Implement erl_drv_consume_timeslice()

3 files changed, 497 insertions, 3 deletions

diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl
index dae36fed8f..dfba7d098f 100644
--- a/erts/emulator/test/driver_SUITE.erl
+++ b/erts/emulator/test/driver_SUITE.erl
@@ -78,7 +78,8 @@
 	 otp_9302/1,
 	 thr_free_drv/1,
 	 async_blast/1,
-	 thr_msg_blast/1]).
+	 thr_msg_blast/1,
+	 consume_timeslice/1]).
 
 -export([bin_prefix/2]).
 
@@ -149,7 +150,8 @@ all() ->
      otp_9302,
      thr_free_drv,
      async_blast,
-     thr_msg_blast].
+     thr_msg_blast,
+     consume_timeslice].
 
 groups() -> 
     [{timer, [],
@@ -2073,10 +2075,329 @@ thr_msg_blast(Config) when is_list(Config) ->
 	    Res
     end.
 
+consume_timeslice(Config) when is_list(Config) ->
+    %%
+    %% Verify that erl_drv_consume_timeslice() works.
+    %%
+    %% The first four cases expect that the command signal is
+    %% delivered immediately, i.e., isn't scheduled. Since there
+    %% are no conflicts these signals should normally be delivered
+    %% immediately. However some builds and configurations may
+    %% schedule these ops anyway, in these cases we do not verify
+    %% scheduling counts.
+    %%
+    %% When signal is delivered immediately we must take into account
+    %% that process and port are "virtualy" scheduled out and in
+    %% in the trace generated.
+    %%
+    %% Port ! {_, {command, _}, and port_command() differs. The send
+    %% instruction needs to check if the caller is out of reductions
+    %% at the end of the instruction, since no erlang function call
+    %% is involved. Otherwise, a sequence of send instructions would
+    %% not be scheduled out even when out of reductions. port_commond()
+    %% doesn't do that since it will always (since R16A) be called via
+    %% the erlang wrappers in the erlang module.
+    %%
+    %% The last two cases tests scheduled operations. We create
+    %% a conflict by executing at the same time on different
+    %% schedulers. When only one scheduler we enable parallelism on
+    %% the port instead.
+    %%
+
+    Path = ?config(data_dir, Config),
+    erl_ddll:start(),
+    ok = load_driver(Path, consume_timeslice_drv),
+    Port = open_port({spawn, consume_timeslice_drv}, [{parallelism, false}]),
+
+    Parent = self(),
+    Go = make_ref(),
+
+    "enabled" = port_control(Port, $E, ""),
+    Proc1 = spawn_link(fun () ->
+			       receive Go -> ok end,
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}}
+		       end),
+    receive after 100 -> ok end,
+    count_pp_sched_start(),
+    Proc1 ! Go,
+    wait_command_msgs(Port, 10),
+    [{Port, Sprt1}, {Proc1, Sproc1}] = count_pp_sched_stop([Port, Proc1]),
+    case Sprt1 of
+	10 ->
+	    true = in_range(5, Sproc1-10, 7);
+	_ ->
+	    case erlang:system_info(lock_checking) of
+		true -> ?t:format("Ignore bad sched count due to lock checking", []);
+		false -> ?t:fail({unexpected_sched_counts, Sprt1, Sproc1})
+	    end
+    end,
+
+    "disabled" = port_control(Port, $D, ""),
+    Proc2 = spawn_link(fun () ->
+			       receive Go -> ok end,
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}},
+			       Port ! {Parent, {command, ""}}
+		       end),
+    receive after 100 -> ok end,
+    count_pp_sched_start(),
+    Proc2 ! Go,
+    wait_command_msgs(Port, 10),
+    [{Port, Sprt2}, {Proc2, Sproc2}] = count_pp_sched_stop([Port, Proc2]),
+    case Sprt2 of
+	10 ->
+	    true = in_range(1, Sproc2-10, 2);
+	_ ->
+	    case erlang:system_info(lock_checking) of
+		true -> ?t:format("Ignore bad sched count due to lock checking", []);
+		false -> ?t:fail({unexpected_sched_counts, Sprt2, Sproc2})
+	    end
+    end,
+
+    "enabled" = port_control(Port, $E, ""),
+    Proc3 = spawn_link(fun () ->
+			       receive Go -> ok end,
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, "")
+		       end),
+    count_pp_sched_start(),
+    Proc3 ! Go,
+    wait_command_msgs(Port, 10),
+    [{Port, Sprt3}, {Proc3, Sproc3}] = count_pp_sched_stop([Port, Proc3]),
+    case Sprt3 of
+	10 ->
+	    true = in_range(5, Sproc3-10, 7);
+	_ ->
+	    case erlang:system_info(lock_checking) of
+		true -> ?t:format("Ignore bad sched count due to lock checking", []);
+		false -> ?t:fail({unexpected_sched_counts, Sprt3, Sproc3})
+	    end
+    end,
+
+    "disabled" = port_control(Port, $D, ""),
+    Proc4 = spawn_link(fun () ->
+			       receive Go -> ok end,
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, ""),
+			       port_command(Port, "")
+		       end),
+    count_pp_sched_start(),
+    Proc4 ! Go,
+    wait_command_msgs(Port, 10),
+    [{Port, Sprt4}, {Proc4, Sproc4}] = count_pp_sched_stop([Port, Proc4]),
+    case Sprt4 of
+	10 ->
+	    true = in_range(1, Sproc4-10, 2);
+	_ ->
+	    case erlang:system_info(lock_checking) of
+		true -> ?t:format("Ignore bad sched count due to lock checking", []);
+		false -> ?t:fail({unexpected_sched_counts, Sprt4, Sproc4})
+	    end
+    end,
+
+    SOnl = erlang:system_info(schedulers_online),
+    %% If only one scheduler use port with parallelism set to true,
+    %% in order to trigger scheduling of command signals
+    Port2 = case SOnl of
+		1 ->
+		    Port ! {self(), close},
+		    receive {Port, closed} -> ok end,
+		    open_port({spawn, consume_timeslice_drv},
+			      [{parallelism, true}]);
+		_ ->
+		    process_flag(scheduler, 1),
+		    1 = erlang:system_info(scheduler_id),
+		    Port
+	    end,
+    count_pp_sched_start(),
+    "enabled" = port_control(Port2, $E, ""),
+    W5 = case SOnl of
+	     1 ->
+		 false;
+	     _ ->
+		 W1= spawn_opt(fun () ->
+				       2 = erlang:system_info(scheduler_id),
+				       "sleeped" = port_control(Port2, $S, "")
+			       end, [link,{scheduler,2}]),
+		 receive after 100 -> ok end,
+		 W1
+	 end,
+    Proc5 = spawn_opt(fun () ->
+			      receive Go -> ok end,
+			      1 = erlang:system_info(scheduler_id),
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}}
+		      end, [link,{scheduler,1}]),
+    receive after 100 -> ok end,
+    Proc5 ! Go,
+    wait_procs_exit([W5, Proc5]),
+    wait_command_msgs(Port2, 10),
+    [{Port2, Sprt5}, {Proc5, Sproc5}] = count_pp_sched_stop([Port2, Proc5]),
+    true = in_range(2, Sproc5, 3),
+    true = in_range(7, Sprt5, 20),
+		  
+    count_pp_sched_start(),
+    "disabled" = port_control(Port2, $D, ""),
+    W6 = case SOnl of
+	     1 ->
+		 false;
+	     _ ->
+		 W2= spawn_opt(fun () ->
+				       2 = erlang:system_info(scheduler_id),
+				       "sleeped" = port_control(Port2, $S, "")
+			       end, [link,{scheduler,2}]),
+		 receive after 100 -> ok end,
+		 W2
+	 end,
+    Proc6 = spawn_opt(fun () ->
+			      receive Go -> ok end,
+			      1 = erlang:system_info(scheduler_id),
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}},
+			      Port2 ! {Parent, {command, ""}}
+		      end, [link,{scheduler,1}]),
+    receive after 100 -> ok end,
+    Proc6 ! Go,
+    wait_procs_exit([W6, Proc6]),
+    wait_command_msgs(Port2, 10),
+    [{Port2, Sprt6}, {Proc6, Sproc6}] = count_pp_sched_stop([Port2, Proc6]),
+    true = in_range(2, Sproc6, 3),
+    true = in_range(3, Sprt6, 6),
+
+    process_flag(scheduler, 0),
+
+    Port2 ! {self(), close},
+    receive {Port2, closed} -> ok end,
+    ok.
+
+wait_command_msgs(_, 0) ->
+    ok;
+wait_command_msgs(Port, N) ->
+    receive
+	{Port, command} ->
+	    wait_command_msgs(Port, N-1)
+    end.
+
+in_range(Low, Val, High) when is_integer(Low),
+			      is_integer(Val),
+			      is_integer(High),
+			      Low =< Val,
+			      Val =< High ->
+    true;
+in_range(Low, Val, High) when is_integer(Low),
+			      is_integer(Val),
+			      is_integer(High) ->
+    false.
+
+count_pp_sched_start() ->
+    erlang:trace(all, true, [running_procs, running_ports, {tracer, self()}]),
+    ok.
+
+count_pp_sched_stop(Ps) ->
+    Td = erlang:trace_delivered(all),
+    erlang:trace(all, false, [running_procs, running_ports, {tracer, self()}]),
+    PNs = lists:map(fun (P) -> {P, 0} end, Ps),
+    receive {trace_delivered, all, Td} -> ok end,
+    Res = count_proc_sched(Ps, PNs),
+    ?t:format("Scheduling counts: ~p~n", [Res]),
+    erlang:display({scheduling_counts, Res}),
+    Res.
+
+do_inc_pn(_P, []) ->
+    throw(undefined);
+do_inc_pn(P, [{P,N}|PNs]) ->
+    [{P,N+1}|PNs];
+do_inc_pn(P, [PN|PNs]) ->
+    [PN|do_inc_pn(P, PNs)].
+
+inc_pn(P, PNs) ->
+    try
+	do_inc_pn(P, PNs)
+    catch
+	throw:undefined -> PNs
+    end.
+
+count_proc_sched(Ps, PNs) ->
+    receive
+	TT when element(1, TT) == trace, element(3, TT) == in ->
+%	    erlang:display(TT),
+	    count_proc_sched(Ps, inc_pn(element(2, TT), PNs));
+	TT when element(1, TT) == trace, element(3, TT) == out ->
+	    count_proc_sched(Ps, PNs)
+    after 0 ->
+	    PNs
+    end.
+    
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% 		Utilities
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+%flush_msgs() ->
+%    receive
+%	M ->
+%	    erlang:display(M),
+%	    flush_msgs()
+%    after 0 ->
+%	    ok
+%    end.
+
+wait_procs_exit([]) ->
+    ok;
+wait_procs_exit([P|Ps]) when is_pid(P) ->
+    Mon = erlang:monitor(process, P),
+    receive
+	{'DOWN', Mon, process, P, _} ->
+	    wait_procs_exit(Ps)
+    end;
+wait_procs_exit([_|Ps]) ->
+    wait_procs_exit(Ps).
+
 get_port_msg(Port, Timeout) ->
     receive
 	{Port, What} ->
diff --git a/erts/emulator/test/driver_SUITE_data/Makefile.src b/erts/emulator/test/driver_SUITE_data/Makefile.src
index b667dff6b6..1fedd72200 100644
--- a/erts/emulator/test/driver_SUITE_data/Makefile.src
+++ b/erts/emulator/test/driver_SUITE_data/Makefile.src
@@ -15,7 +15,8 @@ MISC_DRVS =		outputv_drv@dll@ \
 			otp_9302_drv@dll@ \
 			thr_free_drv@dll@ \
 			async_blast_drv@dll@ \
-			thr_msg_blast_drv@dll@
+			thr_msg_blast_drv@dll@ \
+			consume_timeslice_drv@dll@
 
 SYS_INFO_DRVS = 	sys_info_base_drv@dll@ \
 			sys_info_prev_drv@dll@ \
diff --git a/erts/emulator/test/driver_SUITE_data/consume_timeslice_drv.c b/erts/emulator/test/driver_SUITE_data/consume_timeslice_drv.c
new file mode 100644
index 0000000000..6b0c4cf37d
--- /dev/null
+++ b/erts/emulator/test/driver_SUITE_data/consume_timeslice_drv.c
@@ -0,0 +1,172 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#include "erl_driver.h"
+#ifdef __WIN32__
+#include <windows.h>
+#else
+#include <unistd.h>
+#endif
+#include <stdio.h>
+#include <string.h>
+
+static void stop(ErlDrvData drv_data);
+static ErlDrvData start(ErlDrvPort port,
+			char *command);
+static void output(ErlDrvData drv_data,
+		   char *buf, ErlDrvSizeT len);
+static ErlDrvSSizeT control(ErlDrvData drv_data,
+			    unsigned int command,
+			    char *buf, ErlDrvSizeT len,
+			    char **rbuf, ErlDrvSizeT rlen);
+
+static ErlDrvEntry consume_timeslice_drv_entry = { 
+    NULL /* init */,
+    start,
+    stop,
+    output,
+    NULL /* ready_input */,
+    NULL /* ready_output */,
+    "consume_timeslice_drv",
+    NULL /* finish */,
+    NULL /* handle */,
+    control,
+    NULL /* timeout */,
+    NULL /* outputv */,
+    NULL /* ready_async */,
+    NULL /* flush */,
+    NULL /* call */,
+    NULL /* event */,
+    ERL_DRV_EXTENDED_MARKER,
+    ERL_DRV_EXTENDED_MAJOR_VERSION,
+    ERL_DRV_EXTENDED_MINOR_VERSION,
+    ERL_DRV_FLAG_USE_PORT_LOCKING,
+    NULL /* handle2 */,
+    NULL /* handle_monitor */
+};
+
+typedef struct {
+    ErlDrvPort port;
+    ErlDrvTermData tport;
+    ErlDrvTermData cmd_msg[6];
+    int consume_timeslice;
+} consume_timeslice_data_t;
+
+
+DRIVER_INIT(consume_timeslice_drv)
+{
+    return &consume_timeslice_drv_entry;
+}
+
+static void stop(ErlDrvData drv_data)
+{
+    driver_free((void *) drv_data);
+}
+
+static ErlDrvData start(ErlDrvPort port,
+			char *command)
+{
+    consume_timeslice_data_t *ctsd;
+
+    ctsd = driver_alloc(sizeof(consume_timeslice_data_t));
+    if (!ctsd)
+	return ERL_DRV_ERROR_GENERAL;
+
+    ctsd->port = port;
+    ctsd->tport = driver_mk_port(port);
+    ctsd->consume_timeslice = 0;
+
+    ctsd->cmd_msg[0] = ERL_DRV_PORT;
+    ctsd->cmd_msg[1] = ctsd->tport;
+    ctsd->cmd_msg[2] = ERL_DRV_ATOM;
+    ctsd->cmd_msg[3] = driver_mk_atom("command");
+    ctsd->cmd_msg[4] = ERL_DRV_TUPLE;
+    ctsd->cmd_msg[5] = (ErlDrvTermData) 2;
+
+    return (ErlDrvData) ctsd;
+}
+
+static void output(ErlDrvData drv_data,
+		   char *buf, ErlDrvSizeT len)
+{
+    consume_timeslice_data_t *ctsd = (consume_timeslice_data_t *) drv_data;
+    int res;
+
+    if (ctsd->consume_timeslice) {
+	int res = erl_drv_consume_timeslice(ctsd->port, 50);
+	if (res < 0) {
+	    driver_failure_atom(ctsd->port, "erl_drv_consume_timeslice() failed");
+	    return;
+	}
+    }
+
+    res = erl_drv_output_term(ctsd->tport,
+			      ctsd->cmd_msg,
+			      sizeof(ctsd->cmd_msg)/sizeof(ErlDrvTermData));
+    if (res <= 0) {
+	driver_failure_atom(ctsd->port, "erl_drv_output_term() failed");
+	return;
+    }
+}
+static ErlDrvSSizeT control(ErlDrvData drv_data,
+			    unsigned int command,
+			    char *buf, ErlDrvSizeT len,
+			    char **rbuf, ErlDrvSizeT rlen)
+{
+    consume_timeslice_data_t *ctsd = (consume_timeslice_data_t *) drv_data;
+    int res;
+    char *res_str;
+    ErlDrvSSizeT res_len;
+
+    switch (command) {
+    case 'E':
+	ctsd->consume_timeslice = 1;
+	res_str = "enabled";
+	break;
+    case 'D':
+	ctsd->consume_timeslice = 0;
+	res_str = "disabled";
+	break;
+    case 'S':
+#ifdef __WIN32__
+	Sleep((DWORD) 1000);
+#else
+	sleep(1);
+#endif
+	res_str = "sleeped";
+	break;
+    default:
+	res_str = "what?";
+	break;
+    }
+
+    res_len = strlen(res_str);
+    if (res_len > rlen) {
+	char *abuf = driver_alloc(sizeof(char)*res_len);
+	if (!abuf) {
+	    driver_failure_atom(ctsd->port, "driver_alloc() failed");
+	    return 0;
+	}
+	*rbuf = abuf;
+    }
+
+    memcpy((void *) *rbuf, (void *) res_str, res_len);
+
+    return res_len;
+}