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|
/*
+----------------------------------------------------------------------+
| Zend OPcache |
+----------------------------------------------------------------------+
| Copyright (c) The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| https://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Andi Gutmans <andi@php.net> |
| Zeev Suraski <zeev@php.net> |
| Stanislav Malyshev <stas@zend.com> |
| Dmitry Stogov <dmitry@php.net> |
+----------------------------------------------------------------------+
*/
#include "zend_shared_alloc.h"
#ifdef USE_SHM
#if defined(__FreeBSD__)
# include <machine/param.h>
#endif
#include <sys/types.h>
#include <sys/shm.h>
#include <sys/ipc.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifndef MIN
# define MIN(x, y) ((x) > (y)? (y) : (x))
#endif
#define SEG_ALLOC_SIZE_MAX 32*1024*1024
#define SEG_ALLOC_SIZE_MIN 2*1024*1024
typedef struct {
zend_shared_segment common;
int shm_id;
} zend_shared_segment_shm;
static int create_segments(size_t requested_size, zend_shared_segment_shm ***shared_segments_p, int *shared_segments_count, const char **error_in)
{
int i;
size_t allocate_size = 0, remaining_bytes = requested_size, seg_allocate_size;
int first_segment_id = -1;
key_t first_segment_key = -1;
struct shmid_ds sds;
int shmget_flags;
zend_shared_segment_shm *shared_segments;
seg_allocate_size = SEG_ALLOC_SIZE_MAX;
/* determine segment size we _really_ need:
* no more than to include requested_size
*/
while (requested_size * 2 <= seg_allocate_size && seg_allocate_size > SEG_ALLOC_SIZE_MIN) {
seg_allocate_size >>= 1;
}
shmget_flags = IPC_CREAT|SHM_R|SHM_W|IPC_EXCL;
/* try allocating this much, if not - try shrinking */
while (seg_allocate_size >= SEG_ALLOC_SIZE_MIN) {
allocate_size = MIN(requested_size, seg_allocate_size);
first_segment_id = shmget(first_segment_key, allocate_size, shmget_flags);
if (first_segment_id != -1) {
break;
}
seg_allocate_size >>= 1; /* shrink the allocated block */
}
if (first_segment_id == -1) {
*error_in = "shmget";
return ALLOC_FAILURE;
}
*shared_segments_count = ((requested_size - 1) / seg_allocate_size) + 1;
*shared_segments_p = (zend_shared_segment_shm **) calloc(1, (*shared_segments_count) * sizeof(zend_shared_segment_shm) + sizeof(void *) * (*shared_segments_count));
if (!*shared_segments_p) {
*error_in = "calloc";
return ALLOC_FAILURE;
}
shared_segments = (zend_shared_segment_shm *)((char *)(*shared_segments_p) + sizeof(void *) * (*shared_segments_count));
for (i = 0; i < *shared_segments_count; i++) {
(*shared_segments_p)[i] = shared_segments + i;
}
remaining_bytes = requested_size;
for (i = 0; i < *shared_segments_count; i++) {
allocate_size = MIN(remaining_bytes, seg_allocate_size);
if (i != 0) {
shared_segments[i].shm_id = shmget(IPC_PRIVATE, allocate_size, shmget_flags);
} else {
shared_segments[i].shm_id = first_segment_id;
}
if (shared_segments[i].shm_id == -1) {
return ALLOC_FAILURE;
}
shared_segments[i].common.p = shmat(shared_segments[i].shm_id, NULL, 0);
if (shared_segments[i].common.p == (void *)-1) {
*error_in = "shmat";
shmctl(shared_segments[i].shm_id, IPC_RMID, &sds);
return ALLOC_FAILURE;
}
shmctl(shared_segments[i].shm_id, IPC_RMID, &sds);
shared_segments[i].common.pos = 0;
shared_segments[i].common.size = allocate_size;
remaining_bytes -= allocate_size;
}
return ALLOC_SUCCESS;
}
static int detach_segment(zend_shared_segment_shm *shared_segment)
{
shmdt(shared_segment->common.p);
return 0;
}
static size_t segment_type_size(void)
{
return sizeof(zend_shared_segment_shm);
}
const zend_shared_memory_handlers zend_alloc_shm_handlers = {
(create_segments_t)create_segments,
(detach_segment_t)detach_segment,
segment_type_size
};
#endif /* USE_SHM */
|
