Doubly-linked list element pools

Change-Id: I96e7602be48dfb5bb3867ad1e9f15c543903b3d6
Signed-off-by: Dave Barach <dave@barachs.net>

vppinfra/Makefile.am

@@ -24,6 +24,7 @@ TESTS =
 
 if ENABLE_TESTS
 TESTS  +=  test_bihash_template \
+	   test_dlist \
 	   test_elog \
 	   test_elf \
 	   test_fifo \
@@ -54,6 +55,7 @@ noinst_PROGRAMS = $(TESTS)
 check_PROGRAMS	= $(TESTS)
 
 test_bihash_template_SOURCES = vppinfra/test_bihash_template.c
+test_dlist_SOURCES = vppinfra/test_dlist.c
 test_elog_SOURCES = vppinfra/test_elog.c
 test_elf_SOURCES = vppinfra/test_elf.c
 test_fifo_SOURCES = vppinfra/test_fifo.c
@@ -82,6 +84,7 @@ test_zvec_SOURCES = vppinfra/test_zvec.c
 # All unit tests use ASSERT for failure
 # So we'll need -DDEBUG to enable ASSERTs
 test_bihash_template_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
+test_dlist_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
 test_elog_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
 test_elf_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
 test_fifo_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
@@ -108,6 +111,7 @@ test_vec_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
 test_zvec_CPPFLAGS =	$(AM_CPPFLAGS) -DCLIB_DEBUG
 
 test_bihash_template_LDADD =	libvppinfra.la
+test_dlist_LDADD =	libvppinfra.la
 test_elog_LDADD =	libvppinfra.la
 test_elf_LDADD =	libvppinfra.la
 test_fifo_LDADD =	libvppinfra.la
@@ -134,6 +138,7 @@ test_vec_LDADD =	libvppinfra.la
 test_zvec_LDADD =	libvppinfra.la
 
 test_bihash_template_LDFLAGS = -static
+test_dlist_LDFLAGS = -static
 test_elog_LDFLAGS = -static
 test_elf_LDFLAGS = -static
 test_fifo_LDFLAGS = -static
@@ -178,6 +183,7 @@ nobase_include_HEADERS = \
   vppinfra/cache.h \
   vppinfra/clib.h \
   vppinfra/cpu.h \
+  vppinfra/dlist.h \
   vppinfra/elf.h \
   vppinfra/elf_clib.h \
   vppinfra/elog.h \

vppinfra/vppinfra/bihash_template.c

@@ -418,7 +418,6 @@ u8 * BV(format_bihash) (u8 * s, va_list * args)
 
   s = format (s, "    %lld active elements\n", active_elements);
   s = format (s, "    %d free lists\n", vec_len (h->freelists));
-  s = format (s, "    %U\n", format_mheap, h->mheap, 1 /* verbose */);
 
   return s;
 }

vppinfra/vppinfra/dlist.h

@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * 
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+*/
+
+#ifndef included_dlist_h
+#define included_dlist_h
+
+#include <stdarg.h>
+#include <vppinfra/clib.h>
+#include <vppinfra/vec.h>
+#include <vppinfra/pool.h>
+#include <vppinfra/error.h>
+#include <vppinfra/format.h>
+#include <vppinfra/cache.h>
+
+typedef struct {
+  u32 next;
+  u32 prev;
+  u32 value;
+} dlist_elt_t;
+
+static inline void 
+clib_dlist_init (dlist_elt_t * pool, u32 index)
+{
+  dlist_elt_t * head = pool_elt_at_index (pool, index);
+  memset (head, 0xFF, sizeof (*head));
+}
+
+static inline void 
+clib_dlist_addtail (dlist_elt_t * pool, u32 head_index, u32 new_index)
+{
+  dlist_elt_t * head = pool_elt_at_index (pool, head_index);
+  u32 old_last_index;
+  dlist_elt_t * old_last;
+  dlist_elt_t * new;
+
+  ASSERT(head->value == ~0);
+
+  new = pool_elt_at_index (pool, new_index);
+
+  if (PREDICT_FALSE(head->next == ~0))
+    {
+      head->next = head->prev = new_index;
+      new->next = new->prev = head_index;
+      return;
+    }
+
+  old_last_index = head->prev;
+  old_last = pool_elt_at_index (pool, old_last_index);
+
+  new->next = old_last->next;
+  new->prev = old_last_index;
+  old_last->next = new_index;
+  head->prev = new_index;
+}
+
+static inline void 
+clib_dlist_addhead (dlist_elt_t * pool, u32 head_index, u32 new_index)
+{
+  dlist_elt_t * head = pool_elt_at_index (pool, head_index);
+  dlist_elt_t * old_first;
+  u32 old_first_index;
+  dlist_elt_t * new;
+  
+  ASSERT(head->value == ~0);
+
+  new = pool_elt_at_index (pool, new_index);
+
+  if (PREDICT_FALSE(head->next == ~0))
+    {
+      head->next = head->prev = new_index;
+      new->next = new->prev = head_index;
+      return;
+    }
+
+  old_first_index = head->next;
+  old_first = pool_elt_at_index (pool, old_first_index);
+
+  new->next = old_first_index;
+  new->prev = old_first->prev;
+  old_first->prev = new_index;
+  head->next = new_index;
+}
+
+static inline void
+clib_dlist_remove (dlist_elt_t * pool, u32 index)
+{
+  dlist_elt_t * elt = pool_elt_at_index (pool, index);
+  dlist_elt_t * next_elt, * prev_elt;
+  
+  /* listhead, not so much */
+  ASSERT(elt->value != ~0);
+
+  next_elt = pool_elt_at_index (pool, elt->next);
+  prev_elt = pool_elt_at_index (pool, elt->prev);
+
+  next_elt->prev = elt->prev;
+  prev_elt->next = elt->next;
+
+  elt->prev = elt->next = ~0;
+}
+
+static inline u32 clib_dlist_remove_head (dlist_elt_t * pool, u32 head_index)
+{
+  dlist_elt_t * head = pool_elt_at_index (pool, head_index);
+  u32 rv;
+
+  ASSERT(head->value == ~0);
+
+  if (head->next == ~0)
+    return ~0;
+
+  rv = head->next;
+  clib_dlist_remove (pool, rv);
+  return rv;
+}
+
+static inline u32 clib_dlist_remove_tail (dlist_elt_t * pool, u32 head_index)
+{
+  dlist_elt_t * head = pool_elt_at_index (pool, head_index);
+  u32 rv;
+
+  ASSERT(head->value == ~0);
+
+  if (head->prev == ~0)
+    return ~0;
+
+  rv = head->prev;
+  clib_dlist_remove (pool, rv);
+  return rv;
+}
+
+#endif /* included_dlist_h */

vppinfra/vppinfra/test_dlist.c

@@ -0,0 +1,190 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vppinfra/dlist.h>
+
+typedef struct {
+  dlist_elt_t * test_pool;
+  u32 head_index;
+} test_main_t;
+
+test_main_t test_main;
+
+int test_dlist_main (unformat_input_t * input)
+{
+  test_main_t * tm = &test_main;
+  dlist_elt_t * head, * elt;
+  u32 elt_index, head_index;
+  u32 value;
+  int i;
+  
+  pool_get (tm->test_pool, head);
+  head_index = head - tm->test_pool;
+  clib_dlist_init (tm->test_pool, head - tm->test_pool);
+
+  for (i = 1; i <= 3; i++)
+    {
+      pool_get (tm->test_pool, elt);
+      elt_index = elt - tm->test_pool;
+
+      clib_dlist_init (tm->test_pool, elt_index);
+      elt->value = i;
+      clib_dlist_addtail (tm->test_pool, head_index, elt_index);
+    }
+
+  head = pool_elt_at_index (tm->test_pool, head_index);
+
+  fformat (stdout, "Dump forward links\n");
+  elt_index = head->next;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->next;
+      value = elt->value;
+    }
+
+  fformat (stdout, "Dump reverse links\n");
+  elt_index = head->prev;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->prev;
+      value = elt->value;
+    }
+
+  fformat (stdout, "remove first element\n");
+
+  elt_index = clib_dlist_remove_head (tm->test_pool, head_index);
+  elt = pool_elt_at_index (tm->test_pool, elt_index);
+
+  fformat (stdout, "removed index %d value %d\n", elt_index, elt->value);
+
+  head = pool_elt_at_index (tm->test_pool, head_index);
+
+  fformat (stdout, "Dump forward links\n");
+  elt_index = head->next;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->next;
+      value = elt->value;
+    }
+
+  fformat (stdout, "Dump reverse links\n");
+  elt_index = head->prev;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->prev;
+      value = elt->value;
+    }
+
+  fformat (stdout, "re-insert index %d value %d at head\n", 1, 1);
+
+  clib_dlist_addhead (tm->test_pool, head_index, 1);
+
+  fformat (stdout, "Dump forward links\n");
+  elt_index = head->next;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->next;
+      value = elt->value;
+    }
+
+  fformat (stdout, "Dump reverse links\n");
+  elt_index = head->prev;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->prev;
+      value = elt->value;
+    }
+
+  fformat (stdout, "Remove middle element\n");
+
+  clib_dlist_remove (tm->test_pool, 2);
+  elt = pool_elt_at_index (tm->test_pool, 2);
+
+  fformat (stdout, "removed index %d value %d\n", elt_index, elt->value);
+  
+  fformat (stdout, "Dump forward links\n");
+  elt_index = head->next;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->next;
+      value = elt->value;
+    }
+
+  fformat (stdout, "Dump reverse links\n");
+  elt_index = head->prev;
+  i = 1;
+  value = 0;
+  while (value != ~0)
+    {
+      elt = pool_elt_at_index (tm->test_pool, elt_index);
+      fformat(stdout, "elt %d value %d\n", 
+              i++, elt->value);
+      elt_index = elt->prev;
+      value = elt->value;
+    }
+
+  return 0;
+}
+
+#ifdef CLIB_UNIX
+int main (int argc, char * argv[])
+{
+  unformat_input_t i;
+  int ret;
+
+  clib_mem_init (0, 3ULL<<30);
+
+  unformat_init_command_line (&i, argv);
+  ret = test_dlist_main (&i);
+  unformat_free (&i);
+
+  return ret;
+}
+#endif /* CLIB_UNIX */