numpy · charris · Apr 23, 2021 · Nov 9, 2020 · Nov 10, 2020
diff --git a/benchmarks/benchmarks/__init__.py b/benchmarks/benchmarks/__init__.py
@@ -1 +1,53 @@
 from . import common
+import sys
+import os
+
+def show_cpu_features():
+    from numpy.lib.utils import _opt_info
+    info = _opt_info()
+    info = "NumPy CPU features: " + (info if info else 'nothing enabled')
+    # ASV wrapping stdout & stderr, so we assume having a tty here
+    if 'SHELL' in os.environ and sys.platform != 'win32':
+        # to avoid the red color that imposed by ASV
+        print(f"\033[33m{info}\033[0m")
+    else:
+        print(info)
+
+def dirty_lock(lock_name, lock_on_count=1):
+    # this lock occurred before each round to avoid duplicate printing
+    if not hasattr(os, "getppid"):
+        return False
+    ppid = os.getppid()
+    if not ppid or ppid == os.getpid():
+        # not sure if this gonna happen, but ASV run each round in
+        # a separate process so the lock should be based on the parent
+        # process id only
+        return False
+    lock_path = os.path.abspath(os.path.join(
+        os.path.dirname(__file__), "..", "env", lock_name)
+    )
+    # ASV load the 'benchmark_dir' to discovering the available benchmarks
+    # the issue here is ASV doesn't capture any strings from stdout or stderr
+    # during this stage so we escape it and lock on the second increment
+    try:
+        with open(lock_path, 'a+') as f:
+            f.seek(0)
+            count, _ppid = (f.read().split() + [0, 0])[:2]
+            count, _ppid = int(count), int(_ppid)
+            if _ppid == ppid:
+                if count >= lock_on_count:
+                    return True
+                count += 1
+            else:
+                count = 0
+            f.seek(0)
+            f.truncate()
+            f.write(f"{str(count)} {str(ppid)}")
+    except IOError:
+        pass
+    return False
+
+
+# FIXME: there's no official way to provide extra information to the test log
+if not dirty_lock("print_cpu_features.lock"):
+    show_cpu_features()
diff --git a/numpy/_pytesttester.py b/numpy/_pytesttester.py
@@ -35,25 +35,13 @@
 
 
 def _show_numpy_info():
-    from numpy.core._multiarray_umath import (
-        __cpu_features__, __cpu_baseline__, __cpu_dispatch__
-    )
     import numpy as np
 
     print("NumPy version %s" % np.__version__)
     relaxed_strides = np.ones((10, 1), order="C").flags.f_contiguous
     print("NumPy relaxed strides checking option:", relaxed_strides)
-
-    if len(__cpu_baseline__) == 0 and len(__cpu_dispatch__) == 0:
-        enabled_features = "nothing enabled"
-    else:
-        enabled_features = ' '.join(__cpu_baseline__)
-        for feature in __cpu_dispatch__:
-            if __cpu_features__[feature]:
-                enabled_features += " %s*" % feature
-            else:
-                enabled_features += " %s?" % feature
-    print("NumPy CPU features:", enabled_features)
+    info = np.lib.utils._opt_info()
+    print("NumPy CPU features: ", (info if info else 'nothing enabled'))
 
 
 

diff --git a/numpy/lib/utils.py b/numpy/lib/utils.py
@@ -197,28 +197,28 @@ def deprecate(*args, **kwargs):
 def deprecate_with_doc(msg):
     """
     Deprecates a function and includes the deprecation in its docstring.
-    
-    This function is used as a decorator. It returns an object that can be 
-    used to issue a DeprecationWarning, by passing the to-be decorated 
-    function as argument, this adds warning to the to-be decorated function's 
+
+    This function is used as a decorator. It returns an object that can be
+    used to issue a DeprecationWarning, by passing the to-be decorated
+    function as argument, this adds warning to the to-be decorated function's
     docstring and returns the new function object.
-    
+
     See Also
     --------
-    deprecate : Decorate a function such that it issues a `DeprecationWarning` 
-    
+    deprecate : Decorate a function such that it issues a `DeprecationWarning`
+
     Parameters
     ----------
     msg : str
-        Additional explanation of the deprecation. Displayed in the 
+        Additional explanation of the deprecation. Displayed in the
         docstring after the warning.
 
     Returns
     -------
     obj : object
 
     """
-    return _Deprecate(message=msg)  
+    return _Deprecate(message=msg)
 
 
 #--------------------------------------------
@@ -1042,4 +1042,30 @@ def _median_nancheck(data, result, axis, out):
         result[n] = np.nan
     return result
 
+def _opt_info():
+    """
+    Returns a string contains the supported CPU features by the current build.
+
+    The string format can be explained as follows:
+        - dispatched features that are supported by the running machine
+          end with `*`.
+        - dispatched features that are "not" supported by the running machine
+          end with `?`.
+        - remained features are representing the baseline.
+    """
+    from numpy.core._multiarray_umath import (
+        __cpu_features__, __cpu_baseline__, __cpu_dispatch__
+    )
+
+    if len(__cpu_baseline__) == 0 and len(__cpu_dispatch__) == 0:
+        return ''
+
+    enabled_features = ' '.join(__cpu_baseline__)
+    for feature in __cpu_dispatch__:
+        if __cpu_features__[feature]:
+            enabled_features += f" {feature}*"
+        else:
+            enabled_features += f" {feature}?"
+
+    return enabled_features
 #-----------------------------------------------------------------------------