf2;
char *buf3;
int ps = 5000; /* This is purposely not a pagesize. */
int ps2 = 2*ps;
int ps3 = 3*ps;
int j;
int fd;
/* Allocate 3 pages of buffer. */
if ((buf1 = (char *)malloc(ps3)) == NULL ||
(buf3 = (char *)malloc(ps3)) == NULL)
{
perror ("malloc failed");
exit(1);
}
/* Generate 3 pages of random numbers into buf1. */
for (j = 0; j < ps3; ++j)
*(buf1 + j) = rand();
/* Open for read/write. */
if ((fd = open("conftestmmap", O_CREAT | O_RDWR, 0666)) < 0)
{
perror ("open 1 failed");
exit(1);
}
/* Write 2 pages of the random numbers to the file. */
if (write(fd, buf1, ps2) != ps2)
{
perror ("write 1 failed");
exit(1);
}
/* Now map the file onto buf2. */
if((buf2=mmap(NULL, ps2, PROT_READ, MAP_PRIVATE, fd, 0)) == NULL)
{
perror ("mmap 1 failed");
exit (1);
}
/* Compare buf1 and buf2. */
for (j = 0; j < ps2; ++j)
if (*(buf1 + j) != *(buf2 + j))
{
fprintf (stderr, "read/mmap comparison failed\n");
exit(1);
}
/* Write the 3rd page to the file. */
if (write(fd, buf1+ps2, ps) != ps)
{
perror ("write 2 failed");
exit(1);
}
/* Unamp the memory. */
if (munmap (buf2, ps2) < 0)
{
perror ("munmap failed");
exit(1);
}
/* Close the file. */
if (close (fd) < 0)
{
perror ("close failed");
exit(1);
}
/* Reopen the file. */
if ((fd = open("conftestmmap", O_RDWR, 0666)) < 0)
{
perror ("open 2 failed");
exit(1);
}
/* Recompare all 3 pages. */
/* ... map the file onto buf2. */
if((buf2=mmap(NULL, ps3, PROT_READ, MAP_PRIVATE, fd, 0)) == NULL)
{
perror ("mmap 1 failed");
exit (1);
}
/* ... compare buf1 and buf2. */
for (j = 0; j < ps3; ++j)
if (*(buf1 + j) != *(buf2 + j))
{
fprintf (stderr, "read/mmap/unmap/append/mmap comparison failed");
exit(1);
}
/* Now read it. */
if (read(fd, buf3, ps3) != ps3)
{
perror ("read 1 failed");
exit(1);
}
/* And compare again. */
for (j = 0; j < ps3; ++j)
if (*(buf1 + j) != *(buf3 + j))
{
fprintf (stderr, "read/mmap/unmap/append/read comparison failed");
exit(1);
}
exit(0);
}
], ac_cv_func_mmap=yes, ac_cv_func_mmap=no, ac_cv_func_mmap=no)])
if test $ac_cv_func_mmap = yes; then
AC_DEFINE(HAVE_MMAP)
fi
])
|
