File 3761-Add-process_info-Pid-label-for-retrieving-the-proces.patch of Package erlang
From 2a8c77b210307db2110c4f3c3cdc59ddaed6bd2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Mon, 25 Nov 2024 12:43:30 +0100
Subject: [PATCH] Add `process_info(Pid, label)` for retrieving the process
label
The only documented way to retrieve the label for a process was
by calling `proc_lib:get_label/1`.
This commit teaches `process_info/2` the option `label` for retrieving
the process label. This is especially useful when one needs to
retrieve other process info items at the same time. For example:
process_info(Pid, [label,registered_name])
---
erts/emulator/beam/atom.names | 2 ++
erts/emulator/beam/erl_bif_info.c | 20 ++++++++++++++++++++
erts/emulator/test/process_SUITE.erl | 23 ++++++++++++++++++++++-
erts/preloaded/ebin/erlang.beam | Bin 39168 -> 39168 bytes
erts/preloaded/src/erlang.erl | 7 +++++++
5 files changed, 51 insertions(+), 1 deletion(-)
diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 758c84d1c1..0b328a6d9a 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -578,6 +578,8 @@ atom processes
atom processes_used
atom process_count
atom process_display
+atom DollarProcessLabel='$process_label'
+atom process_limit
atom process_limit
atom process_dump
atom procs
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index c2bd395ad3..b421071579 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -782,6 +782,7 @@ collect_one_suspend_monitor(ErtsMonitor *mon, void *vsmicp, Sint reds)
#define ERTS_PI_IX_PARENT 36
#define ERTS_PI_IX_ASYNC_DIST 37
#define ERTS_PI_IX_DICTIONARY_LOOKUP 38
+#define ERTS_PI_IX_LABEL 39
#define ERTS_PI_FLAG_SINGELTON (1 << 0)
#define ERTS_PI_FLAG_ALWAYS_WRAP (1 << 1)
@@ -834,6 +835,7 @@ static ErtsProcessInfoArgs pi_args[] = {
{am_parent, 0, 0, ERTS_PROC_LOCK_MAIN},
{am_async_dist, 0, 0, ERTS_PROC_LOCK_MAIN},
{am_dictionary, 3, ERTS_PI_FLAG_FORCE_SIG_SEND|ERTS_PI_FLAG_KEY_TUPLE2, ERTS_PROC_LOCK_MAIN},
+ {am_label, 0, ERTS_PI_FLAG_FORCE_SIG_SEND, ERTS_PROC_LOCK_MAIN},
};
#define ERTS_PI_ARGS ((int) (sizeof(pi_args)/sizeof(pi_args[0])))
@@ -966,6 +968,8 @@ pi_arg2ix(Eterm arg, Eterm *extrap)
return ERTS_PI_IX_PARENT;
case am_async_dist:
return ERTS_PI_IX_ASYNC_DIST;
+ case am_label:
+ return ERTS_PI_IX_LABEL;
default:
if (is_tuple_arity(arg, 2)) {
Eterm *tpl = tuple_val(arg);
@@ -2279,6 +2283,22 @@ process_info_aux(Process *c_p,
break;
}
+ case ERTS_PI_IX_LABEL: {
+ Uint sz;
+
+ res = erts_pd_hash_get(rp, am_DollarProcessLabel);
+ sz = (!(flags & ERTS_PI_FLAG_REQUEST_FOR_OTHER) || is_immed(res)
+ ? 0
+ : size_object(res));
+
+ hp = erts_produce_heap(hfact, sz, reserve_size);
+
+ if (sz)
+ res = copy_struct(res, sz, &hp, hfact->off_heap);
+
+ break;
+ }
+
default:
return THE_NON_VALUE; /* will produce badarg */
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl
index c8b86e4e74..9680eb5836 100644
--- a/erts/emulator/test/process_SUITE.erl
+++ b/erts/emulator/test/process_SUITE.erl
@@ -55,6 +55,7 @@
process_info_self_msgq_len_more/1,
process_info_msgq_len_no_very_long_delay/1,
process_info_dict_lookup/1,
+ process_info_label/1,
bump_reductions/1, low_prio/1, binary_owner/1, yield/1, yield2/1,
otp_4725/1, dist_unlink_ack_exit_leak/1, bad_register/1,
garbage_collect/1, otp_6237/1,
@@ -182,7 +183,8 @@ groups() ->
process_info_self_msgq_len_messages,
process_info_self_msgq_len_more,
process_info_msgq_len_no_very_long_delay,
- process_info_dict_lookup]},
+ process_info_dict_lookup,
+ process_info_label]},
{otp_7738, [],
[otp_7738_waiting, otp_7738_suspended,
otp_7738_resume]},
@@ -1728,6 +1730,25 @@ process_info_dict_lookup(Config) when is_list(Config) ->
false = is_process_alive(Pid),
ok.
+process_info_label(Config) when is_list(Config) ->
+ Pid = spawn_link(fun proc_dict_helper/0),
+ LabelKey = '$process_label',
+ Ref = make_ref(),
+ Tuple = {make_ref(), erlang:monotonic_time()},
+
+ undefined = pdh(Pid, put, [LabelKey, Tuple]),
+ erlang:garbage_collect(Pid),
+
+ {label,Tuple} = process_info(Pid, label),
+ Self = self(),
+ [{label,Tuple},{registered_name,[]},{links,[Self]}] =
+ process_info(Pid, [label,registered_name,links]),
+
+ put(LabelKey, Ref),
+ {label,Ref} = process_info(self(), label),
+
+ ok.
+
pdh(Pid, AsyncOp, Args) when AsyncOp == put_async;
AsyncOp == erase_async ->
Pid ! {AsyncOp, Args},
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 061f55cd43..df90b942ea 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -7724,6 +7724,7 @@ process_flag(_Flag, _Value) ->
heap_size |
initial_call |
links |
+ label |
last_calls |
memory |
message_queue_len |
@@ -7768,6 +7769,7 @@ process_flag(_Flag, _Value) ->
{heap_size, Size :: non_neg_integer()} |
{initial_call, mfa()} |
{links, PidsAndPorts :: [pid() | port()]} |
+ {label, term()} |
{last_calls, false | (Calls :: [mfa()])} |
{memory, Size :: non_neg_integer()} |
{message_queue_len, MessageQueueLen :: non_neg_integer()} |
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 061f55cd43..df90b942ea 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -7005,6 +7005,11 @@ receive_replies(ReqId, N, Acc) ->
and port identifiers, with processes or ports to which the process
has a link.</p>
</item>
+ <tag><c>{label, Label}</c></tag>
+ <item>
+ <p>Label is the label for the process. See
+ <seemfa marker="stdlib:proc_lib#get_label/1">proc_lib:get_label/1</seemfa>.</p>
+ </item>
<tag><c>{last_calls, false|Calls}</c></tag>
<item>
<p>The value is <c>false</c> if call saving is not active
--
2.43.0
