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/* $Id$ */
/***
This file is part of PulseAudio.
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
PulseAudio is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with PulseAudio; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <sys/stat.h>
#include <pulsecore/core-error.h>
#include <pulsecore/log.h>
#include <pulsecore/random.h>
#include <pulse/xmalloc.h>
#include "shm.h"
#if defined(__linux__) && !defined(MADV_REMOVE)
#define MADV_REMOVE 9
#endif
#define MAX_SHM_SIZE (1024*1024*20)
static char *segment_name(char *fn, size_t l, unsigned id) {
snprintf(fn, l, "/pulse-shm-%u", id);
return fn;
}
int pa_shm_create_rw(pa_shm *m, size_t size, int shared, mode_t mode) {
char fn[32];
int fd = -1;
assert(m);
assert(size > 0);
assert(size < MAX_SHM_SIZE);
assert(mode >= 0600);
if (!shared) {
m->id = 0;
m->size = size;
#ifdef MAP_ANONYMOUS
if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
pa_log("mmap() failed: %s", pa_cstrerror(errno));
goto fail;
}
#elif defined(HAVE_POSIX_MEMALIGN)
{
int r;
if ((r = posix_memalign(&m->ptr, sysconf(_SC_PAGESIZE), size)) < 0) {
pa_log("posix_memalign() failed: %s", pa_cstrerror(r));
goto fail;
}
}
#else
m->ptr = pa_xmalloc(m->size);
#endif
m->do_unlink = 0;
} else {
pa_random(&m->id, sizeof(m->id));
segment_name(fn, sizeof(fn), m->id);
if ((fd = shm_open(fn, O_RDWR|O_CREAT|O_EXCL, mode & 0444)) < 0) {
pa_log("shm_open() failed: %s", pa_cstrerror(errno));
goto fail;
}
if (ftruncate(fd, m->size = size) < 0) {
pa_log("ftruncate() failed: %s", pa_cstrerror(errno));
goto fail;
}
if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
pa_log("mmap() failed: %s", pa_cstrerror(errno));
goto fail;
}
close(fd);
m->do_unlink = 1;
}
m->shared = shared;
return 0;
fail:
if (fd >= 0) {
shm_unlink(fn);
close(fd);
}
return -1;
}
void pa_shm_free(pa_shm *m) {
char fn[32];
assert(m);
assert(m->ptr && m->ptr != MAP_FAILED);
assert(m->size > 0);
#if !defined(MAP_ANONYMOUS) && defined(HAVE_POSIX_MEMALIGN)
if (!m->shared)
free(m->ptr);
else
#elif !defined(MAP_ANONYMOUS)
if (!m->shared)
pa_xfree(m->ptr);
else
#endif
if (munmap(m->ptr, m->size) < 0)
pa_log("munmap() failed: %s", pa_cstrerror(errno));
if (m->do_unlink) {
segment_name(fn, sizeof(fn), m->id);
if (shm_unlink(fn) < 0)
pa_log(__FILE__":shm_unlink(%s) failed: %s", fn, pa_cstrerror(errno));
}
memset(m, 0, sizeof(*m));
}
void pa_shm_punch(pa_shm *m, size_t offset, size_t size) {
void *ptr;
assert(m);
assert(m->ptr && m->ptr != MAP_FAILED);
assert(m->size > 0);
assert(offset < m->size);
assert(offset+size < m->size);
/* You're welcome to implement this as NOOP on systems that don't
* support it */
ptr = (uint8_t*) m->ptr + offset;
#ifdef __linux__
{
/* On Linux ptr must be page aligned */
long psz = sysconf(_SC_PAGESIZE);
unsigned o;
o = ((unsigned long) ptr) - ((((unsigned long) ptr)/psz) * psz);
if (o > 0) {
ptr = (uint8_t*) ptr + (psz - o);
size -= psz - o;
}
}
#endif
#ifdef MADV_REMOVE
if (madvise(ptr, size, MADV_REMOVE) >= 0)
return;
#endif
#ifdef MADV_FREE
if (madvise(ptr, size, MADV_FREE) >= 0)
return;
#endif
#ifdef MADV_DONTNEED
madvise(ptr, size, MADV_DONTNEED);
#endif
}
int pa_shm_attach_ro(pa_shm *m, unsigned id) {
char fn[32];
int fd = -1;
struct stat st;
assert(m);
segment_name(fn, sizeof(fn), m->id = id);
if ((fd = shm_open(fn, O_RDONLY, 0)) < 0) {
pa_log("shm_open() failed: %s", pa_cstrerror(errno));
goto fail;
}
if (fstat(fd, &st) < 0) {
pa_log("fstat() failed: %s", pa_cstrerror(errno));
goto fail;
}
if (st.st_size <= 0 || st.st_size > MAX_SHM_SIZE) {
pa_log("Invalid shared memory segment size");
goto fail;
}
m->size = st.st_size;
if ((m->ptr = mmap(NULL, m->size, PROT_READ, MAP_SHARED, fd, 0)) == MAP_FAILED) {
pa_log("mmap() failed: %s", pa_cstrerror(errno));
goto fail;
}
m->do_unlink = 0;
m->shared = 1;
close(fd);
return 0;
fail:
if (fd >= 0)
close(fd);
return -1;
}
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