Merge tag 'pull-block-2021-12-22' of https://gitlab.com/hreitz/qemu into staging

Block patches:
- Added support to the iotests for running tests in several parallel
  jobs (using the new -j parameter)

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# gpg:                issuer "hreitz@redhat.com"
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* tag 'pull-block-2021-12-22' of https://gitlab.com/hreitz/qemu:
  iotests: check: multiprocessing support
  iotests/testrunner.py: move updating last_elapsed to run_tests
  iotests/testrunner.py: add doc string for run_test()

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 80 insertions, 10 deletions

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 43a4b694cc..0c27721a41 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -34,6 +34,8 @@ def make_argparser() -> argparse.ArgumentParser:
                    help='show me, do not run tests')
     p.add_argument('-makecheck', action='store_true',
                    help='pretty print output for make check')
+    p.add_argument('-j', dest='jobs', type=int, default=1,
+                   help='run tests in multiple parallel jobs')
 
     p.add_argument('-d', dest='debug', action='store_true', help='debug')
     p.add_argument('-p', dest='print', action='store_true',
@@ -165,6 +167,6 @@ if __name__ == '__main__':
         with TestRunner(env, makecheck=args.makecheck,
                         color=args.color) as tr:
             paths = [os.path.join(env.source_iotests, t) for t in tests]
-            ok = tr.run_tests(paths)
+            ok = tr.run_tests(paths, args.jobs)
             if not ok:
                 sys.exit(1)
diff --git a/tests/qemu-iotests/testrunner.py b/tests/qemu-iotests/testrunner.py
index 0e29c2fddd..0feaa396d0 100644
--- a/tests/qemu-iotests/testrunner.py
+++ b/tests/qemu-iotests/testrunner.py
@@ -26,6 +26,7 @@ import contextlib
 import json
 import termios
 import sys
+from multiprocessing import Pool
 from contextlib import contextmanager
 from typing import List, Optional, Iterator, Any, Sequence, Dict, \
         ContextManager
@@ -126,6 +127,31 @@ class TestResult:
 
 
 class TestRunner(ContextManager['TestRunner']):
+    shared_self = None
+
+    @staticmethod
+    def proc_run_test(test: str, test_field_width: int) -> TestResult:
+        # We are in a subprocess, we can't change the runner object!
+        runner = TestRunner.shared_self
+        assert runner is not None
+        return runner.run_test(test, test_field_width, mp=True)
+
+    def run_tests_pool(self, tests: List[str],
+                       test_field_width: int, jobs: int) -> List[TestResult]:
+
+        # passing self directly to Pool.starmap() just doesn't work, because
+        # it's a context manager.
+        assert TestRunner.shared_self is None
+        TestRunner.shared_self = self
+
+        with Pool(jobs) as p:
+            results = p.starmap(self.proc_run_test,
+                                zip(tests, [test_field_width] * len(tests)))
+
+        TestRunner.shared_self = None
+
+        return results
+
     def __init__(self, env: TestEnv, makecheck: bool = False,
                  color: str = 'auto') -> None:
         self.env = env
@@ -219,7 +245,18 @@ class TestRunner(ContextManager['TestRunner']):
 
         return f'{test}.out'
 
-    def do_run_test(self, test: str) -> TestResult:
+    def do_run_test(self, test: str, mp: bool) -> TestResult:
+        """
+        Run one test
+
+        :param test: test file path
+        :param mp: if true, we are in a multiprocessing environment, use
+                   personal subdirectories for test run
+
+        Note: this method may be called from subprocess, so it does not
+        change ``self`` object in any way!
+        """
+
         f_test = Path(test)
         f_bad = Path(f_test.name + '.out.bad')
         f_notrun = Path(f_test.name + '.notrun')
@@ -243,6 +280,12 @@ class TestRunner(ContextManager['TestRunner']):
 
         args = [str(f_test.resolve())]
         env = self.env.prepare_subprocess(args)
+        if mp:
+            # Split test directories, so that tests running in parallel don't
+            # break each other.
+            for d in ['TEST_DIR', 'SOCK_DIR']:
+                env[d] = os.path.join(env[d], f_test.name)
+                Path(env[d]).mkdir(parents=True, exist_ok=True)
 
         t0 = time.time()
         with f_bad.open('w', encoding="utf-8") as f:
@@ -281,21 +324,36 @@ class TestRunner(ContextManager['TestRunner']):
                               diff=diff, casenotrun=casenotrun)
         else:
             f_bad.unlink()
-            self.last_elapsed.update(test, elapsed)
             return TestResult(status='pass', elapsed=elapsed,
                               casenotrun=casenotrun)
 
     def run_test(self, test: str,
-                 test_field_width: Optional[int] = None) -> TestResult:
+                 test_field_width: Optional[int] = None,
+                 mp: bool = False) -> TestResult:
+        """
+        Run one test and print short status
+
+        :param test: test file path
+        :param test_field_width: width for first field of status format
+        :param mp: if true, we are in a multiprocessing environment, don't try
+                   to rewrite things in stdout
+
+        Note: this method may be called from subprocess, so it does not
+        change ``self`` object in any way!
+        """
+
         last_el = self.last_elapsed.get(test)
         start = datetime.datetime.now().strftime('%H:%M:%S')
 
         if not self.makecheck:
-            self.test_print_one_line(test=test, starttime=start,
-                                     lasttime=last_el, end='\r',
+            self.test_print_one_line(test=test,
+                                     status = 'started' if mp else '...',
+                                     starttime=start,
+                                     lasttime=last_el,
+                                     end = '\n' if mp else '\r',
                                      test_field_width=test_field_width)
 
-        res = self.do_run_test(test)
+        res = self.do_run_test(test, mp)
 
         end = datetime.datetime.now().strftime('%H:%M:%S')
         self.test_print_one_line(test=test, status=res.status,
@@ -309,7 +367,7 @@ class TestRunner(ContextManager['TestRunner']):
 
         return res
 
-    def run_tests(self, tests: List[str]) -> bool:
+    def run_tests(self, tests: List[str], jobs: int = 1) -> bool:
         n_run = 0
         failed = []
         notrun = []
@@ -320,9 +378,16 @@ class TestRunner(ContextManager['TestRunner']):
 
         test_field_width = max(len(os.path.basename(t)) for t in tests) + 2
 
-        for t in tests:
+        if jobs > 1:
+            results = self.run_tests_pool(tests, test_field_width, jobs)
+
+        for i, t in enumerate(tests):
             name = os.path.basename(t)
-            res = self.run_test(t, test_field_width=test_field_width)
+
+            if jobs > 1:
+                res = results[i]
+            else:
+                res = self.run_test(t, test_field_width)
 
             assert res.status in ('pass', 'fail', 'not run')
 
@@ -340,6 +405,9 @@ class TestRunner(ContextManager['TestRunner']):
                     print('\n'.join(res.diff))
             elif res.status == 'not run':
                 notrun.append(name)
+            elif res.status == 'pass':
+                assert res.elapsed is not None
+                self.last_elapsed.update(t, res.elapsed)
 
             sys.stdout.flush()
             if res.interrupted: