Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 589 insertions, 0 deletions

diff --git a/REORG.TODO/nscd/mem.c b/REORG.TODO/nscd/mem.c
new file mode 100644
index 0000000000..092f3ae7c1
--- /dev/null
+++ b/REORG.TODO/nscd/mem.c
@@ -0,0 +1,589 @@
+/* Cache memory handling.
+   Copyright (C) 2004-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+   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; 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, see <http://www.gnu.org/licenses/>.  */
+
+#include <assert.h>
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <libintl.h>
+#include <limits.h>
+#include <obstack.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+
+#include "dbg_log.h"
+#include "nscd.h"
+
+
+static int
+sort_he (const void *p1, const void *p2)
+{
+  struct hashentry *h1 = *(struct hashentry **) p1;
+  struct hashentry *h2 = *(struct hashentry **) p2;
+
+  if (h1 < h2)
+    return -1;
+  if (h1 > h2)
+    return 1;
+  return 0;
+}
+
+
+static int
+sort_he_data (const void *p1, const void *p2)
+{
+  struct hashentry *h1 = *(struct hashentry **) p1;
+  struct hashentry *h2 = *(struct hashentry **) p2;
+
+  if (h1->packet < h2->packet)
+    return -1;
+  if (h1->packet > h2->packet)
+    return 1;
+  return 0;
+}
+
+
+/* Basic definitions for the bitmap implementation.  Only BITMAP_T
+   needs to be changed to choose a different word size.  */
+#define BITMAP_T uint8_t
+#define BITS (CHAR_BIT * sizeof (BITMAP_T))
+#define ALLBITS ((((BITMAP_T) 1) << BITS) - 1)
+#define HIGHBIT (((BITMAP_T) 1) << (BITS - 1))
+
+
+static void
+markrange (BITMAP_T *mark, ref_t start, size_t len)
+{
+  /* Adjust parameters for block alignment.  */
+  assert ((start & BLOCK_ALIGN_M1) == 0);
+  start /= BLOCK_ALIGN;
+  len = (len + BLOCK_ALIGN_M1) / BLOCK_ALIGN;
+
+  size_t elem = start / BITS;
+
+  if (start % BITS != 0)
+    {
+      if (start % BITS + len <= BITS)
+	{
+	  /* All fits in the partial byte.  */
+	  mark[elem] |= (ALLBITS >> (BITS - len)) << (start % BITS);
+	  return;
+	}
+
+      mark[elem++] |= ALLBITS << (start % BITS);
+      len -= BITS - (start % BITS);
+    }
+
+  while (len >= BITS)
+    {
+      mark[elem++] = ALLBITS;
+      len -= BITS;
+    }
+
+  if (len > 0)
+    mark[elem] |= ALLBITS >> (BITS - len);
+}
+
+
+void
+gc (struct database_dyn *db)
+{
+  /* We need write access.  */
+  pthread_rwlock_wrlock (&db->lock);
+
+  /* And the memory handling lock.  */
+  pthread_mutex_lock (&db->memlock);
+
+  /* We need an array representing the data area.  All memory
+     allocation is BLOCK_ALIGN aligned so this is the level at which
+     we have to look at the memory.  We use a mark and sweep algorithm
+     where the marks are placed in this array.  */
+  assert (db->head->first_free % BLOCK_ALIGN == 0);
+
+  BITMAP_T *mark;
+  bool mark_use_malloc;
+  /* In prune_cache we are also using a dynamically allocated array.
+     If the array in the caller is too large we have malloc'ed it.  */
+  size_t stack_used = sizeof (bool) * db->head->module;
+  if (__glibc_unlikely (stack_used > MAX_STACK_USE))
+    stack_used = 0;
+  size_t nmark = (db->head->first_free / BLOCK_ALIGN + BITS - 1) / BITS;
+  size_t memory_needed = nmark * sizeof (BITMAP_T);
+  if (__glibc_likely (stack_used + memory_needed <= MAX_STACK_USE))
+    {
+      mark = (BITMAP_T *) alloca_account (memory_needed, stack_used);
+      mark_use_malloc = false;
+      memset (mark, '\0', memory_needed);
+    }
+  else
+    {
+      mark = (BITMAP_T *) xcalloc (1, memory_needed);
+      mark_use_malloc = true;
+    }
+
+  /* Create an array which can hold pointer to all the entries in hash
+     entries.  */
+  memory_needed = 2 * db->head->nentries * sizeof (struct hashentry *);
+  struct hashentry **he;
+  struct hashentry **he_data;
+  bool he_use_malloc;
+  if (__glibc_likely (stack_used + memory_needed <= MAX_STACK_USE))
+    {
+      he = alloca_account (memory_needed, stack_used);
+      he_use_malloc = false;
+    }
+  else
+    {
+      he = xmalloc (memory_needed);
+      he_use_malloc = true;
+    }
+  he_data = &he[db->head->nentries];
+
+  size_t cnt = 0;
+  for (size_t idx = 0; idx < db->head->module; ++idx)
+    {
+      ref_t *prevp = &db->head->array[idx];
+      ref_t run = *prevp;
+
+      while (run != ENDREF)
+	{
+	  assert (cnt < db->head->nentries);
+	  he[cnt] = (struct hashentry *) (db->data + run);
+
+	  he[cnt]->prevp = prevp;
+	  prevp = &he[cnt]->next;
+
+	  /* This is the hash entry itself.  */
+	  markrange (mark, run, sizeof (struct hashentry));
+
+	  /* Add the information for the data itself.  We do this
+	     only for the one special entry marked with FIRST.  */
+	  if (he[cnt]->first)
+	    {
+	      struct datahead *dh
+		= (struct datahead *) (db->data + he[cnt]->packet);
+	      markrange (mark, he[cnt]->packet, dh->allocsize);
+	    }
+
+	  run = he[cnt]->next;
+
+	  ++cnt;
+	}
+    }
+  assert (cnt == db->head->nentries);
+
+  /* Sort the entries by the addresses of the referenced data.  All
+     the entries pointing to the same DATAHEAD object will have the
+     same key.  Stability of the sorting is unimportant.  */
+  memcpy (he_data, he, cnt * sizeof (struct hashentry *));
+  qsort (he_data, cnt, sizeof (struct hashentry *), sort_he_data);
+
+  /* Sort the entries by their address.  */
+  qsort (he, cnt, sizeof (struct hashentry *), sort_he);
+
+#define obstack_chunk_alloc xmalloc
+#define obstack_chunk_free free
+  struct obstack ob;
+  obstack_init (&ob);
+
+  /* Determine the highest used address.  */
+  size_t high = nmark;
+  while (high > 0 && mark[high - 1] == 0)
+    --high;
+
+  /* No memory used.  */
+  if (high == 0)
+    {
+      db->head->first_free = 0;
+      goto out;
+    }
+
+  /* Determine the highest offset.  */
+  BITMAP_T mask = HIGHBIT;
+  ref_t highref = (high * BITS - 1) * BLOCK_ALIGN;
+  while ((mark[high - 1] & mask) == 0)
+    {
+      mask >>= 1;
+      highref -= BLOCK_ALIGN;
+    }
+
+  /* Now we can iterate over the MARK array and find bits which are not
+     set.  These represent memory which can be recovered.  */
+  size_t byte = 0;
+  /* Find the first gap.  */
+  while (byte < high && mark[byte] == ALLBITS)
+    ++byte;
+
+  if (byte == high
+      || (byte == high - 1 && (mark[byte] & ~(mask | (mask - 1))) == 0))
+    /* No gap.  */
+    goto out;
+
+  mask = 1;
+  cnt = 0;
+  while ((mark[byte] & mask) != 0)
+    {
+      ++cnt;
+      mask <<= 1;
+    }
+  ref_t off_free = (byte * BITS + cnt) * BLOCK_ALIGN;
+  assert (off_free <= db->head->first_free);
+
+  struct hashentry **next_hash = he;
+  struct hashentry **next_data = he_data;
+
+  /* Skip over the hash entries in the first block which does not get
+     moved.  */
+  while (next_hash < &he[db->head->nentries]
+	 && *next_hash < (struct hashentry *) (db->data + off_free))
+    ++next_hash;
+
+  while (next_data < &he_data[db->head->nentries]
+	 && (*next_data)->packet < off_free)
+    ++next_data;
+
+
+  /* Now we start modifying the data.  Make sure all readers of the
+     data are aware of this and temporarily don't use the data.  */
+  ++db->head->gc_cycle;
+  assert ((db->head->gc_cycle & 1) == 1);
+
+
+  /* We do not perform the move operations right away since the
+     he_data array is not sorted by the address of the data.  */
+  struct moveinfo
+  {
+    void *from;
+    void *to;
+    size_t size;
+    struct moveinfo *next;
+  } *moves = NULL;
+
+  while (byte < high)
+    {
+      /* Search for the next filled block.  BYTE is the index of the
+	 entry in MARK, MASK is the bit, and CNT is the bit number.
+	 OFF_FILLED is the corresponding offset.  */
+      if ((mark[byte] & ~(mask - 1)) == 0)
+	{
+	  /* No other bit set in the same element of MARK.  Search in the
+	     following memory.  */
+	  do
+	    ++byte;
+	  while (byte < high && mark[byte] == 0);
+
+	  if (byte == high)
+	    /* That was it.  */
+	    break;
+
+	  mask = 1;
+	  cnt = 0;
+	}
+      /* Find the exact bit.  */
+      while ((mark[byte] & mask) == 0)
+	{
+	  ++cnt;
+	  mask <<= 1;
+	}
+
+      ref_t off_alloc = (byte * BITS + cnt) * BLOCK_ALIGN;
+      assert (off_alloc <= db->head->first_free);
+
+      /* Find the end of the used area.  */
+      if ((mark[byte] & ~(mask - 1)) == (BITMAP_T) ~(mask - 1))
+	{
+	  /* All other bits set.  Search the next bytes in MARK.  */
+	  do
+	    ++byte;
+	  while (byte < high && mark[byte] == ALLBITS);
+
+	  mask = 1;
+	  cnt = 0;
+	}
+      if (byte < high)
+	{
+	  /* Find the exact bit.  */
+	  while ((mark[byte] & mask) != 0)
+	    {
+	      ++cnt;
+	      mask <<= 1;
+	    }
+	}
+
+      ref_t off_allocend = (byte * BITS + cnt) * BLOCK_ALIGN;
+      assert (off_allocend <= db->head->first_free);
+      /* Now we know that we can copy the area from OFF_ALLOC to
+	 OFF_ALLOCEND (not included) to the memory starting at
+	 OFF_FREE.  First fix up all the entries for the
+	 displacement.  */
+      ref_t disp = off_alloc - off_free;
+
+      struct moveinfo *new_move;
+      if (__builtin_expect (stack_used + sizeof (*new_move) <= MAX_STACK_USE,
+			    1))
+	new_move = alloca_account (sizeof (*new_move), stack_used);
+      else
+	new_move = obstack_alloc (&ob, sizeof (*new_move));
+      new_move->from = db->data + off_alloc;
+      new_move->to = db->data + off_free;
+      new_move->size = off_allocend - off_alloc;
+      /* Create a circular list to be always able to append at the end.  */
+      if (moves == NULL)
+	moves = new_move->next = new_move;
+      else
+	{
+	  new_move->next = moves->next;
+	  moves = moves->next = new_move;
+	}
+
+      /* The following loop will prepare to move this much data.  */
+      off_free += off_allocend - off_alloc;
+
+      while (off_alloc < off_allocend)
+	{
+	  /* Determine whether the next entry is for a hash entry or
+	     the data.  */
+	  if ((struct hashentry *) (db->data + off_alloc) == *next_hash)
+	    {
+	      /* Just correct the forward reference.  */
+	      *(*next_hash++)->prevp -= disp;
+
+	      off_alloc += ((sizeof (struct hashentry) + BLOCK_ALIGN_M1)
+			    & ~BLOCK_ALIGN_M1);
+	    }
+	  else
+	    {
+	      assert (next_data < &he_data[db->head->nentries]);
+	      assert ((*next_data)->packet == off_alloc);
+
+	      struct datahead *dh = (struct datahead *) (db->data + off_alloc);
+	      do
+		{
+		  assert ((*next_data)->key >= (*next_data)->packet);
+		  assert ((*next_data)->key + (*next_data)->len
+			  <= (*next_data)->packet + dh->allocsize);
+
+		  (*next_data)->packet -= disp;
+		  (*next_data)->key -= disp;
+		  ++next_data;
+		}
+	      while (next_data < &he_data[db->head->nentries]
+		     && (*next_data)->packet == off_alloc);
+
+	      off_alloc += (dh->allocsize + BLOCK_ALIGN_M1) & ~BLOCK_ALIGN_M1;
+	    }
+	}
+      assert (off_alloc == off_allocend);
+
+      assert (off_alloc <= db->head->first_free);
+      if (off_alloc == db->head->first_free)
+	/* We are done, that was the last block.  */
+	break;
+    }
+  assert (next_hash == &he[db->head->nentries]);
+  assert (next_data == &he_data[db->head->nentries]);
+
+  /* Now perform the actual moves.  */
+  if (moves != NULL)
+    {
+      struct moveinfo *runp = moves->next;
+      do
+	{
+	  assert ((char *) runp->to >= db->data);
+	  assert ((char *) runp->to + runp->size
+		  <= db->data  + db->head->first_free);
+	  assert ((char *) runp->from >= db->data);
+	  assert ((char *) runp->from + runp->size
+		  <= db->data  + db->head->first_free);
+
+	  /* The regions may overlap.  */
+	  memmove (runp->to, runp->from, runp->size);
+	  runp = runp->next;
+	}
+      while (runp != moves->next);
+
+      if (__glibc_unlikely (debug_level >= 3))
+	dbg_log (_("freed %zu bytes in %s cache"),
+		 (size_t) (db->head->first_free
+			   - ((char *) moves->to + moves->size - db->data)),
+		 dbnames[db - dbs]);
+
+      /* The byte past the end of the last copied block is the next
+	 available byte.  */
+      db->head->first_free = (char *) moves->to + moves->size - db->data;
+
+      /* Consistency check.  */
+      if (__glibc_unlikely (debug_level >= 3))
+	{
+	  for (size_t idx = 0; idx < db->head->module; ++idx)
+	    {
+	      ref_t run = db->head->array[idx];
+	      size_t cnt = 0;
+
+	      while (run != ENDREF)
+		{
+		  if (run + sizeof (struct hashentry) > db->head->first_free)
+		    {
+		      dbg_log ("entry %zu in hash bucket %zu out of bounds: "
+			       "%" PRIu32 "+%zu > %zu\n",
+			       cnt, idx, run, sizeof (struct hashentry),
+			       (size_t) db->head->first_free);
+		      break;
+		    }
+
+		  struct hashentry *he = (struct hashentry *) (db->data + run);
+
+		  if (he->key + he->len > db->head->first_free)
+		    dbg_log ("key of entry %zu in hash bucket %zu out of "
+			     "bounds: %" PRIu32 "+%zu > %zu\n",
+			     cnt, idx, he->key, (size_t) he->len,
+			     (size_t) db->head->first_free);
+
+		  if (he->packet + sizeof (struct datahead)
+		      > db->head->first_free)
+		    dbg_log ("packet of entry %zu in hash bucket %zu out of "
+			     "bounds: %" PRIu32 "+%zu > %zu\n",
+			     cnt, idx, he->packet, sizeof (struct datahead),
+			     (size_t) db->head->first_free);
+		  else
+		    {
+		      struct datahead *dh = (struct datahead *) (db->data
+								 + he->packet);
+		      if (he->packet + dh->allocsize
+			  > db->head->first_free)
+			dbg_log ("full key of entry %zu in hash bucket %zu "
+				 "out of bounds: %" PRIu32 "+%zu > %zu",
+				 cnt, idx, he->packet, (size_t) dh->allocsize,
+				 (size_t) db->head->first_free);
+		    }
+
+		  run = he->next;
+		  ++cnt;
+		}
+	    }
+	}
+    }
+
+  /* Make sure the data on disk is updated.  */
+  if (db->persistent)
+    msync (db->head, db->data + db->head->first_free - (char *) db->head,
+	   MS_ASYNC);
+
+
+  /* Now we are done modifying the data.  */
+  ++db->head->gc_cycle;
+  assert ((db->head->gc_cycle & 1) == 0);
+
+  /* We are done.  */
+ out:
+  pthread_mutex_unlock (&db->memlock);
+  pthread_rwlock_unlock (&db->lock);
+
+  if (he_use_malloc)
+    free (he);
+  if (mark_use_malloc)
+    free (mark);
+
+  obstack_free (&ob, NULL);
+}
+
+
+void *
+mempool_alloc (struct database_dyn *db, size_t len, int data_alloc)
+{
+  /* Make sure LEN is a multiple of our maximum alignment so we can
+     keep track of used memory is multiples of this alignment value.  */
+  if ((len & BLOCK_ALIGN_M1) != 0)
+    len += BLOCK_ALIGN - (len & BLOCK_ALIGN_M1);
+
+  if (data_alloc)
+    pthread_rwlock_rdlock (&db->lock);
+
+  pthread_mutex_lock (&db->memlock);
+
+  assert ((db->head->first_free & BLOCK_ALIGN_M1) == 0);
+
+  bool tried_resize = false;
+  void *res;
+ retry:
+  res = db->data + db->head->first_free;
+
+  if (__glibc_unlikely (db->head->first_free + len > db->head->data_size))
+    {
+      if (! tried_resize)
+	{
+	  /* Try to resize the database.  Grow size of 1/8th.  */
+	  size_t oldtotal = (sizeof (struct database_pers_head)
+			     + roundup (db->head->module * sizeof (ref_t),
+					ALIGN)
+			     + db->head->data_size);
+	  size_t new_data_size = (db->head->data_size
+				  + MAX (2 * len, db->head->data_size / 8));
+	  size_t newtotal = (sizeof (struct database_pers_head)
+			     + roundup (db->head->module * sizeof (ref_t), ALIGN)
+			     + new_data_size);
+	  if (newtotal > db->max_db_size)
+	    {
+	      new_data_size -= newtotal - db->max_db_size;
+	      newtotal = db->max_db_size;
+	    }
+
+	  if (db->mmap_used && newtotal > oldtotal
+	      /* We only have to adjust the file size.  The new pages
+		 become magically available.  */
+	      && TEMP_FAILURE_RETRY_VAL (posix_fallocate (db->wr_fd, oldtotal,
+							  newtotal
+							  - oldtotal)) == 0)
+	    {
+	      db->head->data_size = new_data_size;
+	      tried_resize = true;
+	      goto retry;
+	    }
+	}
+
+      if (data_alloc)
+	pthread_rwlock_unlock (&db->lock);
+
+      if (! db->last_alloc_failed)
+	{
+	  dbg_log (_("no more memory for database '%s'"), dbnames[db - dbs]);
+
+	  db->last_alloc_failed = true;
+	}
+
+      ++db->head->addfailed;
+
+      /* No luck.  */
+      res = NULL;
+    }
+  else
+    {
+      db->head->first_free += len;
+
+      db->last_alloc_failed = false;
+
+    }
+
+  pthread_mutex_unlock (&db->memlock);
+
+  return res;
+}