Merge branch 'master' of ecommons@wax.hive:bdberl

Rakefile

@@ -22,7 +22,11 @@ end
 
 rule ".o" => ["%X.c", "%X.h"] do |t|
   puts "compiling #{t.source}..."
-  sh "gcc -g -c -Wall -Werror -fPIC -Ic_src/system/include -I#{erts_dir()}/include #{t.source} -o #{t.name}", :verbose => false
+  sh "gcc -g -c -Wall -Werror -fPIC #{dflag} -Ic_src/system/include -I#{erts_dir()}/include #{t.source} -o #{t.name}", :verbose => false
+end
+
+def dflag()
+  ENV["release"] ? "" : "-DDEBUG"
 end
 
 task :compile_c => ['c_src'] + C_OBJS

c_src/bdberl_drv.c

@@ -134,12 +134,16 @@ static TPool* G_TPOOL_TXNS;
         erl_drv_mutex_unlock(d->port_lock);             \
     }}
 
-
+#ifdef DEBUG
+#  define DBG printf
+#else
+#  define DBG(arg1,...)
+#endif
 
 
 DRIVER_INIT(bdberl_drv) 
 {
-    printf("DRIVER INIT\n");
+    DBG("DRIVER INIT\n");
     // Setup flags we'll use to init the environment
     int flags = 
         DB_INIT_LOCK |          /* Enable support for locking */
@@ -254,9 +258,9 @@ static void bdberl_drv_stop(ErlDrvData handle)
         // Drop the lock prior to starting the wait for the async process
         erl_drv_mutex_unlock(d->port_lock);
 
-        printf("Cancelling async job for port: %p\n", d->port);
+        DBG("Cancelling async job for port: %p\n", d->port);
         bdberl_tpool_cancel(d->async_pool, d->async_job);
-        printf("Canceled async job for port: %p\n", d->port);
+        DBG("Canceled async job for port: %p\n", d->port);
     }
     else
     {
@@ -285,7 +289,7 @@ static void bdberl_drv_stop(ErlDrvData handle)
         close_database(d->dbrefs->dbref, 0, d);
     }
 
-    printf("Stopped port: %p\n", d->port);
+    DBG("Stopped port: %p\n", d->port);
     
     // Release the port instance data
     driver_free(d->work_buffer);
@@ -313,7 +317,7 @@ static void bdberl_drv_finish()
     erl_drv_rwlock_destroy(G_DATABASES_RWLOCK);
     hive_hash_destroy(G_DATABASES_NAMES);
 
-    printf("DRIVER_FINISH\n");
+    DBG("DRIVER_FINISH\n");
 }
 
 static int bdberl_drv_control(ErlDrvData handle, unsigned int cmd, 
@@ -697,7 +701,7 @@ static int close_database(int dbref, unsigned flags, PortData* data)
         Database* database = &G_DATABASES[dbref];
         if (database->ports == 0)
         {
-            printf("Closing actual database for dbref %d\n", dbref);
+            DBG("Closing actual database for dbref %d\n", dbref);
             // Close out the BDB handle
             database->db->close(database->db, flags);
         
@@ -1229,14 +1233,14 @@ static void* deadlock_check(void* arg)
         G_DB_ENV->lock_detect(G_DB_ENV, 0, DB_LOCK_DEFAULT, &count);
         if (count > 0)
         {
-            printf("Rejected deadlocks: %d\n", count);
+            DBG("Rejected deadlocks: %d\n", count);
         }
 
         // TODO: Use nanosleep
         usleep(G_DEADLOCK_CHECK_INTERVAL * 1000);
     }
 
-    printf("Deadlock checker exiting.\n");
+    DBG("Deadlock checker exiting.\n");
     return 0;
 }
 
@@ -1253,7 +1257,7 @@ static void* trickle_write(void* arg)
             // Enough time has passed -- time to run the trickle operation again
             int pages_wrote = 0;
             G_DB_ENV->memp_trickle(G_DB_ENV, G_TRICKLE_PERCENTAGE, &pages_wrote);
-            printf("Wrote %d pages to achieve %d trickle\n", pages_wrote, G_TRICKLE_PERCENTAGE);
+            DBG("Wrote %d pages to achieve %d trickle\n", pages_wrote, G_TRICKLE_PERCENTAGE);
 
             // Reset the counter
             elapsed_secs = 0;
@@ -1266,7 +1270,7 @@ static void* trickle_write(void* arg)
         }
     }
 
-    printf("Trickle writer exiting.\n");
+    DBG("Trickle writer exiting.\n");
     return 0;
 }
 

src/bdberl.erl

@@ -12,7 +12,7 @@
          txn_commit/0, txn_commit/1, txn_abort/0,
          get_cache_size/0, set_cache_size/3,
          get_txn_timeout/0, set_txn_timeout/1,
-         transaction/1,
+         transaction/1, transaction/2,
          put/3, put/4,
          put_r/3, put_r/4,
          put_commit/3, put_commit/4, 
@@ -24,6 +24,8 @@
 
 -include("bdberl.hrl").
 
+-define(is_lock_error(Error), (Error =:= deadlock orelse Error =:= lock_not_granted)).
+
 
 open(Name, Type) ->
     open(Name, Type, [create]).
@@ -97,18 +99,34 @@ txn_abort() ->
         Error ->
             {error, {txn_abort, Error}}
     end.
-            
+
 transaction(Fun) ->
+    transaction(Fun, infinity).
+
+transaction(_Fun, 0) ->
+    txn_abort(),
+    {error, {transaction_failed, retry_limit_reached}};
+transaction(Fun, Retries) ->
     txn_begin(),
     try Fun() of
         abort ->
             txn_abort(),
             {error, transaction_aborted};
+
         Value ->
             txn_commit(),
             {ok, Value}
     catch
-        _ : Reason -> 
+        throw : {error, {_Op, Error}} when ?is_lock_error(Error) ->
+            txn_abort(),
+            erlang:yield(),
+            R = case Retries of
+                    infinity -> infinity;
+                    Retries -> Retries - 1
+                end,
+            transaction(Fun, R);
+
+        _ : Reason ->
             txn_abort(),
             {error, {transaction_failed, Reason}}
     end.
@@ -142,7 +160,6 @@ put_commit_r(Db, Key, Value, Opts) ->
         ok -> ok;
         Error -> throw(Error)
     end.
-            
 
 get(Db, Key) ->
     get(Db, Key, []).
@@ -178,7 +195,7 @@ update(Db, Key, Fun) ->
 
 update(Db, Key, Fun, Args) ->
     F = fun() ->
-            Value = case get(Db, Key, [rmw]) of
+            Value = case get_r(Db, Key, [rmw]) of
                         not_found -> not_found;
                         {ok, Val} -> Val
                     end,
@@ -186,7 +203,7 @@ update(Db, Key, Fun, Args) ->
                            undefined -> Fun(Key, Value);
                            Args      -> Fun(Key, Value, Args)
                        end,
-            ok = put_commit(Db, Key, NewValue),
+            put_commit_r(Db, Key, NewValue),
             NewValue
         end,
     transaction(F).

test/thrash_SUITE.erl

@@ -29,7 +29,7 @@ wait_for_finish(0) ->
 wait_for_finish(Count) ->
     receive
         {finished, Pid} ->
-            io:format("~p is done; ~p remaining.\n", [Pid, Count-1]),
+            ct:print("~p is done; ~p remaining.\n", [Pid, Count-1]),
             wait_for_finish(Count-1)
     end.
 
@@ -47,34 +47,16 @@ thrash_run(Owner) ->
 thrash_incr_loop(Owner, 0) ->
     Owner ! {finished, self()};
 thrash_incr_loop(Owner, Count) ->
-    ct:print("~p\n", [Count]),
+    ct:print("~p", [Count]),
     %% Choose random key
     Key = random:uniform(1200),
     
     %% Start a txn that will read the current value of the key and increment by 1
-    F = fun() ->
+    F = fun(_Key, Value) ->
-                case bdberl:get(0, Key, [rmw]) of
+            case Value of
-                    not_found ->
+                not_found -> 0;
-                        Value = 0;
+                Value     -> Value + 1
-
+            end
-                    {ok, Value} ->
-                        Value
-                end,
-                ok = bdberl:put(0, Key, Value)
         end,
-    ok = do_txn(F, 0),
+    {ok, _} = bdberl:update(0, Key, F),
     thrash_incr_loop(Owner, Count-1).
-
-do_txn(F, Count) ->
-    case bdberl:txn_begin() of
-        ok ->
-            case catch(F()) of
-                {'EXIT', _Reason} ->
-                    io:format("Txn attempt ~p failed; retrying", [Count]),
-                    do_txn(F, Count+1);
-                _Other ->
-                    ok = bdberl:txn_commit()
-            end;
-        {error, _Reason} ->
-            do_txn(F, Count+1)
-    end.