diff options
Diffstat (limited to 'gdb/bcache.c')
| -rw-r--r-- | gdb/bcache.c | 56 |
1 files changed, 52 insertions, 4 deletions
diff --git a/gdb/bcache.c b/gdb/bcache.c index 5a310f3..32454ce 100644 --- a/gdb/bcache.c +++ b/gdb/bcache.c @@ -2,7 +2,7 @@ Written by Fred Fish <fnf@cygnus.com> Rewritten by Jim Blandy <jimb@cygnus.com> - Copyright 1999, 2000, 2002 Free Software Foundation, Inc. + Copyright 1999, 2000, 2002, 2003 Free Software Foundation, Inc. This file is part of GDB. @@ -25,6 +25,7 @@ #include "gdb_obstack.h" #include "bcache.h" #include "gdb_string.h" /* For memcpy declaration */ +#include "gdb_assert.h" #include <stddef.h> #include <stdlib.h> @@ -71,6 +72,13 @@ struct bcache long unique_size; /* size of unique strings, in bytes */ long total_size; /* total number of bytes cached, including dups */ long structure_size; /* total size of bcache, including infrastructure */ + /* Number of times that the hash table is expanded and hence + re-built, and the corresponding number of times that a string is + [re]hashed as part of entering it into the expanded table. The + total number of hashes can be computed by adding TOTAL_COUNT to + expand_hash_count. */ + unsigned long expand_count; + unsigned long expand_hash_count; }; /* The old hash function was stolen from SDBM. This is what DB 3.0 uses now, @@ -117,6 +125,11 @@ expand_hash_table (struct bcache *bcache) struct bstring **new_buckets; unsigned int i; + /* Count the stats. Every unique item needs to be re-hashed and + re-entered. */ + bcache->expand_count++; + bcache->expand_hash_count += bcache->unique_count; + /* Find the next size. */ new_num_buckets = bcache->num_buckets * 2; for (i = 0; i < (sizeof (sizes) / sizeof (sizes[0])); i++) @@ -265,12 +278,16 @@ print_bcache_statistics (struct bcache *c, char *type) int occupied_buckets; int max_chain_length; int median_chain_length; + int max_entry_size; + int median_entry_size; - /* Count the number of occupied buckets, and measure chain lengths. */ + /* Count the number of occupied buckets, tally the various string + lengths, and measure chain lengths. */ { unsigned int b; - int *chain_length - = (int *) alloca (c->num_buckets * sizeof (*chain_length)); + int *chain_length = XCALLOC (c->num_buckets + 1, int); + int *entry_size = XCALLOC (c->unique_count + 1, int); + int stringi = 0; occupied_buckets = 0; @@ -286,7 +303,10 @@ print_bcache_statistics (struct bcache *c, char *type) while (s) { + gdb_assert (b < c->num_buckets); chain_length[b]++; + gdb_assert (stringi < c->unique_count); + entry_size[stringi++] = s->length; s = s->next; } } @@ -295,6 +315,8 @@ print_bcache_statistics (struct bcache *c, char *type) /* To compute the median, we need the set of chain lengths sorted. */ qsort (chain_length, c->num_buckets, sizeof (chain_length[0]), compare_ints); + qsort (entry_size, c->unique_count, sizeof (entry_size[0]), + compare_ints); if (c->num_buckets > 0) { @@ -306,6 +328,19 @@ print_bcache_statistics (struct bcache *c, char *type) max_chain_length = 0; median_chain_length = 0; } + if (c->unique_count > 0) + { + max_entry_size = entry_size[c->unique_count - 1]; + median_entry_size = entry_size[c->unique_count / 2]; + } + else + { + max_entry_size = 0; + median_entry_size = 0; + } + + xfree (chain_length); + xfree (entry_size); } printf_filtered (" Cached '%s' statistics:\n", type); @@ -321,6 +356,15 @@ print_bcache_statistics (struct bcache *c, char *type) print_percentage (c->total_size - c->unique_size, c->total_size); printf_filtered ("\n"); + printf_filtered (" Max entry size: %d\n", max_entry_size); + printf_filtered (" Average entry size: "); + if (c->unique_count > 0) + printf_filtered ("%ld\n", c->unique_size / c->unique_count); + else + printf_filtered ("(not applicable)\n"); + printf_filtered (" Median entry size: %d\n", median_entry_size); + printf_filtered ("\n"); + printf_filtered (" Total memory used by bcache, including overhead: %ld\n", c->structure_size); printf_filtered (" Percentage memory overhead: "); @@ -330,6 +374,10 @@ print_bcache_statistics (struct bcache *c, char *type) printf_filtered ("\n"); printf_filtered (" Hash table size: %3d\n", c->num_buckets); + printf_filtered (" Hash table expands: %lu\n", + c->expand_count); + printf_filtered (" Hash table hashes: %lu\n", + c->total_count + c->expand_hash_count); printf_filtered (" Hash table population: "); print_percentage (occupied_buckets, c->num_buckets); printf_filtered (" Median hash chain length: %3d\n", |