ets: Increase data available in crash dumps and ets:info

OTP-12376

5 files changed, 59 insertions, 25 deletions

diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 8f246ffa07..0d75dbbc04 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -2643,7 +2643,9 @@ BIF_RETTYPE ets_match_object_3(BIF_ALIST_3)
 BIF_RETTYPE ets_info_1(BIF_ALIST_1)
 {
     static Eterm fields[] = {am_protection, am_keypos, am_type, am_named_table,
-	am_node, am_size, am_name, am_heir, am_owner, am_memory, am_compressed};
+                             am_node, am_size, am_name, am_heir, am_owner, am_memory, am_compressed,
+                             am_write_concurrency,
+                             am_read_concurrency};
     Eterm results[sizeof(fields)/sizeof(Eterm)];
     DbTable* tb;
     Eterm res;
@@ -3670,6 +3672,10 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 	    ret = am_protected;
 	else if (tb->common.status & DB_PUBLIC)
 	    ret = am_public;
+    } else if (What == am_write_concurrency) {
+        ret = tb->common.status & DB_FINE_LOCKED ? am_true : am_false;
+    } else if (What == am_read_concurrency) {
+        ret = tb->common.status & DB_FREQ_READ ? am_true : am_false;
     } else if (What == am_name) {
 	ret = tb->common.the_name;
     } else if (What == am_keypos) {
@@ -3752,7 +3758,7 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 			 avg, std_dev_real, std_dev_exp,
 			 make_small(stats.min_chain_len),
 			 make_small(stats.max_chain_len),
-			 make_small(db_kept_items_hash(&tb->hash)));
+			 make_small(stats.kept_items));
 	}
 	else {
 	    ret = am_false;
@@ -3774,6 +3780,11 @@ static void print_table(int to, void *to_arg, int show,  DbTable* tb)
 			+ sizeof(Uint)
 			- 1)
 		       / sizeof(Uint)));
+    erts_print(to, to_arg, "Type: %T\n", table_info(NULL, tb, am_type));
+    erts_print(to, to_arg, "Protection: %T\n", table_info(NULL, tb, am_protection));
+    erts_print(to, to_arg, "Compressed: %T\n", table_info(NULL, tb, am_compressed));
+    erts_print(to, to_arg, "Write Concurrency: %T\n", table_info(NULL, tb, am_write_concurrency));
+    erts_print(to, to_arg, "Read Concurrency: %T\n", table_info(NULL, tb, am_read_concurrency));
 }
 
 void db_info(int to, void *to_arg, int show)    /* Called by break handler */
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 06dac8f161..82d1f894ae 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -646,25 +646,6 @@ restart:
     /* ToDo: Maybe try grow/shrink the table as well */
 }
 
-/* Only used by tests
-*/
-Uint db_kept_items_hash(DbTableHash *tb)
-{
-    Uint kept_items = 0;
-    Uint ix = 0;
-    erts_smp_rwmtx_t* lck = RLOCK_HASH(tb,ix);
-    HashDbTerm* b;
-    do {
-	for (b = BUCKET(tb, ix); b != NULL; b = b->next) {
-	    if (b->hvalue == INVALID_HASH) {
-		++kept_items;
-	    }
-	}	
-	ix = next_slot(tb, ix, &lck);
-    }while (ix);
-    return kept_items;
-}
-
 int db_create_hash(Process *p, DbTable *tbl)
 {
     DbTableHash *tb = &tbl->hash;
@@ -2104,10 +2085,38 @@ int db_mark_all_deleted_hash(DbTable *tbl)
 static void db_print_hash(int to, void *to_arg, int show, DbTable *tbl)
 {
     DbTableHash *tb = &tbl->hash;
+    DbHashStats stats;
     int i;
 
     erts_print(to, to_arg, "Buckets: %d\n", NACTIVE(tb));
-    
+
+#ifdef ERTS_SMP
+    i = tbl->common.is_thread_safe;
+    /* If crash dumping we set table to thread safe in order to
+       avoid taking any locks */
+    if (ERTS_IS_CRASH_DUMPING)
+        tbl->common.is_thread_safe = 1;
+
+    db_calc_stats_hash(&tbl->hash, &stats);
+
+    tbl->common.is_thread_safe = i;
+#else
+    db_calc_stats_hash(&tbl->hash, &stats);
+#endif
+
+    erts_print(to, to_arg, "Chain Length Avg: %f\n", stats.avg_chain_len);
+    erts_print(to, to_arg, "Chain Length Max: %d\n", stats.max_chain_len);
+    erts_print(to, to_arg, "Chain Length Min: %d\n", stats.min_chain_len);
+    erts_print(to, to_arg, "Chain Length Std Dev: %f\n",
+               stats.std_dev_chain_len);
+    erts_print(to, to_arg, "Chain Length Expected Std Dev: %f\n",
+               stats.std_dev_expected);
+
+    if (IS_FIXED(tb))
+        erts_print(to, to_arg, "Fixed: %d\n", stats.kept_items);
+    else
+        erts_print(to, to_arg, "Fixed: false\n");
+
     if (show) {
 	for (i = 0; i < NACTIVE(tb); i++) {
 	    HashDbTerm* list = BUCKET(tb,i);
@@ -2833,6 +2842,7 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
     erts_smp_rwmtx_t* lck;
     int sum = 0;
     int sq_sum = 0;
+    int kept_items = 0;
     int ix;
     int len;
     
@@ -2844,6 +2854,8 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
 	len = 0;
 	for (b = BUCKET(tb,ix); b!=NULL; b=b->next) {
 	    len++;
+            if (b->hvalue == INVALID_HASH)
+                ++kept_items;
 	}
 	sum += len;
 	sq_sum += len*len;
@@ -2855,7 +2867,8 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
     stats->std_dev_chain_len = sqrt((sq_sum - stats->avg_chain_len*sum) / NACTIVE(tb));
     /* Expected	standard deviation from a good uniform hash function, 
        ie binomial distribution (not taking the linear hashing into acount) */
-    stats->std_dev_expected = sqrt(stats->avg_chain_len * (1 - 1.0/NACTIVE(tb)));	
+    stats->std_dev_expected = sqrt(stats->avg_chain_len * (1 - 1.0/NACTIVE(tb)));
+    stats->kept_items = kept_items;
 }
 #ifdef HARDDEBUG
 
diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h
index e68081a5b1..f12cd363b0 100644
--- a/erts/emulator/beam/erl_db_hash.h
+++ b/erts/emulator/beam/erl_db_hash.h
@@ -104,6 +104,7 @@ typedef struct {
     float std_dev_expected;
     int max_chain_len;
     int min_chain_len;
+    int kept_items;
 }DbHashStats;
 
 void db_calc_stats_hash(DbTableHash* tb, DbHashStats*);
diff --git a/lib/stdlib/doc/src/ets.xml b/lib/stdlib/doc/src/ets.xml
index 3df24bf688..aa16e4e3db 100644
--- a/lib/stdlib/doc/src/ets.xml
+++ b/lib/stdlib/doc/src/ets.xml
@@ -456,6 +456,12 @@ Error: fun containing local Erlang function calls
           <item><c>{type, <seealso marker="#type-type">type()</seealso>}</c>          <br></br>
 
            The table type.</item>
+          <item><c>{read_concurrency, boolean()}</c>          <br></br>
+
+           Indicates whether the table uses read_concurrency or not.</item>
+          <item><c>{write_concurrency, boolean()}</c>          <br></br>
+
+           Indicates whether the table uses write_concurrency or not.</item>
         </list>
       </desc>
     </func>
diff --git a/lib/stdlib/src/ets.erl b/lib/stdlib/src/ets.erl
index 42b11a97e2..d3a6a21416 100644
--- a/lib/stdlib/src/ets.erl
+++ b/lib/stdlib/src/ets.erl
@@ -133,7 +133,9 @@ give_away(_, _, _) ->
                  | {owner, pid()}
                  | {protection, access()}
                  | {size, non_neg_integer()}
-                 | {type, type()}.
+                 | {type, type()}
+		 | {write_concurrency, boolean()}
+		 | {read_concurrency, boolean()}.
 
 info(_) ->
     erlang:nif_error(undef).
@@ -142,7 +144,8 @@ info(_) ->
       Tab :: tab(),
       Item :: compressed | fixed | heir | keypos | memory
             | name | named_table | node | owner | protection
-            | safe_fixed | size | stats | type,
+            | safe_fixed | size | stats | type
+	    | write_concurrency | read_concurrency,
       Value :: term().
 
 info(_, _) ->