+#!/usr/bin/env python3
+#
+# SPDX-FileCyoprightText: Kienan Stewart <kstewart@efficios.com>
+# SPDX-License-Identifier: GPL-2.0-only
+
+"""
+Test that the consumerd doesn't leak file descriptor allocations in /dev/shm
+when the relayd exits before instrumented applications start.
+
+@see https://bugs.lttng.org/issues/1411
+"""
+
+import os
+import pathlib
+import subprocess
+import sys
+
+test_utils_import_path = pathlib.Path(__file__).absolute().parents[3] / "utils"
+sys.path.append(str(test_utils_import_path))
+
+import lttngtest
+
+
+def get_consumerd_pid(tap, parent, match_string):
+ pid = 0
+ try:
+ process = subprocess.Popen(
+ ["pgrep", "-P", str(parent), "-f", match_string],
+ stdout=subprocess.PIPE,
+ )
+ process.wait()
+ output = str(process.stdout.read(), encoding="UTF-8").splitlines()
+ if len(output) != 1:
+ raise Exception(
+ "Unexpected number of output lines (got {}): {}".format(
+ len(output), output
+ )
+ )
+ pid = int(output[0])
+ except Exception as e:
+ tap.diagnostic(
+ "Failed to find child process of '{}' matching '{}': '{}'".format(
+ parent, match_string, str(e)
+ )
+ )
+ return pid
+
+
+def count_process_dev_shm_fds(pid):
+ count = 0
+ if pid == 0:
+ return count
+ dir = os.path.join("/proc", str(pid), "fd")
+ for root, dirs, files in os.walk(dir):
+ for f in files:
+ filename = pathlib.Path(os.path.join(root, f))
+ try:
+ if filename.is_symlink() and str(filename.resolve()).startswith(
+ "/dev/shm/shm-ust-consumer"
+ ):
+ count += 1
+ except FileNotFoundError:
+ # As we're walking /proc/XX/fd/, fds may be added or removed
+ continue
+ return count
+
+
+def count_dev_shm_fds(tap, test_env):
+ consumer32_pid = get_consumerd_pid(tap, test_env._sessiond.pid, "ustconsumerd32")
+ fds_consumerd32 = count_process_dev_shm_fds(consumer32_pid)
+ consumer64_pid = get_consumerd_pid(tap, test_env._sessiond.pid, "ustconsumerd64")
+ fds_consumerd64 = count_process_dev_shm_fds(consumer64_pid)
+ return (fds_consumerd32, fds_consumerd64)
+
+
+def test_fd_leak(tap, test_env, buffer_sharing_policy, kill_relayd=True):
+ tap.diagnostic(
+ "test_fd_leak with buffer sharing policy {}, kill relayd: {}".format(
+ buffer_sharing_policy, kill_relayd
+ )
+ )
+ client = lttngtest.LTTngClient(test_env, log=tap.diagnostic)
+ output = lttngtest.NetworkSessionOutputLocation(
+ "net://localhost:{}:{}/".format(
+ test_env.lttng_relayd_control_port, test_env.lttng_relayd_data_port
+ )
+ )
+
+ session = client.create_session(output=output, live=True)
+ channel = session.add_channel(
+ lttngtest.lttngctl.TracingDomain.User,
+ buffer_sharing_policy=buffer_sharing_policy,
+ )
+ channel.add_recording_rule(lttngtest.lttngctl.UserTracepointEventRule())
+ session.start()
+
+ count_post_start = count_dev_shm_fds(tap, test_env)
+
+ # Kill the relayd
+ if kill_relayd:
+ test_env._terminate_relayd()
+
+ test_env.launch_wait_trace_test_application(10)
+ count_post_app1 = count_dev_shm_fds(tap, test_env)
+
+ test_env.launch_wait_trace_test_application(10)
+ count_post_app2 = count_dev_shm_fds(tap, test_env)
+
+ test_env.launch_wait_trace_test_application(10)
+ count_post_app3 = count_dev_shm_fds(tap, test_env)
+
+ session.stop()
+ session.destroy()
+
+ count_post_destroy = count_dev_shm_fds(tap, test_env)
+
+ tap.diagnostic(
+ "FD counts post-start: {}, post-destroy: {}".format(
+ count_post_start, count_post_destroy
+ )
+ )
+ tap.test(
+ count_post_start == count_post_destroy,
+ "Count of consumerd FDs in /dev/shm are equal after session start then after destroy",
+ )
+
+ tap.diagnostic(
+ "FD counts post-app-1: {}, post-app-2: {}, post-app-3: {}".format(
+ count_post_app1, count_post_app2, count_post_app3
+ )
+ )
+ if buffer_sharing_policy == lttngtest.lttngctl.BufferSharingPolicy.PerUID:
+ tap.test(
+ (count_post_app1 == count_post_app2)
+ and (count_post_app2 == count_post_app3),
+ "Count of consumerd FDs in /dev/shm doesn't leak over several application invocations",
+ )
+ else:
+ tap.skip(
+ "Count of consumerds FDs in /dev/shm doesn't leak over several application invocations - no mechanism is available to guarantee buffer reclamation within a given time frame"
+ )
+
+
+tap = lttngtest.TapGenerator(8)
+for kill_relayd in [True, False]:
+ for buffer_sharing_policy in [
+ lttngtest.lttngctl.BufferSharingPolicy.PerUID,
+ lttngtest.lttngctl.BufferSharingPolicy.PerPID,
+ ]:
+ with lttngtest.test_environment(
+ log=tap.diagnostic, with_relayd=True, with_sessiond=True
+ ) as test_env:
+ test_fd_leak(tap, test_env, buffer_sharing_policy, kill_relayd)
+
+sys.exit(0 if tap.is_successful else 1)
projects / lttng-tools.git / commitdiff
