/src/php-src/ext/opcache/zend_shared_alloc.h

Source
/*
   +----------------------------------------------------------------------+
   | Zend OPcache                                                         |
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@php.net>                                 |
   |          Zeev Suraski <zeev@php.net>                                 |
   |          Stanislav Malyshev <stas@zend.com>                          |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/

#ifndef ZEND_SHARED_ALLOC_H
#define ZEND_SHARED_ALLOC_H

#include "zend.h"
#include "ZendAccelerator.h"

#if defined(__APPLE__) && defined(__MACH__) /* darwin */
# ifdef HAVE_SHM_MMAP_POSIX
#  define USE_SHM_OPEN  1
# endif
# ifdef HAVE_SHM_MMAP_ANON
#  define USE_MMAP      1
# endif
#elif defined(__linux__) || defined(_AIX)
# ifdef HAVE_SHM_MMAP_POSIX
#  define USE_SHM_OPEN  1
# endif
# ifdef HAVE_SHM_IPC
#  define USE_SHM       1
# endif
# ifdef HAVE_SHM_MMAP_ANON
#  define USE_MMAP      1
# endif
#elif defined(__sparc) || defined(__sun)
# ifdef HAVE_SHM_MMAP_POSIX
#  define USE_SHM_OPEN  1
# endif
# ifdef HAVE_SHM_IPC
#  define USE_SHM       1
# endif
# if defined(__i386)
#  ifdef HAVE_SHM_MMAP_ANON
#   define USE_MMAP     1
#  endif
# endif
#else
# ifdef HAVE_SHM_MMAP_POSIX
#  define USE_SHM_OPEN  1
# endif
# ifdef HAVE_SHM_MMAP_ANON
#  define USE_MMAP      1
# endif
# ifdef HAVE_SHM_IPC
#  define USE_SHM       1
# endif
#endif

#define ALLOC_FAILURE           0
#define ALLOC_SUCCESS           1
#define FAILED_REATTACHED       2
#define SUCCESSFULLY_REATTACHED 4
#define ALLOC_FAIL_MAPPING      8
#define ALLOC_FALLBACK          9
#define NO_SHM_BACKEND          10

typedef struct _zend_shared_segment {
    size_t  size;
    size_t  end;
    size_t  pos;  /* position for simple stack allocator */
    void   *p;
} zend_shared_segment;

typedef int (*create_segments_t)(size_t requested_size, zend_shared_segment ***shared_segments, int *shared_segment_count, const char **error_in);
typedef int (*detach_segment_t)(zend_shared_segment *shared_segment);

typedef struct {
  create_segments_t create_segments;
  detach_segment_t detach_segment;
  size_t (*segment_type_size)(void);
} zend_shared_memory_handlers;

typedef struct _handler_entry {
  const char                  *name;
  const zend_shared_memory_handlers *handler;
} zend_shared_memory_handler_entry;

typedef struct _zend_shared_memory_state {
  size_t *positions;  /* current positions for each segment */
  size_t shared_free; /* amount of free shared memory */
} zend_shared_memory_state;

typedef struct _zend_smm_shared_globals {
    /* Shared Memory Manager */
    zend_shared_segment      **shared_segments;
    /* Number of allocated shared segments */
    int                        shared_segments_count;
    /* Amount of free shared memory */
    size_t                     shared_free;
    /* Amount of shared memory allocated by garbage */
    size_t                     wasted_shared_memory;
    /* No more shared memory flag */
    bool                  memory_exhausted;
    /* Saved Shared Allocator State */
    zend_shared_memory_state   shared_memory_state;
  /* Pointer to the application's shared data structures */
  void                      *app_shared_globals;
  /* Reserved shared memory */
  void                      *reserved;
  size_t                     reserved_size;
} zend_smm_shared_globals;

ZEND_EXT_API extern zend_smm_shared_globals *smm_shared_globals;

#define ZSMMG(element)    (smm_shared_globals->element)

#define SHARED_ALLOC_REATTACHED   (SUCCESS+1)

BEGIN_EXTERN_C()

int zend_shared_alloc_startup(size_t requested_size, size_t reserved_size);
void zend_shared_alloc_shutdown(void);

/* allocate shared memory block */
void *zend_shared_alloc(size_t size);

/**
 * Wrapper for zend_shared_alloc() which aligns at 64-byte boundary if
 * AVX or SSE2 are used.
 */
static inline void *zend_shared_alloc_aligned(size_t size) {
#if defined(__AVX__) || defined(__SSE2__)
  /* Align to 64-byte boundary */
  void *p = zend_shared_alloc(size + 64);
  return (void *)(((uintptr_t)p + 63L) & ~63L);
#else
  return zend_shared_alloc(size);
#endif
}

/* copy into shared memory */
void *zend_shared_memdup_get_put_free(void *source, size_t size);
void *zend_shared_memdup_put_free(void *source, size_t size);
void *zend_shared_memdup_free(void *source, size_t size);
void *zend_shared_memdup_get_put(void *source, size_t size);
void *zend_shared_memdup_put(void *source, size_t size);
void *zend_shared_memdup(void *source, size_t size);

int  zend_shared_memdup_size(void *p, size_t size);

bool zend_accel_in_shm(void *ptr);

typedef union _align_test {
  void   *ptr;
  double  dbl;
  zend_long  lng;
} align_test;

#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
# define PLATFORM_ALIGNMENT (alignof(align_test) < 8 ? 8 : alignof(align_test))
#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
# define PLATFORM_ALIGNMENT (_Alignof(align_test) < 8 ? 8 : _Alignof(align_test))
#elif ZEND_GCC_VERSION >= 2000 || defined(__clang__)
# define PLATFORM_ALIGNMENT (__alignof__(align_test) < 8 ? 8 : __alignof__(align_test))
#else
# define PLATFORM_ALIGNMENT (sizeof(align_test))
#endif

#define ZEND_ALIGNED_SIZE(size) \
  ZEND_MM_ALIGNED_SIZE_EX(size, PLATFORM_ALIGNMENT)

/* exclusive locking */
void zend_shared_alloc_lock(void);
void zend_shared_alloc_unlock(void); /* returns the allocated size during lock..unlock */
void zend_shared_alloc_safe_unlock(void);

/* old/new mapping functions */
void zend_shared_alloc_init_xlat_table(void);
void zend_shared_alloc_destroy_xlat_table(void);
void zend_shared_alloc_clear_xlat_table(void);
uint32_t zend_shared_alloc_checkpoint_xlat_table(void);
void zend_shared_alloc_restore_xlat_table(uint32_t checkpoint);
void zend_shared_alloc_register_xlat_entry(const void *key, const void *value);
void *zend_shared_alloc_get_xlat_entry(const void *key);

size_t zend_shared_alloc_get_free_memory(void);
void zend_shared_alloc_save_state(void);
void zend_shared_alloc_restore_state(void);
const char *zend_accel_get_shared_model(void);

/**
 * Memory write protection
 *
 * @param protected true to protect shared memory (read-only), false
 * to unprotect shared memory (writable)
 */
void zend_accel_shared_protect(bool protected);

#ifdef USE_MMAP
extern const zend_shared_memory_handlers zend_alloc_mmap_handlers;
#endif

#ifdef USE_SHM
extern const zend_shared_memory_handlers zend_alloc_shm_handlers;
#endif

#ifdef USE_SHM_OPEN
extern const zend_shared_memory_handlers zend_alloc_posix_handlers;
#endif

#ifdef ZEND_WIN32
extern const zend_shared_memory_handlers zend_alloc_win32_handlers;
void zend_shared_alloc_create_lock(void);
void zend_shared_alloc_lock_win32(void);
void zend_shared_alloc_unlock_win32(void);
#endif

END_EXTERN_C()

#endif /* ZEND_SHARED_ALLOC_H */

Coverage Report

Created: 2026-06-02 06:39