Merge janus.mylan:/usr/home/serg/Abk/mysql-5.1

into  janus.mylan:/usr/home/serg/Abk/mysql-maria1


Makefile.am:
  Auto merged
client/mysqldump.c:
  Auto merged
configure.in:
  Auto merged
libmysqld/Makefile.am:
  Auto merged
mysql-test/mysql-test-run.pl:
  Auto merged
mysql-test/r/mysqldump.result:
  Auto merged
mysql-test/t/disabled.def:
  Auto merged
mysql-test/t/mysqldump.test:
  Auto merged
mysys/mf_tempfile.c:
  Auto merged
sql/Makefile.am:
  Auto merged
sql/ha_partition.cc:
  Auto merged
sql/ha_partition.h:
  Auto merged
sql/handler.cc:
  Auto merged
sql/lock.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_plugin.cc:
  Auto merged
sql/sql_select.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
sql/table.cc:
  Auto merged
sql/table.h:
  Auto merged
BUILD/compile-dist:
  SCCS merged

1 files changed, 523 insertions, 0 deletions

diff --git a/mysys/lf_alloc-pin.c b/mysys/lf_alloc-pin.c
new file mode 100644
index 00000000000..51c4df7c94a
--- /dev/null
+++ b/mysys/lf_alloc-pin.c
@@ -0,0 +1,523 @@
+/* QQ: TODO multi-pinbox */
+/* Copyright (C) 2006 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/*
+  wait-free concurrent allocator based on pinning addresses
+
+  It works as follows: every thread (strictly speaking - every CPU, but
+  it's too difficult to do) has a small array of pointers. They're called
+  "pins".  Before using an object its address must be stored in this array
+  (pinned).  When an object is no longer necessary its address must be
+  removed from this array (unpinned). When a thread wants to free() an
+  object it scans all pins of all threads to see if somebody has this
+  object pinned.  If yes - the object is not freed (but stored in a
+  "purgatory").  To reduce the cost of a single free() pins are not scanned
+  on every free() but only added to (thread-local) purgatory. On every
+  LF_PURGATORY_SIZE free() purgatory is scanned and all unpinned objects
+  are freed.
+
+  Pins are used to solve ABA problem. To use pins one must obey
+  a pinning protocol:
+
+   1. Let's assume that PTR is a shared pointer to an object. Shared means
+      that any thread may modify it anytime to point to a different object
+      and free the old object. Later the freed object may be potentially
+      allocated by another thread. If we're unlucky that other thread may
+      set PTR to point to this object again. This is ABA problem.
+   2. Create a local pointer LOCAL_PTR.
+   3. Pin the PTR in a loop:
+      do
+      {
+        LOCAL_PTR= PTR;
+        pin(PTR, PIN_NUMBER);
+      } while (LOCAL_PTR != PTR)
+   4. It is guaranteed that after the loop has ended, LOCAL_PTR
+      points to an object (or NULL, if PTR may be NULL), that
+      will never be freed. It is not guaranteed though
+      that LOCAL_PTR == PTR (as PTR can change any time)
+   5. When done working with the object, remove the pin:
+      unpin(PIN_NUMBER)
+   6. When copying pins (as in the list traversing loop:
+        pin(CUR, 1);
+        while ()
+        {
+          do                            // standard
+          {                             //  pinning
+            NEXT=CUR->next;             //   loop
+            pin(NEXT, 0);               //    see #3
+          } while (NEXT != CUR->next);  //     above
+          ...
+          ...
+          CUR=NEXT;
+          pin(CUR, 1);                  // copy pin[0] to pin[1]
+        }
+      which keeps CUR address constantly pinned), note than pins may be
+      copied only upwards (!!!), that is pin[N] to pin[M], M > N.
+   7. Don't keep the object pinned longer than necessary - the number of
+      pins you have is limited (and small), keeping an object pinned
+      prevents its reuse and cause unnecessary mallocs.
+
+  Explanations:
+
+   3. The loop is important. The following can occur:
+        thread1> LOCAL_PTR= PTR
+        thread2> free(PTR); PTR=0;
+        thread1> pin(PTR, PIN_NUMBER);
+      now thread1 cannot access LOCAL_PTR, even if it's pinned,
+      because it points to a freed memory. That is, it *must*
+      verify that it has indeed pinned PTR, the shared pointer.
+
+   6. When a thread wants to free some LOCAL_PTR, and it scans
+      all lists of pins to see whether it's pinned, it does it
+      upwards, from low pin numbers to high. Thus another thread
+      must copy an address from one pin to another in the same
+      direction - upwards, otherwise the scanning thread may
+      miss it.
+
+  Implementation details:
+
+  Pins are given away from a "pinbox". Pinbox is stack-based allocator.
+  It used dynarray for storing pins, new elements are allocated by dynarray
+  as necessary, old are pushed in the stack for reuse. ABA is solved by
+  versioning a pointer - because we use an array, a pointer to pins is 16 bit,
+  upper 16 bits are used for a version.
+
+  It is assumed that pins belong to a thread and are not transferable
+  between threads (LF_PINS::stack_ends_here being a primary reason
+  for this limitation).
+*/
+
+#include <my_global.h>
+#include <my_sys.h>
+#include <lf.h>
+
+#define LF_PINBOX_MAX_PINS 65536
+
+static void _lf_pinbox_real_free(LF_PINS *pins);
+
+/*
+  Initialize a pinbox. Normally called from lf_alloc_init.
+  See the latter for details.
+*/
+void lf_pinbox_init(LF_PINBOX *pinbox, uint free_ptr_offset,
+                    lf_pinbox_free_func *free_func, void *free_func_arg)
+{
+  DBUG_ASSERT(free_ptr_offset % sizeof(void *) == 0);
+  compile_time_assert(sizeof(LF_PINS) == 128);
+  lf_dynarray_init(&pinbox->pinarray, sizeof(LF_PINS));
+  pinbox->pinstack_top_ver= 0;
+  pinbox->pins_in_array= 0;
+  pinbox->free_ptr_offset= free_ptr_offset;
+  pinbox->free_func= free_func;
+  pinbox->free_func_arg= free_func_arg;
+}
+
+void lf_pinbox_destroy(LF_PINBOX *pinbox)
+{
+  lf_dynarray_destroy(&pinbox->pinarray);
+}
+
+/*
+  Get pins from a pinbox. Usually called via lf_alloc_get_pins() or
+  lf_hash_get_pins().
+
+  SYNOPSYS
+    pinbox      -
+    stack_end   - a pointer to the end (top/bottom, depending on the
+                  STACK_DIRECTION) of stack. Used for safe alloca. There's
+                  no safety margin deducted, a caller should take care of it,
+                  if necessary.
+
+  DESCRIPTION
+    get a new LF_PINS structure from a stack of unused pins,
+    or allocate a new one out of dynarray.
+
+  NOTE
+    It is assumed that pins belong to a thread and are not transferable
+    between threads.
+*/
+LF_PINS *_lf_pinbox_get_pins(LF_PINBOX *pinbox, void *stack_end)
+{
+  uint32 pins, next, top_ver;
+  LF_PINS *el;
+  /*
+    We have an array of max. 64k elements.
+    The highest index currently allocated is pinbox->pins_in_array.
+    Freed elements are in a lifo stack, pinstack_top_ver.
+    pinstack_top_ver is 32 bits; 16 low bits are the index in the
+    array, to the first element of the list. 16 high bits are a version
+    (every time the 16 low bits are updated, the 16 high bits are
+    incremented). Versioniong prevents the ABA problem.
+  */
+  top_ver= pinbox->pinstack_top_ver;
+  do
+  {
+    if (!(pins= top_ver % LF_PINBOX_MAX_PINS))
+    {
+      /* the stack of free elements is empty */
+      pins= my_atomic_add32(&pinbox->pins_in_array, 1)+1;
+      if (unlikely(pins >= LF_PINBOX_MAX_PINS))
+        return 0;
+      /*
+        note that the first allocated element has index 1 (pins==1).
+        index 0 is reserved to mean "NULL pointer"
+      */
+      el= (LF_PINS *)_lf_dynarray_lvalue(&pinbox->pinarray, pins);
+      if (unlikely(!el))
+        return 0;
+      break;
+    }
+    el= (LF_PINS *)_lf_dynarray_value(&pinbox->pinarray, pins);
+    next= el->link;
+  } while (!my_atomic_cas32(&pinbox->pinstack_top_ver, &top_ver,
+                            top_ver-pins+next+LF_PINBOX_MAX_PINS));
+  /*
+    set el->link to the index of el in the dynarray (el->link has two usages:
+    - if element is allocated, it's its own index
+    - if element is free, it's its next element in the free stack
+  */
+  el->link= pins;
+  el->purgatory_count= 0;
+  el->pinbox= pinbox;
+  el->stack_ends_here= stack_end;
+  return el;
+}
+
+/*
+  Put pins back to a pinbox. Usually called via lf_alloc_put_pins() or
+  lf_hash_put_pins().
+
+  DESCRIPTION
+    empty the purgatory (XXX deadlock warning below!),
+    push LF_PINS structure to a stack
+*/
+void _lf_pinbox_put_pins(LF_PINS *pins)
+{
+  LF_PINBOX *pinbox= pins->pinbox;
+  uint32 top_ver, nr;
+  nr= pins->link;
+#ifdef MY_LF_EXTRA_DEBUG
+  {
+    int i;
+    for (i= 0; i < LF_PINBOX_PINS; i++)
+      DBUG_ASSERT(pins->pin[i] == 0);
+  }
+#endif
+  /*
+    XXX this will deadlock if other threads will wait for
+    the caller to do something after _lf_pinbox_put_pins(),
+    and they would have pinned addresses that the caller wants to free.
+    Thus: only free pins when all work is done and nobody can wait for you!!!
+  */
+  while (pins->purgatory_count)
+  {
+    _lf_pinbox_real_free(pins);
+    if (pins->purgatory_count)
+    {
+      my_atomic_rwlock_wrunlock(&pins->pinbox->pinarray.lock);
+      pthread_yield();
+      my_atomic_rwlock_wrlock(&pins->pinbox->pinarray.lock);
+    }
+  }
+  top_ver= pinbox->pinstack_top_ver;
+  do
+  {
+    pins->link= top_ver % LF_PINBOX_MAX_PINS;
+  } while (!my_atomic_cas32(&pinbox->pinstack_top_ver, &top_ver,
+                            top_ver-pins->link+nr+LF_PINBOX_MAX_PINS));
+  return;
+}
+
+static int ptr_cmp(void **a, void **b)
+{
+  return *a < *b ? -1 : *a == *b ? 0 : 1;
+}
+
+#define add_to_purgatory(PINS, ADDR)                                    \
+  do                                                                    \
+  {                                                                     \
+    *(void **)((char *)(ADDR)+(PINS)->pinbox->free_ptr_offset)=         \
+      (PINS)->purgatory;                                                \
+    (PINS)->purgatory= (ADDR);                                          \
+    (PINS)->purgatory_count++;                                          \
+  } while (0)
+
+/*
+  Free an object allocated via pinbox allocator
+
+  DESCRIPTION
+    add an object to purgatory. if necessary, call _lf_pinbox_real_free()
+    to actually free something.
+*/
+void _lf_pinbox_free(LF_PINS *pins, void *addr)
+{
+  add_to_purgatory(pins, addr);
+  if (pins->purgatory_count % LF_PURGATORY_SIZE)
+    _lf_pinbox_real_free(pins);
+}
+
+struct st_harvester {
+  void **granary;
+  int npins;
+};
+
+/*
+  callback for _lf_dynarray_iterate:
+  scan all pins of all threads and accumulate all pins
+*/
+static int harvest_pins(LF_PINS *el, struct st_harvester *hv)
+{
+  int i;
+  LF_PINS *el_end= el+min(hv->npins, LF_DYNARRAY_LEVEL_LENGTH);
+  for (; el < el_end; el++)
+  {
+    for (i= 0; i < LF_PINBOX_PINS; i++)
+    {
+      void *p= el->pin[i];
+      if (p)
+        *hv->granary++= p;
+    }
+  }
+  /*
+    hv->npins may become negative below, but it means that
+    we're on the last dynarray page and harvest_pins() won't be
+    called again. We don't bother to make hv->npins() correct
+    (that is 0) in this case.
+  */
+  hv->npins-= LF_DYNARRAY_LEVEL_LENGTH;
+  return 0;
+}
+
+/*
+  callback for _lf_dynarray_iterate:
+  scan all pins of all threads and see if addr is present there
+*/
+static int match_pins(LF_PINS *el, void *addr)
+{
+  int i;
+  LF_PINS *el_end= el+LF_DYNARRAY_LEVEL_LENGTH;
+  for (; el < el_end; el++)
+    for (i= 0; i < LF_PINBOX_PINS; i++)
+      if (el->pin[i] == addr)
+        return 1;
+  return 0;
+}
+
+#if STACK_DIRECTION < 0
+#define available_stack_size(END,CUR) (long) ((char*)(CUR) - (char*)(END))
+#else
+#define available_stack_size(END,CUR) (long) ((char*)(END) - (char*)(CUR))
+#endif
+
+/*
+  Scan the purgatory and free everything that can be freed
+*/
+static void _lf_pinbox_real_free(LF_PINS *pins)
+{
+  int npins, alloca_size;
+  void *list, **addr;
+  struct st_lf_alloc_node *first, *last= NULL;
+  LF_PINBOX *pinbox= pins->pinbox;
+
+  npins= pinbox->pins_in_array+1;
+
+#ifdef HAVE_ALLOCA
+  alloca_size= sizeof(void *)*LF_PINBOX_PINS*npins;
+  /* create a sorted list of pinned addresses, to speed up searches */
+  if (available_stack_size(&pinbox, pins->stack_ends_here) > alloca_size)
+  {
+    struct st_harvester hv;
+    addr= (void **) alloca(alloca_size);
+    hv.granary= addr;
+    hv.npins= npins;
+    /* scan the dynarray and accumulate all pinned addresses */
+    _lf_dynarray_iterate(&pinbox->pinarray,
+                         (lf_dynarray_func)harvest_pins, &hv);
+
+    npins= hv.granary-addr;
+    /* and sort them */
+    if (npins)
+      qsort(addr, npins, sizeof(void *), (qsort_cmp)ptr_cmp);
+  }
+  else
+#endif
+    addr= 0;
+
+  list= pins->purgatory;
+  pins->purgatory= 0;
+  pins->purgatory_count= 0;
+  while (list)
+  {
+    void *cur= list;
+    list= *(void **)((char *)cur+pinbox->free_ptr_offset);
+    if (npins)
+    {
+      if (addr) /* use binary search */
+      {
+        void **a, **b, **c;
+        for (a= addr, b= addr+npins-1, c= a+(b-a)/2; (b-a) > 1; c= a+(b-a)/2)
+          if (cur == *c)
+            a= b= c;
+          else if (cur > *c)
+            a= c;
+          else
+            b= c;
+        if (cur == *a || cur == *b)
+          goto found;
+      }
+      else /* no alloca - no cookie. linear search here */
+      {
+        if (_lf_dynarray_iterate(&pinbox->pinarray,
+                                 (lf_dynarray_func)match_pins, cur))
+          goto found;
+      }
+    }
+    /* not pinned - freeing */
+    if (last)
+      last= last->next= (struct st_lf_alloc_node *)cur;
+    else
+      first= last= (struct st_lf_alloc_node *)cur;
+    continue;
+found:
+    /* pinned - keeping */
+    add_to_purgatory(pins, cur);
+  }
+  if (last)
+    pinbox->free_func(first, last, pinbox->free_func_arg);
+}
+
+/* lock-free memory allocator for fixed-size objects */
+
+LF_REQUIRE_PINS(1);
+
+/*
+  callback for _lf_pinbox_real_free to free a list of unpinned objects -
+  add it back to the allocator stack
+
+  DESCRIPTION
+    'first' and 'last' are the ends of the linked list of st_lf_alloc_node's:
+    first->el->el->....->el->last. Use first==last to free only one element.
+*/
+static void alloc_free(struct st_lf_alloc_node *first,
+                       struct st_lf_alloc_node *last,
+                       LF_ALLOCATOR *allocator)
+{
+  struct st_lf_alloc_node *tmp;
+  tmp= allocator->top;
+  do
+  {
+    last->next= tmp;
+  } while (!my_atomic_casptr((void **)&allocator->top, (void **)&tmp, first) &&
+           LF_BACKOFF);
+}
+
+/*
+  initialize lock-free allocator
+
+  SYNOPSYS
+    allocator           -
+    size                a size of an object to allocate
+    free_ptr_offset     an offset inside the object to a sizeof(void *)
+                        memory that is guaranteed to be unused after
+                        the object is put in the purgatory. Unused by ANY
+                        thread, not only the purgatory owner.
+                        This memory will be used to link waiting-to-be-freed
+                        objects in a purgatory list.
+*/
+void lf_alloc_init(LF_ALLOCATOR *allocator, uint size, uint free_ptr_offset)
+{
+  lf_pinbox_init(&allocator->pinbox, free_ptr_offset,
+                 (lf_pinbox_free_func *)alloc_free, allocator);
+  allocator->top= 0;
+  allocator->mallocs= 0;
+  allocator->element_size= size;
+  DBUG_ASSERT(size >= sizeof(void*) + free_ptr_offset);
+}
+
+/*
+  destroy the allocator, free everything that's in it
+
+  NOTE
+    As every other init/destroy function here and elsewhere it
+    is not thread safe. No, this function is no different, ensure
+    that no thread needs the allocator before destroying it.
+    We are not responsible for any damage that may be caused by
+    accessing the allocator when it is being or has been destroyed.
+    Oh yes, and don't put your cat in a microwave.
+*/
+void lf_alloc_destroy(LF_ALLOCATOR *allocator)
+{
+  struct st_lf_alloc_node *node= allocator->top;
+  while (node)
+  {
+    struct st_lf_alloc_node *tmp= node->next;
+    my_free((void *)node, MYF(0));
+    node= tmp;
+  }
+  lf_pinbox_destroy(&allocator->pinbox);
+  allocator->top= 0;
+}
+
+/*
+  Allocate and return an new object.
+
+  DESCRIPTION
+    Pop an unused object from the stack or malloc it is the stack is empty.
+    pin[0] is used, it's removed on return.
+*/
+void *_lf_alloc_new(LF_PINS *pins)
+{
+  LF_ALLOCATOR *allocator= (LF_ALLOCATOR *)(pins->pinbox->free_func_arg);
+  struct st_lf_alloc_node *node;
+  for (;;)
+  {
+    do
+    {
+      node= allocator->top;
+      _lf_pin(pins, 0, node);
+    } while (node != allocator->top && LF_BACKOFF);
+    if (!node)
+    {
+      node= (void *)my_malloc(allocator->element_size, MYF(MY_WME));
+#ifdef MY_LF_EXTRA_DEBUG
+      if (likely(node))
+        my_atomic_add32(&allocator->mallocs, 1);
+#endif
+      break;
+    }
+    if (my_atomic_casptr((void **)&allocator->top, (void *)&node, node->next))
+      break;
+  }
+  _lf_unpin(pins, 0);
+  return node;
+}
+
+/*
+  count the number of objects in a pool.
+
+  NOTE
+    This is NOT thread-safe !!!
+*/
+uint lf_alloc_pool_count(LF_ALLOCATOR *allocator)
+{
+  uint i;
+  struct st_lf_alloc_node *node;
+  for (node= allocator->top, i= 0; node; node= node->next, i++)
+    /* no op */;
+  return i;
+}
+