From bdea64b482b1d34c9eed69be9f3dcf0714dde3fa Mon Sep 17 00:00:00 2001
From: David Cortes <david.cortes.rivera@gmail.com>
Date: Thu, 7 Apr 2022 21:36:29 +0200
Subject: [PATCH 1/2] temporary workaround for not modifying global OMP config

---
 R-package/DESCRIPTION   | 2 +-
 R-package/NAMESPACE     | 2 ++
 R-package/R/lgb.train.R | 6 ++++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/R-package/DESCRIPTION b/R-package/DESCRIPTION
index 7efb865f33e8..7d70e00d22f5 100755
--- a/R-package/DESCRIPTION
+++ b/R-package/DESCRIPTION
@@ -50,7 +50,6 @@ VignetteBuilder: knitr
 Suggests:
     knitr,
     processx,
-    RhpcBLASctl,
     rmarkdown,
     testthat
 Depends:
@@ -63,6 +62,7 @@ Imports:
     Matrix (>= 1.1-0),
     methods,
     parallel,
+    RhpcBLASctl,
     utils
 SystemRequirements:
     C++11
diff --git a/R-package/NAMESPACE b/R-package/NAMESPACE
index 33152e33bc1d..b56a6d1d7c06 100644
--- a/R-package/NAMESPACE
+++ b/R-package/NAMESPACE
@@ -40,6 +40,8 @@ export(slice)
 import(methods)
 importFrom(Matrix,Matrix)
 importFrom(R6,R6Class)
+importFrom(RhpcBLASctl,omp_get_max_threads)
+importFrom(RhpcBLASctl,omp_set_num_threads)
 importFrom(data.table,":=")
 importFrom(data.table,as.data.table)
 importFrom(data.table,data.table)
diff --git a/R-package/R/lgb.train.R b/R-package/R/lgb.train.R
index 5557399aa47d..52d38a9b4474 100644
--- a/R-package/R/lgb.train.R
+++ b/R-package/R/lgb.train.R
@@ -1,3 +1,5 @@
+#' @name importFrom RhpcBLASctl omp_get_max_threads omp_set_num_threads
+
 #' @name lgb.train
 #' @title Main training logic for LightGBM
 #' @description Logic to train with LightGBM
@@ -149,6 +151,10 @@ lgb.train <- function(params = list(),
   interaction_constraints <- params[["interaction_constraints"]]
   params["interaction_constraints"] <- NULL
 
+  # This is a temporary workround for GH issue 4705
+  curr_threads <- RhpcBLASctl::omp_get_max_threads()
+  on.exit(RhpcBLASctl::omp_set_num_threads(curr_threads))
+
   # Construct datasets, if needed
   data$update_params(params = params)
   data$construct()

From 7e6f214a39adccd1c22d2ef44077849d90e1e70f Mon Sep 17 00:00:00 2001
From: David Cortes <david.cortes.rivera@gmail.com>
Date: Thu, 7 Apr 2022 22:00:40 +0200
Subject: [PATCH 2/2] correct wrong roxygen command:

---
 R-package/R/lgb.train.R | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/R-package/R/lgb.train.R b/R-package/R/lgb.train.R
index 52d38a9b4474..f57486ab3c38 100644
--- a/R-package/R/lgb.train.R
+++ b/R-package/R/lgb.train.R
@@ -1,4 +1,4 @@
-#' @name importFrom RhpcBLASctl omp_get_max_threads omp_set_num_threads
+#' @importFrom RhpcBLASctl omp_get_max_threads omp_set_num_threads
 
 #' @name lgb.train
 #' @title Main training logic for LightGBM