From 706b85fa96ba4ff5f64cfef92ad46c6a599bd3a4 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Thu, 24 Oct 2019 16:02:05 +0200
Subject: [PATCH 1/4] expose threading layer of mkl

---
 threadpoolctl.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/threadpoolctl.py b/threadpoolctl.py
index 8e4e1376..23d0f4ee 100644
--- a/threadpoolctl.py
+++ b/threadpoolctl.py
@@ -243,6 +243,9 @@ def threadpool_info():
         # we map it to 1 for consistency with other libraries.
         if module['num_threads'] == -1 and module['internal_api'] == 'blis':
             module['num_threads'] = 1
+        if module['internal_api'] == 'mkl':
+            layer = _get_mkl_threading_layer(module['dynlib'])
+            module['threading_layer'] = layer
         # Remove the wrapper for the module and its function
         del module['set_num_threads'], module['get_num_threads']
         del module['dynlib']
@@ -251,6 +254,17 @@ def threadpool_info():
     return infos
 
 
+def _get_mkl_threading_layer(mkl_dynlib):
+    """Return the threading layer of MKL"""
+    # The function mkl_set_threading_layer returns the current threading layer
+    # Calling it with an invalid threading layer allows us to safely get
+    # the threading layer
+    set_threading_layer = getattr(mkl_dynlib, "MKL_Set_Threading_Layer")
+    layer_map = {0: "intel", 1: "sequential", 2: "pgi",
+                 3: "gnu", 4: "tbb", -1: "not specified"}
+    return layer_map[set_threading_layer(-1)]
+
+
 def _get_version(dynlib, internal_api):
     if internal_api == "mkl":
         return _get_mkl_version(dynlib)

From 4ebace5aba695bbbe6aaae1cc2d27a7af4c7d345 Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Fri, 25 Oct 2019 11:34:52 +0200
Subject: [PATCH 2/4] add a test and explicitly set the threading layer in a ci
 job

---
 .azure_pipeline.yml         |  1 +
 tests/test_threadpoolctl.py | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/.azure_pipeline.yml b/.azure_pipeline.yml
index af4cd24d..41bde87a 100644
--- a/.azure_pipeline.yml
+++ b/.azure_pipeline.yml
@@ -58,6 +58,7 @@ jobs:
         VERSION_PYTHON: '*'
         CC_OUTER_LOOP: 'clang-8'
         CC_INNER_LOOP: 'gcc'
+        MKL_THREADING_LAYER: 'INTEL'
       # Same but with numpy / scipy installed with pip from PyPI and switched
       # compilers.
       pylatest_pip_openblas_gcc_clang:
diff --git a/tests/test_threadpoolctl.py b/tests/test_threadpoolctl.py
index d7698456..5083a23d 100644
--- a/tests/test_threadpoolctl.py
+++ b/tests/test_threadpoolctl.py
@@ -1,3 +1,4 @@
+import os
 import re
 import ctypes
 import pytest
@@ -301,3 +302,17 @@ def test_get_original_num_threads(limit):
                 with pytest.warns(None, match='Multiple value possible'):
                     expected = min([module['num_threads'] for module in original_infos])
                     assert original_num_threads['blas'] == expected
+
+
+def test_mkl_threading_layer():
+    mkl_info = [module for module in threadpool_info()
+                if module['internal_api'] == 'mkl']
+
+    if not mkl_info:
+        pytest.skip("mkl runtime missing")
+
+    expected_layer = os.getenv("MKL_THREADING_LAYER")
+    actual_layer = mkl_info[0]['threading_layer']
+
+    if expected_layer:
+        assert actual_layer == expected_layer.lower()

From 9d81b07695b9f6c5e8cd595c47fa3ed3feab041b Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Fri, 25 Oct 2019 11:36:46 +0200
Subject: [PATCH 3/4] cln

---
 tests/test_threadpoolctl.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tests/test_threadpoolctl.py b/tests/test_threadpoolctl.py
index 5083a23d..c0d2c130 100644
--- a/tests/test_threadpoolctl.py
+++ b/tests/test_threadpoolctl.py
@@ -305,11 +305,13 @@ def test_get_original_num_threads(limit):
 
 
 def test_mkl_threading_layer():
+    # Check that threadpool_info correctly recovers the threading layer used
+    # by mkl
     mkl_info = [module for module in threadpool_info()
                 if module['internal_api'] == 'mkl']
 
     if not mkl_info:
-        pytest.skip("mkl runtime missing")
+        pytest.skip("requires MKL")
 
     expected_layer = os.getenv("MKL_THREADING_LAYER")
     actual_layer = mkl_info[0]['threading_layer']

From 91dfa970d4bf792119755c1706842e59d0c4eb3a Mon Sep 17 00:00:00 2001
From: jeremie du boisberranger <jeremiedbb@yahoo.fr>
Date: Wed, 6 Nov 2019 13:57:47 +0100
Subject: [PATCH 4/4] add change log entry

---
 CHANGES.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/CHANGES.md b/CHANGES.md
index 4850acd5..35fe4605 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,11 @@
+1.2.0 (TBD)
+===========
+
+- Expose MKL threading layer in informations displayed by `threadpool_info`.
+  This information is referenced in the `threading_layer` field.
+  https://github.com/joblib/threadpoolctl/pull/48
+
+
 1.1.0 (2019-09-12)
 ==================