Bug Summary

File:lwan-thread.c
Warning:line 887, column 38
Assigned value is garbage or undefined

Annotated Source Code

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clang -cc1 -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 -mframe-pointer=all -fmath-errno -fno-rounding-math -mconstructor-aliases -fno-plt -munwind-tables -target-cpu x86-64 -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib/clang/11.1.0 -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/11.1.0/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 -stack-protector 2 -fgnuc-version=4.2.1 -analyzer-output=html -faddrsig -o /home/buildbot/lwan-worker/clang-analyze/CLANG/2021-05-22-172440-821575-1 -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_SO_ATTACH_REUSEPORT_CBPF)
35#include <linux1/filter.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 = recv(fd, buffer, DEFAULT_BUFFER_SIZE4096, 0);
75
76 if (!r)
77 break;
78
79 if (r < 0) {
80 switch (errno(*__errno_location ())) {
81 case EAGAIN11:
82 break;
83 case EINTR4:
84 continue;
85 default:
86 return;
87 }
88 }
89
90 coro_yield(conn->coro, CONN_CORO_WANT_READ);
91 }
92
93 /* close(2) will be called when the coroutine yields with CONN_CORO_ABORT */
94}
95
96static __thread __uint128_t lehmer64_state;
97
98static void lwan_random_seed_prng_for_thread(uint64_t fallback_seed)
99{
100 if (lwan_getentropy(&lehmer64_state, sizeof(lehmer64_state), 0) < 0) {
101 lwan_status_warning("Couldn't get proper entropy for PRNG, using fallback seed")lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 101, __FUNCTION__, "Couldn't get proper entropy for PRNG, using fallback seed"
)
;
102 for (int i = 0; i < 4; i++) {
103 lehmer64_state |= fallback_seed;
104 lehmer64_state <<= 32;
105 }
106 }
107}
108
109uint64_t lwan_random_uint64()
110{
111 /* https://lemire.me/blog/2019/03/19/the-fastest-conventional-random-number-generator-that-can-pass-big-crush/ */
112 lehmer64_state *= 0xda942042e4dd58b5ull;
113 return (uint64_t)(lehmer64_state >> 64);
114}
115
116__attribute__((noreturn)) static int process_request_coro(struct coro *coro,
117 void *data)
118{
119 /* NOTE: This function should not return; coro_yield should be used
120 * instead. This ensures the storage for `strbuf` is alive when the
121 * coroutine ends and lwan_strbuf_free() is called. */
122 struct lwan_connection *conn = data;
123 struct lwan *lwan = conn->thread->lwan;
124 int fd = lwan_connection_get_fd(lwan, conn);
125 enum lwan_request_flags flags = lwan->config.request_flags;
126 struct lwan_strbuf strbuf = LWAN_STRBUF_STATIC_INIT(struct lwan_strbuf) { .buffer = "" };
127 char request_buffer[DEFAULT_BUFFER_SIZE4096];
128 struct lwan_value buffer = {.value = request_buffer, .len = 0};
129 char *next_request = NULL((void*)0);
130 char *header_start[N_HEADER_START64];
131 struct lwan_proxy proxy;
132 const int error_when_n_packets = lwan_calculate_n_packets(DEFAULT_BUFFER_SIZE4096);
133
134 coro_defer(coro, lwan_strbuf_free_defer, &strbuf);
135
136 const size_t init_gen = 1; /* 1 call to coro_defer() */
137 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"
, 137, __extension__ __PRETTY_FUNCTION__); }))
;
138
139 while (true1) {
140 struct lwan_request_parser_helper helper = {
141 .buffer = &buffer,
142 .next_request = next_request,
143 .error_when_n_packets = error_when_n_packets,
144 .header_start = header_start,
145 };
146 struct lwan_request request = {.conn = conn,
147 .global_response_headers = &lwan->headers,
148 .fd = fd,
149 .response = {.buffer = &strbuf},
150 .flags = flags,
151 .proxy = &proxy,
152 .helper = &helper};
153
154 lwan_process_request(lwan, &request);
155
156 /* Run the deferred instructions now (except those used to initialize
157 * the coroutine), so that if the connection is gracefully closed,
158 * the storage for ``helper'' is still there. */
159 coro_deferred_run(coro, init_gen);
160
161 if (UNLIKELY(!(conn->flags & CONN_IS_KEEP_ALIVE))__builtin_expect(((!(conn->flags & CONN_IS_KEEP_ALIVE)
)), (0))
) {
162 graceful_close(lwan, conn, request_buffer);
163 break;
164 }
165
166 if (next_request && *next_request) {
167 conn->flags |= CONN_CORK;
168
169 if (!(conn->flags & CONN_EVENTS_WRITE))
170 coro_yield(coro, CONN_CORO_WANT_WRITE);
171 } else {
172 conn->flags &= ~CONN_CORK;
173 coro_yield(coro, CONN_CORO_WANT_READ);
174 }
175
176 /* Ensure string buffer is reset between requests, and that the backing
177 * store isn't over 2KB. */
178 lwan_strbuf_reset_trim(&strbuf, 2048);
179
180 /* Only allow flags from config. */
181 flags = request.flags & (REQUEST_PROXIED | REQUEST_ALLOW_CORS);
182 next_request = helper.next_request;
183 }
184
185 coro_yield(coro, CONN_CORO_ABORT);
186 __builtin_unreachable();
187}
188
189static ALWAYS_INLINEinline __attribute__((always_inline)) uint32_t
190conn_flags_to_epoll_events(enum lwan_connection_flags flags)
191{
192 static const uint32_t map[CONN_EVENTS_MASK + 1] = {
193 [0 /* Suspended (timer or await) */] = EPOLLRDHUPEPOLLRDHUP,
194 [CONN_EVENTS_WRITE] = EPOLLOUTEPOLLOUT | EPOLLRDHUPEPOLLRDHUP,
195 [CONN_EVENTS_READ] = EPOLLINEPOLLIN | EPOLLRDHUPEPOLLRDHUP,
196 [CONN_EVENTS_READ_WRITE] = EPOLLINEPOLLIN | EPOLLOUTEPOLLOUT | EPOLLRDHUPEPOLLRDHUP,
197 };
198
199 return map[flags & CONN_EVENTS_MASK];
200}
201
202static void update_epoll_flags(int fd,
203 struct lwan_connection *conn,
204 int epoll_fd,
205 enum lwan_connection_coro_yield yield_result)
206{
207 static const enum lwan_connection_flags or_mask[CONN_CORO_MAX] = {
208 [CONN_CORO_YIELD] = 0,
209
210 [CONN_CORO_WANT_READ_WRITE] = CONN_EVENTS_READ_WRITE,
211 [CONN_CORO_WANT_READ] = CONN_EVENTS_READ,
212 [CONN_CORO_WANT_WRITE] = CONN_EVENTS_WRITE,
213
214 /* While the coro is suspended, we're not interested in either EPOLLIN
215 * or EPOLLOUT events. We still want to track this fd in epoll, though,
216 * so unset both so that only EPOLLRDHUP (plus the implicitly-set ones)
217 * are set. */
218 [CONN_CORO_SUSPEND] = CONN_SUSPENDED,
219
220 /* Ideally, when suspending a coroutine, the current flags&CONN_EVENTS_MASK
221 * would have to be stored and restored -- however, resuming as if the
222 * client coroutine is interested in a write event always guarantees that
223 * they'll be resumed as they're TCP sockets. There's a good chance that
224 * trying to read from a socket after resuming a coroutine will succeed,
225 * but if it doesn't because read() returns -EAGAIN, the I/O wrappers will
226 * yield with CONN_CORO_WANT_READ anyway. */
227 [CONN_CORO_RESUME] = CONN_EVENTS_WRITE,
228 };
229 static const enum lwan_connection_flags and_mask[CONN_CORO_MAX] = {
230 [CONN_CORO_YIELD] = ~0,
231
232 [CONN_CORO_WANT_READ_WRITE] = ~0,
233 [CONN_CORO_WANT_READ] = ~CONN_EVENTS_WRITE,
234 [CONN_CORO_WANT_WRITE] = ~CONN_EVENTS_READ,
235
236 [CONN_CORO_SUSPEND] = ~CONN_EVENTS_READ_WRITE,
237 [CONN_CORO_RESUME] = ~CONN_SUSPENDED,
238 };
239 enum lwan_connection_flags prev_flags = conn->flags;
240
241 conn->flags |= or_mask[yield_result];
242 conn->flags &= and_mask[yield_result];
243
244 if (conn->flags == prev_flags)
245 return;
246
247 struct epoll_event event = {
248 .events = conn_flags_to_epoll_events(conn->flags),
249 .data.ptr = conn,
250 };
251
252 if (UNLIKELY(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &event) < 0)__builtin_expect(((epoll_ctl(epoll_fd, 3, fd, &event) <
0)), (0))
)
253 lwan_status_perror("epoll_ctl")lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 253, __FUNCTION__, "epoll_ctl")
;
254}
255
256static void clear_async_await_flag(void *data)
257{
258 struct lwan_connection *async_fd_conn = data;
259
260 async_fd_conn->flags &= ~CONN_ASYNC_AWAIT;
261}
262
263static enum lwan_connection_coro_yield
264resume_async(struct timeout_queue *tq,
265 enum lwan_connection_coro_yield yield_result,
266 int64_t from_coro,
267 struct lwan_connection *conn,
268 int epoll_fd)
269{
270 static const enum lwan_connection_flags to_connection_flags[] = {
271 [CONN_CORO_ASYNC_AWAIT_READ] = CONN_EVENTS_READ,
272 [CONN_CORO_ASYNC_AWAIT_WRITE] = CONN_EVENTS_WRITE,
273 [CONN_CORO_ASYNC_AWAIT_READ_WRITE] = CONN_EVENTS_READ_WRITE,
274 };
275 int await_fd = (int)((uint64_t)from_coro >> 32);
276 enum lwan_connection_flags flags;
277 int op;
278
279 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"
, 279, __extension__ __PRETTY_FUNCTION__); }))
;
280 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"
, 281, __extension__ __PRETTY_FUNCTION__); }))
281 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"
, 281, __extension__ __PRETTY_FUNCTION__); }))
;
282
283 flags = to_connection_flags[yield_result];
284
285 struct lwan_connection *await_fd_conn = &tq->lwan->conns[await_fd];
286 if (LIKELY(await_fd_conn->flags & CONN_ASYNC_AWAIT)__builtin_expect((!!(await_fd_conn->flags & CONN_ASYNC_AWAIT
)), (1))
) {
287 if (LIKELY((await_fd_conn->flags & CONN_EVENTS_MASK) == flags)__builtin_expect((!!((await_fd_conn->flags & CONN_EVENTS_MASK
) == flags)), (1))
)
288 return CONN_CORO_SUSPEND;
289
290 op = EPOLL_CTL_MOD3;
291 } else {
292 op = EPOLL_CTL_ADD1;
293 flags |= CONN_ASYNC_AWAIT;
294 coro_defer(conn->coro, clear_async_await_flag, await_fd_conn);
295 }
296
297 struct epoll_event event = {.events = conn_flags_to_epoll_events(flags),
298 .data.ptr = conn};
299 if (LIKELY(!epoll_ctl(epoll_fd, op, await_fd, &event))__builtin_expect((!!(!epoll_ctl(epoll_fd, op, await_fd, &
event))), (1))
) {
300 await_fd_conn->flags &= ~CONN_EVENTS_MASK;
301 await_fd_conn->flags |= flags;
302 return CONN_CORO_SUSPEND;
303 }
304
305 return CONN_CORO_ABORT;
306}
307
308static ALWAYS_INLINEinline __attribute__((always_inline)) void resume_coro(struct timeout_queue *tq,
309 struct lwan_connection *conn,
310 int epoll_fd)
311{
312 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"
, 312, __extension__ __PRETTY_FUNCTION__); }))
;
313
314 int64_t from_coro = coro_resume(conn->coro);
315 enum lwan_connection_coro_yield yield_result = from_coro & 0xffffffff;
316
317 if (UNLIKELY(yield_result >= CONN_CORO_ASYNC)__builtin_expect(((yield_result >= CONN_CORO_ASYNC)), (0)))
318 yield_result = resume_async(tq, yield_result, from_coro, conn, epoll_fd);
319
320 if (UNLIKELY(yield_result == CONN_CORO_ABORT)__builtin_expect(((yield_result == CONN_CORO_ABORT)), (0)))
321 return timeout_queue_expire(tq, conn);
322
323 return update_epoll_flags(lwan_connection_get_fd(tq->lwan, conn), conn,
324 epoll_fd, yield_result);
325}
326
327static void update_date_cache(struct lwan_thread *thread)
328{
329 time_t now = time(NULL((void*)0));
330
331 lwan_format_rfc_time(now, thread->date.date);
332 lwan_format_rfc_time(now + (time_t)thread->lwan->config.expires,
333 thread->date.expires);
334}
335
336static bool_Bool send_buffer_without_coro(int fd, const char *buf, size_t buf_len)
337{
338 size_t total_sent = 0;
339
340 for (int try = 0; try < 10; try++) {
341 size_t to_send = buf_len - total_sent;
342 if (!to_send)
343 return true1;
344
345 ssize_t sent = write(fd, buf + total_sent, to_send);
346 if (sent <= 0) {
347 if (errno(*__errno_location ()) == EINTR4)
348 continue;
349 break;
350 }
351
352 total_sent += (size_t)sent;
353 }
354
355 return false0;
356}
357
358static bool_Bool send_string_without_coro(int fd, const char *str)
359{
360 return send_buffer_without_coro(fd, str, strlen(str));
361}
362
363static ALWAYS_INLINEinline __attribute__((always_inline)) bool_Bool spawn_coro(struct lwan_connection *conn,
364 struct coro_switcher *switcher,
365 struct timeout_queue *tq)
366{
367 struct lwan_thread *t = conn->thread;
368
369 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"
, 369, __extension__ __PRETTY_FUNCTION__); }))
;
370 assert(!(conn->flags & CONN_ASYNC_AWAIT))((void) sizeof ((!(conn->flags & CONN_ASYNC_AWAIT)) ? 1
: 0), __extension__ ({ if (!(conn->flags & CONN_ASYNC_AWAIT
)) ; else __assert_fail ("!(conn->flags & CONN_ASYNC_AWAIT)"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 370, __extension__ __PRETTY_FUNCTION__); }))
;
371 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"
, 371, __extension__ __PRETTY_FUNCTION__); }))
;
372 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"
, 372, __extension__ __PRETTY_FUNCTION__); }))
;
373 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"
, 374, __extension__ __PRETTY_FUNCTION__); }))
374 (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"
, 374, __extension__ __PRETTY_FUNCTION__); }))
;
375
376 *conn = (struct lwan_connection){
377 .coro = coro_new(switcher, process_request_coro, conn),
378 .flags = CONN_EVENTS_READ,
379 .time_to_expire = tq->current_time + tq->move_to_last_bump,
380 .thread = t,
381 };
382 if (LIKELY(conn->coro)__builtin_expect((!!(conn->coro)), (1))) {
383 timeout_queue_insert(tq, conn);
384 return true1;
385 }
386
387 conn->flags = 0;
388
389 int fd = lwan_connection_get_fd(tq->lwan, conn);
390
391 lwan_status_error("Couldn't spawn coroutine for file descriptor %d", fd)lwan_status_error_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 391, __FUNCTION__, "Couldn't spawn coroutine for file descriptor %d"
, fd)
;
392
393 if (!send_string_without_coro(fd, "HTTP/1.0 503 Unavailable"))
394 goto out;
395 if (!send_string_without_coro(fd, "\r\nConnection: close"))
396 goto out;
397 if (!send_string_without_coro(fd, "\r\nContent-Type: text/html"))
398 goto out;
399 if (send_buffer_without_coro(fd, lwan_strbuf_get_buffer(&tq->lwan->headers),
400 lwan_strbuf_get_length(&tq->lwan->headers))) {
401 struct lwan_strbuf buffer;
402
403 lwan_strbuf_init(&buffer);
404 lwan_fill_default_response(&buffer, HTTP_UNAVAILABLE);
405
406 send_buffer_without_coro(fd, lwan_strbuf_get_buffer(&buffer),
407 lwan_strbuf_get_length(&buffer));
408
409 lwan_strbuf_free(&buffer);
410 }
411
412out:
413 shutdown(fd, SHUT_RDWRSHUT_RDWR);
414 close(fd);
415 return false0;
416}
417
418static bool_Bool process_pending_timers(struct timeout_queue *tq,
419 struct lwan_thread *t,
420 int epoll_fd)
421{
422 struct timeout *timeout;
423 bool_Bool should_expire_timers = false0;
424
425 while ((timeout = timeouts_get(t->wheel))) {
426 struct lwan_request *request;
427
428 if (timeout == &tq->timeout) {
429 should_expire_timers = true1;
430 continue;
431 }
432
433 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))
;
434
435 update_epoll_flags(request->fd, request->conn, epoll_fd,
436 CONN_CORO_RESUME);
437 }
438
439 if (should_expire_timers) {
440 timeout_queue_expire_waiting(tq);
441
442 /* tq timeout expires every 1000ms if there are connections, so
443 * update the date cache at this point as well. */
444 update_date_cache(t);
445
446 if (!timeout_queue_empty(tq)) {
447 timeouts_add(t->wheel, &tq->timeout, 1000);
448 return true1;
449 }
450
451 timeouts_del(t->wheel, &tq->timeout);
452 }
453
454 return false0;
455}
456
457static int
458turn_timer_wheel(struct timeout_queue *tq, struct lwan_thread *t, int epoll_fd)
459{
460 const int infinite_timeout = -1;
461 timeout_t wheel_timeout;
462 struct timespec now;
463
464 if (UNLIKELY(clock_gettime(monotonic_clock_id, &now) < 0)__builtin_expect(((clock_gettime(monotonic_clock_id, &now
) < 0)), (0))
)
465 lwan_status_critical("Could not get monotonic time")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 465, __FUNCTION__, "Could not get monotonic time")
;
466
467 timeouts_update(t->wheel,
468 (timeout_t)(now.tv_sec * 1000 + now.tv_nsec / 1000000));
469
470 /* Check if there's an expired timer. */
471 wheel_timeout = timeouts_timeout(t->wheel);
472 if (wheel_timeout > 0) {
473 return (int)wheel_timeout; /* No, but will soon. Wake us up in
474 wheel_timeout ms. */
475 }
476
477 if (UNLIKELY((int64_t)wheel_timeout < 0)__builtin_expect((((int64_t)wheel_timeout < 0)), (0)))
478 return infinite_timeout; /* None found. */
479
480 if (!process_pending_timers(tq, t, epoll_fd))
481 return infinite_timeout; /* No more timers to process. */
482
483 /* After processing pending timers, determine when to wake up. */
484 return (int)timeouts_timeout(t->wheel);
485}
486
487static bool_Bool accept_waiting_clients(const struct lwan_thread *t)
488{
489 const struct lwan_connection *conns = t->lwan->conns;
490
491 while (true1) {
492 int fd =
493 accept4(t->listen_fd, NULL((void*)0), NULL((void*)0), SOCK_NONBLOCKSOCK_NONBLOCK | SOCK_CLOEXECSOCK_CLOEXEC);
494
495 if (LIKELY(fd >= 0)__builtin_expect((!!(fd >= 0)), (1))) {
496 const struct lwan_connection *conn = &conns[fd];
497 struct epoll_event ev = {
498 .data.ptr = (void *)conn,
499 .events = conn_flags_to_epoll_events(CONN_EVENTS_READ),
500 };
501 int r = epoll_ctl(conn->thread->epoll_fd, EPOLL_CTL_ADD1, fd, &ev);
502
503 if (UNLIKELY(r < 0)__builtin_expect(((r < 0)), (0))) {
504 /* FIXME: send a "busy" response here? No coroutine has been
505 * created at this point to use the usual stuff, though. */
506 lwan_status_perror("Could not add file descriptor %d to epoll "lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 508, __FUNCTION__, "Could not add file descriptor %d to epoll "
"set %d. Dropping connection", fd, conn->thread->epoll_fd
)
507 "set %d. Dropping connection",lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 508, __FUNCTION__, "Could not add file descriptor %d to epoll "
"set %d. Dropping connection", fd, conn->thread->epoll_fd
)
508 fd, conn->thread->epoll_fd)lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 508, __FUNCTION__, "Could not add file descriptor %d to epoll "
"set %d. Dropping connection", fd, conn->thread->epoll_fd
)
;
509 shutdown(fd, SHUT_RDWRSHUT_RDWR);
510 close(fd);
511 }
512
513#if defined(HAVE_SO_INCOMING_CPU) && defined(__x86_64__1)
514 /* Ignore errors here, as this is just a hint */
515 (void)setsockopt(fd, SOL_SOCKET1, SO_INCOMING_CPU49, &t->cpu, sizeof(t->cpu));
516#endif
517
518 continue;
519 }
520
521 switch (errno(*__errno_location ())) {
522 default:
523 lwan_status_perror("Unexpected error while accepting connections")lwan_status_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 523, __FUNCTION__, "Unexpected error while accepting connections"
)
;
524 /* fallthrough */
525
526 case EAGAIN11:
527 return true1;
528
529 case EBADF9:
530 case ECONNABORTED103:
531 case EINVAL22:
532 lwan_status_info("Listening socket closed")lwan_status_info_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 532, __FUNCTION__, "Listening socket closed")
;
533 return false0;
534 }
535 }
536
537 __builtin_unreachable();
538}
539
540static int create_listen_socket(struct lwan_thread *t,
541 unsigned int num,
542 unsigned int num_sockets)
543{
544 int listen_fd;
545
546 listen_fd = lwan_create_listen_socket(t->lwan, num == 0);
547 if (listen_fd < 0)
548 lwan_status_critical("Could not create listen_fd")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 548, __FUNCTION__, "Could not create listen_fd")
;
549
550 /* Ignore errors here, as this is just a hint */
551#if defined(HAVE_SO_ATTACH_REUSEPORT_CBPF)
552 /* From socket(7): "These options may be set repeatedly at any time on
553 * any socket in the group to replace the current BPF program used by
554 * all sockets in the group." */
555 if (num == 0) {
556 /* From socket(7): "The BPF program must return an index between 0 and
557 * N-1 representing the socket which should receive the packet (where N
558 * is the number of sockets in the group)." */
559 const uint32_t cpu_ad_off = (uint32_t)SKF_AD_OFF(-0x1000) + SKF_AD_CPU36;
560 struct sock_filter filter[] = {
561 {BPF_LD0x00 | BPF_W0x00 | BPF_ABS0x20, 0, 0, cpu_ad_off}, /* A = curr_cpu_index */
562 {BPF_ALU0x04 | BPF_MOD0x90 | BPF_K0x00, 0, 0, num_sockets}, /* A %= num_sockets */
563 {BPF_RET0x06 | BPF_A0x10, 0, 0, 0}, /* return A */
564 };
565 struct sock_fprog fprog = {.filter = filter, .len = N_ELEMENTS(filter)((!sizeof(char[1 - 2 * __builtin_types_compatible_p( __typeof__
(filter), __typeof__(&(filter)[0]))])) | sizeof(filter) /
sizeof(filter[0]))
};
566
567 if (!(num_sockets & (num_sockets - 1))) {
568 /* FIXME: Is this strength reduction already made by the kernel? */
569 filter[1].code &= (uint16_t)~BPF_MOD0x90;
570 filter[1].code |= BPF_AND0x50;
571 filter[1].k = num_sockets - 1;
572 }
573
574 (void)setsockopt(listen_fd, SOL_SOCKET1, SO_ATTACH_REUSEPORT_CBPF51,
575 &fprog, sizeof(fprog));
576 (void)setsockopt(listen_fd, SOL_SOCKET1, SO_LOCK_FILTER44,
577 (int[]){1}, sizeof(int));
578 }
579#elif defined(HAVE_SO_INCOMING_CPU) && defined(__x86_64__1)
580 (void)setsockopt(listen_fd, SOL_SOCKET1, SO_INCOMING_CPU49, &t->cpu,
581 sizeof(t->cpu));
582#endif
583
584 struct epoll_event event = {
585 .events = EPOLLINEPOLLIN | EPOLLETEPOLLET | EPOLLERREPOLLERR,
586 .data.ptr = NULL((void*)0),
587 };
588 if (epoll_ctl(t->epoll_fd, EPOLL_CTL_ADD1, listen_fd, &event) < 0)
589 lwan_status_critical_perror("Could not add socket to epoll")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 589, __FUNCTION__, "Could not add socket to epoll")
;
590
591 return listen_fd;
592}
593
594static void *thread_io_loop(void *data)
595{
596 struct lwan_thread *t = data;
597 int epoll_fd = t->epoll_fd;
598 const int max_events = LWAN_MIN((int)t->lwan->thread.max_fd, 1024)({ const __typeof__(((int)t->lwan->thread.max_fd) + 0) lwan_tmp_id4
= ((int)t->lwan->thread.max_fd); const __typeof__((1024
) + 0) lwan_tmp_id5 = (1024); lwan_tmp_id4 > lwan_tmp_id5 ?
lwan_tmp_id5 : lwan_tmp_id4; })
;
599 struct lwan *lwan = t->lwan;
600 struct epoll_event *events;
601 struct coro_switcher switcher;
602 struct timeout_queue tq;
603
604 lwan_status_debug("Worker thread #%zd starting",lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 605, __FUNCTION__, "Worker thread #%zd starting", t - t->
lwan->thread.threads + 1)
605 t - t->lwan->thread.threads + 1)lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 605, __FUNCTION__, "Worker thread #%zd starting", t - t->
lwan->thread.threads + 1)
;
606 lwan_set_thread_name("worker");
607
608 events = calloc((size_t)max_events, sizeof(*events));
609 if (UNLIKELY(!events)__builtin_expect(((!events)), (0)))
610 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"
, 610, __FUNCTION__, "Could not allocate memory for events")
;
611
612 update_date_cache(t);
613
614 timeout_queue_init(&tq, lwan);
615
616 lwan_random_seed_prng_for_thread((uint64_t)(epoll_fd | time(NULL((void*)0))));
617
618 pthread_barrier_wait(&lwan->thread.barrier);
619
620 for (;;) {
621 int timeout = turn_timer_wheel(&tq, t, epoll_fd);
622 int n_fds = epoll_wait(epoll_fd, events, max_events, timeout);
623 bool_Bool accepted_connections = false0;
624
625 if (UNLIKELY(n_fds < 0)__builtin_expect(((n_fds < 0)), (0))) {
626 if (errno(*__errno_location ()) == EBADF9 || errno(*__errno_location ()) == EINVAL22)
627 break;
628 continue;
629 }
630
631 for (struct epoll_event *event = events; n_fds--; event++) {
632 struct lwan_connection *conn;
633
634 if (!event->data.ptr) {
635 if (LIKELY(accept_waiting_clients(t))__builtin_expect((!!(accept_waiting_clients(t))), (1))) {
636 accepted_connections = true1;
637 continue;
638 }
639 close(epoll_fd);
640 epoll_fd = -1;
641 break;
642 }
643
644 conn = event->data.ptr;
645
646 if (UNLIKELY(event->events & (EPOLLRDHUP | EPOLLHUP))__builtin_expect(((event->events & (EPOLLRDHUP | EPOLLHUP
))), (0))
) {
647 timeout_queue_expire(&tq, conn);
648 continue;
649 }
650
651 if (!conn->coro) {
652 if (UNLIKELY(!spawn_coro(conn, &switcher, &tq))__builtin_expect(((!spawn_coro(conn, &switcher, &tq))
), (0))
)
653 continue;
654 }
655
656 resume_coro(&tq, conn, epoll_fd);
657 timeout_queue_move_to_last(&tq, conn);
658 }
659
660 if (accepted_connections)
661 timeouts_add(t->wheel, &tq.timeout, 1000);
662 }
663
664 pthread_barrier_wait(&lwan->thread.barrier);
665
666 timeout_queue_expire_all(&tq);
667 free(events);
668
669 return NULL((void*)0);
670}
671
672static void create_thread(struct lwan *l, struct lwan_thread *thread)
673{
674 int ignore;
675 pthread_attr_t attr;
676
677 thread->lwan = l;
678
679 thread->wheel = timeouts_open(&ignore);
680 if (!thread->wheel)
681 lwan_status_critical("Could not create timer wheel")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 681, __FUNCTION__, "Could not create timer wheel")
;
682
683 if ((thread->epoll_fd = epoll_create1(EPOLL_CLOEXECEPOLL_CLOEXEC)) < 0)
684 lwan_status_critical_perror("epoll_create")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 684, __FUNCTION__, "epoll_create")
;
685
686 if (pthread_attr_init(&attr))
687 lwan_status_critical_perror("pthread_attr_init")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 687, __FUNCTION__, "pthread_attr_init")
;
688
689 if (pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEMPTHREAD_SCOPE_SYSTEM))
690 lwan_status_critical_perror("pthread_attr_setscope")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 690, __FUNCTION__, "pthread_attr_setscope")
;
691
692 if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLEPTHREAD_CREATE_JOINABLE))
693 lwan_status_critical_perror("pthread_attr_setdetachstate")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 693, __FUNCTION__, "pthread_attr_setdetachstate")
;
694
695 if (pthread_create(&thread->self, &attr, thread_io_loop, thread))
696 lwan_status_critical_perror("pthread_create")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 696, __FUNCTION__, "pthread_create")
;
697
698 if (pthread_attr_destroy(&attr))
699 lwan_status_critical_perror("pthread_attr_destroy")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 699, __FUNCTION__, "pthread_attr_destroy")
;
700}
701
702#if defined(__linux__1) && defined(__x86_64__1)
703static bool_Bool read_cpu_topology(struct lwan *l, uint32_t siblings[])
704{
705 char path[PATH_MAX4096];
706
707 for (uint32_t i = 0; i < l->available_cpus; i++)
708 siblings[i] = 0xbebacafe;
709
710 for (unsigned int i = 0; i < l->available_cpus; i++) {
711 FILE *sib;
712 uint32_t id, sibling;
713 char separator;
714
715 snprintf(path, sizeof(path),
716 "/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list",
717 i);
718
719 sib = fopen(path, "re");
720 if (!sib) {
721 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"
, 722, __FUNCTION__, "Could not open `%s` to determine CPU topology"
, path)
722 path)lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 722, __FUNCTION__, "Could not open `%s` to determine CPU topology"
, path)
;
723 return false0;
724 }
725
726 switch (fscanf(sib, "%u%c%u", &id, &separator, &sibling)) {
727 case 2: /* No SMT */
728 siblings[i] = id;
729 break;
730 case 3: /* SMT */
731 if (!(separator == ',' || separator == '-')) {
732 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"
, 732, __FUNCTION__, "Expecting either ',' or '-' for sibling separator"
)
;
733 __builtin_unreachable();
734 }
735
736 siblings[i] = sibling;
737 break;
738 default:
739 lwan_status_critical("%s has invalid format", path)lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 739, __FUNCTION__, "%s has invalid format", path)
;
740 __builtin_unreachable();
741 }
742
743 fclose(sib);
744 }
745
746 /* Perform a sanity check here, as some systems seem to filter out the
747 * result of sysconf() to obtain the number of configured and online
748 * CPUs but don't bother changing what's available through sysfs as far
749 * as the CPU topology information goes. It's better to fall back to a
750 * possibly non-optimal setup than just crash during startup while
751 * trying to perform an out-of-bounds array access. */
752 for (unsigned int i = 0; i < l->available_cpus; i++) {
753 if (siblings[i] == 0xbebacafe) {
754 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"
, 754, __FUNCTION__, "Could not determine sibling for CPU %d"
, i)
;
755 return false0;
756 }
757
758 if (siblings[i] >= l->available_cpus) {
759 lwan_status_warning("CPU information topology says CPU %d exists, "lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 762, __FUNCTION__, "CPU information topology says CPU %d exists, "
"but max available CPUs is %d (online CPUs: %d). " "Is Lwan running in a (broken) container?"
, siblings[i], l->available_cpus, l->online_cpus)
760 "but max available CPUs is %d (online CPUs: %d). "lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 762, __FUNCTION__, "CPU information topology says CPU %d exists, "
"but max available CPUs is %d (online CPUs: %d). " "Is Lwan running in a (broken) container?"
, siblings[i], l->available_cpus, l->online_cpus)
761 "Is Lwan running in a (broken) container?",lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 762, __FUNCTION__, "CPU information topology says CPU %d exists, "
"but max available CPUs is %d (online CPUs: %d). " "Is Lwan running in a (broken) container?"
, siblings[i], l->available_cpus, l->online_cpus)
762 siblings[i], l->available_cpus, l->online_cpus)lwan_status_warning_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 762, __FUNCTION__, "CPU information topology says CPU %d exists, "
"but max available CPUs is %d (online CPUs: %d). " "Is Lwan running in a (broken) container?"
, siblings[i], l->available_cpus, l->online_cpus)
;
763 return false0;
764 }
765 }
766
767 return true1;
768}
769
770static void
771siblings_to_schedtbl(struct lwan *l, uint32_t siblings[], uint32_t schedtbl[])
772{
773 int *seen = alloca(l->available_cpus * sizeof(int))__builtin_alloca (l->available_cpus * sizeof(int));
774 unsigned int n_schedtbl = 0;
775
776 for (uint32_t i = 0; i < l->available_cpus; i++)
777 seen[i] = -1;
778
779 for (uint32_t i = 0; i < l->available_cpus; i++) {
780 if (seen[siblings[i]] < 0) {
781 seen[siblings[i]] = (int)i;
782 } else {
783 schedtbl[n_schedtbl++] = (uint32_t)seen[siblings[i]];
784 schedtbl[n_schedtbl++] = i;
785 }
786 }
787
788 if (n_schedtbl != l->available_cpus)
789 memcpy(schedtbl, seen, l->available_cpus * sizeof(int));
790}
791
792static bool_Bool
793topology_to_schedtbl(struct lwan *l, uint32_t schedtbl[], uint32_t n_threads)
794{
795 uint32_t *siblings = alloca(l->available_cpus * sizeof(uint32_t))__builtin_alloca (l->available_cpus * sizeof(uint32_t));
796
797 if (read_cpu_topology(l, siblings)) {
8
Assuming the condition is true
9
Taking true branch
798 uint32_t *affinity = alloca(l->available_cpus * sizeof(uint32_t))__builtin_alloca (l->available_cpus * sizeof(uint32_t));
799
800 siblings_to_schedtbl(l, siblings, affinity);
801
802 for (uint32_t i = 0; i < n_threads; i++)
10
Assuming 'i' is >= 'n_threads'
11
Loop condition is false. Execution continues on line 804
803 schedtbl[i] = affinity[i % l->available_cpus];
804 return true1;
12
Returning without writing to '*schedtbl'
13
Returning the value 1, which participates in a condition later
805 }
806
807 for (uint32_t i = 0; i < n_threads; i++)
808 schedtbl[i] = (i / 2) % l->thread.count;
809 return false0;
810}
811
812static void
813adjust_threads_affinity(struct lwan *l, uint32_t *schedtbl, uint32_t mask)
814{
815 for (uint32_t i = 0; i < l->thread.count; i++) {
816 cpu_set_t set;
817
818 CPU_ZERO(&set)do __builtin_memset (&set, '\0', sizeof (cpu_set_t)); while
(0)
;
819 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; }))
;
820
821 if (pthread_setaffinity_np(l->thread.threads[i].self, sizeof(set),
822 &set))
823 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"
, 823, __FUNCTION__, "Could not set affinity for thread %d", i
)
;
824 }
825}
826#elif defined(__x86_64__1)
827static bool_Bool
828topology_to_schedtbl(struct lwan *l, uint32_t schedtbl[], uint32_t n_threads)
829{
830 for (uint32_t i = 0; i < n_threads; i++)
831 schedtbl[i] = (i / 2) % l->thread.count;
832 return false0;
833}
834
835static void
836adjust_threads_affinity(struct lwan *l, uint32_t *schedtbl, uint32_t n)
837{
838}
839#endif
840
841void lwan_thread_init(struct lwan *l)
842{
843 const unsigned int total_conns = l->thread.max_fd * l->thread.count;
844
845 if (pthread_barrier_init(&l->thread.barrier, NULL((void*)0),
1
Assuming the condition is false
2
Taking false branch
846 (unsigned)l->thread.count + 1))
847 lwan_status_critical("Could not create barrier")lwan_status_critical_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 847, __FUNCTION__, "Could not create barrier")
;
848
849 lwan_status_debug("Initializing threads")lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 849, __FUNCTION__, "Initializing threads")
;
850
851 l->thread.threads =
852 calloc((size_t)l->thread.count, sizeof(struct lwan_thread));
853 if (!l->thread.threads)
3
Assuming field 'threads' is non-null
4
Taking false branch
854 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"
, 854, __FUNCTION__, "Could not allocate memory for threads")
;
855
856#ifdef __x86_64__1
857 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; })]
858 "Two connections per cache line")extern int (*__Static_assert_function (void)) [!!sizeof (struct
{ int __error_if_negative: (sizeof(struct lwan_connection) ==
32) ? 2 : -1; })]
;
859#ifdef _SC_LEVEL1_DCACHE_LINESIZE_SC_LEVEL1_DCACHE_LINESIZE
860 assert(sysconf(_SC_LEVEL1_DCACHE_LINESIZE) == 64)((void) sizeof ((sysconf(_SC_LEVEL1_DCACHE_LINESIZE) == 64) ?
1 : 0), __extension__ ({ if (sysconf(_SC_LEVEL1_DCACHE_LINESIZE
) == 64) ; else __assert_fail ("sysconf(_SC_LEVEL1_DCACHE_LINESIZE) == 64"
, "/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 860, __extension__ __PRETTY_FUNCTION__); }))
;
5
Assuming the condition is true
6
Taking true branch
861#endif
862
863 lwan_status_debug("%d CPUs of %d are online. "lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 865, __FUNCTION__, "%d CPUs of %d are online. " "Reading topology to pre-schedule clients"
, l->online_cpus, l->available_cpus)
864 "Reading topology to pre-schedule clients",lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 865, __FUNCTION__, "%d CPUs of %d are online. " "Reading topology to pre-schedule clients"
, l->online_cpus, l->available_cpus)
865 l->online_cpus, l->available_cpus)lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 865, __FUNCTION__, "%d CPUs of %d are online. " "Reading topology to pre-schedule clients"
, l->online_cpus, l->available_cpus)
;
866
867 /*
868 * Pre-schedule each file descriptor, to reduce some operations in the
869 * fast path.
870 *
871 * Since struct lwan_connection is guaranteed to be 32-byte long, two of
872 * them can fill up a cache line. Assume siblings share cache lines and
873 * use the CPU topology to group two connections per cache line in such
874 * a way that false sharing is avoided.
875 */
876 uint32_t n_threads = (uint32_t)lwan_nextpow2((size_t)((l->thread.count - 1) * 2));
877 uint32_t *schedtbl = alloca(n_threads * sizeof(uint32_t))__builtin_alloca (n_threads * sizeof(uint32_t));
878
879 bool_Bool adj_affinity = topology_to_schedtbl(l, schedtbl, n_threads);
7
Calling 'topology_to_schedtbl'
14
Returning from 'topology_to_schedtbl'
880
881 n_threads--; /* Transform count into mask for AND below */
882
883 if (adj_affinity
14.1
'adj_affinity' is true
) {
15
Taking true branch
884 /* Save which CPU this tread will be pinned at so we can use
885 * SO_INCOMING_CPU later. */
886 for (unsigned int i = 0; i < l->thread.count; i++)
16
Assuming 'i' is < field 'count'
17
Loop condition is true. Entering loop body
887 l->thread.threads[i].cpu = schedtbl[i & n_threads];
18
Assigned value is garbage or undefined
888 }
889
890 for (unsigned int i = 0; i < total_conns; i++)
891 l->conns[i].thread = &l->thread.threads[schedtbl[i & n_threads]];
892#else
893 for (unsigned int i = 0; i < l->thread.count; i++)
894 l->thread.threads[i].cpu = i % l->online_cpus;
895 for (unsigned int i = 0; i < total_conns; i++)
896 l->conns[i].thread = &l->thread.threads[i % l->thread.count];
897#endif
898
899 for (unsigned int i = 0; i < l->thread.count; i++) {
900 struct lwan_thread *thread = &l->thread.threads[i];
901
902 create_thread(l, thread);
903
904 if ((thread->listen_fd = create_listen_socket(thread, i, l->thread.count)) < 0)
905 lwan_status_critical_perror("Could not create listening socket")lwan_status_critical_perror_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 905, __FUNCTION__, "Could not create listening socket")
;
906 }
907
908#ifdef __x86_64__1
909 if (adj_affinity)
910 adjust_threads_affinity(l, schedtbl, n_threads);
911#endif
912
913 pthread_barrier_wait(&l->thread.barrier);
914
915 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"
, 915, __FUNCTION__, "Worker threads created and ready to serve"
)
;
916}
917
918void lwan_thread_shutdown(struct lwan *l)
919{
920 lwan_status_debug("Shutting down threads")lwan_status_debug_debug("/home/buildbot/lwan-worker/clang-analyze/build/src/lib/lwan-thread.c"
, 920, __FUNCTION__, "Shutting down threads")
;
921
922 for (unsigned int i = 0; i < l->thread.count; i++) {
923 struct lwan_thread *t = &l->thread.threads[i];
924 int epoll_fd = t->epoll_fd;
925 int listen_fd = t->listen_fd;
926
927 t->listen_fd = -1;
928 t->epoll_fd = -1;
929 close(epoll_fd);
930 close(listen_fd);
931 }
932
933 pthread_barrier_wait(&l->thread.barrier);
934 pthread_barrier_destroy(&l->thread.barrier);
935
936 for (unsigned int i = 0; i < l->thread.count; i++) {
937 struct lwan_thread *t = &l->thread.threads[i];
938
939 pthread_join(l->thread.threads[i].self, NULL((void*)0));
940 timeouts_close(t->wheel);
941 }
942
943 free(l->thread.threads);
944}