malloc_decls.h - mozsearch

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// Helper header to declare all the supported malloc functions.

// MALLOC_DECL arguments are:

//   - function name

//   - return type

//   - argument types

#ifndef malloc_decls_h

#  define malloc_decls_h

#  include "mozjemalloc_types.h"

#  define MALLOC_FUNCS_MALLOC_BASE 1

#  define MALLOC_FUNCS_MALLOC_EXTRA 2

#  define MALLOC_FUNCS_MALLOC \

    (MALLOC_FUNCS_MALLOC_BASE | MALLOC_FUNCS_MALLOC_EXTRA)

#  define MALLOC_FUNCS_JEMALLOC 4

#  define MALLOC_FUNCS_ARENA_BASE 8

#  define MALLOC_FUNCS_ARENA_ALLOC 16

#  define MALLOC_FUNCS_ARENA \

    (MALLOC_FUNCS_ARENA_BASE | MALLOC_FUNCS_ARENA_ALLOC)

#  define MALLOC_FUNCS_ALL \

    (MALLOC_FUNCS_MALLOC | MALLOC_FUNCS_JEMALLOC | MALLOC_FUNCS_ARENA)

#endif  // malloc_decls_h

#ifndef MALLOC_FUNCS

#  define MALLOC_FUNCS MALLOC_FUNCS_ALL

#endif

#ifdef MALLOC_DECL

// NOTHROW_MALLOC_DECL is intended for functions where the standard library

// declares the functions in question as `throw()`.  Not all platforms

// consistent declare certain functions as `throw()`, though.

// Bionic and OS X don't seem to care about `throw()`ness.

#  if defined(ANDROID) || defined(XP_DARWIN)

#    undef NOTHROW_MALLOC_DECL

#    define NOTHROW_MALLOC_DECL MALLOC_DECL

// Some places don't care about the distinction.

#  elif !defined(NOTHROW_MALLOC_DECL)

#    define NOTHROW_MALLOC_DECL MALLOC_DECL

#  endif

#  if MALLOC_FUNCS & MALLOC_FUNCS_MALLOC_BASE

MALLOC_DECL(malloc, void*, size_t)

MALLOC_DECL(calloc, void*, size_t, size_t)

MALLOC_DECL(realloc, void*, void*, size_t)

NOTHROW_MALLOC_DECL(free, void, void*)

NOTHROW_MALLOC_DECL(memalign, void*, size_t, size_t)

#  endif

#  if MALLOC_FUNCS & MALLOC_FUNCS_MALLOC_EXTRA

NOTHROW_MALLOC_DECL(posix_memalign, int, void**, size_t, size_t)

NOTHROW_MALLOC_DECL(aligned_alloc, void*, size_t, size_t)

NOTHROW_MALLOC_DECL(valloc, void*, size_t)

NOTHROW_MALLOC_DECL(malloc_usable_size, size_t, usable_ptr_t)

MALLOC_DECL(malloc_good_size, size_t, size_t)

#  endif

#  if MALLOC_FUNCS & MALLOC_FUNCS_JEMALLOC

// The 2nd argument points to an optional array exactly

// jemalloc_stats_num_bins() long to be filled in (if non-null).

// This must only be called on the main thread.

MALLOC_DECL(jemalloc_stats_internal, void, jemalloc_stats_t*,

            jemalloc_bin_stats_t*)

// Return the size of the jemalloc_bin_stats_t array.

MALLOC_DECL(jemalloc_stats_num_bins, size_t)

// Tell jemalloc this is the main thread. jemalloc will use this to validate

// that main thread only arenas are only used on the main thread.

MALLOC_DECL(jemalloc_set_main_thread, void)

// On some operating systems (Mac), we use madvise(MADV_FREE) to hand pages

// back to the operating system.  On Mac, the operating system doesn't take

// this memory back immediately; instead, the OS takes it back only when the

// machine is running out of physical memory.

//

// This is great from the standpoint of efficiency, but it makes measuring our

// actual RSS difficult, because pages which we've MADV_FREE'd shouldn't count

// against our RSS.

//

// This function explicitly purges any MADV_FREE'd pages from physical memory,

// causing our reported RSS match the amount of memory we're actually using.

//

// Note that this call is expensive in two ways.  First, it may be slow to

// execute, because it may make a number of slow syscalls to free memory.  This

// function holds the big jemalloc locks, so basically all threads are blocked

// while this function runs.

//

// This function is also expensive in that the next time we go to access a page

// which we've just explicitly decommitted, the operating system has to attach

// to it a physical page!  If we hadn't run this function, the OS would have

// less work to do.

//

// If MALLOC_DOUBLE_PURGE is not defined, this function does nothing.

//

// It may only be used from the main thread.

MALLOC_DECL(jemalloc_purge_freed_pages, void)

// Free all unused dirty pages in all arenas. Calling this function will slow

// down subsequent allocations so it is recommended to use it only when

// memory needs to be reclaimed at all costs (see bug 805855). This function

// provides functionality similar to mallctl("arenas.purge") in jemalloc 3.

// It may only be used from the main thread.

MALLOC_DECL(jemalloc_free_dirty_pages, void)

// Free dirty pages until the max dirty pages threshold is satisfied. Useful

// after lowering the max dirty pages threshold to get RSS back to normal.

MALLOC_DECL(jemalloc_free_excess_dirty_pages, void)

// Change the value of opt_randomize_small to control small allocation

// randomization and maybe perform a reinitialization of the arena's PRNG.

MALLOC_DECL(jemalloc_reset_small_alloc_randomization, void, bool)

// Opt in or out of a thread local arena (bool argument is whether to opt-in

// (true) or out (false)).

MALLOC_DECL(jemalloc_thread_local_arena, void, bool)

// Provide information about any allocation enclosing the given address.

MALLOC_DECL(jemalloc_ptr_info, void, const void*, jemalloc_ptr_info_t*)

#  endif

#  if MALLOC_FUNCS & MALLOC_FUNCS_ARENA_BASE

// Creates a separate arena, and returns its id, valid to use with moz_arena_*

// functions. A helper is provided in mozmemory.h that doesn't take any

// arena_params_t: moz_create_arena.

MALLOC_DECL(moz_create_arena_with_params, arena_id_t, arena_params_t*)

// Dispose of the given arena. Subsequent uses of the arena will crash.

// Passing an invalid id (inexistent or already disposed) to this function

// will crash. The arena must be empty prior to calling this function.

MALLOC_DECL(moz_dispose_arena, void, arena_id_t)

// Set the default modifier for mMaxDirty. The value is the number of shifts

// applied to the value. Positive value is handled as <<, negative >>.

// Arenas may override the default modifier.

MALLOC_DECL(moz_set_max_dirty_page_modifier, void, int32_t)

#  endif

#  if MALLOC_FUNCS & MALLOC_FUNCS_ARENA_ALLOC

// Same as the functions without the moz_arena_ prefix, but using arenas

// created with moz_create_arena.

// The contract, even if not enforced at runtime in some configurations,

// is that moz_arena_realloc and moz_arena_free will crash if the given

// arena doesn't own the given pointer. All functions will crash if the

// arena id is invalid.

// Although discouraged, plain realloc and free can still be used on

// pointers allocated with these functions. Realloc will properly keep

// new pointers in the same arena as the original.

MALLOC_DECL(moz_arena_malloc, void*, arena_id_t, size_t)

MALLOC_DECL(moz_arena_calloc, void*, arena_id_t, size_t, size_t)

MALLOC_DECL(moz_arena_realloc, void*, arena_id_t, void*, size_t)

MALLOC_DECL(moz_arena_free, void, arena_id_t, void*)

MALLOC_DECL(moz_arena_memalign, void*, arena_id_t, size_t, size_t)

#  endif

#endif  // MALLOC_DECL

#undef NOTHROW_MALLOC_DECL

#undef MALLOC_DECL

#undef MALLOC_FUNCS