Remove the 'message_queue_data' option 'mixed'

11 files changed, 25 insertions, 86 deletions

diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index 1bbde7f1e0..2fae3bfb1f 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -660,11 +660,11 @@
         <p>Sets the initial process dictionary size of processes to the size
           <c><![CDATA[Size]]></c>.</p>
       </item>
-      <tag><marker id="+hmqd"><c>+hmqd off_heap|on_heap|mixed</c></marker></tag>
+      <tag><marker id="+hmqd"><c>+hmqd off_heap|on_heap</c></marker></tag>
       <item><p>
 	Sets the default value for the process flag
 	<c>message_queue_data</c>. If <c>+hmqd</c> is not
-	passed, <c>mixed</c> will be the default. For more information,
+	passed, <c>on_heap</c> will be the default. For more information,
 	see the documentation of
         <seealso marker="erlang#process_flag_message_queue_data"><c>process_flag(message_queue_data,
 	MQD)</c></seealso>.
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 9287b32fec..ddde1c96c4 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -4449,11 +4449,6 @@ os_prompt% </pre>
 	    off heap. This is how messages always have been stored
 	    up until ERTS version 8.0.
 	  </p></item>
-          <tag><c>mixed</c></tag>
-	  <item><p>
-	    Messages may be placed either on the heap or outside
-	    of the heap.
-	  </p></item>
         </taglist>
 	<p>
 	  The default <c>message_queue_data</c> process flag is determined
@@ -4877,7 +4872,7 @@ os_prompt% </pre>
           <item>
             <p>Returns the current state of the <c>message_queue_data</c>
 	    process flag. <c><anno>MQD</anno></c> is either <c>off_heap</c>,
-	    <c>on_heap</c>, or <c>mixed</c>. For more information, see the
+	    or <c>on_heap</c>. For more information, see the
 	    documentation of
             <seealso marker="#process_flag_message_queue_data"><c>process_flag(message_queue_data,
 	    MQD)</c></seealso>.</p>
@@ -5808,7 +5803,7 @@ true</pre>
           <item>
             <p>Sets the state of the <c>message_queue_data</c> process
 	    flag. <c><anno>MQD</anno></c> should be either <c>off_heap</c>,
-	    <c>on_heap</c>, or <c>mixed</c>. The default
+	    or <c>on_heap</c>. The default
 	    <c>message_queue_data</c> process flag is determined by the
 	    <seealso marker="erl#+hmqd"><c>+hmqd</c></seealso> <c>erl</c>
 	    command line argument. For more information, see the
@@ -7164,7 +7159,7 @@ ok
           <tag><marker id="system_info_message_queue_data"><c>message_queue_data</c></marker></tag>
           <item>
             <p>Returns the default value of the <c>message_queue_data</c>
-	    process flag which is either <c>off_heap</c>, <c>on_heap</c>, or <c>mixed</c>.
+	    process flag which is either <c>off_heap</c>, or <c>on_heap</c>.
 	    This default is set by the <c>erl</c> command line argument
 	    <seealso marker="erl#+hmqd"><c>+hmqd</c></seealso>. For more information on the
 	    <c>message_queue_data</c> process flag, see documentation of
diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 8f65e71531..464058535a 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -389,7 +389,6 @@ atom min_heap_size
 atom min_bin_vheap_size
 atom minor_version
 atom Minus='-'
-atom mixed
 atom module
 atom module_info
 atom monitored_by
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 2a3bd4afe5..e77da526fd 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -917,9 +917,6 @@ BIF_RETTYPE spawn_opt_1(BIF_ALIST_1)
 		    goto error;
 	    } else if (arg == am_message_queue_data) {
 		switch (val) {
-		case am_mixed:
-		    so.flags &= ~(SPO_OFF_HEAP_MSGQ|SPO_ON_HEAP_MSGQ);
-		    break;
 		case am_on_heap:
 		    so.flags &= ~SPO_OFF_HEAP_MSGQ;
 		    so.flags |= SPO_ON_HEAP_MSGQ;
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 2e195db0ee..b410578d37 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -1565,9 +1565,6 @@ process_info_aux(Process *BIF_P,
 	case F_ON_HEAP_MSGQ:
 	    res = am_on_heap;
 	    break;
-	case 0:
-	    res = am_mixed;
-	    break;
 	default:
 	    res = am_error;
 	    ERTS_INTERNAL_ERROR("Inconsistent message queue management state");
@@ -2809,8 +2806,6 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	    BIF_RET(am_off_heap);
 	case SPO_ON_HEAP_MSGQ:
 	    BIF_RET(am_on_heap);
-	case 0:
-	    BIF_RET(am_mixed);
 	default:
 	    ERTS_INTERNAL_ERROR("Inconsistent message queue management state");
 	    BIF_RET(am_error);
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 0649fb68de..fbdafec4ef 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -585,7 +585,7 @@ void erts_usage(void)
     erts_fprintf(stderr, "-hpds size     initial process dictionary size (default %d)\n",
 	       erts_pd_initial_size);
     erts_fprintf(stderr, "-hmqd  val     set default message queue data flag for processes,\n");
-    erts_fprintf(stderr, "               valid values are: off_heap | on_heap | mixed\n");
+    erts_fprintf(stderr, "               valid values are: off_heap | on_heap\n");
 
     /*    erts_fprintf(stderr, "-i module  set the boot module (default init)\n"); */
 
@@ -1526,9 +1526,7 @@ erl_start(int argc, char **argv)
 			    erts_pd_initial_size));
             } else if (has_prefix("mqd", sub_param)) {
 		arg = get_arg(sub_param+3, argv[i+1], &i);
-		if (sys_strcmp(arg, "mixed") == 0)
-		    erts_default_spo_flags &= ~(SPO_ON_HEAP_MSGQ|SPO_OFF_HEAP_MSGQ);
-		else if (sys_strcmp(arg, "on_heap") == 0) {
+		if (sys_strcmp(arg, "on_heap") == 0) {
 		    erts_default_spo_flags &= ~SPO_OFF_HEAP_MSGQ;
 		    erts_default_spo_flags |= SPO_ON_HEAP_MSGQ;
 		}
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index 579f6e427d..d82532b354 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -1123,11 +1123,9 @@ erts_change_message_queue_management(Process *c_p, Eterm new_state)
 	    break;
 	case am_on_heap:
 	    c_p->flags |= F_ON_HEAP_MSGQ;
+	    c_p->flags &= ~F_OFF_HEAP_MSGQ;
 	    erts_smp_atomic32_read_bor_nob(&c_p->state,
 					   ERTS_PSFLG_ON_HEAP_MSGQ);
-	    /* fall through */
-	case am_mixed:
-	    c_p->flags &= ~F_OFF_HEAP_MSGQ;
 	    /*
 	     * We are not allowed to clear ERTS_PSFLG_OFF_HEAP_MSGQ
 	     * if a off heap change is ongoing. It will be adjusted
@@ -1151,11 +1149,6 @@ erts_change_message_queue_management(Process *c_p, Eterm new_state)
 	switch (new_state) {
 	case am_on_heap:
 	    break;
-	case am_mixed:
-	    c_p->flags &= ~F_ON_HEAP_MSGQ;
-	    erts_smp_atomic32_read_band_nob(&c_p->state,
-					    ~ERTS_PSFLG_ON_HEAP_MSGQ);
-	    break;
 	case am_off_heap:
 	    c_p->flags &= ~F_ON_HEAP_MSGQ;
 	    erts_smp_atomic32_read_band_nob(&c_p->state,
@@ -1167,25 +1160,6 @@ erts_change_message_queue_management(Process *c_p, Eterm new_state)
 	}
 	break;
 
-    case 0:
-	res = am_mixed;
-
-	switch (new_state) {
-	case am_mixed:
-	    break;
-	case am_on_heap:
-	    c_p->flags |= F_ON_HEAP_MSGQ;
-	    erts_smp_atomic32_read_bor_nob(&c_p->state,
-					   ERTS_PSFLG_ON_HEAP_MSGQ);
-	    break;
-	case am_off_heap:
-	    goto change_to_off_heap;
-	default:
-	    res = THE_NON_VALUE; /* badarg */
-	    break;
-	}
-	break;
-
     default:
 	res = am_error;
 	ERTS_INTERNAL_ERROR("Inconsistent message queue management state");
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index a853ec585b..f8cbe60e76 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -149,7 +149,7 @@ extern BeamInstr beam_apply[];
 extern BeamInstr beam_exit[];
 extern BeamInstr beam_continue_exit[];
 
-int ERTS_WRITE_UNLIKELY(erts_default_spo_flags) = 0;
+int ERTS_WRITE_UNLIKELY(erts_default_spo_flags) = SPO_ON_HEAP_MSGQ;
 int ERTS_WRITE_UNLIKELY(erts_eager_check_io) = 1;
 int ERTS_WRITE_UNLIKELY(erts_sched_compact_load);
 int ERTS_WRITE_UNLIKELY(erts_sched_balance_util) = 0;
@@ -11206,6 +11206,8 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	flags |= F_ON_HEAP_MSGQ;
     }
 
+    ASSERT((flags & F_ON_HEAP_MSGQ) || (flags & F_OFF_HEAP_MSGQ));
+
     if (!rq)
 	rq = erts_get_runq_proc(parent);
 
@@ -11218,6 +11220,11 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	goto error;
     }
 
+    ASSERT((erts_smp_atomic32_read_nob(&p->state)
+	    & ERTS_PSFLG_ON_HEAP_MSGQ)
+	   || (erts_smp_atomic32_read_nob(&p->state)
+	       & ERTS_PSFLG_OFF_HEAP_MSGQ));
+
 #ifdef BM_COUNTERS
     processes_busy++;
 #endif
diff --git a/erts/emulator/test/message_queue_data_SUITE.erl b/erts/emulator/test/message_queue_data_SUITE.erl
index 226462676c..44e77dfad0 100644
--- a/erts/emulator/test/message_queue_data_SUITE.erl
+++ b/erts/emulator/test/message_queue_data_SUITE.erl
@@ -52,18 +52,12 @@ basic(Config) when is_list(Config) ->
     ok = rpc:call(Node2, ?MODULE, basic_test, [on_heap]),
     stop_node(Node2),
 
-    {ok, Node3} = start_node(Config, "+hmqd mixed"),
-    ok = rpc:call(Node3, ?MODULE, basic_test, [mixed]),
-    stop_node(Node3),
-
     ok.
 
 is_valid_mqd_value(off_heap) ->
     true;
 is_valid_mqd_value(on_heap) ->
     true;
-is_valid_mqd_value(mixed) ->
-    true;
 is_valid_mqd_value(_) ->
     false.
 
@@ -78,9 +72,6 @@ basic_test(Default) ->
     {message_queue_data, off_heap} = process_info(self(), message_queue_data),
     off_heap = process_flag(message_queue_data, on_heap),
     {message_queue_data, on_heap} = process_info(self(), message_queue_data),
-    on_heap = process_flag(message_queue_data, mixed),
-    {message_queue_data, mixed} = process_info(self(), message_queue_data),
-    mixed = process_flag(message_queue_data, Default),
     {'EXIT', _} = (catch process_flag(message_queue_data, blupp)),
 
     P1 = spawn_opt(fun () -> receive after infinity -> ok end end,
@@ -101,12 +92,6 @@ basic_test(Default) ->
     unlink(P3),
     exit(P3, bye),
 
-    P4 = spawn_opt(fun () -> receive after infinity -> ok end end,
-		   [link, {message_queue_data, mixed}]),
-    {message_queue_data, mixed} = process_info(P4, message_queue_data),
-    unlink(P4),
-    exit(P4, bye),
-
     {'EXIT', _} = (catch spawn_opt(fun () -> receive after infinity -> ok end end,
 		   [link, {message_queue_data, blapp}])),
 
@@ -116,21 +101,18 @@ process_info_messages(Config) when is_list(Config) ->
     Tester = self(),
     P1 = spawn_opt(fun () ->
 			   receive after 500 -> ok end,
-			   mixed = process_flag(message_queue_data, off_heap),
+			   on_heap = process_flag(message_queue_data, off_heap),
 			   Tester ! first,
 			   receive after 500 -> ok end,
 			   off_heap = process_flag(message_queue_data, on_heap),
 			   Tester ! second,
 			   receive after 500 -> ok end,
-			   on_heap = process_flag(message_queue_data, mixed),
+			   on_heap = process_flag(message_queue_data, off_heap),
 			   Tester ! third,
-			   receive after 500 -> ok end,
-			   mixed = process_flag(message_queue_data, off_heap),
-			   Tester ! fourth,
 			    
 			   receive after infinity -> ok end
 		   end,
-		   [link, {message_queue_data, mixed}]),
+		   [link, {message_queue_data, on_heap}]),
     
     P1 ! "A",
     receive first -> ok end,
@@ -139,25 +121,20 @@ process_info_messages(Config) when is_list(Config) ->
     P1 ! "C",
     receive third -> ok end,
     P1 ! "D",
-    receive fourth -> ok end,
-    P1 ! "E",
 
-    {messages, ["A", "B", "C", "D", "E"]} = process_info(P1, messages),
+    {messages, ["A", "B", "C", "D"]} = process_info(P1, messages),
 
     P2 = spawn_opt(fun () ->
 			   receive after 500 -> ok end,
-			   mixed = process_flag(message_queue_data, off_heap),
+			   on_heap = process_flag(message_queue_data, off_heap),
 			   Tester ! first,
 			   receive after 500 -> ok end,
 			   off_heap = process_flag(message_queue_data, on_heap),
 			   Tester ! second,
 			   receive after 500 -> ok end,
-			   on_heap = process_flag(message_queue_data, mixed),
+			   on_heap = process_flag(message_queue_data, off_heap),
 			   Tester ! third,
 			   receive after 500 -> ok end,
-			   mixed = process_flag(message_queue_data, off_heap),
-			   Tester ! fourth,
-			   receive after 500 -> ok end,
 
 			   Tester ! process_info(self(), messages),
 
@@ -165,11 +142,10 @@ process_info_messages(Config) when is_list(Config) ->
 			   receive M2 -> M2 = "B" end,
 			   receive M3 -> M3 = "C" end,
 			   receive M4 -> M4 = "D" end,
-			   receive M5 -> M5 = "E" end,
 
 			   Tester ! self()
 		   end,
-		   [link, {message_queue_data, mixed}]),
+		   [link, {message_queue_data, on_heap}]),
 
     P2 ! "A",
     receive first -> ok end,
@@ -178,12 +154,10 @@ process_info_messages(Config) when is_list(Config) ->
     P2 ! "C",
     receive third -> ok end,
     P2 ! "D",
-    receive fourth -> ok end,
-    P2 ! "E",
 
     receive
 	Msg ->
-	    {messages, ["A", "B", "C", "D", "E"]} = Msg
+	    {messages, ["A", "B", "C", "D"]} = Msg
     end,
     
     receive P2 -> ok end,
diff --git a/erts/preloaded/ebin/erlang.beam b/erts/preloaded/ebin/erlang.beam
index 8379bf1768..12262bb5b0 100644
--- a/erts/preloaded/ebin/erlang.beam
+++ b/erts/preloaded/ebin/erlang.beam
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 3d152c4e92..f3f8696f32 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -2059,7 +2059,7 @@ open_port(PortName, PortSettings) ->
       low | normal | high | max.
 
 -type message_queue_data() ::
-	off_heap | on_heap | mixed.
+	off_heap | on_heap.
 
 -spec process_flag(trap_exit, Boolean) -> OldBoolean when
       Boolean :: boolean(),