Move function that reports total used memory

Tests were failing because they required vm_memory_monitor process to be running

re #1259

[#145451399]

Signed-off-by: Gerhard Lazu <gerhard@rabbitmq.com>

2 files changed, 97 insertions, 100 deletions

diff --git a/src/rabbit_vm.erl b/src/rabbit_vm.erl
index 648ad9d8a3..06b91e041d 100644
--- a/src/rabbit_vm.erl
+++ b/src/rabbit_vm.erl
@@ -16,7 +16,7 @@
 
 -module(rabbit_vm).
 
--export([memory/0, binary/0, ets_tables_memory/1]).
+-export([memory/0, total_memory/0, binary/0, ets_tables_memory/1]).
 
 -define(MAGIC_PLUGINS, ["cowboy", "sockjs", "rfc4627_jsonrpc"]).
 
@@ -51,7 +51,7 @@ memory() ->
 			   0
 		   end,
     MgmtDbETS           = ets_memory([rabbit_mgmt_storage]),
-    {OsTotal, _}    = vm_memory_monitor:get_memory_use(bytes),
+    OsTotal             = total_memory(),
 
 
     [{total,     ErlangTotal},
@@ -101,12 +101,103 @@ memory() ->
 
      {total,               OsTotal}
     ].
-
 %% [1] - erlang:memory(processes) can be less than the sum of its
 %% parts. Rather than display something nonsensical, just silence any
 %% claims about negative memory. See
 %% http://erlang.org/pipermail/erlang-questions/2012-September/069320.html
 
+%% Memory reported by erlang:memory(total) is not supposed to
+%% be equal to the total size of all pages mapped to the emulator,
+%% according to http://erlang.org/doc/man/erlang.html#memory-0
+%% erlang:memory(total) under-reports memory usage by around 20%
+-spec total_memory() -> Bytes :: integer().
+total_memory() ->
+    case get_memory_calculation_strategy() of
+        rss ->
+            case get_system_process_resident_memory() of
+                {ok, MemInBytes} ->
+                    MemInBytes;
+                {error, Reason}  ->
+                    rabbit_log:debug("Unable to get system memory used. Reason: ~p."
+                                     " Falling back to erlang memory reporting",
+                                     [Reason]),
+                    erlang:memory(total)
+            end;
+        erlang ->
+            erlang:memory(total)
+    end.
+
+-spec get_memory_calculation_strategy() -> rss | erlang.
+get_memory_calculation_strategy() ->
+    case application:get_env(rabbit, vm_memory_calculation_strategy, rss) of
+        erlang ->
+            erlang;
+        rss ->
+            rss;
+        UnsupportedValue ->
+            rabbit_log:warning(
+              "Unsupported value '~p' for vm_memory_calculation_strategy. "
+              "Supported values: (rss|erlang). "
+              "Defaulting to 'rss'",
+              [UnsupportedValue]
+            ),
+            rss
+    end.
+
+-spec get_system_process_resident_memory() -> {ok, Bytes :: integer()} | {error, term()}.
+get_system_process_resident_memory() ->
+    try
+        get_system_process_resident_memory(os:type())
+    catch _:Error ->
+            {error, {"Failed to get process resident memory", Error}}
+    end.
+
+get_system_process_resident_memory({unix,darwin}) ->
+    get_ps_memory();
+
+get_system_process_resident_memory({unix, linux}) ->
+    get_ps_memory();
+
+get_system_process_resident_memory({unix,freebsd}) ->
+    get_ps_memory();
+
+get_system_process_resident_memory({unix,openbsd}) ->
+    get_ps_memory();
+
+get_system_process_resident_memory({win32,_OSname}) ->
+    OsPid = os:getpid(),
+    Cmd = " tasklist /fi \"pid eq " ++ OsPid ++ "\" /fo LIST 2>&1 ",
+    CmdOutput = os:cmd(Cmd),
+    %% Memory usage is displayed in kilobytes
+    %% with comma-separated thousands
+    case re:run(CmdOutput, "Mem Usage:\\s+([0-9,]+)\\s+K", [{capture, all_but_first, list}]) of
+        {match, [Match]} ->
+            NoCommas = [ N || N <- Match, N =/= $, ],
+            {ok, list_to_integer(NoCommas) * 1024};
+        _ ->
+            {error, {unexpected_output_from_command, Cmd, CmdOutput}}
+    end;
+
+get_system_process_resident_memory({unix, sunos}) ->
+    get_ps_memory();
+
+get_system_process_resident_memory({unix, aix}) ->
+    get_ps_memory();
+
+get_system_process_resident_memory(_OsType) ->
+    {error, not_implemented_for_os}.
+
+get_ps_memory() ->
+    OsPid = os:getpid(),
+    Cmd = "ps -p " ++ OsPid ++ " -o rss=",
+    CmdOutput = os:cmd(Cmd),
+    case re:run(CmdOutput, "[0-9]+", [{capture, first, list}]) of
+        {match, [Match]} ->
+            {ok, list_to_integer(Match) * 1024};
+        _ ->
+            {error, {unexpected_output_from_command, Cmd, CmdOutput}}
+    end.
+
 binary() ->
     All = interesting_sups(),
     {Sums, Rest} =
diff --git a/src/vm_memory_monitor.erl b/src/vm_memory_monitor.erl
index 6731466c17..bc45d04d62 100644
--- a/src/vm_memory_monitor.erl
+++ b/src/vm_memory_monitor.erl
@@ -117,14 +117,14 @@ get_memory_limit() ->
 
 get_memory_use(bytes) ->
     MemoryLimit = get_memory_limit(),
-    {get_used_memory(), case MemoryLimit > 0.0 of
+    {rabbit_vm:total_memory(), case MemoryLimit > 0.0 of
                             true  -> MemoryLimit;
                             false -> infinity
                         end};
 get_memory_use(ratio) ->
     MemoryLimit = get_memory_limit(),
     case MemoryLimit > 0.0 of
-        true  -> get_used_memory() / MemoryLimit;
+        true  -> rabbit_vm:total_memory() / MemoryLimit;
         false -> infinity
     end.
 
@@ -268,7 +268,7 @@ parse_mem_limit(_) ->
 internal_update(State = #state { memory_limit = MemLimit,
                                  alarmed      = Alarmed,
                                  alarm_funs   = {AlarmSet, AlarmClear} }) ->
-    MemUsed = get_used_memory(),
+    MemUsed = rabbit_vm:total_memory(),
     NewAlarmed = MemUsed > MemLimit,
     case {Alarmed, NewAlarmed} of
         {false, true} -> emit_update_info(set, MemUsed, MemLimit),
@@ -366,52 +366,6 @@ get_total_memory(_OsType) ->
     unknown.
 
 
-get_ps_memory() ->
-    OsPid = os:getpid(),
-    Cmd = "ps -p " ++ OsPid ++ " -o rss=",
-    CmdOutput = cmd(Cmd),
-    case re:run(CmdOutput, "[0-9]+", [{capture, first, list}]) of
-        {match, [Match]} ->
-            {ok, list_to_integer(Match) * 1024};
-        _ ->
-            {error, {unexpected_output_from_command, Cmd, CmdOutput}}
-    end.
-
-get_system_process_resident_memory({unix,darwin}) ->
-    get_ps_memory();
-
-get_system_process_resident_memory({unix, linux}) ->
-    get_ps_memory();
-
-get_system_process_resident_memory({unix,freebsd}) ->
-    get_ps_memory();
-
-get_system_process_resident_memory({unix,openbsd}) ->
-    get_ps_memory();
-
-get_system_process_resident_memory({win32,_OSname}) ->
-    OsPid = os:getpid(),
-    Cmd = " tasklist /fi \"pid eq " ++ OsPid ++ "\" /fo LIST 2>&1 ",
-    CmdOutput = os:cmd(Cmd),
-    %% Memory usage is displayed in kilobytes
-    %% with comma-separated thousands
-    case re:run(CmdOutput, "Mem Usage:\\s+([0-9,]+)\\s+K", [{capture, all_but_first, list}]) of
-        {match, [Match]} ->
-            NoCommas = [ N || N <- Match, N =/= $, ],
-            {ok, list_to_integer(NoCommas) * 1024};
-        _ ->
-            {error, {unexpected_output_from_command, Cmd, CmdOutput}}
-    end;
-
-get_system_process_resident_memory({unix, sunos}) ->
-    get_ps_memory();
-
-get_system_process_resident_memory({unix, aix}) ->
-    get_ps_memory();
-
-get_system_process_resident_memory(_OsType) ->
-    {error, not_implemented_for_os}.
-
 %% A line looks like "Foo bar: 123456."
 parse_line_mach(Line) ->
     [Name, RHS | _Rest] = string:tokens(Line, ":"),
@@ -494,51 +448,3 @@ read_proc_file(IoDevice, Acc) ->
         {ok, Res} -> read_proc_file(IoDevice, [Res | Acc]);
         eof       -> Acc
     end.
-
--spec get_memory_calculation_strategy() -> rss | erlang.
-get_memory_calculation_strategy() ->
-    case application:get_env(rabbit, vm_memory_calculation_strategy, rss) of
-        erlang ->
-            erlang;
-        rss ->
-            rss;
-        UnsupportedValue ->
-            rabbit_log:warning(
-              "Unsupported value '~p' for vm_memory_calculation_strategy. "
-              "Supported values: (rss|erlang). "
-              "Defaulting to 'rss'",
-              [UnsupportedValue]
-            ),
-            rss
-    end.
-
-
-%% Memory reported by erlang:memory(total) is not supposed to
-%% be equal to the total size of all pages mapped to the emulator,
-%% according to http://erlang.org/doc/man/erlang.html#memory-0
-%% erlang:memory(total) under-reports memory usage by around 20%
--spec get_used_memory() -> Bytes :: integer().
-get_used_memory() ->
-    case get_memory_calculation_strategy() of
-        rss ->
-            case get_system_process_resident_memory() of
-                {ok, MemInBytes} ->
-                    MemInBytes;
-                {error, Reason}  ->
-                    rabbit_log:debug("Unable to get system memory used. Reason: ~p."
-                                     " Falling back to erlang memory reporting",
-                                     [Reason]),
-                    erlang:memory(total)
-            end;
-        erlang ->
-            erlang:memory(total)
-    end.
-
-
--spec get_system_process_resident_memory() -> {ok, Bytes :: integer()} | {error, term()}.
-get_system_process_resident_memory() ->
-    try
-        get_system_process_resident_memory(os:type())
-    catch _:Error ->
-            {error, {"Failed to get process resident memory", Error}}
-    end.