Bug Summary

File:lwan-thread.c
Warning:line 683, column 25
Assigned value is garbage or undefined

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name lwan-thread.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=all -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -fno-plt -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib/clang/10.0.1 -include /home/buildbot/lwan-worker/clang-analyze/build/lwan-build-config.h -D _FILE_OFFSET_BITS=64 -D _TIME_BITS=64 -I /home/buildbot/lwan-worker/clang-analyze/build/src/lib/missing -I /usr/include/luajit-2.0 -I /usr/include/valgrind -I /home/buildbot/lwan-worker/clang-analyze/build/src/lib -I /home/buildbot/lwan-worker/clang-analyze/build -internal-isystem /usr/local/include -internal-isystem /usr/lib/clang/10.0.1/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -Wno-unused-parameter -Wno-free-nonheap-object -std=gnu99 -fdebug-compilation-dir /home/buildbot/lwan-worker/clang-analyze/build/src/lib -ferror-limit 19 -fmessage-length 0 -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -analyzer-output=html -faddrsig -o /home/buildbot/lwan-worker/clang-analyze/CLANG/2020-09-09-035814-2101835-1 -x c /home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c
1/*
2 * lwan - simple web server
3 * Copyright (c) 2012, 2013 Leandro A. F. Pereira <leandro@hardinfo.org>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
18 * USA.
19 */
20
21#define _GNU_SOURCE
22#include <assert.h>
23#include <errno(*__errno_location ()).h>
24#include <fcntl.h>
25#include <pthread.h>
26#include <sched.h>
27#include <stdlib.h>
28#include <string.h>
29#include <sys/epoll.h>
30#include <sys/ioctl.h>
31#include <sys/socket.h>
32#include <unistd.h>
33
34#if defined(HAVE_EVENTFD)
35#include <sys/eventfd.h>
36#endif
37
38#include "lwan-private.h"
39#include "lwan-tq.h"
40#include "list.h"
41
42static void lwan_strbuf_free_defer(void *data)
43{
44 lwan_strbuf_free((struct lwan_strbuf *)data);
45}
46
47static void graceful_close(struct lwan *l,
48 struct lwan_connection *conn,
49 char buffer[static DEFAULT_BUFFER_SIZE4096])
50{
51 int fd = lwan_connection_get_fd(l, conn);
52
53 while (TIOCOUTQ0x5411) {
54 /* This ioctl isn't probably doing what it says on the tin; the details
55 * are subtle, but it seems to do the trick to allow gracefully closing
56 * the connection in some cases with minimal system calls. */
57 int bytes_waiting;
58 int r = ioctl(fd, TIOCOUTQ0x5411, &bytes_waiting);
59
60 if (!r && !bytes_waiting) /* See note about close(2) below. */
61 return;
62 if (r < 0 && errno(*__errno_location ()) == EINTR4)
63 continue;
64
65 break;
66 }
67
68 if (UNLIKELY(shutdown(fd, SHUT_WR) < 0)__builtin_expect(((shutdown(fd, SHUT_WR) < 0)), (0))) {
69 if (UNLIKELY(errno == ENOTCONN)__builtin_expect((((*__errno_location ()) == 107)), (0)))
70 return;
71 }
72
73 for (int tries = 0; tries < 20; tries++) {
74 ssize_t r = read(fd, buffer, DEFAULT_BUFFER_SIZE4096);
75
76 if (!r)
77 break;
78
79 if (r < 0) {
80 switch (errno(*__errno_location ())) {
81 case EAGAIN11:
82 coro_yield(conn->coro, CONN_CORO_WANT_READ);
83 /* Fallthrough */
84 case EINTR4:
85 continue;
86 default:
87 return;
88 }
89 }
90
91 coro_yield(conn->coro, CONN_CORO_YIELD);
92 }
93
94 /* close(2) will be called when the coroutine yields with CONN_CORO_ABORT */
95}
96
97__attribute__((noreturn)) static int process_request_coro(struct coro *coro,
98 void *data)
99{
100 /* NOTE: This function should not return; coro_yield should be used
101 * instead. This ensures the storage for `strbuf` is alive when the
102 * coroutine ends and lwan_strbuf_free() is called. */
103 struct lwan_connection *conn = data;
104 struct lwan *lwan = conn->thread->lwan;
105 int fd = lwan_connection_get_fd(lwan, conn);
106 enum lwan_request_flags flags = lwan->config.request_flags;
107 struct lwan_strbuf strbuf = LWAN_STRBUF_STATIC_INIT(struct lwan_strbuf) { .buffer = "" };
108 char request_buffer[DEFAULT_BUFFER_SIZE4096];
109 struct lwan_value buffer = {.value = request_buffer, .len = 0};
110 char *next_request = NULL((void*)0);
111 char *header_start[N_HEADER_START64];
112 struct lwan_proxy proxy;
113 const int error_when_n_packets = lwan_calculate_n_packets(DEFAULT_BUFFER_SIZE4096);
114
115 coro_defer(coro, lwan_strbuf_free_defer, &strbuf);
116
117 const size_t init_gen = 1; /* 1 call to coro_defer() */
118 assert(init_gen == coro_deferred_get_generation(coro))((void) sizeof ((init_gen == coro_deferred_get_generation(coro
)) ? 1 : 0), __extension__ ({ if (init_gen == coro_deferred_get_generation
(coro)) ; else __assert_fail ("init_gen == coro_deferred_get_generation(coro)"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 118, __extension__ __PRETTY_FUNCTION__); }));
119
120 while (true1) {
121 struct lwan_request_parser_helper helper = {
122 .buffer = &buffer,
123 .next_request = next_request,
124 .error_when_n_packets = error_when_n_packets,
125 .header_start = header_start,
126 };
127 struct lwan_request request = {.conn = conn,
128 .global_response_headers = &lwan->headers,
129 .fd = fd,
130 .response = {.buffer = &strbuf},
131 .flags = flags,
132 .proxy = &proxy,
133 .helper = &helper};
134
135 lwan_process_request(lwan, &request);
136
137 /* Run the deferred instructions now (except those used to initialize
138 * the coroutine), so that if the connection is gracefully closed,
139 * the storage for ``helper'' is still there. */
140 coro_deferred_run(coro, init_gen);
141
142 if (UNLIKELY(!(conn->flags & CONN_IS_KEEP_ALIVE))__builtin_expect(((!(conn->flags & CONN_IS_KEEP_ALIVE)
)), (0))) {
143 graceful_close(lwan, conn, request_buffer);
144 break;
145 }
146
147 if (next_request && *next_request) {
148 conn->flags |= CONN_CORK;
149 coro_yield(coro, CONN_CORO_WANT_WRITE);
150 } else {
151 conn->flags &= ~CONN_CORK;
152 coro_yield(coro, CONN_CORO_WANT_READ);
153 }
154
155 lwan_strbuf_reset(&strbuf);
156
157 /* Only allow flags from config. */
158 flags = request.flags & (REQUEST_PROXIED | REQUEST_ALLOW_CORS);
159 next_request = helper.next_request;
160 }
161
162 coro_yield(coro, CONN_CORO_ABORT);
163 __builtin_unreachable();
164}
165
166static ALWAYS_INLINEinline __attribute__((always_inline)) uint32_t
167conn_flags_to_epoll_events(enum lwan_connection_flags flags)
168{
169 static const uint32_t map[CONN_EVENTS_MASK + 1] = {
170 [0 /* Suspended (timer or await) */] = EPOLLRDHUPEPOLLRDHUP,
171 [CONN_EVENTS_WRITE] = EPOLLOUTEPOLLOUT | EPOLLRDHUPEPOLLRDHUP,
172 [CONN_EVENTS_READ] = EPOLLINEPOLLIN | EPOLLRDHUPEPOLLRDHUP,
173 [CONN_EVENTS_READ_WRITE] = EPOLLINEPOLLIN | EPOLLOUTEPOLLOUT | EPOLLRDHUPEPOLLRDHUP,
174 };
175
176 return map[flags & CONN_EVENTS_MASK];
177}
178
179static void update_epoll_flags(int fd,
180 struct lwan_connection *conn,
181 int epoll_fd,
182 enum lwan_connection_coro_yield yield_result)
183{
184 static const enum lwan_connection_flags or_mask[CONN_CORO_MAX] = {
185 [CONN_CORO_YIELD] = 0,
186
187 [CONN_CORO_WANT_READ_WRITE] = CONN_EVENTS_READ_WRITE,
188 [CONN_CORO_WANT_READ] = CONN_EVENTS_READ,
189 [CONN_CORO_WANT_WRITE] = CONN_EVENTS_WRITE,
190
191 /* While the coro is suspended, we're not interested in either EPOLLIN
192 * or EPOLLOUT events. We still want to track this fd in epoll, though,
193 * so unset both so that only EPOLLRDHUP (plus the implicitly-set ones)
194 * are set. */
195 [CONN_CORO_SUSPEND_TIMER] = CONN_SUSPENDED_TIMER,
196 [CONN_CORO_SUSPEND_ASYNC_AWAIT] = CONN_SUSPENDED_ASYNC_AWAIT,
197
198 /* Ideally, when suspending a coroutine, the current flags&CONN_EVENTS_MASK
199 * would have to be stored and restored -- however, resuming as if the
200 * client coroutine is interested in a write event always guarantees that
201 * they'll be resumed as they're TCP sockets. There's a good chance that
202 * trying to read from a socket after resuming a coroutine will succeed,
203 * but if it doesn't because read() returns -EAGAIN, the I/O wrappers will
204 * yield with CONN_CORO_WANT_READ anyway. */
205 [CONN_CORO_RESUME] = CONN_EVENTS_WRITE,
206 };
207 static const enum lwan_connection_flags and_mask[CONN_CORO_MAX] = {
208 [CONN_CORO_YIELD] = ~0,
209
210 [CONN_CORO_WANT_READ_WRITE] = ~0,
211 [CONN_CORO_WANT_READ] = ~CONN_EVENTS_WRITE,
212 [CONN_CORO_WANT_WRITE] = ~CONN_EVENTS_READ,
213
214 [CONN_CORO_SUSPEND_TIMER] = ~(CONN_EVENTS_READ_WRITE | CONN_SUSPENDED_ASYNC_AWAIT),
215 [CONN_CORO_SUSPEND_ASYNC_AWAIT] = ~(CONN_EVENTS_READ_WRITE | CONN_SUSPENDED_TIMER),
216 [CONN_CORO_RESUME] = ~CONN_SUSPENDED,
217 };
218 enum lwan_connection_flags prev_flags = conn->flags;
219
220 conn->flags |= or_mask[yield_result];
221 conn->flags &= and_mask[yield_result];
222
223 if (conn->flags == prev_flags)
224 return;
225
226 struct epoll_event event = {
227 .events = conn_flags_to_epoll_events(conn->flags),
228 .data.ptr = conn,
229 };
230
231 if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &event) < 0)__builtin_expect(((epoll_ctl(epoll_fd, 3, fd, &event) <
0)), (0)))
232 lwan_status_perror("epoll_ctl")lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 232, __FUNCTION__, "epoll_ctl");
233}
234
235static void clear_async_await_flag(void *data)
236{
237 struct lwan_connection *async_fd_conn = data;
238
239 async_fd_conn->flags &= ~CONN_ASYNC_AWAIT;
240}
241
242static enum lwan_connection_coro_yield
243resume_async(struct timeout_queue *tq,
244 enum lwan_connection_coro_yield yield_result,
245 int64_t from_coro,
246 struct lwan_connection *conn,
247 int epoll_fd)
248{
249 static const enum lwan_connection_flags to_connection_flags[] = {
250 [CONN_CORO_ASYNC_AWAIT_READ] = CONN_EVENTS_READ,
251 [CONN_CORO_ASYNC_AWAIT_WRITE] = CONN_EVENTS_WRITE,
252 [CONN_CORO_ASYNC_AWAIT_READ_WRITE] = CONN_EVENTS_READ_WRITE,
253 };
254 int await_fd = (int)((uint64_t)from_coro >> 32);
255 enum lwan_connection_flags flags;
256 int op;
257
258 assert(await_fd >= 0)((void) sizeof ((await_fd >= 0) ? 1 : 0), __extension__ ({
if (await_fd >= 0) ; else __assert_fail ("await_fd >= 0"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 258, __extension__ __PRETTY_FUNCTION__); }));
259 assert(yield_result >= CONN_CORO_ASYNC_AWAIT_READ &&((void) sizeof ((yield_result >= CONN_CORO_ASYNC_AWAIT_READ
&& yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE
) ? 1 : 0), __extension__ ({ if (yield_result >= CONN_CORO_ASYNC_AWAIT_READ
&& yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE
) ; else __assert_fail ("yield_result >= CONN_CORO_ASYNC_AWAIT_READ && yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 260, __extension__ __PRETTY_FUNCTION__); }))
260 yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE)((void) sizeof ((yield_result >= CONN_CORO_ASYNC_AWAIT_READ
&& yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE
) ? 1 : 0), __extension__ ({ if (yield_result >= CONN_CORO_ASYNC_AWAIT_READ
&& yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE
) ; else __assert_fail ("yield_result >= CONN_CORO_ASYNC_AWAIT_READ && yield_result <= CONN_CORO_ASYNC_AWAIT_READ_WRITE"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 260, __extension__ __PRETTY_FUNCTION__); }));
261
262 flags = to_connection_flags[yield_result];
263
264 struct lwan_connection *await_fd_conn = &tq->lwan->conns[await_fd];
265 if (LIKELY(await_fd_conn->flags & CONN_ASYNC_AWAIT)__builtin_expect((!!(await_fd_conn->flags & CONN_ASYNC_AWAIT
)), (1))) {
266 if (LIKELY((await_fd_conn->flags & CONN_EVENTS_MASK) == flags)__builtin_expect((!!((await_fd_conn->flags & CONN_EVENTS_MASK
) == flags)), (1)))
267 return CONN_CORO_SUSPEND_ASYNC_AWAIT;
268
269 op = EPOLL_CTL_MOD3;
270 } else {
271 op = EPOLL_CTL_ADD1;
272 flags |= CONN_ASYNC_AWAIT;
273 coro_defer(conn->coro, clear_async_await_flag, await_fd_conn);
274 }
275
276 struct epoll_event event = {.events = conn_flags_to_epoll_events(flags),
277 .data.ptr = conn};
278 if (LIKELY(!epoll_ctl(epoll_fd, op, await_fd, &event))__builtin_expect((!!(!epoll_ctl(epoll_fd, op, await_fd, &
event))), (1))) {
279 await_fd_conn->flags &= ~CONN_EVENTS_MASK;
280 await_fd_conn->flags |= flags;
281 return CONN_CORO_SUSPEND_ASYNC_AWAIT;
282 }
283
284 return CONN_CORO_ABORT;
285}
286
287static ALWAYS_INLINEinline __attribute__((always_inline)) void resume_coro(struct timeout_queue *tq,
288 struct lwan_connection *conn,
289 int epoll_fd)
290{
291 assert(conn->coro)((void) sizeof ((conn->coro) ? 1 : 0), __extension__ ({ if
(conn->coro) ; else __assert_fail ("conn->coro", "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 291, __extension__ __PRETTY_FUNCTION__); }));
292
293 int64_t from_coro = coro_resume(conn->coro);
294 enum lwan_connection_coro_yield yield_result = from_coro & 0xffffffff;
295
296 if (UNLIKELY(yield_result >= CONN_CORO_ASYNC)__builtin_expect(((yield_result >= CONN_CORO_ASYNC)), (0)))
297 yield_result = resume_async(tq, yield_result, from_coro, conn, epoll_fd);
298
299 if (UNLIKELY(yield_result == CONN_CORO_ABORT)__builtin_expect(((yield_result == CONN_CORO_ABORT)), (0)))
300 return timeout_queue_expire(tq, conn);
301
302 return update_epoll_flags(lwan_connection_get_fd(tq->lwan, conn), conn,
303 epoll_fd, yield_result);
304}
305
306static void update_date_cache(struct lwan_thread *thread)
307{
308 time_t now = time(NULL((void*)0));
309
310 lwan_format_rfc_time(now, thread->date.date);
311 lwan_format_rfc_time(now + (time_t)thread->lwan->config.expires,
312 thread->date.expires);
313}
314
315static ALWAYS_INLINEinline __attribute__((always_inline)) void spawn_coro(struct lwan_connection *conn,
316 struct coro_switcher *switcher,
317 struct timeout_queue *tq)
318{
319 struct lwan_thread *t = conn->thread;
320
321 assert(!conn->coro)((void) sizeof ((!conn->coro) ? 1 : 0), __extension__ ({ if
(!conn->coro) ; else __assert_fail ("!conn->coro", "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 321, __extension__ __PRETTY_FUNCTION__); }));
322 assert(t)((void) sizeof ((t) ? 1 : 0), __extension__ ({ if (t) ; else __assert_fail
("t", "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 322, __extension__ __PRETTY_FUNCTION__); }));
323 assert((uintptr_t)t >= (uintptr_t)tq->lwan->thread.threads)((void) sizeof (((uintptr_t)t >= (uintptr_t)tq->lwan->
thread.threads) ? 1 : 0), __extension__ ({ if ((uintptr_t)t >=
(uintptr_t)tq->lwan->thread.threads) ; else __assert_fail
("(uintptr_t)t >= (uintptr_t)tq->lwan->thread.threads"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 323, __extension__ __PRETTY_FUNCTION__); }));
324 assert((uintptr_t)t <((void) sizeof (((uintptr_t)t < (uintptr_t)(tq->lwan->
thread.threads + tq->lwan->thread.count)) ? 1 : 0), __extension__
({ if ((uintptr_t)t < (uintptr_t)(tq->lwan->thread.
threads + tq->lwan->thread.count)) ; else __assert_fail
("(uintptr_t)t < (uintptr_t)(tq->lwan->thread.threads + tq->lwan->thread.count)"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 325, __extension__ __PRETTY_FUNCTION__); }))
325 (uintptr_t)(tq->lwan->thread.threads + tq->lwan->thread.count))((void) sizeof (((uintptr_t)t < (uintptr_t)(tq->lwan->
thread.threads + tq->lwan->thread.count)) ? 1 : 0), __extension__
({ if ((uintptr_t)t < (uintptr_t)(tq->lwan->thread.
threads + tq->lwan->thread.count)) ; else __assert_fail
("(uintptr_t)t < (uintptr_t)(tq->lwan->thread.threads + tq->lwan->thread.count)"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 325, __extension__ __PRETTY_FUNCTION__); }));
326
327 *conn = (struct lwan_connection) {
328 .coro = coro_new(switcher, process_request_coro, conn),
329 .flags = CONN_EVENTS_READ,
330 .time_to_expire = tq->current_time + tq->move_to_last_bump,
331 .thread = t,
332 };
333 if (UNLIKELY(!conn->coro)__builtin_expect(((!conn->coro)), (0))) {
334 conn->flags = 0;
335 lwan_status_error("Could not create coroutine")lwan_status_error_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 335, __FUNCTION__, "Could not create coroutine");
336 return;
337 }
338
339 timeout_queue_insert(tq, conn);
340}
341
342static void accept_nudge(int pipe_fd,
343 struct lwan_thread *t,
344 struct lwan_connection *conns,
345 struct timeout_queue *tq,
346 struct coro_switcher *switcher,
347 int epoll_fd)
348{
349 uint64_t event;
350 int new_fd;
351
352 /* Errors are ignored here as pipe_fd serves just as a way to wake the
353 * thread from epoll_wait(). It's fine to consume the queue at this
354 * point, regardless of the error type. */
355 (void)read(pipe_fd, &event, sizeof(event));
356
357 while (spsc_queue_pop(&t->pending_fds, &new_fd)) {
358 struct lwan_connection *conn = &conns[new_fd];
359 struct epoll_event ev = {
360 .data.ptr = conn,
361 .events = conn_flags_to_epoll_events(CONN_EVENTS_READ),
362 };
363
364 if (LIKELY(!epoll_ctl(epoll_fd, EPOLL_CTL_ADD, new_fd, &ev))__builtin_expect((!!(!epoll_ctl(epoll_fd, 1, new_fd, &ev)
)), (1)))
365 spawn_coro(conn, switcher, tq);
366 }
367
368 timeouts_add(t->wheel, &tq->timeout, 1000);
369}
370
371static bool_Bool process_pending_timers(struct timeout_queue *tq,
372 struct lwan_thread *t,
373 int epoll_fd)
374{
375 struct timeout *timeout;
376 bool_Bool should_expire_timers = false0;
377
378 while ((timeout = timeouts_get(t->wheel))) {
379 struct lwan_request *request;
380
381 if (timeout == &tq->timeout) {
382 should_expire_timers = true1;
383 continue;
384 }
385
386 request = container_of(timeout, struct lwan_request, timeout)((struct lwan_request *) ((char *)(timeout) - __builtin_offsetof
(struct lwan_request, timeout)) + ((typeof(*(timeout)) *)0 !=
(typeof(((struct lwan_request *)0)->timeout) *)0));
387
388 update_epoll_flags(request->fd, request->conn, epoll_fd,
389 CONN_CORO_RESUME);
390 }
391
392 if (should_expire_timers) {
393 timeout_queue_expire_waiting(tq);
394
395 /* tq timeout expires every 1000ms if there are connections, so
396 * update the date cache at this point as well. */
397 update_date_cache(t);
398
399 if (!timeout_queue_empty(tq)) {
400 timeouts_add(t->wheel, &tq->timeout, 1000);
401 return true1;
402 }
403
404 timeouts_del(t->wheel, &tq->timeout);
405 }
406
407 return false0;
408}
409
410static int
411turn_timer_wheel(struct timeout_queue *tq, struct lwan_thread *t, int epoll_fd)
412{
413 timeout_t wheel_timeout;
414 struct timespec now;
415
416 if (UNLIKELY(clock_gettime(monotonic_clock_id, &now) < 0)__builtin_expect(((clock_gettime(monotonic_clock_id, &now
) < 0)), (0)))
417 lwan_status_critical("Could not get monotonic time")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 417, __FUNCTION__, "Could not get monotonic time");
418
419 timeouts_update(t->wheel,
420 (timeout_t)(now.tv_sec * 1000 + now.tv_nsec / 1000000));
421
422 wheel_timeout = timeouts_timeout(t->wheel);
423 if (UNLIKELY((int64_t)wheel_timeout < 0)__builtin_expect((((int64_t)wheel_timeout < 0)), (0)))
424 goto infinite_timeout;
425
426 if (wheel_timeout == 0) {
427 if (!process_pending_timers(tq, t, epoll_fd))
428 goto infinite_timeout;
429
430 wheel_timeout = timeouts_timeout(t->wheel);
431 if (wheel_timeout == 0)
432 goto infinite_timeout;
433 }
434
435 return (int)wheel_timeout;
436
437infinite_timeout:
438 return -1;
439}
440
441static void *thread_io_loop(void *data)
442{
443 struct lwan_thread *t = data;
444 int epoll_fd = t->epoll_fd;
445 const int read_pipe_fd = t->pipe_fd[0];
446 const int max_events = LWAN_MIN((int)t->lwan->thread.max_fd, 1024)({ const __typeof__(((int)t->lwan->thread.max_fd) + 0) lwan_tmp_id6
= ((int)t->lwan->thread.max_fd); const __typeof__((1024
) + 0) lwan_tmp_id7 = (1024); lwan_tmp_id6 > lwan_tmp_id7 ?
lwan_tmp_id7 : lwan_tmp_id6; });
447 struct lwan *lwan = t->lwan;
448 struct epoll_event *events;
449 struct coro_switcher switcher;
450 struct timeout_queue tq;
451
452 lwan_status_debug("Worker thread #%zd starting",lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 453, __FUNCTION__, "Worker thread #%zd starting", t - t->
lwan->thread.threads + 1)
453 t - t->lwan->thread.threads + 1)lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 453, __FUNCTION__, "Worker thread #%zd starting", t - t->
lwan->thread.threads + 1);
454 lwan_set_thread_name("worker");
455
456 events = calloc((size_t)max_events, sizeof(*events));
457 if (UNLIKELY(!events)__builtin_expect(((!events)), (0)))
458 lwan_status_critical("Could not allocate memory for events")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 458, __FUNCTION__, "Could not allocate memory for events");
459
460 update_date_cache(t);
461
462 timeout_queue_init(&tq, lwan);
463
464 pthread_barrier_wait(&lwan->thread.barrier);
465
466 for (;;) {
467 int timeout = turn_timer_wheel(&tq, t, epoll_fd);
468 int n_fds = epoll_wait(epoll_fd, events, max_events, timeout);
469
470 if (UNLIKELY(n_fds < 0)__builtin_expect(((n_fds < 0)), (0))) {
471 if (errno(*__errno_location ()) == EBADF9 || errno(*__errno_location ()) == EINVAL22)
472 break;
473 continue;
474 }
475
476 for (struct epoll_event *event = events; n_fds--; event++) {
477 struct lwan_connection *conn;
478
479 if (UNLIKELY(!event->data.ptr)__builtin_expect(((!event->data.ptr)), (0))) {
480 accept_nudge(read_pipe_fd, t, lwan->conns, &tq, &switcher,
481 epoll_fd);
482 continue;
483 }
484
485 conn = event->data.ptr;
486
487 if (UNLIKELY(event->events & (EPOLLRDHUP | EPOLLHUP))__builtin_expect(((event->events & (EPOLLRDHUP | EPOLLHUP
))), (0))) {
488 timeout_queue_expire(&tq, conn);
489 continue;
490 }
491
492 resume_coro(&tq, conn, epoll_fd);
493 timeout_queue_move_to_last(&tq, conn);
494 }
495 }
496
497 pthread_barrier_wait(&lwan->thread.barrier);
498
499 timeout_queue_expire_all(&tq);
500 free(events);
501
502 return NULL((void*)0);
503}
504
505static void create_thread(struct lwan *l, struct lwan_thread *thread,
506 const size_t n_queue_fds)
507{
508 int ignore;
509 pthread_attr_t attr;
510
511 memset(thread, 0, sizeof(*thread));
512 thread->lwan = l;
513
514 thread->wheel = timeouts_open(&ignore);
515 if (!thread->wheel)
516 lwan_status_critical("Could not create timer wheel")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 516, __FUNCTION__, "Could not create timer wheel");
517
518 if ((thread->epoll_fd = epoll_create1(EPOLL_CLOEXECEPOLL_CLOEXEC)) < 0)
519 lwan_status_critical_perror("epoll_create")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 519, __FUNCTION__, "epoll_create");
520
521 if (pthread_attr_init(&attr))
522 lwan_status_critical_perror("pthread_attr_init")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 522, __FUNCTION__, "pthread_attr_init");
523
524 if (pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEMPTHREAD_SCOPE_SYSTEM))
525 lwan_status_critical_perror("pthread_attr_setscope")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 525, __FUNCTION__, "pthread_attr_setscope");
526
527 if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLEPTHREAD_CREATE_JOINABLE))
528 lwan_status_critical_perror("pthread_attr_setdetachstate")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 528, __FUNCTION__, "pthread_attr_setdetachstate");
529
530#if defined(HAVE_EVENTFD)
531 int efd = eventfd(0, EFD_NONBLOCKEFD_NONBLOCK | EFD_SEMAPHOREEFD_SEMAPHORE | EFD_CLOEXECEFD_CLOEXEC);
532 if (efd < 0)
533 lwan_status_critical_perror("eventfd")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 533, __FUNCTION__, "eventfd");
534
535 thread->pipe_fd[0] = thread->pipe_fd[1] = efd;
536#else
537 if (pipe2(thread->pipe_fd, O_NONBLOCK04000 | O_CLOEXEC02000000) < 0)
538 lwan_status_critical_perror("pipe")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 538, __FUNCTION__, "pipe");
539#endif
540
541 struct epoll_event event = { .events = EPOLLINEPOLLIN, .data.ptr = NULL((void*)0) };
542 if (epoll_ctl(thread->epoll_fd, EPOLL_CTL_ADD1, thread->pipe_fd[0], &event) < 0)
543 lwan_status_critical_perror("epoll_ctl")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 543, __FUNCTION__, "epoll_ctl");
544
545 if (pthread_create(&thread->self, &attr, thread_io_loop, thread))
546 lwan_status_critical_perror("pthread_create")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 546, __FUNCTION__, "pthread_create");
547
548 if (pthread_attr_destroy(&attr))
549 lwan_status_critical_perror("pthread_attr_destroy")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 549, __FUNCTION__, "pthread_attr_destroy");
550
551 if (spsc_queue_init(&thread->pending_fds, n_queue_fds) < 0) {
552 lwan_status_critical("Could not initialize pending fd "lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 553, __FUNCTION__, "Could not initialize pending fd " "queue width %zu elements"
, n_queue_fds)
553 "queue width %zu elements", n_queue_fds)lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 553, __FUNCTION__, "Could not initialize pending fd " "queue width %zu elements"
, n_queue_fds);
554 }
555}
556
557void lwan_thread_nudge(struct lwan_thread *t)
558{
559 uint64_t event = 1;
560
561 if (UNLIKELY(write(t->pipe_fd[1], &event, sizeof(event)) < 0)__builtin_expect(((write(t->pipe_fd[1], &event, sizeof
(event)) < 0)), (0)))
562 lwan_status_perror("write")lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 562, __FUNCTION__, "write");
563}
564
565void lwan_thread_add_client(struct lwan_thread *t, int fd)
566{
567 for (int i = 0; i < 10; i++) {
568 bool_Bool pushed = spsc_queue_push(&t->pending_fds, fd);
569
570 if (LIKELY(pushed)__builtin_expect((!!(pushed)), (1)))
571 return;
572
573 /* Queue is full; nudge the thread to consume it. */
574 lwan_thread_nudge(t);
575 }
576
577 lwan_status_error("Dropping connection %d", fd)lwan_status_error_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 577, __FUNCTION__, "Dropping connection %d", fd);
578 /* FIXME: send "busy" response now, even without receiving request? */
579 close(fd);
580}
581
582#if defined(__linux__1) && defined(__x86_64__1)
583static bool_Bool read_cpu_topology(struct lwan *l, uint32_t siblings[])
584{
585 char path[PATH_MAX4096];
586
587 for (unsigned int i = 0; i < l->n_cpus; i++) {
20
←
Loop condition is true. Entering loop body
→
25
←
Loop condition is true. Entering loop body
→
30
←
Loop condition is true. Entering loop body
→
35
←
Loop condition is false. Execution continues on line 627
→
588 FILE *sib;
589 uint32_t id, sibling;
590 char separator;
591
592 snprintf(path, sizeof(path),
593 "/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list",
594 i);
595
596 sib = fopen(path, "re");
597 if (!sib) {
21
←
Assuming 'sib' is non-null, which participates in a condition later
→
22
←
Taking false branch
→
26
←
Assuming 'sib' is non-null, which participates in a condition later
→
27
←
Taking false branch
→
31
←
Assuming 'sib' is non-null, which participates in a condition later
→
32
←
Taking false branch
→
598 lwan_status_warning("Could not open `%s` to determine CPU topology",lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 599, __FUNCTION__, "Could not open `%s` to determine CPU topology"
, path)
599 path)lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 599, __FUNCTION__, "Could not open `%s` to determine CPU topology"
, path);
600 return false0;
601 }
602
603 switch (fscanf(sib, "%u%c%u", &id, &separator, &sibling)) {
23
←
Control jumps to 'case 2:' at line 604
→
28
←
Control jumps to 'case 2:' at line 604
→
33
←
Control jumps to 'case 2:' at line 604
→
604 case 2: /* No SMT */
605 siblings[i] = id;
606 break;
24
←
 Execution continues on line 620
→
29
←
 Execution continues on line 620
→
34
←
 Execution continues on line 620
→
607 case 3: /* SMT */
608 if (!(separator == ',' || separator == '-')) {
609 lwan_status_critical("Expecting either ',' or '-' for sibling separator")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 609, __FUNCTION__, "Expecting either ',' or '-' for sibling separator"
);
610 __builtin_unreachable();
611 }
612
613 siblings[i] = sibling;
614 break;
615 default:
616 lwan_status_critical("%s has invalid format", path)lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 616, __FUNCTION__, "%s has invalid format", path);
617 __builtin_unreachable();
618 }
619
620 fclose(sib);
621 }
622
623 /* Some systems may lie about the number of online CPUs (obtainable with
624 * sysconf()), but don't filter out the CPU topology information from
625 * sysfs, which might reference CPU numbers higher than the amount
626 * obtained with sysconf(). */
627 for (unsigned int i = 0; i < l->n_cpus; i++) {
36
←
Loop condition is true. Entering loop body
→
41
←
Loop condition is true. Entering loop body
→
46
←
Loop condition is true. Entering loop body
→
51
←
Loop condition is false. Execution continues on line 641
→
628 if (siblings[i] == 0xbebacafe) {
37
←
Assuming the condition is false
→
38
←
Taking false branch
→
42
←
Assuming the condition is false
→
43
←
Taking false branch
→
47
←
Assuming the condition is false
→
48
←
Taking false branch
→
629 lwan_status_warning("Could not determine sibling for CPU %d", i)lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 629, __FUNCTION__, "Could not determine sibling for CPU %d"
, i);
630 return false0;
631 }
632
633 if (siblings[i] > l->n_cpus) {
39
←
Assuming the condition is false
→
40
←
Taking false branch
→
44
←
Assuming the condition is false
→
45
←
Taking false branch
→
49
←
Assuming the condition is false
→
50
←
Taking false branch
→
634 lwan_status_warning("CPU topology information says CPU %d exists, "lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 636, __FUNCTION__, "CPU topology information says CPU %d exists, "
"but max CPUs is %d. Is Lwan running in a " "container?", siblings
[i], l->n_cpus)
635 "but max CPUs is %d. Is Lwan running in a "lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 636, __FUNCTION__, "CPU topology information says CPU %d exists, "
"but max CPUs is %d. Is Lwan running in a " "container?", siblings
[i], l->n_cpus)
636 "container?", siblings[i], l->n_cpus)lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 636, __FUNCTION__, "CPU topology information says CPU %d exists, "
"but max CPUs is %d. Is Lwan running in a " "container?", siblings
[i], l->n_cpus);
637 return false0;
638 }
639 }
640
641 return true1;
52
←
Returning the value 1, which participates in a condition later
→
642}
643
644static void
645siblings_to_schedtbl(struct lwan *l, uint32_t siblings[], uint32_t schedtbl[])
646{
647 int *seen = alloca(l->n_cpus * sizeof(int))__builtin_alloca (l->n_cpus * sizeof(int));
648 int n_schedtbl = 0;
649
650 for (uint32_t i = 0; i < l->n_cpus; i++)
56
←
Loop condition is true. Entering loop body
→
57
←
Loop condition is true. Entering loop body
→
58
←
Loop condition is true. Entering loop body
→
59
←
Loop condition is false. Execution continues on line 653
→
651 seen[i] = -1;
652
653 for (uint32_t i = 0; i < l->n_cpus; i++) {
60
←
Loop condition is true. Entering loop body
→
63
←
Loop condition is true. Entering loop body
→
66
←
Loop condition is true. Entering loop body
→
69
←
Loop condition is false. Execution continues on line 662
→
654 if (seen[siblings[i]] < 0) {
61
←
Assuming the condition is false
→
62
←
Taking false branch
→
64
←
Assuming the condition is true
→
65
←
Taking true branch
→
67
←
Assuming the condition is true
→
68
←
Taking true branch
→
655 seen[siblings[i]] = (int)i;
656 } else {
657 schedtbl[n_schedtbl++] = (uint32_t)seen[siblings[i]];
658 schedtbl[n_schedtbl++] = i;
659 }
660 }
661
662 if (!n_schedtbl
69.1
'n_schedtbl' is 2
)
70
←
Taking false branch
→
663 memcpy(schedtbl, seen, l->n_cpus * sizeof(int));
664}
665
666static void
667topology_to_schedtbl(struct lwan *l, uint32_t schedtbl[], uint32_t n_threads)
668{
669 uint32_t *siblings = alloca(l->n_cpus * sizeof(uint32_t))__builtin_alloca (l->n_cpus * sizeof(uint32_t));
670
671 for (uint32_t i = 0; i < l->n_cpus; i++)
11
←
Assuming 'i' is < field 'n_cpus'
→
12
←
Loop condition is true. Entering loop body
→
13
←
Assuming 'i' is < field 'n_cpus'
→
14
←
Loop condition is true. Entering loop body
→
15
←
Assuming 'i' is < field 'n_cpus'
→
16
←
Loop condition is true. Entering loop body
→
17
←
Assuming 'i' is >= field 'n_cpus'
→
18
←
Loop condition is false. Execution continues on line 674
→
672 siblings[i] = 0xbebacafe;
673
674 if (!read_cpu_topology(l, siblings)) {
19
←
Calling 'read_cpu_topology'
→
53
←
Returning from 'read_cpu_topology'
→
54
←
Taking false branch
→
675 for (uint32_t i = 0; i < n_threads; i++)
676 schedtbl[i] = (i / 2) % l->thread.count;
677 } else {
678 uint32_t *affinity = alloca(l->n_cpus * sizeof(uint32_t))__builtin_alloca (l->n_cpus * sizeof(uint32_t));
679
680 siblings_to_schedtbl(l, siblings, affinity);
55
←
Calling 'siblings_to_schedtbl'
→
71
←
Returning from 'siblings_to_schedtbl'
→
681
682 for (uint32_t i = 0; i < n_threads; i++)
72
←
Assuming 'i' is < 'n_threads'
→
73
←
Loop condition is true. Entering loop body
→
74
←
Assuming 'i' is < 'n_threads'
→
75
←
Loop condition is true. Entering loop body
→
76
←
Assuming 'i' is < 'n_threads'
→
77
←
Loop condition is true. Entering loop body
→
683 schedtbl[i] = affinity[i % l->n_cpus];
78
←
Assigned value is garbage or undefined
684 }
685}
686
687static void
688adjust_threads_affinity(struct lwan *l, uint32_t *schedtbl, uint32_t mask)
689{
690 for (uint32_t i = 0; i < l->thread.count; i++) {
691 cpu_set_t set;
692
693 CPU_ZERO(&set)do __builtin_memset (&set, '\0', sizeof (cpu_set_t)); while
(0);
694 CPU_SET(schedtbl[i & mask], &set)(__extension__ ({ size_t __cpu = (schedtbl[i & mask]); __cpu
/ 8 < (sizeof (cpu_set_t)) ? (((__cpu_mask *) ((&set)
->__bits))[((__cpu) / (8 * sizeof (__cpu_mask)))] |= ((__cpu_mask
) 1 << ((__cpu) % (8 * sizeof (__cpu_mask))))) : 0; }));
695
696 if (pthread_setaffinity_np(l->thread.threads[i].self, sizeof(set),
697 &set))
698 lwan_status_warning("Could not set affinity for thread %d", i)lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 698, __FUNCTION__, "Could not set affinity for thread %d", i
);
699 }
700}
701#elif defined(__x86_64__1)
702static void
703topology_to_schedtbl(struct lwan *l, uint32_t schedtbl[], uint32_t n_threads)
704{
705 for (uint32_t i = 0; i < n_threads; i++)
706 schedtbl[i] = (i / 2) % l->thread.count;
707}
708
709static void
710adjust_threads_affinity(struct lwan *l, uint32_t *schedtbl, uint32_t n)
711{
712}
713#endif
714
715void lwan_thread_init(struct lwan *l)
716{
717 if (pthread_barrier_init(&l->thread.barrier, NULL((void*)0),
1
Assuming the condition is false
→
2
←
Taking false branch
→
718 (unsigned)l->thread.count + 1))
719 lwan_status_critical("Could not create barrier")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 719, __FUNCTION__, "Could not create barrier");
720
721 lwan_status_debug("Initializing threads")lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 721, __FUNCTION__, "Initializing threads");
722
723 l->thread.threads =
724 calloc((size_t)l->thread.count, sizeof(struct lwan_thread));
725 if (!l->thread.threads)
3
←
Assuming field 'threads' is non-null
→
4
←
Taking false branch
→
726 lwan_status_critical("Could not allocate memory for threads")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 726, __FUNCTION__, "Could not allocate memory for threads");
727
728 const size_t n_queue_fds = LWAN_MIN(l->thread.max_fd / l->thread.count,({ const __typeof__((l->thread.max_fd / l->thread.count
) + 0) lwan_tmp_id8 = (l->thread.max_fd / l->thread.count
); const __typeof__(((size_t)(2 * lwan_socket_get_backlog_size
())) + 0) lwan_tmp_id9 = ((size_t)(2 * lwan_socket_get_backlog_size
())); lwan_tmp_id8 > lwan_tmp_id9 ? lwan_tmp_id9 : lwan_tmp_id8
; })
5
←
Assuming 'lwan_tmp_id4' is <= 'lwan_tmp_id5'
→
6
←
'?' condition is false
→
729 (size_t)(2 * lwan_socket_get_backlog_size()))({ const __typeof__((l->thread.max_fd / l->thread.count
) + 0) lwan_tmp_id8 = (l->thread.max_fd / l->thread.count
); const __typeof__(((size_t)(2 * lwan_socket_get_backlog_size
())) + 0) lwan_tmp_id9 = ((size_t)(2 * lwan_socket_get_backlog_size
())); lwan_tmp_id8 > lwan_tmp_id9 ? lwan_tmp_id9 : lwan_tmp_id8
; });
730 lwan_status_debug("Pending client file descriptor queue has %zu items", n_queue_fds)lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 730, __FUNCTION__, "Pending client file descriptor queue has %zu items"
, n_queue_fds);
731 for (unsigned int i = 0; i
6.1
'i' is < field 'count'
 < l->thread.count; i++)
7
←
Loop condition is true. Entering loop body
→
8
←
Assuming 'i' is >= field 'count'
→
9
←
Loop condition is false. Execution continues on line 734
→
732 create_thread(l, &l->thread.threads[i], n_queue_fds);
733
734 const unsigned int total_conns = l->thread.max_fd * l->thread.count;
735#ifdef __x86_64__1
736 static_assert(sizeof(struct lwan_connection) == 32,extern int (*__Static_assert_function (void)) [!!sizeof (struct
{ int __error_if_negative: (sizeof(struct lwan_connection) ==
32) ? 2 : -1; })]
737 "Two connections per cache line")extern int (*__Static_assert_function (void)) [!!sizeof (struct
{ int __error_if_negative: (sizeof(struct lwan_connection) ==
32) ? 2 : -1; })];
738 /*
739 * Pre-schedule each file descriptor, to reduce some operations in the
740 * fast path.
741 *
742 * Since struct lwan_connection is guaranteed to be 32-byte long, two of
743 * them can fill up a cache line. Assume siblings share cache lines and
744 * use the CPU topology to group two connections per cache line in such
745 * a way that false sharing is avoided.
746 */
747 uint32_t n_threads = (uint32_t)lwan_nextpow2((size_t)((l->thread.count - 1) * 2));
748 uint32_t *schedtbl = alloca(n_threads * sizeof(uint32_t))__builtin_alloca (n_threads * sizeof(uint32_t));
749
750 topology_to_schedtbl(l, schedtbl, n_threads);
10
←
Calling 'topology_to_schedtbl'
→
751
752 n_threads--; /* Transform count into mask for AND below */
753 adjust_threads_affinity(l, schedtbl, n_threads);
754 for (unsigned int i = 0; i < total_conns; i++)
755 l->conns[i].thread = &l->thread.threads[schedtbl[i & n_threads]];
756#else
757 for (unsigned int i = 0; i < total_conns; i++)
758 l->conns[i].thread = &l->thread.threads[i % l->thread.count];
759#endif
760
761 pthread_barrier_wait(&l->thread.barrier);
762
763 lwan_status_debug("Worker threads created and ready to serve")lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 763, __FUNCTION__, "Worker threads created and ready to serve"
);
764}
765
766void lwan_thread_shutdown(struct lwan *l)
767{
768 lwan_status_debug("Shutting down threads")lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 768, __FUNCTION__, "Shutting down threads");
769
770 for (unsigned int i = 0; i < l->thread.count; i++) {
771 struct lwan_thread *t = &l->thread.threads[i];
772
773 close(t->epoll_fd);
774 lwan_thread_nudge(t);
775 }
776
777 pthread_barrier_wait(&l->thread.barrier);
778 pthread_barrier_destroy(&l->thread.barrier);
779
780 for (unsigned int i = 0; i < l->thread.count; i++) {
781 struct lwan_thread *t = &l->thread.threads[i];
782
783 close(t->pipe_fd[0]);
784#if !defined(HAVE_EVENTFD)
785 close(t->pipe_fd[1]);
786#endif
787
788 pthread_join(l->thread.threads[i].self, NULL((void*)0));
789 spsc_queue_free(&t->pending_fds);
790 timeouts_close(t->wheel);
791 }
792
793 free(l->thread.threads);
794}