[ros-diffs] [fireball] 31756: - Add BGET (public domain heap implementation).

Author: fireball
Date: Sun Jan 13 16:03:42 2008
New Revision: 31756

URL: http://svn.reactos.org/svn/reactos?rev=31756&view=rev
Log:
- Add BGET (public domain heap implementation).

Added:
    trunk/reactos/boot/freeldr/freeldr/include/bget.h   (with props)
    trunk/reactos/boot/freeldr/freeldr/rtl/bget.c   (with props)
Modified:
    trunk/reactos/boot/freeldr/freeldr/freeldr_base.rbuild

Modified: trunk/reactos/boot/freeldr/freeldr/freeldr_base.rbuild
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/freel…
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/freeldr_base.rbuild (original)
+++ trunk/reactos/boot/freeldr/freeldr/freeldr_base.rbuild Sun Jan 13 16:03:42 2008
@@ -51,6 +51,7 @@
 		<file>reactos.c</file>
 	</directory>
 	<directory name="rtl">
+		<file>bget.c</file>
 		<file>libsupp.c</file>
 	</directory>
 	<directory name="ui">

Added: trunk/reactos/boot/freeldr/freeldr/include/bget.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/inclu…
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/include/bget.h (added)
+++ trunk/reactos/boot/freeldr/freeldr/include/bget.h Sun Jan 13 16:03:42 2008
@@ -1,0 +1,30 @@
+/*
+
+    Interface definitions for bget.c, the memory management package.
+
+*/
+
+#ifndef _
+#ifdef PROTOTYPES
+#define  _(x)  x		      /* If compiler knows prototypes */
+#else
+#define  _(x)  ()                     /* It it doesn't */
+#endif /* PROTOTYPES */
+#endif
+
+typedef long bufsize;
+void	bpool	    _((void *buffer, bufsize len));
+void   *bget	    _((bufsize size));
+void   *bgetz	    _((bufsize size));
+void   *bgetr	    _((void *buffer, bufsize newsize));
+void	brel	    _((void *buf));
+void	bectl	    _((int (*compact)(bufsize sizereq, int sequence),
+		       void *(*acquire)(bufsize size),
+		       void (*release)(void *buf), bufsize pool_incr));
+void	bstats	    _((bufsize *curalloc, bufsize *totfree, bufsize *maxfree,
+		       long *nget, long *nrel));
+void	bstatse     _((bufsize *pool_incr, long *npool, long *npget,
+		       long *nprel, long *ndget, long *ndrel));
+void	bufdump     _((void *buf));
+void	bpoold	    _((void *pool, int dumpalloc, int dumpfree));
+int	bpoolv	    _((void *pool));

Propchange: trunk/reactos/boot/freeldr/freeldr/include/bget.h
------------------------------------------------------------------------------
    svn:eol-style = native

Added: trunk/reactos/boot/freeldr/freeldr/rtl/bget.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/rtl/b…
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/rtl/bget.c (added)
+++ trunk/reactos/boot/freeldr/freeldr/rtl/bget.c Sun Jan 13 16:03:42 2008
@@ -1,0 +1,1593 @@
+/*
+
+			       B G E T
+
+			   Buffer allocator
+
+    Designed and implemented in April of 1972 by John Walker, based on the
+    Case Algol OPRO$ algorithm implemented in 1966.
+
+    Reimplemented in 1975 by John Walker for the Interdata 70.
+    Reimplemented in 1977 by John Walker for the Marinchip 9900.
+    Reimplemented in 1982 by Duff Kurland for the Intel 8080.
+
+    Portable C version implemented in September of 1990 by an older, wiser
+    instance of the original implementor.
+
+    Souped up and/or weighed down  slightly  shortly  thereafter  by  Greg
+    Lutz.
+
+    AMIX  edition, including the new compaction call-back option, prepared
+    by John Walker in July of 1992.
+
+    Bug in built-in test program fixed, ANSI compiler warnings eradicated,
+    buffer pool validator  implemented,  and  guaranteed  repeatable  test
+    added by John Walker in October of 1995.
+
+    This program is in the public domain.
+
+     1. This is the book of the generations of Adam.   In the day that God
+	created man, in the likeness of God made he him;
+     2. Male and female created he them;  and  blessed	them,  and  called
+	their name Adam, in the day when they were created.
+     3. And  Adam  lived  an hundred and thirty years,	and begat a son in
+	his own likeness, and after his image; and called his name Seth:
+     4. And the days of  Adam  after  he  had  begotten  Seth  were  eight
+	hundred years: and he begat sons and daughters:
+     5. And  all  the  days  that Adam lived were nine	hundred and thirty
+	years: and he died.
+     6. And Seth lived an hundred and five years, and begat Enos:
+     7. And Seth lived after he begat Enos eight hundred and seven  years,
+	and begat sons and daughters:
+     8.  And  all the days of Seth were nine hundred and twelve years: and
+	 he died.
+     9. And Enos lived ninety years, and begat Cainan:
+    10. And Enos lived after he begat  Cainan eight  hundred  and  fifteen
+	years, and begat sons and daughters:
+    11. And  all  the days of Enos were nine hundred  and five years:  and
+	he died.
+    12. And Cainan lived seventy years and begat Mahalaleel:
+    13. And Cainan lived  after he  begat  Mahalaleel  eight  hundred  and
+	forty years, and begat sons and daughters:
+    14. And  all the days of Cainan were nine  hundred and ten years:  and
+	he died.
+    15. And Mahalaleel lived sixty and five years, and begat Jared:
+    16. And Mahalaleel lived  after  he  begat	Jared  eight  hundred  and
+	thirty years, and begat sons and daughters:
+    17. And  all  the  days  of Mahalaleel  were eight hundred	ninety and
+	five years: and he died.
+    18. And Jared lived an hundred sixty and  two  years,   and  he  begat
+	Enoch:
+    19. And  Jared  lived  after he begat Enoch  eight hundred years,  and
+	begat sons and daughters:
+    20. And all the days of Jared  were nine hundred sixty and two  years:
+	and he died.
+    21. And Enoch lived sixty and five years, and begat Methuselah:
+    22. And  Enoch  walked   with  God	after  he  begat Methuselah  three
+	hundred years, and begat sons and daughters:
+    23. And all the days of  Enoch  were  three  hundred  sixty  and  five
+	years:
+    24. And Enoch walked with God: and he was not; for God took him.
+    25. And  Methuselah  lived	an  hundred  eighty and  seven years,  and
+	begat Lamech.
+    26. And Methuselah lived after he  begat Lamech seven  hundred  eighty
+	and two years, and begat sons and daughters:
+    27. And  all the days of Methuselah  were nine hundred  sixty and nine
+	years: and he died.
+    28. And Lamech lived an hundred eighty  and two  years,  and  begat  a
+	son:
+    29. And  he called his name Noah, saying,  This same shall	comfort us
+	concerning  our  work and toil of our hands, because of the ground
+	which the LORD hath cursed.
+    30. And  Lamech  lived  after  he begat Noah  five hundred	ninety and
+	five years, and begat sons and daughters:
+    31. And all the days of Lamech were  seven hundred seventy	and  seven
+	years: and he died.
+    32. And  Noah  was five hundred years old:	and Noah begat Shem,  Ham,
+	and Japheth.
+
+    And buffers begat buffers, and links begat	links,	and  buffer  pools
+    begat  links  to chains of buffer pools containing buffers, and lo the
+    buffers and links and pools of buffers and pools of links to chains of
+    pools  of  buffers were fruitful and they multiplied and the Operating
+    System looked down upon them and said that it was Good.
+
+
+    INTRODUCTION
+    ============
+
+    BGET  is a comprehensive memory allocation package which is easily
+    configured to the needs of an application.	BGET is  efficient  in
+    both  the  time  needed to allocate and release buffers and in the
+    memory  overhead  required	for  buffer   pool   management.    It
+    automatically    consolidates   contiguous	 space	 to   minimise
+    fragmentation.  BGET is configured	by  compile-time  definitions,
+    Major options include:
+
+	*   A  built-in  test  program	to  exercise  BGET   and
+	    demonstrate how the various functions are used.
+
+        *   Allocation  by  either the "first fit" or "best fit"
+	    method.
+
+	*   Wiping buffers at release time to catch  code  which
+	    references previously released storage.
+
+	*   Built-in  routines to dump individual buffers or the
+	    entire buffer pool.
+
+	*   Retrieval of allocation and pool size statistics.
+
+	*   Quantisation of buffer sizes to a power  of  two  to
+	    satisfy hardware alignment constraints.
+
+	*   Automatic  pool compaction, growth, and shrinkage by
+	    means of call-backs to user defined functions.
+
+    Applications  of  BGET  can  range	from  storage  management   in
+    ROM-based  embedded programs to providing the framework upon which
+    a  multitasking  system  incorporating   garbage   collection   is
+    constructed.   BGET  incorporates  extensive  internal consistency
+    checking using the <assert.h> mechanism; all these checks  can  be
+    turned off by compiling with NDEBUG defined, yielding a version of
+    BGET with minimal size and maximum speed.
+
+    The  basic	algorithm  underlying  BGET  has withstood the test of
+    time;  more  than  25  years   have   passed   since   the	 first
+    implementation  of	this  code.  And yet, it is substantially more
+    efficient than the native allocation  schemes  of  many  operating
+    systems: the Macintosh and Microsoft Windows to name two, on which
+    programs have obtained substantial speed-ups by layering  BGET  as
+    an application level memory manager atop the underlying system's.
+
+    BGET has been implemented on the largest mainframes and the lowest
+    of	microprocessors.   It  has served as the core for multitasking
+    operating systems, multi-thread applications, embedded software in
+    data  network switching processors, and a host of C programs.  And
+    while it has accreted flexibility and additional options over  the
+    years,  it	remains  fast, memory efficient, portable, and easy to
+    integrate into your program.
+
+
+    BGET IMPLEMENTATION ASSUMPTIONS
+    ===============================
+
+    BGET is written in as portable a dialect of C  as  possible.   The
+    only   fundamental	 assumption   about  the  underlying  hardware
+    architecture is that memory is allocated is a linear  array  which
+    can  be  addressed  as a vector of C "char" objects.  On segmented
+    address space architectures, this generally means that BGET should
+    be used to allocate storage within a single segment (although some
+    compilers	simulate   linear   address   spaces   on    segmented
+    architectures).   On  segmented  architectures,  then, BGET buffer
+    pools  may not be larger than a segment, but since BGET allows any
+    number of separate buffer pools, there is no limit	on  the  total
+    storage  which  can  be  managed,  only  on the largest individual
+    object which can be allocated.  Machines  with  a  linear  address
+    architecture,  such  as  the VAX, 680x0, Sparc, MIPS, or the Intel
+    80386 and above in native mode, may use BGET without restriction.
+
+
+    GETTING STARTED WITH BGET
+    =========================
+
+    Although BGET can be configured in a multitude of fashions,  there
+    are  three	basic  ways  of  working  with	BGET.	The  functions
+    mentioned below are documented in the following  section.	Please
+    excuse  the  forward  references which are made in the interest of
+    providing a roadmap to guide you  to  the  BGET  functions  you're
+    likely to need.
+
+    Embedded Applications
+    ---------------------
+
+    Embedded applications  typically  have  a  fixed  area  of	memory
+    dedicated  to  buffer  allocation (often in a separate RAM address
+    space distinct from the ROM that contains  the  executable	code).
+    To	use  BGET in such an environment, simply call bpool() with the
+    start address and length of the buffer  pool  area	in  RAM,  then
+    allocate  buffers  with  bget()  and  release  them  with  brel().
+    Embedded applications with very limited RAM but abundant CPU speed
+    may  benefit  by configuring BGET for BestFit allocation (which is
+    usually not worth it in other environments).
+
+    Malloc() Emulation
+    ------------------
+
+    If the C library malloc() function is too  slow,  not  present  in
+    your  development environment (for example, an a native Windows or
+    Macintosh program), or otherwise unsuitable, you  can  replace  it
+    with  BGET.  Initially define a buffer pool of an appropriate size
+    with bpool()--usually obtained by making a call to	the  operating
+    system's  low-level  memory allocator.  Then allocate buffers with
+    bget(), bgetz(), and bgetr() (the last two permit  the  allocation
+    of	buffers initialised to zero and [inefficient] re-allocation of
+    existing buffers for  compatibility  with  C  library  functions).
+    Release buffers by calling brel().	If a buffer allocation request
+    fails, obtain more storage from the underlying  operating  system,
+    add it to the buffer pool by another call to bpool(), and continue
+    execution.
+
+    Automatic Storage Management
+    ----------------------------
+
+    You can use BGET as your application's native memory  manager  and
+    implement  automatic  storage  pool  expansion,  contraction,  and
+    optionally application-specific  memory  compaction  by  compiling
+    BGET  with	the  BECtl  variable defined, then calling bectl() and
+    supplying  functions  for  storage	compaction,  acquisition,  and
+    release,  as  well as a standard pool expansion increment.	All of
+    these functions are optional (although it doesn't make much  sense
+    to	provide  a  release  function without an acquisition function,
+    does it?).	Once the call-back functions have  been  defined  with
+    bectl(),  you simply use bget() and brel() to allocate and release
+    storage as before.	You can supply an  initial  buffer  pool  with
+    bpool()  or  rely  on  automatic  allocation to acquire the entire
+    pool.  When a call on  bget()  cannot  be  satisfied,  BGET  first
+    checks  if	a compaction function has been supplied.  If so, it is
+    called (with the space required to satisfy the allocation  request
+    and a sequence number to allow the compaction routine to be called
+    successively without looping).  If the compaction function is able
+    to  free any storage (it needn't know whether the storage it freed
+    was adequate) it should return a  nonzero  value,  whereupon  BGET
+    will retry the allocation request and, if it fails again, call the
+    compaction function again with the next-higher sequence number.
+
+    If	the  compaction  function  returns zero, indicating failure to
+    free space, or no compaction function is defined, BGET next  tests
+    whether  a	non-NULL  allocation function was supplied to bectl().
+    If so, that function is called with  an  argument  indicating  how
+    many  bytes  of  additional  space are required.  This will be the
+    standard pool expansion increment supplied in the call to  bectl()
+    unless  the  original  bget()  call requested a buffer larger than
+    this; buffers larger than the standard pool block can  be  managed
+    "off  the books" by BGET in this mode.  If the allocation function
+    succeeds in obtaining the storage, it returns a pointer to the new
+    block  and	BGET  expands  the  buffer  pool;  if  it  fails,  the
+    allocation request fails and returns NULL to  the  caller.	 If  a
+    non-NULL  release  function  is  supplied,	expansion blocks which
+    become totally empty are released  to  the	global	free  pool  by
+    passing their addresses to the release function.
+
+    Equipped  with  appropriate  allocation,  release,	and compaction
+    functions, BGET can be used as part of very  sophisticated	memory
+    management	 strategies,  including  garbage  collection.	(Note,
+    however, that BGET is *not* a garbage  collector  by  itself,  and
+    that  developing  such a system requires much additional logic and
+    careful design of the application's memory allocation strategy.)
+
+
+    BGET FUNCTION DESCRIPTIONS
+    ==========================
+
+    Functions implemented in this file (some are enabled by certain of
+    the optional settings below):
+
+	    void bpool(void *buffer, bufsize len);
+
+    Create a buffer pool of <len> bytes, using the storage starting at
+    <buffer>.	You  can  call	bpool()  subsequently  to   contribute
+    additional storage to the overall buffer pool.
+
+	    void *bget(bufsize size);
+
+    Allocate  a  buffer of <size> bytes.  The address of the buffer is
+    returned, or NULL if insufficient memory was available to allocate
+    the buffer.
+
+	    void *bgetz(bufsize size);
+
+    Allocate a buffer of <size> bytes and clear it to all zeroes.  The
+    address of the buffer is returned, or NULL if insufficient	memory
+    was available to allocate the buffer.
+
+	    void *bgetr(void *buffer, bufsize newsize);
+
+    Reallocate a buffer previously allocated by bget(),  changing  its
+    size  to  <newsize>  and  preserving  all  existing data.  NULL is
+    returned if insufficient memory is	available  to  reallocate  the
+    buffer, in which case the original buffer remains intact.
+
+	    void brel(void *buf);
+
+    Return  the  buffer  <buf>, previously allocated by bget(), to the
+    free space pool.
+
+	    void bectl(int (*compact)(bufsize sizereq, int sequence),
+		       void *(*acquire)(bufsize size),
+		       void (*release)(void *buf),
+		       bufsize pool_incr);
+
+    Expansion control: specify functions through which the package may
+    compact  storage  (or  take  other	appropriate  action)  when  an
+    allocation	request  fails,  and  optionally automatically acquire
+    storage for expansion blocks  when	necessary,  and  release  such
+    blocks when they become empty.  If <compact> is non-NULL, whenever
+    a buffer allocation request fails, the <compact> function will  be
+    called with arguments specifying the number of bytes (total buffer
+    size,  including  header  overhead)  required   to	 satisfy   the
+    allocation request, and a sequence number indicating the number of
+    consecutive  calls	on  <compact>  attempting  to	satisfy   this
+    allocation	request.   The sequence number is 1 for the first call
+    on <compact> for a given allocation  request,  and	increments  on
+    subsequent	calls,	permitting  the  <compact>  function  to  take
+    increasingly dire measures in an attempt to free up  storage.   If
+    the  <compact>  function  returns  a nonzero value, the allocation
+    attempt is re-tried.  If <compact> returns 0 (as  it  must	if  it
+    isn't  able  to  release  any  space  or add storage to the buffer
+    pool), the allocation request fails, which can  trigger  automatic
+    pool expansion if the <acquire> argument is non-NULL.  At the time
+    the  <compact>  function  is  called,  the	state  of  the	buffer
+    allocator  is  identical  to  that	at  the  moment the allocation
+    request was made; consequently, the <compact>  function  may  call
+    brel(), bpool(), bstats(), and/or directly manipulate  the	buffer
+    pool  in  any  manner which would be valid were the application in
+    control.  This does not, however, relieve the  <compact>  function
+    of the need to ensure that whatever actions it takes do not change
+    things   underneath  the  application  that  made  the  allocation
+    request.  For example, a <compact> function that released a buffer
+    in	the  process  of  being reallocated with bgetr() would lead to
+    disaster.  Implementing a safe and effective  <compact>  mechanism
+    requires  careful  design of an application's memory architecture,
+    and cannot generally be easily retrofitted into existing code.
+
+    If <acquire> is non-NULL, that function will be called whenever an
+    allocation	request  fails.  If the <acquire> function succeeds in
+    allocating the requested space and returns a pointer  to  the  new
+    area,  allocation will proceed using the expanded buffer pool.  If
+    <acquire> cannot obtain the requested space, it should return NULL
+    and   the	entire	allocation  process  will  fail.   <pool_incr>
+    specifies the normal expansion block size.	Providing an <acquire>
+    function will cause subsequent bget()  requests  for  buffers  too
+    large  to  be  managed in the linked-block scheme (in other words,
+    larger than <pool_incr> minus the buffer overhead) to be satisfied
+    directly by calls to the <acquire> function.  Automatic release of
+    empty pool blocks will occur only if all pool blocks in the system
+    are the size given by <pool_incr>.
+
+	    void bstats(bufsize *curalloc, bufsize *totfree,
+			bufsize *maxfree, long *nget, long *nrel);
+
+    The amount	of  space  currently  allocated  is  stored  into  the
+    variable  pointed  to by <curalloc>.  The total free space (sum of
+    all free blocks in the pool) is stored into the  variable  pointed
+    to	by  <totfree>, and the size of the largest single block in the
+    free space	pool  is  stored  into	the  variable  pointed	to  by
+    <maxfree>.	 The  variables  pointed  to  by <nget> and <nrel> are
+    filled, respectively, with	the  number  of  successful  (non-NULL
+    return) bget() calls and the number of brel() calls.
+
+	    void bstatse(bufsize *pool_incr, long *npool,
+			 long *npget, long *nprel,
+			 long *ndget, long *ndrel);
+
+    Extended  statistics: The expansion block size will be stored into
+    the variable pointed to by <pool_incr>, or the negative thereof if
+    automatic  expansion  block  releases are disabled.  The number of
+    currently active pool blocks will  be  stored  into  the  variable
+    pointed  to  by  <npool>.  The variables pointed to by <npget> and
+    <nprel> will be filled with, respectively, the number of expansion
+    block   acquisitions   and	releases  which  have  occurred.   The
+    variables pointed to by <ndget> and <ndrel> will  be  filled  with
+    the  number  of  bget()  and  brel()  calls, respectively, managed
+    through blocks directly allocated by the acquisition  and  release
+    functions.
+
+	    void bufdump(void *buf);
+
+    The buffer pointed to by <buf> is dumped on standard output.
+
+	    void bpoold(void *pool, int dumpalloc, int dumpfree);
+
+    All buffers in the buffer pool <pool>, previously initialised by a
+    call on bpool(), are listed in ascending memory address order.  If
+    <dumpalloc> is nonzero, the  contents  of  allocated  buffers  are
+    dumped;  if <dumpfree> is nonzero, the contents of free blocks are
+    dumped.
+
+	    int bpoolv(void *pool);
+
+    The  named	buffer	pool,  previously  initialised	by  a  call on
+    bpool(), is validated for bad pointers, overwritten data, etc.  If
+    compiled with NDEBUG not defined, any error generates an assertion
+    failure.  Otherwise 1 is returned if the pool is valid,  0	if  an
+    error is found.
+
+
+    BGET CONFIGURATION
+    ==================
+*/
+
+/*#define TestProg    20000*/	      /* Generate built-in test program
+					 if defined.  The value specifies
+					 how many buffer allocation attempts
+					 the test program should make. */
+
+#define SizeQuant   4		      /* Buffer allocation size quantum:
+					 all buffers allocated are a
+					 multiple of this size.  This
+					 MUST be a power of two. */
+
+#define BufDump     1		      /* Define this symbol to enable the
+					 bpoold() function which dumps the
+					 buffers in a buffer pool. */
+
+#define BufValid    1		      /* Define this symbol to enable the
+					 bpoolv() function for validating
+					 a buffer pool. */ 
+
+#define DumpData    1		      /* Define this symbol to enable the
+					 bufdump() function which allows
+					 dumping the contents of an allocated
+					 or free buffer. */
+
+#define BufStats    1		      /* Define this symbol to enable the
+					 bstats() function which calculates
+					 the total free space in the buffer
+					 pool, the largest available
+					 buffer, and the total space
+					 currently allocated. */
+
+#define FreeWipe    1		      /* Wipe free buffers to a guaranteed
+					 pattern of garbage to trip up
+					 miscreants who attempt to use
+					 pointers into released buffers. */
+
+#define BestFit     1		      /* Use a best fit algorithm when
+					 searching for space for an
+					 allocation request.  This uses
+					 memory more efficiently, but
+					 allocation will be much slower. */
+
+#define BECtl	    1		      /* Define this symbol to enable the
+					 bectl() function for automatic
+					 pool space control.  */
+
+#include <stdio.h>
+
+#ifdef lint
+#define NDEBUG			      /* Exits in asserts confuse lint */
+/* LINTLIBRARY */                     /* Don't complain about def, no ref */
+extern char *sprintf();               /* Sun includes don't define sprintf */
+#endif
+
+#define NDEBUG
+
+#include <assert.h>
+#include <memory.h>
+
+#ifdef BufDump			      /* BufDump implies DumpData */
+#ifndef DumpData
+#define DumpData    1
+#endif
+#endif
+
+#ifdef DumpData
+#include <ctype.h>
+#endif
+
+/*  Declare the interface, including the requested buffer size type,
+    bufsize.  */
+
+#include "bget.h"
+
+#define MemSize     int 	      /* Type for size arguments to memxxx()
+					 functions such as memcmp(). */
+
+/* Queue links */
+
+struct qlinks {
+    struct bfhead *flink;	      /* Forward link */
+    struct bfhead *blink;	      /* Backward link */
+};
+
+/* Header in allocated and free buffers */
+
+struct bhead {
+    bufsize prevfree;		      /* Relative link back to previous
+					 free buffer in memory or 0 if
+					 previous buffer is allocated.	*/
+    bufsize bsize;		      /* Buffer size: positive if free,
+					 negative if allocated. */
+};
+#define BH(p)	((struct bhead *) (p))
+
+/*  Header in directly allocated buffers (by acqfcn) */
+
+struct bdhead {
+    bufsize tsize;		      /* Total size, including overhead */
+    struct bhead bh;		      /* Common header */
+};
+#define BDH(p)	((struct bdhead *) (p))
+
+/* Header in free buffers */
+
+struct bfhead {
+    struct bhead bh;		      /* Common allocated/free header */
+    struct qlinks ql;		      /* Links on free list */
+};
+#define BFH(p)	((struct bfhead *) (p))
+
+static struct bfhead freelist = {     /* List of free buffers */
+    {0, 0},
+    {&freelist, &freelist}
+};
+
+
+#ifdef BufStats
+static bufsize totalloc = 0;	      /* Total space currently allocated */
+static long numget = 0, numrel = 0;   /* Number of bget() and brel() calls */
+#ifdef BECtl
+static long numpblk = 0;	      /* Number of pool blocks */
+static long numpget = 0, numprel = 0; /* Number of block gets and rels */
+static long numdget = 0, numdrel = 0; /* Number of direct gets and rels */
+#endif /* BECtl */
+#endif /* BufStats */
+
+#ifdef BECtl
+
+/* Automatic expansion block management functions */
+
+static int (*compfcn) _((bufsize sizereq, int sequence)) = NULL;
+static void *(*acqfcn) _((bufsize size)) = NULL;
+static void (*relfcn) _((void *buf)) = NULL;
+
+static bufsize exp_incr = 0;	      /* Expansion block size */
+static bufsize pool_len = 0;	      /* 0: no bpool calls have been made
+					 -1: not all pool blocks are
+					     the same size
+					 >0: (common) block size for all
+					     bpool calls made so far
+				      */
+#endif
+
+/*  Minimum allocation quantum: */
+
+#define QLSize	(sizeof(struct qlinks))
+#define SizeQ	((SizeQuant > QLSize) ? SizeQuant : QLSize)
+
+#define V   (void)		      /* To denote unwanted returned values */
+
+/* End sentinel: value placed in bsize field of dummy block delimiting
+   end of pool block.  The most negative number which will  fit  in  a
+   bufsize, defined in a way that the compiler will accept. */
+
+#define ESent	((bufsize) (-(((1L << (sizeof(bufsize) * 8 - 2)) - 1) * 2) - 2))
+
+/*  BGET  --  Allocate a buffer.  */
+
+void *bget(requested_size)
+  bufsize requested_size;
+{
+    bufsize size = requested_size;
+    struct bfhead *b;
+#ifdef BestFit
+    struct bfhead *best;
+#endif
+    void *buf;
+#ifdef BECtl
+    int compactseq = 0;
+#endif
+
+    assert(size > 0);
+
+    if (size < SizeQ) { 	      /* Need at least room for the */
+	size = SizeQ;		      /*    queue links.  */
+    }
+#ifdef SizeQuant
+#if SizeQuant > 1
+    size = (size + (SizeQuant - 1)) & (~(SizeQuant - 1));
+#endif
+#endif
+
+    size += sizeof(struct bhead);     /* Add overhead in allocated buffer
+					 to size required. */
+
+#ifdef BECtl
+    /* If a compact function was provided in the call to bectl(), wrap
+       a loop around the allocation process  to  allow	compaction  to
+       intervene in case we don't find a suitable buffer in the chain. */
+
+    while (1) {
+#endif
+	b = freelist.ql.flink;
+#ifdef BestFit
+	best = &freelist;
+#endif
+
+
+	/* Scan the free list searching for the first buffer big enough
+	   to hold the requested size buffer. */
+
+#ifdef BestFit
+	while (b != &freelist) {
+	    if (b->bh.bsize >= size) {
+		if ((best == &freelist) || (b->bh.bsize < best->bh.bsize)) {
+		    best = b;
+		}
+	    }
+	    b = b->ql.flink;		  /* Link to next buffer */
+	}
+	b = best;
+#endif /* BestFit */
+
+	while (b != &freelist) {
+	    if ((bufsize) b->bh.bsize >= size) {
+
+		/* Buffer  is big enough to satisfy  the request.  Allocate it
+		   to the caller.  We must decide whether the buffer is  large
+		   enough  to  split  into  the part given to the caller and a
+		   free buffer that remains on the free list, or  whether  the
+		   entire  buffer  should  be  removed	from the free list and
+		   given to the caller in its entirety.   We  only  split  the
+		   buffer if enough room remains for a header plus the minimum
+		   quantum of allocation. */
+
+		if ((b->bh.bsize - size) > (SizeQ + (sizeof(struct bhead)))) {
+		    struct bhead *ba, *bn;
+
+		    ba = BH(((char *) b) + (b->bh.bsize - size));
+		    bn = BH(((char *) ba) + size);
+		    assert(bn->prevfree == b->bh.bsize);
+		    /* Subtract size from length of free block. */
+		    b->bh.bsize -= size;
+		    /* Link allocated buffer to the previous free buffer. */
+		    ba->prevfree = b->bh.bsize;
+		    /* Plug negative size into user buffer. */
+		    ba->bsize = -(bufsize) size;
+		    /* Mark buffer after this one not preceded by free block. */
+		    bn->prevfree = 0;
+
+#ifdef BufStats
+		    totalloc += size;
+		    numget++;		  /* Increment number of bget() calls */
+#endif
+		    buf = (void *) ((((char *) ba) + sizeof(struct bhead)));
+		    return buf;
+		} else {
+		    struct bhead *ba;
+
+		    ba = BH(((char *) b) + b->bh.bsize);
+		    assert(ba->prevfree == b->bh.bsize);
+
+                    /* The buffer isn't big enough to split.  Give  the  whole
+		       shebang to the caller and remove it from the free list. */
+
+		    assert(b->ql.blink->ql.flink == b);
+		    assert(b->ql.flink->ql.blink == b);
+		    b->ql.blink->ql.flink = b->ql.flink;
+		    b->ql.flink->ql.blink = b->ql.blink;
+
+#ifdef BufStats
+		    totalloc += b->bh.bsize;
+		    numget++;		  /* Increment number of bget() calls */
+#endif
+		    /* Negate size to mark buffer allocated. */
+		    b->bh.bsize = -(b->bh.bsize);
+
+		    /* Zero the back pointer in the next buffer in memory
+		       to indicate that this buffer is allocated. */
+		    ba->prevfree = 0;
+
+		    /* Give user buffer starting at queue links. */
+		    buf =  (void *) &(b->ql);
+		    return buf;
+		}
+	    }
+	    b = b->ql.flink;		  /* Link to next buffer */
+	}
+#ifdef BECtl
+
+        /* We failed to find a buffer.  If there's a compact  function
+	   defined,  notify  it  of the size requested.  If it returns
+	   TRUE, try the allocation again. */
+
+	if ((compfcn == NULL) || (!(*compfcn)(size, ++compactseq))) {
+	    break;
+	}
+    }
+
+    /* No buffer available with requested size free. */
+
+    /* Don't give up yet -- look in the reserve supply. */
+
+    if (acqfcn != NULL) {
+	if (size > exp_incr - sizeof(struct bhead)) {
+
+	    /* Request	is  too  large	to  fit in a single expansion
+	       block.  Try to satisy it by a direct buffer acquisition. */
+
+	    struct bdhead *bdh;
+
+	    size += sizeof(struct bdhead) - sizeof(struct bhead);
+	    if ((bdh = BDH((*acqfcn)((bufsize) size))) != NULL) {
+
+		/*  Mark the buffer special by setting the size field
+		    of its header to zero.  */
+		bdh->bh.bsize = 0;
+		bdh->bh.prevfree = 0;
+		bdh->tsize = size;
+#ifdef BufStats
+		totalloc += size;
+		numget++;	      /* Increment number of bget() calls */
+		numdget++;	      /* Direct bget() call count */
+#endif
+		buf =  (void *) (bdh + 1);
+		return buf;
+	    }
+
+	} else {
+
+	    /*	Try to obtain a new expansion block */
+
+	    void *newpool;
+
+	    if ((newpool = (*acqfcn)((bufsize) exp_incr)) != NULL) {
+		bpool(newpool, exp_incr);
+                buf =  bget(requested_size);  /* This can't, I say, can't
+						 get into a loop. */
+		return buf;
+	    }
+	}
+    }
+
+    /*	Still no buffer available */
+
+#endif /* BECtl */
+
+    return NULL;
+}
+
+/*  BGETZ  --  Allocate a buffer and clear its contents to zero.  We clear
+	       the  entire  contents  of  the buffer to zero, not just the
+	       region requested by the caller. */
+
+void *bgetz(size)
+  bufsize size;
+{
+    char *buf = (char *) bget(size);
+
+    if (buf != NULL) {
+	struct bhead *b;
+	bufsize rsize;
+
+	b = BH(buf - sizeof(struct bhead));
+	rsize = -(b->bsize);
+	if (rsize == 0) {
+	    struct bdhead *bd;
+
+	    bd = BDH(buf - sizeof(struct bdhead));
+	    rsize = bd->tsize - sizeof(struct bdhead);
+	} else {
+	    rsize -= sizeof(struct bhead);
+	}
+	assert(rsize >= size);
+	V memset(buf, 0, (MemSize) rsize);
+    }
+    return ((void *) buf);
+}
+
+/*  BGETR  --  Reallocate a buffer.  This is a minimal implementation,
+	       simply in terms of brel()  and  bget().	 It  could  be
+	       enhanced to allow the buffer to grow into adjacent free
+	       blocks and to avoid moving data unnecessarily.  */
+
+void *bgetr(buf, size)
+  void *buf;
+  bufsize size;
+{
+    void *nbuf;
+    bufsize osize;		      /* Old size of buffer */
+    struct bhead *b;
+
+    if ((nbuf = bget(size)) == NULL) { /* Acquire new buffer */
+	return NULL;
+    }
+    if (buf == NULL) {
+	return nbuf;
+    }
+    b = BH(((char *) buf) - sizeof(struct bhead));
+    osize = -b->bsize;
+#ifdef BECtl
+    if (osize == 0) {
+	/*  Buffer acquired directly through acqfcn. */
+	struct bdhead *bd;
+
+	bd = BDH(((char *) buf) - sizeof(struct bdhead));
+	osize = bd->tsize - sizeof(struct bdhead);
+    } else
+#endif
+	osize -= sizeof(struct bhead);
+    assert(osize > 0);
+    V memcpy((char *) nbuf, (char *) buf, /* Copy the data */
+	     (MemSize) ((size < osize) ? size : osize));
+    brel(buf);
+    return nbuf;
+}
+
+/*  BREL  --  Release a buffer.  */
+
+void brel(buf)
+  void *buf;
+{
+    struct bfhead *b, *bn;
+
+    b = BFH(((char *) buf) - sizeof(struct bhead));
+#ifdef BufStats
+    numrel++;			      /* Increment number of brel() calls */
+#endif
+    assert(buf != NULL);
+
+#ifdef BECtl
+    if (b->bh.bsize == 0) {	      /* Directly-acquired buffer? */
+	struct bdhead *bdh;
+
+	bdh = BDH(((char *) buf) - sizeof(struct bdhead));
+	assert(b->bh.prevfree == 0);
+#ifdef BufStats
+	totalloc -= bdh->tsize;
+	assert(totalloc >= 0);
+	numdrel++;		      /* Number of direct releases */
+#endif /* BufStats */
+#ifdef FreeWipe
+	V memset((char *) buf, 0x55,
+		 (MemSize) (bdh->tsize - sizeof(struct bdhead)));
+#endif /* FreeWipe */
+	assert(relfcn != NULL);
+	(*relfcn)((void *) bdh);      /* Release it directly. */
+	return;
+    }
+#endif /* BECtl */
+
+    /* Buffer size must be negative, indicating that the buffer is
+       allocated. */
+
+    if (b->bh.bsize >= 0) {
+	bn = NULL;
+    }
+    assert(b->bh.bsize < 0);
+
+    /*	Back pointer in next buffer must be zero, indicating the
+	same thing: */
+
+    assert(BH((char *) b - b->bh.bsize)->prevfree == 0);
+
+#ifdef BufStats
+    totalloc += b->bh.bsize;
+    assert(totalloc >= 0);
+#endif
+
+    /* If the back link is nonzero, the previous buffer is free.  */
+
+    if (b->bh.prevfree != 0) {
+
+	/* The previous buffer is free.  Consolidate this buffer  with	it
+	   by  adding  the  length  of	this  buffer  to the previous free
+	   buffer.  Note that we subtract the size  in	the  buffer  being
+           released,  since  it's  negative to indicate that the buffer is
+	   allocated. */
+
+	register bufsize size = b->bh.bsize;
+
+        /* Make the previous buffer the one we're working on. */
+	assert(BH((char *) b - b->bh.prevfree)->bsize == b->bh.prevfree);
+	b = BFH(((char *) b) - b->bh.prevfree);
+	b->bh.bsize -= size;
+    } else {
+
+        /* The previous buffer isn't allocated.  Insert this buffer
+	   on the free list as an isolated free block. */
+
+	assert(freelist.ql.blink->ql.flink == &freelist);
+	assert(freelist.ql.flink->ql.blink == &freelist);
+	b->ql.flink = &freelist;
+	b->ql.blink = freelist.ql.blink;
+	freelist.ql.blink = b;
+	b->ql.blink->ql.flink = b;
+	b->bh.bsize = -b->bh.bsize;
+    }
+
+    /* Now we look at the next buffer in memory, located by advancing from
+       the  start  of  this  buffer  by its size, to see if that buffer is
+       free.  If it is, we combine  this  buffer  with	the  next  one	in
+       memory, dechaining the second buffer from the free list. */
+
+    bn =  BFH(((char *) b) + b->bh.bsize);
+    if (bn->bh.bsize > 0) {
+
+	/* The buffer is free.	Remove it from the free list and add
+	   its size to that of our buffer. */
+
+	assert(BH((char *) bn + bn->bh.bsize)->prevfree == bn->bh.bsize);
+	assert(bn->ql.blink->ql.flink == bn);
+	assert(bn->ql.flink->ql.blink == bn);
+	bn->ql.blink->ql.flink = bn->ql.flink;
+	bn->ql.flink->ql.blink = bn->ql.blink;
+	b->bh.bsize += bn->bh.bsize;
+
+	/* Finally,  advance  to   the	buffer	that   follows	the  newly
+	   consolidated free block.  We must set its  backpointer  to  the
+	   head  of  the  consolidated free block.  We know the next block
+	   must be an allocated block because the process of recombination
+	   guarantees  that  two  free	blocks will never be contiguous in
+	   memory.  */
+
+	bn = BFH(((char *) b) + b->bh.bsize);
+    }
+#ifdef FreeWipe
+    V memset(((char *) b) + sizeof(struct bfhead), 0x55,
+	    (MemSize) (b->bh.bsize - sizeof(struct bfhead)));
+#endif
+    assert(bn->bh.bsize < 0);
+
+    /* The next buffer is allocated.  Set the backpointer in it  to  point
+       to this buffer; the previous free buffer in memory. */
+
+    bn->bh.prevfree = b->bh.bsize;
+
+#ifdef BECtl
+
+    /*	If  a  block-release function is defined, and this free buffer
+	constitutes the entire block, release it.  Note that  pool_len
+	is  defined  in  such a way that the test will fail unless all
+	pool blocks are the same size.	*/
+
+    if (relfcn != NULL &&
+	((bufsize) b->bh.bsize) == (pool_len - sizeof(struct bhead))) {
+
+	assert(b->bh.prevfree == 0);
+	assert(BH((char *) b + b->bh.bsize)->bsize == ESent);
+	assert(BH((char *) b + b->bh.bsize)->prevfree == b->bh.bsize);
+	/*  Unlink the buffer from the free list  */
+	b->ql.blink->ql.flink = b->ql.flink;
+	b->ql.flink->ql.blink = b->ql.blink;
+
+	(*relfcn)(b);
+#ifdef BufStats
+	numprel++;		      /* Nr of expansion block releases */
+	numpblk--;		      /* Total number of blocks */
+	assert(numpblk == numpget - numprel);
+#endif /* BufStats */
+    }
+#endif /* BECtl */
+}
+
+#ifdef BECtl
+
+/*  BECTL  --  Establish automatic pool expansion control  */
+
+void bectl(compact, acquire, release, pool_incr)
+  int (*compact) _((bufsize sizereq, int sequence));
+  void *(*acquire) _((bufsize size));
+  void (*release) _((void *buf));
+  bufsize pool_incr;
+{
+    compfcn = compact;
+    acqfcn = acquire;
+    relfcn = release;
+    exp_incr = pool_incr;
+}
+#endif
+
+/*  BPOOL  --  Add a region of memory to the buffer pool.  */
+
+void bpool(buf, len)
+  void *buf;
+  bufsize len;
+{
+    struct bfhead *b = BFH(buf);
+    struct bhead *bn;
+
+#ifdef SizeQuant
+    len &= ~(SizeQuant - 1);
+#endif
+#ifdef BECtl
+    if (pool_len == 0) {
+	pool_len = len;
+    } else if (len != pool_len) {
+	pool_len = -1;
+    }
+#ifdef BufStats
+    numpget++;			      /* Number of block acquisitions */
+    numpblk++;			      /* Number of blocks total */
+    assert(numpblk == numpget - numprel);
+#endif /* BufStats */
+#endif /* BECtl */
+
+    /* Since the block is initially occupied by a single free  buffer,
+       it  had	better	not  be  (much) larger than the largest buffer
+       whose size we can store in bhead.bsize. */
+
+    assert(len - sizeof(struct bhead) <= -((bufsize) ESent + 1));
+
+    /* Clear  the  backpointer at  the start of the block to indicate that
+       there  is  no  free  block  prior  to  this   one.    That   blocks
+       recombination when the first block in memory is released. */
+
+    b->bh.prevfree = 0;
+
+    /* Chain the new block to the free list. */
+
+    assert(freelist.ql.blink->ql.flink == &freelist);
+    assert(freelist.ql.flink->ql.blink == &freelist);
+    b->ql.flink = &freelist;
+    b->ql.blink = freelist.ql.blink;
+    freelist.ql.blink = b;
+    b->ql.blink->ql.flink = b;
+
+    /* Create a dummy allocated buffer at the end of the pool.	This dummy
+       buffer is seen when a buffer at the end of the pool is released and
+       blocks  recombination  of  the last buffer with the dummy buffer at
+       the end.  The length in the dummy buffer  is  set  to  the  largest
+       negative  number  to  denote  the  end  of  the pool for diagnostic
+       routines (this specific value is  not  counted  on  by  the  actual
+       allocation and release functions). */
+
+    len -= sizeof(struct bhead);
+    b->bh.bsize = (bufsize) len;
+#ifdef FreeWipe
+    V memset(((char *) b) + sizeof(struct bfhead), 0x55,
+	     (MemSize) (len - sizeof(struct bfhead)));
+#endif
+    bn = BH(((char *) b) + len);
+    bn->prevfree = (bufsize) len;
+    /* Definition of ESent assumes two's complement! */
+    assert((~0) == -1);
+    bn->bsize = ESent;
+}
+
+#ifdef BufStats
+
+/*  BSTATS  --	Return buffer allocation free space statistics.  */
+
+void bstats(curalloc, totfree, maxfree, nget, nrel)
+  bufsize *curalloc, *totfree, *maxfree;
+  long *nget, *nrel;
+{
+    struct bfhead *b = freelist.ql.flink;
+
+    *nget = numget;
+    *nrel = numrel;
+    *curalloc = totalloc;
+    *totfree = 0;
+    *maxfree = -1;
+    while (b != &freelist) {
+	assert(b->bh.bsize > 0);
+	*totfree += b->bh.bsize;
+	if (b->bh.bsize > *maxfree) {
+	    *maxfree = b->bh.bsize;
+	}
+	b = b->ql.flink;	      /* Link to next buffer */
+    }
+}
+
+#ifdef BECtl
+
+/*  BSTATSE  --  Return extended statistics  */
+
+void bstatse(pool_incr, npool, npget, nprel, ndget, ndrel)
+  bufsize *pool_incr;
+  long *npool, *npget, *nprel, *ndget, *ndrel;
+{
+    *pool_incr = (pool_len < 0) ? -exp_incr : exp_incr;
+    *npool = numpblk;
+    *npget = numpget;
+    *nprel = numprel;
+    *ndget = numdget;
+    *ndrel = numdrel;
+}
+#endif /* BECtl */
+#endif /* BufStats */
+
+#ifdef DumpData
+
+/*  BUFDUMP  --  Dump the data in a buffer.  This is called with the  user
+		 data pointer, and backs up to the buffer header.  It will
+		 dump either a free block or an allocated one.	*/
+
+void bufdump(buf)
+  void *buf;
+{
+    struct bfhead *b;
+    unsigned char *bdump;
+    bufsize bdlen;
+
+    b = BFH(((char *) buf) - sizeof(struct bhead));
+    assert(b->bh.bsize != 0);
+    if (b->bh.bsize < 0) {
+	bdump = (unsigned char *) buf;
+	bdlen = (-b->bh.bsize) - sizeof(struct bhead);
+    } else {
+	bdump = (unsigned char *) (((char *) b) + sizeof(struct bfhead));
+	bdlen = b->bh.bsize - sizeof(struct bfhead);
+    }
+
+    while (bdlen > 0) {
+	int i, dupes = 0;
+	bufsize l = bdlen;
+	char bhex[50], bascii[20];
+
+	if (l > 16) {
+	    l = 16;
+	}
+
+	for (i = 0; i < l; i++) {
+            V sprintf(bhex + i * 3, "%02X ", bdump[i]);
+            bascii[i] = isprint(bdump[i]) ? bdump[i] : ' ';
+	}
+	bascii[i] = 0;
+        V printf("%-48s   %s\n", bhex, bascii);
+	bdump += l;
+	bdlen -= l;
+	while ((bdlen > 16) && (memcmp((char *) (bdump - 16),
+				       (char *) bdump, 16) == 0)) {
+	    dupes++;
+	    bdump += 16;
+	    bdlen -= 16;
+	}
+	if (dupes > 1) {
+	    V printf(
+                "     (%d lines [%d bytes] identical to above line
skipped)\n",
+		dupes, dupes * 16);
+	} else if (dupes == 1) {
+	    bdump -= 16;
+	    bdlen += 16;
+	}
+    }
+}
+#endif
+
+#ifdef BufDump
+
+/*  BPOOLD  --	Dump a buffer pool.  The buffer headers are always listed.
+		If DUMPALLOC is nonzero, the contents of allocated buffers
+		are  dumped.   If  DUMPFREE  is  nonzero,  free blocks are
+		dumped as well.  If FreeWipe  checking	is  enabled,  free
+		blocks	which  have  been clobbered will always be dumped. */
+
+void bpoold(buf, dumpalloc, dumpfree)
+  void *buf;
+  int dumpalloc, dumpfree;
+{
+    struct bfhead *b = BFH(buf);
+
+    while (b->bh.bsize != ESent) {
+	bufsize bs = b->bh.bsize;
+
+	if (bs < 0) {
+	    bs = -bs;
+            V printf("Allocated buffer: size %6ld bytes.\n", (long) bs);
+	    if (dumpalloc) {
+		bufdump((void *) (((char *) b) + sizeof(struct bhead)));
+	    }
+	} else {
+            char *lerr = "";
+
+	    assert(bs > 0);
+	    if ((b->ql.blink->ql.flink != b) ||
+		(b->ql.flink->ql.blink != b)) {
+                lerr = "  (Bad free list links)";
+	    }
+            V printf("Free block:       size %6ld bytes.%s\n",
+		(long) bs, lerr);
+#ifdef FreeWipe
+	    lerr = ((char *) b) + sizeof(struct bfhead);
+	    if ((bs > sizeof(struct bfhead)) && ((*lerr != 0x55) ||
+		(memcmp(lerr, lerr + 1,
+		  (MemSize) (bs - (sizeof(struct bfhead) + 1))) != 0))) {
+		V printf(
+                    "(Contents of above free block have been overstored.)\n");
+		bufdump((void *) (((char *) b) + sizeof(struct bhead)));
+	    } else
+#endif
+	    if (dumpfree) {
+		bufdump((void *) (((char *) b) + sizeof(struct bhead)));
+	    }
+	}
+	b = BFH(((char *) b) + bs);
+    }
+}
+#endif /* BufDump */
+
+#ifdef BufValid
+
+/*  BPOOLV  --  Validate a buffer pool.  If NDEBUG isn't defined,
+		any error generates an assertion failure.  */
+
+int bpoolv(buf)
+  void *buf;
+{
+    struct bfhead *b = BFH(buf);
+
+    while (b->bh.bsize != ESent) {
+	bufsize bs = b->bh.bsize;
+
+	if (bs < 0) {
+	    bs = -bs;
+	} else {
+            char *lerr = "";
+
+	    assert(bs > 0);
+	    if (bs <= 0) {
+		return 0;
+	    }
+	    if ((b->ql.blink->ql.flink != b) ||
+		(b->ql.flink->ql.blink != b)) {
+                V printf("Free block: size %6ld bytes.  (Bad free list
links)\n",
+		     (long) bs);
+		assert(0);
+		return 0;
+	    }
+#ifdef FreeWipe
+	    lerr = ((char *) b) + sizeof(struct bfhead);
+	    if ((bs > sizeof(struct bfhead)) && ((*lerr != 0x55) ||
+		(memcmp(lerr, lerr + 1,
+		  (MemSize) (bs - (sizeof(struct bfhead) + 1))) != 0))) {
+		V printf(
+                    "(Contents of above free block have been overstored.)\n");
+		bufdump((void *) (((char *) b) + sizeof(struct bhead)));
+		assert(0);
+		return 0;
+	    }
+#endif
+	}
+	b = BFH(((char *) b) + bs);
+    }
+    return 1;
+}
+#endif /* BufValid */
+
+        /***********************\
+	*			*
+	* Built-in test program *
+	*			*
+        \***********************/
+
+#ifdef TestProg
+
+#define Repeatable  1		      /* Repeatable pseudorandom sequence */
+				      /* If Repeatable is not defined, a
+					 time-seeded pseudorandom sequence
+					 is generated, exercising BGET with
+					 a different pattern of calls on each
+					 run. */
+#define OUR_RAND		      /* Use our own built-in version of
+					 rand() to guarantee the test is
+					 100% repeatable. */
+
+#ifdef BECtl
+#define PoolSize    300000	      /* Test buffer pool size */
+#else
+#define PoolSize    50000	      /* Test buffer pool size */
+#endif
+#define ExpIncr     32768	      /* Test expansion block size */
+#define CompactTries 10 	      /* Maximum tries at compacting */
+
+#define dumpAlloc   0		      /* Dump allocated buffers ? */
+#define dumpFree    0		      /* Dump free buffers ? */
+
+#ifndef Repeatable
+extern long time();
+#endif
+
+extern char *malloc();
+extern int free _((char *));
+
+static char *bchain = NULL;	      /* Our private buffer chain */
+static char *bp = NULL; 	      /* Our initial buffer pool */
+
+#include <math.h>
+
+#ifdef OUR_RAND
+
+static unsigned long int next = 1;
+
+/* Return next random integer */
+
+int rand()
+{
+	next = next * 1103515245L + 12345;
+	return (unsigned int) (next / 65536L) % 32768L;
+}
+
+/* Set seed for random generator */
+
+void srand(seed)
+  unsigned int seed;
+{
+	next = seed;
+}
+#endif
+
+/*  STATS  --  Edit statistics returned by bstats() or bstatse().  */
+
+static void stats(when)
+  char *when;
+{
+    bufsize cural, totfree, maxfree;
+    long nget, nfree;
+#ifdef BECtl
+    bufsize pincr;
+    long totblocks, npget, nprel, ndget, ndrel;
+#endif
+
+    bstats(&cural, &totfree, &maxfree, &nget, &nfree);
+    V printf(
+        "%s: %ld gets, %ld releases.  %ld in use, %ld free, largest = %ld\n",
+	when, nget, nfree, (long) cural, (long) totfree, (long) maxfree);
+#ifdef BECtl
+    bstatse(&pincr, &totblocks, &npget, &nprel, &ndget, &ndrel);
+    V printf(
+         "  Blocks: size = %ld, %ld (%ld bytes) in use, %ld gets, %ld
frees\n",
+	 (long)pincr, totblocks, pincr * totblocks, npget, nprel);
+    V printf("  %ld direct gets, %ld direct frees\n", ndget, ndrel);
+#endif /* BECtl */
+}
+
+#ifdef BECtl
+static int protect = 0; 	      /* Disable compaction during bgetr() */
+
+/*  BCOMPACT  --  Compaction call-back function.  */
+
+static int bcompact(bsize, seq)
+  bufsize bsize;
+  int seq;
+{
+#ifdef CompactTries
+    char *bc = bchain;
+    int i = rand() & 0x3;
+
+#ifdef COMPACTRACE
+    V printf("Compaction requested.  %ld bytes needed, sequence %d.\n",
+	(long) bsize, seq);
+#endif
+
+    if (protect || (seq > CompactTries)) {
+#ifdef COMPACTRACE
+        V printf("Compaction gave up.\n");
+#endif
+	return 0;
+    }
+
+    /* Based on a random cast, release a random buffer in the list
+       of allocated buffers. */
+
+    while (i > 0 && bc != NULL) {
+	bc = *((char **) bc);
+	i--;
+    }
+    if (bc != NULL) {
+	char *fb;
+
+	fb = *((char **) bc);
+	if (fb != NULL) {
+	    *((char **) bc) = *((char **) fb);
+	    brel((void *) fb);
+	    return 1;
+	}
+    }
+
+#ifdef COMPACTRACE
+    V printf("Compaction bailed out.\n");
+#endif
+#endif /* CompactTries */
+    return 0;
+}
+
+/*  BEXPAND  --  Expand pool call-back function.  */
+
+static void *bexpand(size)
+  bufsize size;
+{
+    void *np = NULL;
+    bufsize cural, totfree, maxfree;
+    long nget, nfree;
+
+    /* Don't expand beyond the total allocated size given by PoolSize. */
+
+    bstats(&cural, &totfree, &maxfree, &nget, &nfree);
+
+    if (cural < PoolSize) {
+	np = (void *) malloc((unsigned) size);
+    }
+#ifdef EXPTRACE
+    V printf("Expand pool by %ld -- %s.\n", (long) size,
+        np == NULL ? "failed" : "succeeded");
+#endif
+    return np;
+}
+
+/*  BSHRINK  --  Shrink buffer pool call-back function.  */
+
+static void bshrink(buf)
+  void *buf;
+{
+    if (((char *) buf) == bp) {
+#ifdef EXPTRACE
+        V printf("Initial pool released.\n");
+#endif
+	bp = NULL;
+    }
+#ifdef EXPTRACE
+    V printf("Shrink pool.\n");
+#endif
+    free((char *) buf);
+}
+
+#endif /* BECtl */
+
+/*  Restrict buffer requests to those large enough to contain our pointer and
+    small enough for the CPU architecture.  */
+
+static bufsize blimit(bs)
+  bufsize bs;
+{
+    if (bs < sizeof(char *)) {
+	bs = sizeof(char *);
+    }
+
+    /* This is written out in this ugly fashion because the
+       cool expression in sizeof(int) that auto-configured
+       to any length int befuddled some compilers. */
+
+    if (sizeof(int) == 2) {
+	if (bs > 32767) {
+	    bs = 32767;
+	}
+    } else {
+	if (bs > 200000) {
+	    bs = 200000;
+	}
+    }
+    return bs;
+}
+
+int main()
+{
+    int i;
+    double x;
+
+    /* Seed the random number generator.  If Repeatable is defined, we
+       always use the same seed.  Otherwise, we seed from the clock to
+       shake things up from run to run. */
+
+#ifdef Repeatable
+    V srand(1234);
+#else
+    V srand((int) time((long *) NULL));
+#endif
+
+    /*	Compute x such that pow(x, p) ranges between 1 and 4*ExpIncr as
+	p ranges from 0 to ExpIncr-1, with a concentration in the lower
+	numbers.  */
+
+    x = 4.0 * ExpIncr;
+    x = log(x);
+    x = exp(log(4.0 * ExpIncr) / (ExpIncr - 1.0));
+
+#ifdef BECtl
+    bectl(bcompact, bexpand, bshrink, (bufsize) ExpIncr);
+    bp = malloc(ExpIncr);
+    assert(bp != NULL);
+    bpool((void *) bp, (bufsize) ExpIncr);
+#else
+    bp = malloc(PoolSize);
+    assert(bp != NULL);
+    bpool((void *) bp, (bufsize) PoolSize);
+#endif
+
+    stats("Create pool");
+    V bpoolv((void *) bp);
+    bpoold((void *) bp, dumpAlloc, dumpFree);
+
+    for (i = 0; i < TestProg; i++) {
+	char *cb;
+	bufsize bs = pow(x, (double) (rand() & (ExpIncr - 1)));
+
+	assert(bs <= (((bufsize) 4) * ExpIncr));
+	bs = blimit(bs);
+	if (rand() & 0x400) {
+	    cb = (char *) bgetz(bs);
+	} else {
+	    cb = (char *) bget(bs);
+	}
+	if (cb == NULL) {
+#ifdef EasyOut
+	    break;
+#else
+	    char *bc = bchain;
+
+	    if (bc != NULL) {
+		char *fb;
+
+		fb = *((char **) bc);
+		if (fb != NULL) {
+		    *((char **) bc) = *((char **) fb);
+		    brel((void *) fb);
+		}
+		continue;
+	    }
+#endif
+	}
+	*((char **) cb) = (char *) bchain;
+	bchain = cb;
+
+	/* Based on a random cast, release a random buffer in the list
+	   of allocated buffers. */
+
+	if ((rand() & 0x10) == 0) {
+	    char *bc = bchain;
+	    int i = rand() & 0x3;
+
+	    while (i > 0 && bc != NULL) {
+		bc = *((char **) bc);
+		i--;
+	    }
+	    if (bc != NULL) {
+		char *fb;
+
+		fb = *((char **) bc);
+		if (fb != NULL) {
+		    *((char **) bc) = *((char **) fb);
+		    brel((void *) fb);
+		}
+	    }
+	}
+
+	/* Based on a random cast, reallocate a random buffer in the list
+	   to a random size */
+
+	if ((rand() & 0x20) == 0) {
+	    char *bc = bchain;
+	    int i = rand() & 0x3;
+
+	    while (i > 0 && bc != NULL) {
+		bc = *((char **) bc);
+		i--;
+	    }
+	    if (bc != NULL) {
+		char *fb;
+
+		fb = *((char **) bc);
+		if (fb != NULL) {
+		    char *newb;
+
+		    bs = pow(x, (double) (rand() & (ExpIncr - 1)));
+		    bs = blimit(bs);
+#ifdef BECtl
+		    protect = 1;      /* Protect against compaction */
+#endif
+		    newb = (char *) bgetr((void *) fb, bs);
+#ifdef BECtl
+		    protect = 0;
+#endif
+		    if (newb != NULL) {
+			*((char **) bc) = newb;
+		    }
+		}
+	    }
+	}
+    }
+    stats("\nAfter allocation");
+    if (bp != NULL) {
+	V bpoolv((void *) bp);
+	bpoold((void *) bp, dumpAlloc, dumpFree);
+    }
+
+    while (bchain != NULL) {
+	char *buf = bchain;
+
+	bchain = *((char **) buf);
+	brel((void *) buf);
+    }
+    stats("\nAfter release");
+#ifndef BECtl
+    if (bp != NULL) {
+	V bpoolv((void *) bp);
+	bpoold((void *) bp, dumpAlloc, dumpFree);
+    }
+#endif
+
+    return 0;
+}
+#endif

Propchange: trunk/reactos/boot/freeldr/freeldr/rtl/bget.c
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