diff options
Diffstat (limited to 'tests')
| -rw-r--r-- | tests/check.py | 82 | ||||
| -rw-r--r-- | tests/clock-back.c | 16 |
2 files changed, 84 insertions, 14 deletions
diff --git a/tests/check.py b/tests/check.py index e15a996..379982d 100644 --- a/tests/check.py +++ b/tests/check.py @@ -2653,17 +2653,82 @@ def server_timers(aup, pure, work): stats = host.stop() assert stats[0]['ticks'] >= 10, stats seen['stateless'] = stats[0]['ticks'] - # The wall clock set back an hour 0.2 s in (build/clock-back.so): the - # timers wait on the monotonic clock, so they go on ticking. + return seen + + +def cpu_seconds(pid): + """The CPU time a process has used (user and system).""" import os - host = HttpHost([pure / 'build/pure-serve', '--module', module, '--store', work / 'heartbeat-back'], - env={**os.environ, 'LD_PRELOAD': str(pure / 'build/clock-back.so')}) + with open(f'/proc/{pid}/stat') as stat: + fields = stat.read().rsplit(')', 1)[1].split() + return (int(fields[11]) + int(fields[12])) / os.sysconf('SC_CLK_TCK') + + +def server_clocks(aup, pure, work): + """The wall clock moved an hour while a node runs (build/clock-back.so + moves what the node reads of it, from its start): its timers, the pauses + of a wire whose receiver is down, the owner's waits and a store's group + commit all count on the monotonic clock. Were a wait's deadline read + from the wall clock, set back it would end at once, again and again (a + core spun, the wire tried thousands of times); set forward it would last + an hour (the timers stopped, the wire tried once, and a lone commit + after a group waited that long for the others to join it).""" + import os + import socket + import struct + import threading + import time + module, source = work / 'clocks.pmod', work / 'clocks.aup' + source.write_text(HEARTBEAT_SOURCE) + compile_module(aup, source, module) + with socket.socket() as probe: + probe.bind(('127.0.0.1', 0)) + nobody = probe.getsockname()[1] + seen = {} + for shift in (-3600, 3600): + env = {**os.environ, 'LD_PRELOAD': str(pure / 'build/clock-back.so'), 'CLOCK_BACK_MS': '0', + 'CLOCK_SHIFT_S': str(shift)} + host = HttpHost([pure / 'build/pure-serve', '--module', module, '--store', work / f'clocks{shift}', + '--send', f'pulse=http://127.0.0.1:{nobody}/inputs/pulse'], env=env) + try: + time.sleep(0.2) + began, used = time.time(), cpu_seconds(host.process.pid) + time.sleep(1.0) + share = (cpu_seconds(host.process.pid) - used) / (time.time() - began) + finally: + stats = host.stop()[-1] + assert stats['ticks'] >= 30 and share < 0.25 and 3 <= stats['delivery_attempts'] <= 12, \ + (shift, stats['ticks'], share, stats['delivery_attempts']) + seen[f'shift_{shift}'] = {'ticks': stats['ticks'], 'cpu_share': round(share, 3), + 'wire_attempts': stats['delivery_attempts']} + editor = work / 'clocks-editor.pmod' + compile_module(aup, EDITOR, editor) + env = {**os.environ, 'LD_PRELOAD': str(pure / 'build/clock-back.so'), 'CLOCK_BACK_MS': '0', 'CLOCK_SHIFT_S': '3600'} + host = HttpHost([pure / 'build/pure-serve', '--module', editor, '--store', work / 'clocks-docs', '--threads', 3], + env=env) + new = struct.pack('<II', 0, 0) # an edit that makes the document: at 0, none removed, then its bytes + statuses, alone = [], 0.0 try: - time.sleep(0.6) + for round_number in range(20): # three at once, grouped; then one alone + together = threading.Barrier(3) + + def put(k): + together.wait() + statuses.append(host.request('PUT', f'd{round_number}-{k}', new + b'x' * 100000, 0)[0]) + + threads = [threading.Thread(target=put, args=(k,)) for k in range(3)] + for thread in threads: + thread.start() + for thread in threads: + thread.join() + began = time.time() + statuses.append(host.request('PUT', f'alone-{round_number}', new + b'y', 0)[0]) + alone = max(alone, time.time() - began) finally: - stats = host.stop() - assert stats[0]['ticks'] >= 20, stats - seen['clock_set_back'] = stats[0]['ticks'] + stats = host.stop()[-1] + assert statuses == [200] * 80 and alone < 1 and stats['grouped_commits'] > stats['commit_groups'], \ + (statuses, alone, stats) + seen['alone_after_groups_s'] = round(alone, 4) return seen @@ -2846,6 +2911,7 @@ def main(): server_app(aup, pure, work, range(args.seeds), threads=3) report['server_json_requests'] = server_json(aup, pure, work) report['server_timer_beats'] = server_timers(aup, pure, work) + report['server_clocks'] = server_clocks(aup, pure, work) report['server_plain_edit'] = server_plain_edit(aup, pure, work) report['server_links'] = server_links(aup, pure, work) report['server_links_udp'] = server_links_udp(aup, pure, work) diff --git a/tests/clock-back.c b/tests/clock-back.c index 50870ca..2ab83e0 100644 --- a/tests/clock-back.c +++ b/tests/clock-back.c @@ -1,8 +1,12 @@ #define _GNU_SOURCE -/* LD_PRELOAD: the wall clock (CLOCK_REALTIME) set back an hour from - * CLOCK_BACK_MS milliseconds (200 unless given) after the process first - * asks for it, as a person or NTP may set it. A program's timers must go on - * all the same: they wait on the monotonic clock (tests/check.py). */ +/* LD_PRELOAD: the wall clock (CLOCK_REALTIME) set back an hour (moved + * CLOCK_SHIFT_S seconds: -3600 unless given) from CLOCK_BACK_MS milliseconds + * (200 unless given) after the process first asks for it, as a person or NTP + * may set it. Only what the process reads moves, so a wait until a deadline + * read from the wall clock ends at once (set back) or lasts an hour (set + * forward), as one would with the clock set the other way after it was read. + * A program's timers and waits must go on all the same: they count on the + * monotonic clock (tests/check.py). */ #include <dlfcn.h> #include <stdlib.h> #include <time.h> @@ -17,7 +21,7 @@ int clock_gettime(clockid_t id, struct timespec *t) { real(CLOCK_MONOTONIC, &now); long long ms = (long long)now.tv_sec * 1000 + now.tv_nsec / 1000000; if (began < 0) began = ms; - const char *after = getenv("CLOCK_BACK_MS"); - if (ms - began >= (after ? atoll(after) : 200)) t->tv_sec -= 3600; + const char *after = getenv("CLOCK_BACK_MS"), *shift = getenv("CLOCK_SHIFT_S"); + if (ms - began >= (after ? atoll(after) : 200)) t->tv_sec += shift ? atoll(shift) : -3600; return result; } |