File 1063-Don-t-crash-if-the-number-of-file-descript... of Package erlang

Overview Repositories Revisions Requests Users Attributes Meta

File 1063-Don-t-crash-if-the-number-of-file-descriptors-is-unl.patch of Package erlang (Revision ac78bcc5a6f7a4d1efd770008567e9f7)

Currently displaying revision ac78bcc5a6f7a4d1efd770008567e9f7 , Show latest

From 667e1b04eb2e8745c23e1d6ded0fedaeae9b5c31 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 4 Dec 2020 08:46:45 +0100
Subject: [PATCH] Don't crash if the number of file descriptors is unlimited

On macOS 11, the maximum number of file descriptors can be
unlimited.  `erl` refuses to start if it can't read out the
limit.

It is not practical for `erl` to use a huge number such as 134217728
as the default value, because that value is also used as the size of
the port table. (Making the port table's size dynamic is not something
we want do in a maintenance release.)

Therefore we will set it to 24576, which is the value returned by
`sysctl kern.maxfilesperproc`, and which seems to be the practical
limit.  (Raising that limit might be possible, but it can only be done
by disabling System Integrity Protection (SIP) and editing a bunch of
configuration files.  Anyone who has done that will have to set ulimit
explicitly to number of file descriptors they want to use.)

https://bugs.erlang.org/browse/ERL-1417
---
 erts/emulator/sys/common/erl_poll.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index 4e5918d1be..257f7e29a0 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -2062,6 +2062,21 @@ ERTS_POLL_EXPORT(erts_poll_init)(int *concurrent_updates)
     max_fds = OPEN_MAX;
 #endif
 
+    if (max_fds < 0 && errno == 0) {
+        /* On macOS 11 and higher, it possible to have an unlimited
+         * number of open files per process.  ERTS will need an actual
+         * limit, though, so we will set it to a largish value.  The
+         * number below is the hard number of file descriptors per
+         * process as returned by `sysctl kern.maxfilesperproc`, which
+         * seems to be the limit in practice.
+         *
+         * Note: The size of the port table will be based on max_fds,
+         * so we don't want to set it to a huge value such as
+         * MAX_INT.
+         */
+        max_fds = 24576;
+    }
+
 #if ERTS_POLL_USE_SELECT && defined(FD_SETSIZE) && \
 	!defined(_DARWIN_UNLIMITED_SELECT)
     if (max_fds > FD_SETSIZE)
-- 
2.26.2

Places

File 1063-Don-t-crash-if-the-number-of-file-descriptors-is-unl.patch of Package erlang (Revision ac78bcc5a6f7a4d1efd770008567e9f7)

Places