0fe13749d0
This creates a mapping with twice the size of the allocated memory. The second half of that mapping points at the same memory as the first half. This is useful for ring buffers, because any read starting in the first half can overflow into the second half as long as the read size is smaller than the size of the memory area. Signed-off-by: Felix Fietkau <nbd@nbd.name>
151 lines
3.5 KiB
C
151 lines
3.5 KiB
C
/*
|
|
* utils - misc libubox utility functions
|
|
*
|
|
* Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include <sys/mman.h>
|
|
#include <stdarg.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include "utils.h"
|
|
|
|
#define foreach_arg(_arg, _addr, _len, _first_addr, _first_len) \
|
|
for (_addr = (_first_addr), _len = (_first_len); \
|
|
_addr; \
|
|
_addr = va_arg(_arg, void **), _len = _addr ? va_arg(_arg, size_t) : 0)
|
|
|
|
void *__calloc_a(size_t len, ...)
|
|
{
|
|
va_list ap, ap1;
|
|
void *ret;
|
|
void **cur_addr;
|
|
size_t cur_len;
|
|
int alloc_len = 0;
|
|
char *ptr;
|
|
|
|
va_start(ap, len);
|
|
|
|
va_copy(ap1, ap);
|
|
foreach_arg(ap1, cur_addr, cur_len, &ret, len)
|
|
alloc_len += cur_len;
|
|
va_end(ap1);
|
|
|
|
ptr = calloc(1, alloc_len);
|
|
if (!ptr)
|
|
return NULL;
|
|
alloc_len = 0;
|
|
foreach_arg(ap, cur_addr, cur_len, &ret, len) {
|
|
*cur_addr = &ptr[alloc_len];
|
|
alloc_len += cur_len;
|
|
}
|
|
va_end(ap);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __APPLE__
|
|
#include <mach/mach_host.h> /* host_get_clock_service() */
|
|
#include <mach/mach_port.h> /* mach_port_deallocate() */
|
|
#include <mach/mach_init.h> /* mach_host_self(), mach_task_self() */
|
|
#include <mach/clock.h> /* clock_get_time() */
|
|
|
|
static clock_serv_t clock_realtime;
|
|
static clock_serv_t clock_monotonic;
|
|
|
|
static void __constructor clock_name_init(void)
|
|
{
|
|
mach_port_t host_self = mach_host_self();
|
|
|
|
host_get_clock_service(host_self, CLOCK_REALTIME, &clock_realtime);
|
|
host_get_clock_service(host_self, CLOCK_MONOTONIC, &clock_monotonic);
|
|
}
|
|
|
|
static void __destructor clock_name_dealloc(void)
|
|
{
|
|
mach_port_t self = mach_task_self();
|
|
|
|
mach_port_deallocate(self, clock_realtime);
|
|
mach_port_deallocate(self, clock_monotonic);
|
|
}
|
|
|
|
int clock_gettime(int type, struct timespec *tv)
|
|
{
|
|
int retval = -1;
|
|
mach_timespec_t mts;
|
|
|
|
switch (type) {
|
|
case CLOCK_REALTIME:
|
|
retval = clock_get_time(clock_realtime, &mts);
|
|
break;
|
|
case CLOCK_MONOTONIC:
|
|
retval = clock_get_time(clock_monotonic, &mts);
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
tv->tv_sec = mts.tv_sec;
|
|
tv->tv_nsec = mts.tv_nsec;
|
|
out:
|
|
return retval;
|
|
}
|
|
|
|
#endif
|
|
|
|
void *cbuf_alloc(unsigned int order)
|
|
{
|
|
char path[] = "/tmp/cbuf-XXXXXX";
|
|
unsigned long size = cbuf_size(order);
|
|
void *ret = NULL;
|
|
int fd;
|
|
|
|
fd = mkstemp(path);
|
|
if (fd < 0)
|
|
return NULL;
|
|
|
|
if (unlink(path))
|
|
goto close;
|
|
|
|
if (ftruncate(fd, cbuf_size(order)))
|
|
goto close;
|
|
|
|
#ifndef MAP_ANONYMOUS
|
|
#define MAP_ANONYMOUS MAP_ANON
|
|
#endif
|
|
|
|
ret = mmap(NULL, size * 2, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0);
|
|
if (ret == MAP_FAILED) {
|
|
ret = NULL;
|
|
goto close;
|
|
}
|
|
|
|
if (mmap(ret, size, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED,
|
|
fd, 0) != ret ||
|
|
mmap(ret + size, size, PROT_READ | PROT_WRITE,
|
|
MAP_FIXED | MAP_SHARED, fd, 0) != ret + size) {
|
|
munmap(ret, size * 2);
|
|
ret = NULL;
|
|
}
|
|
|
|
close:
|
|
close(fd);
|
|
return ret;
|
|
}
|
|
|
|
void cbuf_free(void *ptr, unsigned int order)
|
|
{
|
|
munmap(ptr, cbuf_size(order) * 2);
|
|
}
|