Add fixed-size, preallocated pool support

[vpp.git] / src / vppinfra / pool.c

diff --git a/src/vppinfra/pool.c b/src/vppinfra/pool.c
new file mode 100644 (file)
index 0000000..ed83b41
--- /dev/null
+++ b/src/vppinfra/pool.c
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2017 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.
+ */
+/*
+  Copyright (c) 2001, 2002, 2003, 2004 Eliot Dresselhaus
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <vppinfra/pool.h>
+
+void
+_pool_init_fixed (void **pool_ptr, u32 elt_size, u32 max_elts)
+{
+  u8 *mmap_base;
+  u64 vector_size;
+  u64 free_index_size;
+  u64 total_size;
+  u64 page_size;
+  pool_header_t *fh;
+  vec_header_t *vh;
+  u8 *v;
+  u32 *fi;
+  u32 i;
+  u32 set_bits;
+
+  ASSERT (elt_size);
+  ASSERT (max_elts);
+
+  vector_size = pool_aligned_header_bytes + vec_header_bytes (0)
+    + (u64) elt_size *max_elts;
+
+  free_index_size = vec_header_bytes (0) + sizeof (u32) * max_elts;
+
+  /* Round up to a cache line boundary */
+  vector_size = (vector_size + CLIB_CACHE_LINE_BYTES - 1)
+    & ~(CLIB_CACHE_LINE_BYTES - 1);
+
+  free_index_size = (free_index_size + CLIB_CACHE_LINE_BYTES - 1)
+    & ~(CLIB_CACHE_LINE_BYTES - 1);
+
+  total_size = vector_size + free_index_size;
+
+  /* Round up to an even number of pages */
+  page_size = clib_mem_get_page_size ();
+  total_size = (total_size + page_size - 1) & ~(page_size - 1);
+
+  /* mmap demand zero memory */
+
+  mmap_base = mmap (0, total_size, PROT_READ | PROT_WRITE,
+                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+  if (mmap_base == MAP_FAILED)
+    {
+      clib_unix_warning ("mmap");
+      *pool_ptr = 0;
+    }
+
+  /* First comes the pool header */
+  fh = (pool_header_t *) mmap_base;
+  /* Find the user vector pointer */
+  v = (u8 *) (mmap_base + pool_aligned_header_bytes);
+  /* Finally, the vector header */
+  vh = _vec_find (v);
+
+  fh->free_bitmap = 0;         /* No free elts (yet) */
+  fh->max_elts = max_elts;
+  fh->mmap_base = mmap_base;
+  fh->mmap_size = total_size;
+
+  vh->len = max_elts;
+
+  /* Build the free-index vector */
+  vh = (vec_header_t *) (v + vector_size);
+  vh->len = max_elts;
+  fi = (u32 *) (vh + 1);
+
+  fh->free_indices = fi;
+
+  /* Set the entire free bitmap */
+  clib_bitmap_alloc (fh->free_bitmap, max_elts);
+  memset (fh->free_bitmap, 0xff, vec_len (fh->free_bitmap) * sizeof (uword));
+
+  /* Clear any extraneous set bits */
+  set_bits = vec_len (fh->free_bitmap) * BITS (uword);
+
+  for (i = max_elts; i < set_bits; i++)
+    fh->free_bitmap = clib_bitmap_set (fh->free_bitmap, i, 0);
+
+  /* Create the initial free vector */
+  for (i = 0; i < max_elts; i++)
+    fi[i] = (max_elts - 1) - i;
+
+  *pool_ptr = v;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */