EbuildPhase: async_check_locale

Change config.environ() check_locale calls to async_check_locale
calls in the EbuildPhase _async_start method in order to eliminate
synchronous waiting for child processes in the main event loop
thread.

Bug: https://bugs.gentoo.org/923841
Signed-off-by: Zac Medico <zmedico@gentoo.org>

3 files changed, 39 insertions, 24 deletions

diff --git a/lib/portage/package/ebuild/config.py b/lib/portage/package/ebuild/config.py
index d7b0ca567..35c77486e 100644
--- a/lib/portage/package/ebuild/config.py
+++ b/lib/portage/package/ebuild/config.py
@@ -29,7 +29,6 @@ portage.proxy.lazyimport.lazyimport(
     "portage.dbapi.vartree:vartree",
     "portage.package.ebuild.doebuild:_phase_func_map",
     "portage.util.compression_probe:_compressors",
-    "portage.util.locale:check_locale,split_LC_ALL",
 )
 from portage import bsd_chflags, load_mod, os, selinux, _unicode_decode
 from portage.const import (
@@ -3368,20 +3367,17 @@ class config:
                 mydict["EBUILD_PHASE_FUNC"] = phase_func
 
         if eapi_attrs.posixish_locale:
-            split_LC_ALL(mydict)
-            mydict["LC_COLLATE"] = "C"
-            # check_locale() returns None when check can not be executed.
-            if check_locale(silent=True, env=mydict) is False:
-                # try another locale
-                for l in ("C.UTF-8", "en_US.UTF-8", "en_GB.UTF-8", "C"):
-                    mydict["LC_CTYPE"] = l
-                    if check_locale(silent=True, env=mydict):
-                        # TODO: output the following only once
-                        # 						writemsg(_("!!! LC_CTYPE unsupported, using %s instead\n")
-                        # 								% mydict["LC_CTYPE"])
-                        break
-                else:
-                    raise AssertionError("C locale did not pass the test!")
+            if mydict.get("LC_ALL"):
+                # Sometimes this method is called for processes
+                # that are not ebuild phases, so only raise
+                # AssertionError for actual ebuild phases.
+                if phase and phase not in ("clean", "cleanrm", "fetch"):
+                    raise AssertionError(
+                        f"LC_ALL={mydict['LC_ALL']} for posixish locale. It seems that split_LC_ALL was not called for phase {phase}?"
+                    )
+            elif "LC_ALL" in mydict:
+                # Delete placeholder from split_LC_ALL.
+                del mydict["LC_ALL"]
 
         if not eapi_attrs.exports_PORTDIR:
             mydict.pop("PORTDIR", None)
diff --git a/lib/portage/util/futures/_asyncio/__init__.py b/lib/portage/util/futures/_asyncio/__init__.py
index 8f1b8e827..e78686bc5 100644
--- a/lib/portage/util/futures/_asyncio/__init__.py
+++ b/lib/portage/util/futures/_asyncio/__init__.py
@@ -15,6 +15,7 @@ __all__ = (
     "set_child_watcher",
     "get_event_loop_policy",
     "set_event_loop_policy",
+    "run",
     "shield",
     "sleep",
     "Task",
@@ -106,6 +107,14 @@ def set_child_watcher(watcher):
     return get_event_loop_policy().set_child_watcher(watcher)
 
 
+# Emulate run since it's the preferred python API.
+def run(coro):
+    return _safe_loop().run_until_complete(coro)
+
+
+run.__doc__ = _real_asyncio.run.__doc__
+
+
 def create_subprocess_exec(*args, **kwargs):
     """
     Create a subprocess.
diff --git a/lib/portage/util/locale.py b/lib/portage/util/locale.py
index b5da8d949..b6a41e765 100644
--- a/lib/portage/util/locale.py
+++ b/lib/portage/util/locale.py
@@ -17,6 +17,7 @@ import traceback
 import portage
 from portage.util import _unicode_decode, writemsg_level
 from portage.util._ctypes import find_library, LoadLibrary
+from portage.util.futures import asyncio
 
 
 locale_categories = (
@@ -121,7 +122,10 @@ def check_locale(silent=False, env=None):
     warning and returns False if it is not. Returns None if the check
     can not be executed due to platform limitations.
     """
+    return asyncio.run(async_check_locale(silent=silent, env=env))
 
+
+async def async_check_locale(silent=False, env=None):
     if env is not None:
         for v in ("LC_ALL", "LC_CTYPE", "LANG"):
             if v in env:
@@ -135,20 +139,17 @@ def check_locale(silent=False, env=None):
         except KeyError:
             pass
 
-    # TODO: Make async version of check_locale and call it from
-    # EbuildPhase instead of config.environ(), since it's bad to
-    # synchronously wait for the process in the main event loop
-    # thread where config.environ() tends to be called.
     proc = multiprocessing.Process(
         target=_set_and_check_locale,
         args=(silent, env, None if env is None else portage._native_string(mylocale)),
     )
     proc.start()
-    proc.join()
+    proc = portage.process.MultiprocessingProcess(proc)
+    await proc.wait()
 
     pyret = None
-    if proc.exitcode >= 0:
-        ret = proc.exitcode
+    if proc.returncode >= 0:
+        ret = proc.returncode
         if ret != 2:
             pyret = ret == 0
 
@@ -157,13 +158,22 @@ def check_locale(silent=False, env=None):
     return pyret
 
 
+async_check_locale.__doc__ = check_locale.__doc__
+async_check_locale.__doc__ += """
+    This function is a coroutine.
+"""
+
+
 def split_LC_ALL(env):
     """
     Replace LC_ALL with split-up LC_* variables if it is defined.
     Works on the passed environment (or settings instance).
     """
     lc_all = env.get("LC_ALL")
-    if lc_all is not None:
+    if lc_all:
         for c in locale_categories:
             env[c] = lc_all
-        del env["LC_ALL"]
+        # Set empty so that config.reset() can restore LC_ALL state,
+        # since del can permanently delete variables which are not
+        # stored in the config's backupenv.
+        env["LC_ALL"] = ""