From dd62635d97eb3d9b335611196c52351cd7aa245a Mon Sep 17 00:00:00 2001
From: Pavel Borzenkov <pavel@borzenkov.net>
Date: Tue, 4 Oct 2022 18:33:02 +0200
Subject: [PATCH] libnfs: allow building with pthread support

libnfs is not thread-safe by default. Making it thread-safe requires building
it with pthread support and enabling multi-threading at runtime using
nfs_mt_service_thread_start() function.

The patch allows to optionally build libnfs with multi-threading support.

This is not enabled by default to avoid runtime costs for programs that don't
require libnfs to be thread-safe, so a separate top level package 'libnfs-pthread'
is added.
---
 pkgs/development/libraries/libnfs/default.nix | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/libraries/libnfs/default.nix b/pkgs/development/libraries/libnfs/default.nix
index cbfc06bc81c5..d9beee7933fa 100644
--- a/pkgs/development/libraries/libnfs/default.nix
+++ b/pkgs/development/libraries/libnfs/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, autoreconfHook }:
+{ lib, stdenv, fetchFromGitHub, fetchpatch, autoreconfHook }:
 
 stdenv.mkDerivation rec {
   pname = "libnfs";
@@ -13,7 +13,22 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ autoreconfHook ];
 
-  NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-error=tautological-compare";
+  patches = [
+    # Fixes 100% CPU usage in multi-threaded mode
+    (fetchpatch {
+      url = "https://github.com/sahlberg/libnfs/commit/34d6fe37e986da5b0ced86cd028a88e482537d5a.patch";
+      sha256 = "sha256-i7mi+TVdkLb4MztT5Ic/Q8XBIWk9lo8v5bNjHOr6LaI=";
+    })
+    # Fixes deprecation warnings on macOS
+    (fetchpatch {
+      url = "https://github.com/sahlberg/libnfs/commit/f6631c54a7b0385988f11357bf96728a6d7345b9.patch";
+      sha256 = "sha256-xLRZ9J1vr04n//gNv9ljUBt5LHUGBRRVIXJCMlFbHFI=";
+    })
+  ];
+
+  configureFlags = [
+    "--enable-pthread"
+  ];
 
   enableParallelBuilding = true;