aboutsummaryrefslogtreecommitdiffstats
path: root/lib
diff options
context:
space:
mode:
authorPer Hedeland <[email protected]>2012-01-04 10:57:59 +0100
committerHenrik Nord <[email protected]>2012-01-04 15:24:08 +0100
commit949ee23d72e4412fed3059c04e395f995388a5fb (patch)
tree7806efe10aae7c0a03cf4a9bf28d9e494061c730 /lib
parent34dca57472ba2f4e82bb03d3713e3318613093bb (diff)
downloadotp-949ee23d72e4412fed3059c04e395f995388a5fb.tar.gz
otp-949ee23d72e4412fed3059c04e395f995388a5fb.tar.bz2
otp-949ee23d72e4412fed3059c04e395f995388a5fb.zip
Fix returned error from gen_tcp:accept/1,2 when running out of ports
The {error, enfile} return value is badly misleading and confusing for this case, since the Posix ENFILE errno value has a well-defined meaning that has nothing to do with Erlang ports. The fix changes the return value to {error, system_limit}, which is consistent with e.g. various file(3) functions. inet:format_error/1 has also been updated to support system_limit in the same manner as file:format_error/1.
Diffstat (limited to 'lib')
-rw-r--r--lib/kernel/doc/src/gen_tcp.xml4
-rw-r--r--lib/kernel/doc/src/inet.xml2
-rw-r--r--lib/kernel/src/gen_tcp.erl2
-rw-r--r--lib/kernel/src/inet.erl6
-rw-r--r--lib/kernel/test/gen_tcp_misc_SUITE.erl53
5 files changed, 60 insertions, 7 deletions
diff --git a/lib/kernel/doc/src/gen_tcp.xml b/lib/kernel/doc/src/gen_tcp.xml
index 8a5d40bb16..9f362841ce 100644
--- a/lib/kernel/doc/src/gen_tcp.xml
+++ b/lib/kernel/doc/src/gen_tcp.xml
@@ -235,7 +235,9 @@ do_recv(Sock, Bs) ->
<p>Returns <c>{ok, <anno>Socket</anno>}</c> if a connection is established,
or <c>{error, closed}</c> if <c><anno>ListenSocket</anno></c> is closed,
or <c>{error, timeout}</c> if no connection is established
- within the specified time. May also return a POSIX error
+ within the specified time,
+ or <c>{error, system_limit}</c> if all available ports in the
+ Erlang emulator are in use. May also return a POSIX error
value if something else goes wrong, see inet(3) for possible
error values.</p>
<p>Packets can be sent to the returned socket <c><anno>Socket</anno></c>
diff --git a/lib/kernel/doc/src/inet.xml b/lib/kernel/doc/src/inet.xml
index 1a05b4ba99..86950b3ecc 100644
--- a/lib/kernel/doc/src/inet.xml
+++ b/lib/kernel/doc/src/inet.xml
@@ -149,7 +149,7 @@ fe80::204:acff:fe17:bf38
<fsummary>Return a descriptive string for an error reason</fsummary>
<desc>
<p>Returns a diagnostic error string. See the section below
- for possible <c><anno>Posix</anno></c> values and the corresponding
+ for possible Posix values and the corresponding
strings.</p>
</desc>
</func>
diff --git a/lib/kernel/src/gen_tcp.erl b/lib/kernel/src/gen_tcp.erl
index 4d6c7f5f1d..02a6190034 100644
--- a/lib/kernel/src/gen_tcp.erl
+++ b/lib/kernel/src/gen_tcp.erl
@@ -194,7 +194,7 @@ listen(Port, Opts) ->
-spec accept(ListenSocket) -> {ok, Socket} | {error, Reason} when
ListenSocket :: socket(),
Socket :: socket(),
- Reason :: closed | timeout | inet:posix().
+ Reason :: closed | timeout | system_limit | inet:posix().
accept(S) ->
case inet_db:lookup_socket(S) of
diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl
index 49f64a9236..4de3c1c6b1 100644
--- a/lib/kernel/src/inet.erl
+++ b/lib/kernel/src/inet.erl
@@ -1218,11 +1218,13 @@ port_list(Name) ->
%% utils
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
--spec format_error(Posix) -> string() when
- Posix :: posix().
+-spec format_error(Reason) -> string() when
+ Reason :: posix() | system_limit.
format_error(exbadport) -> "invalid port state";
format_error(exbadseq) -> "bad command sequence";
+format_error(system_limit) ->
+ "a system limit was hit, probably not enough ports";
format_error(Tag) ->
erl_posix_msg:message(Tag).
diff --git a/lib/kernel/test/gen_tcp_misc_SUITE.erl b/lib/kernel/test/gen_tcp_misc_SUITE.erl
index 3da4b07c05..d9bba0dbb0 100644
--- a/lib/kernel/test/gen_tcp_misc_SUITE.erl
+++ b/lib/kernel/test/gen_tcp_misc_SUITE.erl
@@ -39,7 +39,8 @@
accept_timeouts_in_order/1,accept_timeouts_in_order2/1,
accept_timeouts_in_order3/1,accept_timeouts_mixed/1,
killing_acceptor/1,killing_multi_acceptors/1,killing_multi_acceptors2/1,
- several_accepts_in_one_go/1,active_once_closed/1, send_timeout/1, send_timeout_active/1,
+ several_accepts_in_one_go/1, accept_system_limit/1,
+ active_once_closed/1, send_timeout/1, send_timeout_active/1,
otp_7731/1, zombie_sockets/1, otp_7816/1, otp_8102/1,
otp_9389/1]).
@@ -71,7 +72,7 @@ all() ->
accept_timeouts_in_order, accept_timeouts_in_order2,
accept_timeouts_in_order3, accept_timeouts_mixed,
killing_acceptor, killing_multi_acceptors,
- killing_multi_acceptors2, several_accepts_in_one_go,
+ killing_multi_acceptors2, several_accepts_in_one_go, accept_system_limit,
active_once_closed, send_timeout, send_timeout_active, otp_7731,
zombie_sockets, otp_7816, otp_8102, otp_9389].
@@ -1837,6 +1838,54 @@ wait_until_accepting(Proc,N) ->
end.
+accept_system_limit(suite) ->
+ [];
+accept_system_limit(doc) ->
+ ["Check that accept returns {error, system_limit} "
+ "(and not {error, enfile}) when running out of ports"];
+accept_system_limit(Config) when is_list(Config) ->
+ ?line {ok, LS} = gen_tcp:listen(0, []),
+ ?line {ok, TcpPort} = inet:port(LS),
+ ?line Connector = spawn_link(fun () -> connector(TcpPort) end),
+ ?line ok = acceptor(LS, false, []),
+ ?line Connector ! stop,
+ ok.
+
+acceptor(LS, GotSL, A) ->
+ case gen_tcp:accept(LS, 1000) of
+ {ok, S} ->
+ acceptor(LS, GotSL, [S|A]);
+ {error, system_limit} ->
+ acceptor(LS, true, A);
+ {error, timeout} when GotSL ->
+ ok;
+ {error, timeout} ->
+ error
+ end.
+
+connector(TcpPort) ->
+ ManyPorts = open_ports([]),
+ ConnF = fun (Port) ->
+ case catch gen_tcp:connect({127,0,0,1}, TcpPort, []) of
+ {ok, Sock} ->
+ Sock;
+ _Error ->
+ port_close(Port)
+ end
+ end,
+ R = [ConnF(Port) || Port <- lists:sublist(ManyPorts, 10)],
+ receive stop -> R end.
+
+open_ports(L) ->
+ case catch open_port({spawn_driver, "ram_file_drv"}, []) of
+ Port when is_port(Port) ->
+ open_ports([Port|L]);
+ {'EXIT', {system_limit, _}} ->
+ {L1, L2} = lists:split(5, L),
+ [port_close(Port) || Port <- L1],
+ L2
+ end.
+
active_once_closed(suite) ->
[];