The patch below adds:
- acinclude.m4: A new macro A_FUNC_SMMAP to check that sharing pages
through mmap() works. This is taken from Joerg Schilling's star.
- configure.in: A_FUNC_SMMAP
- ogg123/buffer.c: If we have a working mmap(), use it to create
a region of shared memory instead of using System V IPC.
Works on BSD. Should also work on SVR4 and offspring (Solaris),
and Linux.
--- acinclude.m4.orig Wed Feb 28 03:36:50 2001
+++ acinclude.m4 Sat Mar 17 17:39:58 2001
@@ -300,3 +300,65 @@
AC_SUBST(AO_LIBS)
rm -f conf.aotest
])
+
+dnl Shamelessly stolen from Joerg Schilling's star.
+dnl Copyright 1998 J. Schilling
+
+dnl Checks if mmap() works to get shared memory
+dnl Defines HAVE_SMMAP on success.
+AC_DEFUN(AC_FUNC_SMMAP,
+[AC_CACHE_CHECK([if mmap works to get shared memory], ac_cv_func_smmap,
+ [AC_TRY_RUN([
+#include <sys/types.h>
+#include <sys/mman.h>
+
+char *
+mkshare()
+{
+ int size = 8192;
+ int f;
+ char *addr;
+
+ if ((f = open("/dev/zero", 2)) < 0)
+ exit(1);
+ addr = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, f, 0);
+ if (addr == (char *)-1)
+ exit(1);
+ close(f);
+
+ return (addr);
+}
+
+main()
+{
+ char *addr;
+
+ addr = mkshare(8192);
+ *addr = 'I';
+
+ switch (fork()) {
+
+ case -1:
+ printf("help\n"); exit(1);
+
+ case 0: /* child */
+ *addr = 'N';
+ _exit(0);
+ break;
+ default: /* parent */
+ wait(0);
+ sleep(1);
+ break;
+ }
+
+ if (*addr != 'N')
+ exit(1);
+ exit(0);
+}
+],
+ [ac_cv_func_smmap=yes],
+ [ac_cv_func_smmap=no],
+ [ac_cv_func_smmap=no])])
+if test $ac_cv_func_smmap = yes; then
+ AC_DEFINE(HAVE_SMMAP)
+fi])
--- configure.in.orig Mon Feb 26 06:56:46 2001
+++ configure.in Sat Mar 17 17:39:45 2001
@@ -67,7 +67,7 @@
dnl Check for library functions
dnl --------------------------------------------------
-dnl none
+AC_FUNC_SMMAP
dnl --------------------------------------------------
dnl Work around FHS stupidity
--- ogg123/buffer.c.old Sat Mar 17 15:37:07 2001
+++ ogg123/buffer.c Sat Mar 17 17:40:16 2001
@@ -6,16 +6,16 @@
*/
#include <sys/types.h>
+#if HAVE_SMMAP
+#include <sys/mman.h>
+#else
#include <sys/ipc.h>
#include <sys/shm.h>
+#endif
#include <sys/time.h>
#include <unistd.h> /* for fork and pipe*/
#include <fcntl.h>
-#ifndef DARWIN
-#include <malloc.h>
-#endif
-
#include "ogg123.h"
#include "buffer.h"
@@ -72,6 +72,22 @@
int childpid;
buf_t *buf;
+#if HAVE_SMMAP
+ int fd;
+
+ if ((fd = open("/dev/zero", O_RDWR)) < 0)
+ {
+ perror ("cannot open /dev/zero");
+ exit (1);
+ }
+ if ((buf = (buf_t *) mmap (0, sizeof(buf_t) + sizeof (chunk_t) * (size - 1),
+ PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) < 0)
+ {
+ perror("mmap");
+ exit(1);
+ }
+ close(fd);
+#else
/* Get the shared memory segment. */
int shmid = shmget (IPC_PRIVATE,
sizeof(buf_t) + sizeof (chunk_t) * (size - 1),
@@ -94,6 +110,7 @@
/* Remove segment after last process detaches it or terminates. */
shmctl(shmid, IPC_RMID, 0);
+#endif /* HAVE_SMMAP */
buffer_init (buf, size);
--
Christian "naddy" Weisgerber
naddy@mips.inka.de
--- >8 ----
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