From ab1d4a5d58af8452b26f57f244bcd0d39b409c5e Mon Sep 17 00:00:00 2001
From: Century Systems <centurysys@users.noreply.github.com>
Date: Thu, 23 Feb 2023 03:53:04 +0900
Subject: [PATCH] ioselectors_epoll: for NuttX, limit initial numFD to
 configured value. (#21421)

ioselectors: ioselectors_epoll: for NuttX, limit initial numFD to configured value.

In the NuttX build config, there is a setting called "FS_NEPOLL_DESCRIPTORS".

--------
config FS_NEPOLL_DESCRIPTORS
	int "Maximum number of default epoll descriptors for epoll_create1(2)"
	default 8
	---help---
		The maximum number of default epoll descriptors for epoll_create1(2)
--------

For NuttX, change the number of fd arrays allocated by newSelector() to that value.

Signed-off-by: Takeyoshi Kikuchi <kikuchi@centurysys.co.jp>
---
 lib/posix/posix_other_consts.nim         | 3 +++
 lib/pure/ioselects/ioselectors_epoll.nim | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/posix/posix_other_consts.nim b/lib/posix/posix_other_consts.nim
index 506c921581..08069fe9a7 100644
--- a/lib/posix/posix_other_consts.nim
+++ b/lib/posix/posix_other_consts.nim
@@ -750,3 +750,6 @@ var SEEK_SET* {.importc: "SEEK_SET", header: "<unistd.h>".}: cint
 var SEEK_CUR* {.importc: "SEEK_CUR", header: "<unistd.h>".}: cint
 var SEEK_END* {.importc: "SEEK_END", header: "<unistd.h>".}: cint
 
+# <nuttx/config.h>
+when defined(nuttx):
+  var NEPOLL_MAX* {.importc: "CONFIG_FS_NEPOLL_DESCRIPTORS", header: "<nuttx/config.h>".}: cint
diff --git a/lib/pure/ioselects/ioselectors_epoll.nim b/lib/pure/ioselects/ioselectors_epoll.nim
index 8526eb8a33..08cb6ed744 100644
--- a/lib/pure/ioselects/ioselectors_epoll.nim
+++ b/lib/pure/ioselects/ioselectors_epoll.nim
@@ -72,11 +72,16 @@ type
   SelectEvent* = ptr SelectEventImpl
 
 proc newSelector*[T](): Selector[T] =
+  proc initialNumFD(): int {.inline.} =
+    when defined(nuttx):
+      result = NEPOLL_MAX
+    else:
+      result = 1024
   # Retrieve the maximum fd count (for current OS) via getrlimit()
   var maxFD = maxDescriptors()
   doAssert(maxFD > 0)
   # Start with a reasonable size, checkFd() will grow this on demand
-  const numFD = 1024
+  let numFD = initialNumFD()
 
   var epollFD = epoll_create1(O_CLOEXEC)
   if epollFD < 0: