There's a common synchronization problem when a script (Python test)
uses a C program to set up some state (usually start a receiving
process for traffic). The script needs to know when the process
has fully initialized. The inverse of the problem exists for shutting
the process down - we need a reliable way to tell the process to exit.
We added helpers to do this safely in
commit 71477137994f ("selftests: drv-net: add a way to wait for a local
process")
unfortunately the two operations (wait for init, and shutdown) are
controlled by a single parameter (ksft_wait). Add support for using
ksft_ready without using the second fd for exit.
This is useful for programs which wait for a specific number of packets
to rx so exit_wait is a good match, but we still need to wait for init.
Reviewed-by: Petr Machata <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
---
cc: [email protected]
---
tools/testing/selftests/net/lib/py/utils.py | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/net/lib/py/utils.py
b/tools/testing/selftests/net/lib/py/utils.py
index cb40ecef9456..106ee1f2df86 100644
--- a/tools/testing/selftests/net/lib/py/utils.py
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -32,7 +32,7 @@ import time
Use bkg() instead to run a command in the background.
"""
def __init__(self, comm, shell=None, fail=True, ns=None, background=False,
- host=None, timeout=5, ksft_wait=None):
+ host=None, timeout=5, ksft_ready=None, ksft_wait=None):
if ns:
comm = f'ip netns exec {ns} ' + comm
@@ -52,21 +52,25 @@ import time
# ksft_wait lets us wait for the background process to fully start,
# we pass an FD to the child process, and wait for it to write
back.
# Similarly term_fd tells child it's time to exit.
- pass_fds = ()
+ pass_fds = []
env = os.environ.copy()
if ksft_wait is not None:
- rfd, ready_fd = os.pipe()
wait_fd, self.ksft_term_fd = os.pipe()
- pass_fds = (ready_fd, wait_fd, )
- env["KSFT_READY_FD"] = str(ready_fd)
+ pass_fds.append(wait_fd)
env["KSFT_WAIT_FD"] = str(wait_fd)
+ ksft_ready = True # ksft_wait implies ready
+ if ksft_ready is not None:
+ rfd, ready_fd = os.pipe()
+ pass_fds.append(ready_fd)
+ env["KSFT_READY_FD"] = str(ready_fd)
self.proc = subprocess.Popen(comm, shell=shell,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
pass_fds=pass_fds,
env=env)
if ksft_wait is not None:
- os.close(ready_fd)
os.close(wait_fd)
+ if ksft_ready is not None:
+ os.close(ready_fd)
msg = fd_read_timeout(rfd, ksft_wait)
os.close(rfd)
if not msg:
@@ -116,10 +120,10 @@ import time
with bkg("my_binary", ksft_wait=5):
"""
def __init__(self, comm, shell=None, fail=None, ns=None, host=None,
- exit_wait=False, ksft_wait=None):
+ exit_wait=False, ksft_ready=None, ksft_wait=None):
super().__init__(comm, background=True,
shell=shell, fail=fail, ns=ns, host=host,
- ksft_wait=ksft_wait)
+ ksft_ready=ksft_ready, ksft_wait=ksft_wait)
self.terminate = not exit_wait and not ksft_wait
self._exit_wait = exit_wait
self.check_fail = fail
--
2.51.1
