mem.h revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
* Copyright (C) 1997-2001, 2004-2013, 2015, 2016 Internet Systems Consortium, Inc. ("ISC")
*
* 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/.
*/
#ifndef ISC_MEM_H
#define ISC_MEM_H 1
/*! \file isc/mem.h */
#include <stdio.h>
#include <isc/json.h>
#include <isc/lang.h>
#include <isc/mutex.h>
#include <isc/platform.h>
#include <isc/types.h>
#include <isc/xml.h>
ISC_LANG_BEGINDECLS
#define ISC_MEM_LOWATER 0
#define ISC_MEM_HIWATER 1
typedef void (*isc_mem_water_t)(void *, int);
typedef void * (*isc_memalloc_t)(void *, size_t);
typedef void (*isc_memfree_t)(void *, void *);
/*%
* Define ISC_MEM_TRACKLINES=1 to turn on detailed tracing of memory
* allocation and freeing by file and line number.
*/
#ifndef ISC_MEM_TRACKLINES
#define ISC_MEM_TRACKLINES 1
#endif
/*%
* Define ISC_MEM_CHECKOVERRUN=1 to turn on checks for using memory outside
* the requested space. This will increase the size of each allocation.
*
* If we are performing a Coverity static analysis then ISC_MEM_CHECKOVERRUN
* can hide bugs that would otherwise discovered so force to zero.
*/
#ifdef __COVERITY__
#undef ISC_MEM_CHECKOVERRUN
#define ISC_MEM_CHECKOVERRUN 0
#endif
#ifndef ISC_MEM_CHECKOVERRUN
#define ISC_MEM_CHECKOVERRUN 1
#endif
/*%
* Define ISC_MEM_FILL=1 to fill each block of memory returned to the system
* with the byte string '0xbe'. This helps track down uninitialized pointers
* and the like. On freeing memory, the space is filled with '0xde' for
* the same reasons.
*
* If we are performing a Coverity static analysis then ISC_MEM_FILL
* can hide bugs that would otherwise discovered so force to zero.
*/
#ifdef __COVERITY__
#undef ISC_MEM_FILL
#define ISC_MEM_FILL 0
#endif
#ifndef ISC_MEM_FILL
#define ISC_MEM_FILL 1
#endif
/*%
* Define ISC_MEMPOOL_NAMES=1 to make memory pools store a symbolic
* name so that the leaking pool can be more readily identified in
* case of a memory leak.
*/
#ifndef ISC_MEMPOOL_NAMES
#define ISC_MEMPOOL_NAMES 1
#endif
LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_debugging;
LIBISC_EXTERNAL_DATA extern unsigned int isc_mem_defaultflags;
/*@{*/
#define ISC_MEM_DEBUGTRACE 0x00000001U
#define ISC_MEM_DEBUGRECORD 0x00000002U
#define ISC_MEM_DEBUGUSAGE 0x00000004U
#define ISC_MEM_DEBUGSIZE 0x00000008U
#define ISC_MEM_DEBUGCTX 0x00000010U
#define ISC_MEM_DEBUGALL 0x0000001FU
/*!<
* The variable isc_mem_debugging holds a set of flags for
* turning certain memory debugging options on or off at
* runtime. It is initialized to the value ISC_MEM_DEGBUGGING,
* which is 0 by default but may be overridden at compile time.
* The following flags can be specified:
*
* \li #ISC_MEM_DEBUGTRACE
* Log each allocation and free to isc_lctx.
*
* \li #ISC_MEM_DEBUGRECORD
* Remember each allocation, and match them up on free.
* Crash if a free doesn't match an allocation.
*
* \li #ISC_MEM_DEBUGUSAGE
* If a hi_water mark is set, print the maximum inuse memory
* every time it is raised once it exceeds the hi_water mark.
*
* \li #ISC_MEM_DEBUGSIZE
* Check the size argument being passed to isc_mem_put() matches
* that passed to isc_mem_get().
*
* \li #ISC_MEM_DEBUGCTX
* Check the mctx argument being passed to isc_mem_put() matches
* that passed to isc_mem_get().
*/
/*@}*/
#if ISC_MEM_TRACKLINES
#define _ISC_MEM_FILELINE , __FILE__, __LINE__
#define _ISC_MEM_FLARG , const char *, unsigned int
#else
#define _ISC_MEM_FILELINE
#define _ISC_MEM_FLARG
#endif
/*!
* Define ISC_MEM_USE_INTERNAL_MALLOC=1 to use the internal malloc()
* implementation in preference to the system one. The internal malloc()
* is very space-efficient, and quite fast on uniprocessor systems. It
* performs poorly on multiprocessor machines.
* JT: we can overcome the performance issue on multiprocessor machines
* by carefully separating memory contexts.
*/
#ifndef ISC_MEM_USE_INTERNAL_MALLOC
#define ISC_MEM_USE_INTERNAL_MALLOC 1
#endif
/*
* Flags for isc_mem_create2()calls.
*/
#define ISC_MEMFLAG_NOLOCK 0x00000001 /* no lock is necessary */
#define ISC_MEMFLAG_INTERNAL 0x00000002 /* use internal malloc */
#if ISC_MEM_USE_INTERNAL_MALLOC
#define ISC_MEMFLAG_DEFAULT ISC_MEMFLAG_INTERNAL
#else
#define ISC_MEMFLAG_DEFAULT 0
#endif
/*%<
* We use either isc___mem (three underscores) or isc__mem (two) depending on
* whether it's for BIND9's internal purpose (with -DBIND9) or generic export
* library.
*/
#define ISCMEMFUNC(sfx) isc__mem_ ## sfx
#define ISCMEMPOOLFUNC(sfx) isc__mempool_ ## sfx
#define isc_mem_get(c, s) ISCMEMFUNC(get)((c), (s) _ISC_MEM_FILELINE)
#define isc_mem_allocate(c, s) ISCMEMFUNC(allocate)((c), (s) _ISC_MEM_FILELINE)
#define isc_mem_reallocate(c, p, s) ISCMEMFUNC(reallocate)((c), (p), (s) _ISC_MEM_FILELINE)
#define isc_mem_strdup(c, p) ISCMEMFUNC(strdup)((c), (p) _ISC_MEM_FILELINE)
#define isc_mempool_get(c) ISCMEMPOOLFUNC(get)((c) _ISC_MEM_FILELINE)
/*%
* isc_mem_putanddetach() is a convenience function for use where you
* have a structure with an attached memory context.
*
* Given:
*
* \code
* struct {
* ...
* isc_mem_t *mctx;
* ...
* } *ptr;
*
* isc_mem_t *mctx;
*
* isc_mem_putanddetach(&ptr->mctx, ptr, sizeof(*ptr));
* \endcode
*
* is the equivalent of:
*
* \code
* mctx = NULL;
* isc_mem_attach(ptr->mctx, &mctx);
* isc_mem_detach(&ptr->mctx);
* isc_mem_put(mctx, ptr, sizeof(*ptr));
* isc_mem_detach(&mctx);
* \endcode
*/
/*% memory and memory pool methods */
typedef struct isc_memmethods {
void (*attach)(isc_mem_t *source, isc_mem_t **targetp);
void (*detach)(isc_mem_t **mctxp);
void (*destroy)(isc_mem_t **mctxp);
void *(*memget)(isc_mem_t *mctx, size_t size _ISC_MEM_FLARG);
void (*memput)(isc_mem_t *mctx, void *ptr, size_t size _ISC_MEM_FLARG);
void (*memputanddetach)(isc_mem_t **mctxp, void *ptr,
size_t size _ISC_MEM_FLARG);
void *(*memallocate)(isc_mem_t *mctx, size_t size _ISC_MEM_FLARG);
void *(*memreallocate)(isc_mem_t *mctx, void *ptr,
size_t size _ISC_MEM_FLARG);
char *(*memstrdup)(isc_mem_t *mctx, const char *s _ISC_MEM_FLARG);
void (*memfree)(isc_mem_t *mctx, void *ptr _ISC_MEM_FLARG);
void (*setdestroycheck)(isc_mem_t *mctx, isc_boolean_t flag);
void (*setwater)(isc_mem_t *ctx, isc_mem_water_t water,
void *water_arg, size_t hiwater, size_t lowater);
void (*waterack)(isc_mem_t *ctx, int flag);
size_t (*inuse)(isc_mem_t *mctx);
size_t (*maxinuse)(isc_mem_t *mctx);
size_t (*total)(isc_mem_t *mctx);
isc_boolean_t (*isovermem)(isc_mem_t *mctx);
isc_result_t (*mpcreate)(isc_mem_t *mctx, size_t size,
isc_mempool_t **mpctxp);
} isc_memmethods_t;
typedef struct isc_mempoolmethods {
void (*destroy)(isc_mempool_t **mpctxp);
void *(*get)(isc_mempool_t *mpctx _ISC_MEM_FLARG);
void (*put)(isc_mempool_t *mpctx, void *mem _ISC_MEM_FLARG);
unsigned int (*getallocated)(isc_mempool_t *mpctx);
void (*setmaxalloc)(isc_mempool_t *mpctx, unsigned int limit);
void (*setfreemax)(isc_mempool_t *mpctx, unsigned int limit);
void (*setname)(isc_mempool_t *mpctx, const char *name);
void (*associatelock)(isc_mempool_t *mpctx, isc_mutex_t *lock);
void (*setfillcount)(isc_mempool_t *mpctx, unsigned int limit);
} isc_mempoolmethods_t;
/*%
* This structure is actually just the common prefix of a memory context
* implementation's version of an isc_mem_t.
* \brief
* Direct use of this structure by clients is forbidden. mctx implementations
* may change the structure. 'magic' must be ISCAPI_MCTX_MAGIC for any of the
* isc_mem_ routines to work. mctx implementations must maintain all mctx
* invariants.
*/
struct isc_mem {
unsigned int impmagic;
unsigned int magic;
isc_memmethods_t *methods;
};
#define ISCAPI_MCTX_MAGIC ISC_MAGIC('A','m','c','x')
#define ISCAPI_MCTX_VALID(m) ((m) != NULL && \
(m)->magic == ISCAPI_MCTX_MAGIC)
/*%
* This is the common prefix of a memory pool context. The same note as
* that for the mem structure applies.
*/
struct isc_mempool {
unsigned int impmagic;
unsigned int magic;
isc_mempoolmethods_t *methods;
};
#define ISCAPI_MPOOL_MAGIC ISC_MAGIC('A','m','p','l')
#define ISCAPI_MPOOL_VALID(mp) ((mp) != NULL && \
(mp)->magic == ISCAPI_MPOOL_MAGIC)
#define isc_mem_put(c, p, s) \
do { \
ISCMEMFUNC(put)((c), (p), (s) _ISC_MEM_FILELINE); \
(p) = NULL; \
} while (0)
#define isc_mem_putanddetach(c, p, s) \
do { \
ISCMEMFUNC(putanddetach)((c), (p), (s) _ISC_MEM_FILELINE); \
(p) = NULL; \
} while (0)
#define isc_mem_free(c, p) \
do { \
ISCMEMFUNC(free)((c), (p) _ISC_MEM_FILELINE); \
(p) = NULL; \
} while (0)
#define isc_mempool_put(c, p) \
do { \
ISCMEMPOOLFUNC(put)((c), (p) _ISC_MEM_FILELINE); \
(p) = NULL; \
} while (0)
/*@{*/
isc_result_t
isc_mem_create(size_t max_size, size_t target_size,
isc_mem_t **mctxp);
isc_result_t
isc_mem_create2(size_t max_size, size_t target_size,
isc_mem_t **mctxp, unsigned int flags);
isc_result_t
isc_mem_createx(size_t max_size, size_t target_size,
isc_memalloc_t memalloc, isc_memfree_t memfree,
void *arg, isc_mem_t **mctxp);
isc_result_t
isc_mem_createx2(size_t max_size, size_t target_size,
isc_memalloc_t memalloc, isc_memfree_t memfree,
void *arg, isc_mem_t **mctxp, unsigned int flags);
/*!<
* \brief Create a memory context.
*
* 'max_size' and 'target_size' are tuning parameters. When
* ISC_MEMFLAG_INTERNAL is set, allocations smaller than 'max_size'
* will be satisfied by getting blocks of size 'target_size' from the
* system allocator and breaking them up into pieces; larger allocations
* will use the system allocator directly. If 'max_size' and/or
* 'target_size' are zero, default values will be * used. When
* ISC_MEMFLAG_INTERNAL is not set, 'target_size' is ignored.
*
* 'max_size' is also used to size the statistics arrays and the array
* used to record active memory when ISC_MEM_DEBUGRECORD is set. Setting
* 'max_size' too low can have detrimental effects on performance.
*
* A memory context created using isc_mem_createx() will obtain
* memory from the system by calling 'memalloc' and 'memfree',
* passing them the argument 'arg'. A memory context created
* using isc_mem_create() will use the standard library malloc()
* and free().
*
* If ISC_MEMFLAG_NOLOCK is set in 'flags', the corresponding memory context
* will be accessed without locking. The user who creates the context must
* ensure there be no race. Since this can be a source of bug, it is generally
* inadvisable to use this flag unless the user is very sure about the race
* condition and the access to the object is highly performance sensitive.
*
* Requires:
* mctxp != NULL && *mctxp == NULL */
/*@}*/
/*@{*/
void
isc_mem_attach(isc_mem_t *, isc_mem_t **);
void
isc_mem_detach(isc_mem_t **);
/*!<
* \brief Attach to / detach from a memory context.
*
* This is intended for applications that use multiple memory contexts
* in such a way that it is not obvious when the last allocations from
* a given context has been freed and destroying the context is safe.
*
* Most applications do not need to call these functions as they can
* simply create a single memory context at the beginning of main()
* and destroy it at the end of main(), thereby guaranteeing that it
* is not destroyed while there are outstanding allocations.
*/
/*@}*/
void
isc_mem_destroy(isc_mem_t **);
/*%<
* Destroy a memory context.
*/
isc_result_t
isc_mem_ondestroy(isc_mem_t *ctx,
isc_task_t *task,
isc_event_t **event);
/*%<
* Request to be notified with an event when a memory context has
* been successfully destroyed.
*/
void
isc_mem_stats(isc_mem_t *mctx, FILE *out);
/*%<
* Print memory usage statistics for 'mctx' on the stream 'out'.
*/
void
isc_mem_setdestroycheck(isc_mem_t *mctx,
isc_boolean_t on);
/*%<
* If 'on' is ISC_TRUE, 'mctx' will check for memory leaks when
* destroyed and abort the program if any are present.
*/
/*@{*/
void
isc_mem_setquota(isc_mem_t *, size_t);
size_t
isc_mem_getquota(isc_mem_t *);
/*%<
* Set/get the memory quota of 'mctx'. This is a hard limit
* on the amount of memory that may be allocated from mctx;
* if it is exceeded, allocations will fail.
*/
/*@}*/
size_t
isc_mem_inuse(isc_mem_t *mctx);
/*%<
* Get an estimate of the amount of memory in use in 'mctx', in bytes.
* This includes quantization overhead, but does not include memory
* allocated from the system but not yet used.
*/
size_t
isc_mem_maxinuse(isc_mem_t *mctx);
/*%<
* Get an estimate of the largest amount of memory that has been in
* use in 'mctx' at any time.
*/
size_t
isc_mem_total(isc_mem_t *mctx);
/*%<
* Get the total amount of memory in 'mctx', in bytes, including memory
* not yet used.
*/
isc_boolean_t
isc_mem_isovermem(isc_mem_t *mctx);
/*%<
* Return true iff the memory context is in "over memory" state, i.e.,
* a hiwater mark has been set and the used amount of memory has exceeds
* the mark.
*/
void
isc_mem_setwater(isc_mem_t *mctx, isc_mem_water_t water, void *water_arg,
size_t hiwater, size_t lowater);
/*%<
* Set high and low water marks for this memory context.
*
* When the memory usage of 'mctx' exceeds 'hiwater',
* '(water)(water_arg, #ISC_MEM_HIWATER)' will be called. 'water' needs to
* call isc_mem_waterack() with #ISC_MEM_HIWATER to acknowledge the state
* change. 'water' may be called multiple times.
*
* When the usage drops below 'lowater', 'water' will again be called, this
* time with #ISC_MEM_LOWATER. 'water' need to calls isc_mem_waterack() with
* #ISC_MEM_LOWATER to acknowledge the change.
*
* static void
* water(void *arg, int mark) {
* struct foo *foo = arg;
*
* LOCK(&foo->marklock);
* if (foo->mark != mark) {
* foo->mark = mark;
* ....
* isc_mem_waterack(foo->mctx, mark);
* }
* UNLOCK(&foo->marklock);
* }
*
* If 'water' is NULL then 'water_arg', 'hi_water' and 'lo_water' are
* ignored and the state is reset.
*
* Requires:
*
* 'water' is not NULL.
* hi_water >= lo_water
*/
void
isc_mem_waterack(isc_mem_t *ctx, int mark);
/*%<
* Called to acknowledge changes in signaled by calls to 'water'.
*/
void
isc_mem_printactive(isc_mem_t *mctx, FILE *file);
/*%<
* Print to 'file' all active memory in 'mctx'.
*
* Requires ISC_MEM_DEBUGRECORD to have been set.
*/
void
isc_mem_printallactive(FILE *file);
/*%<
* Print to 'file' all active memory in all contexts.
*
* Requires ISC_MEM_DEBUGRECORD to have been set.
*/
void
isc_mem_checkdestroyed(FILE *file);
/*%<
* Check that all memory contexts have been destroyed.
* Prints out those that have not been.
* Fatally fails if there are still active contexts.
*/
unsigned int
isc_mem_references(isc_mem_t *ctx);
/*%<
* Return the current reference count.
*/
void
isc_mem_setname(isc_mem_t *ctx, const char *name, void *tag);
/*%<
* Name 'ctx'.
*
* Notes:
*
*\li Only the first 15 characters of 'name' will be copied.
*
*\li 'tag' is for debugging purposes only.
*
* Requires:
*
*\li 'ctx' is a valid ctx.
*/
const char *
isc_mem_getname(isc_mem_t *ctx);
/*%<
* Get the name of 'ctx', as previously set using isc_mem_setname().
*
* Requires:
*\li 'ctx' is a valid ctx.
*
* Returns:
*\li A non-NULL pointer to a null-terminated string.
* If the ctx has not been named, the string is
* empty.
*/
void *
isc_mem_gettag(isc_mem_t *ctx);
/*%<
* Get the tag value for 'task', as previously set using isc_mem_setname().
*
* Requires:
*\li 'ctx' is a valid ctx.
*
* Notes:
*\li This function is for debugging purposes only.
*
* Requires:
*\li 'ctx' is a valid task.
*/
#ifdef HAVE_LIBXML2
int
isc_mem_renderxml(xmlTextWriterPtr writer);
/*%<
* Render all contexts' statistics and status in XML for writer.
*/
#endif /* HAVE_LIBXML2 */
#ifdef HAVE_JSON
isc_result_t
isc_mem_renderjson(json_object *memobj);
/*%<
* Render all contexts' statistics and status in JSON.
*/
#endif /* HAVE_JSON */
/*
* Memory pools
*/
isc_result_t
isc_mempool_create(isc_mem_t *mctx, size_t size, isc_mempool_t **mpctxp);
/*%<
* Create a memory pool.
*
* Requires:
*\li mctx is a valid memory context.
*\li size > 0
*\li mpctxp != NULL and *mpctxp == NULL
*
* Defaults:
*\li maxalloc = UINT_MAX
*\li freemax = 1
*\li fillcount = 1
*
* Returns:
*\li #ISC_R_NOMEMORY -- not enough memory to create pool
*\li #ISC_R_SUCCESS -- all is well.
*/
void
isc_mempool_destroy(isc_mempool_t **mpctxp);
/*%<
* Destroy a memory pool.
*
* Requires:
*\li mpctxp != NULL && *mpctxp is a valid pool.
*\li The pool has no un"put" allocations outstanding
*/
void
isc_mempool_setname(isc_mempool_t *mpctx, const char *name);
/*%<
* Associate a name with a memory pool. At most 15 characters may be used.
*
* Requires:
*\li mpctx is a valid pool.
*\li name != NULL;
*/
void
isc_mempool_associatelock(isc_mempool_t *mpctx, isc_mutex_t *lock);
/*%<
* Associate a lock with this memory pool.
*
* This lock is used when getting or putting items using this memory pool,
* and it is also used to set or get internal state via the isc_mempool_get*()
* and isc_mempool_set*() set of functions.
*
* Multiple pools can each share a single lock. For instance, if "manager"
* type object contained pools for various sizes of events, and each of
* these pools used a common lock. Note that this lock must NEVER be used
* by other than mempool routines once it is given to a pool, since that can
* easily cause double locking.
*
* Requires:
*
*\li mpctpx is a valid pool.
*
*\li lock != NULL.
*
*\li No previous lock is assigned to this pool.
*
*\li The lock is initialized before calling this function via the normal
* means of doing that.
*/
/*
* The following functions get/set various parameters. Note that due to
* the unlocked nature of pools these are potentially random values unless
* the imposed externally provided locking protocols are followed.
*
* Also note that the quota limits will not always take immediate effect.
* For instance, setting "maxalloc" to a number smaller than the currently
* allocated count is permitted. New allocations will be refused until
* the count drops below this threshold.
*
* All functions require (in addition to other requirements):
* mpctx is a valid memory pool
*/
unsigned int
isc_mempool_getfreemax(isc_mempool_t *mpctx);
/*%<
* Returns the maximum allowed size of the free list.
*/
void
isc_mempool_setfreemax(isc_mempool_t *mpctx, unsigned int limit);
/*%<
* Sets the maximum allowed size of the free list.
*/
unsigned int
isc_mempool_getfreecount(isc_mempool_t *mpctx);
/*%<
* Returns current size of the free list.
*/
unsigned int
isc_mempool_getmaxalloc(isc_mempool_t *mpctx);
/*!<
* Returns the maximum allowed number of allocations.
*/
void
isc_mempool_setmaxalloc(isc_mempool_t *mpctx, unsigned int limit);
/*%<
* Sets the maximum allowed number of allocations.
*
* Additional requirements:
*\li limit > 0
*/
unsigned int
isc_mempool_getallocated(isc_mempool_t *mpctx);
/*%<
* Returns the number of items allocated from this pool.
*/
unsigned int
isc_mempool_getfillcount(isc_mempool_t *mpctx);
/*%<
* Returns the number of items allocated as a block from the parent memory
* context when the free list is empty.
*/
void
isc_mempool_setfillcount(isc_mempool_t *mpctx, unsigned int limit);
/*%<
* Sets the fillcount.
*
* Additional requirements:
*\li limit > 0
*/
/*
* Pseudo-private functions for use via macros. Do not call directly.
*/
void *
ISCMEMFUNC(get)(isc_mem_t *, size_t _ISC_MEM_FLARG);
void
ISCMEMFUNC(putanddetach)(isc_mem_t **, void *, size_t _ISC_MEM_FLARG);
void
ISCMEMFUNC(put)(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
void *
ISCMEMFUNC(allocate)(isc_mem_t *, size_t _ISC_MEM_FLARG);
void *
ISCMEMFUNC(reallocate)(isc_mem_t *, void *, size_t _ISC_MEM_FLARG);
void
ISCMEMFUNC(free)(isc_mem_t *, void * _ISC_MEM_FLARG);
char *
ISCMEMFUNC(strdup)(isc_mem_t *, const char *_ISC_MEM_FLARG);
void *
ISCMEMPOOLFUNC(get)(isc_mempool_t * _ISC_MEM_FLARG);
void
ISCMEMPOOLFUNC(put)(isc_mempool_t *, void * _ISC_MEM_FLARG);
/*%<
* See isc_mem_create2() above.
*/
typedef isc_result_t
(*isc_memcreatefunc_t)(size_t init_max_size, size_t target_size,
isc_mem_t **ctxp, unsigned int flags);
isc_result_t
isc_mem_register(isc_memcreatefunc_t createfunc);
/*%<
* Register a new memory management implementation and add it to the list of
* supported implementations. This function must be called when a different
* memory management library is used than the one contained in the ISC library.
*/
isc_result_t
isc__mem_register(void);
/*%<
* A short cut function that specifies the memory management module in the ISC
* library for isc_mem_register(). An application that uses the ISC library
* usually do not have to care about this function: it would call
* isc_lib_register(), which internally calls this function.
*/
ISC_LANG_ENDDECLS
#endif /* ISC_MEM_H */