diff options
Diffstat (limited to 'sysdep/unix')
| -rw-r--r-- | sysdep/unix/Makefile | 2 | ||||
| -rw-r--r-- | sysdep/unix/coroutine.c | 179 | ||||
| -rw-r--r-- | sysdep/unix/io.c | 120 | ||||
| -rw-r--r-- | sysdep/unix/log.c | 45 | ||||
| -rw-r--r-- | sysdep/unix/main.c | 4 | ||||
| -rw-r--r-- | sysdep/unix/unix.h | 1 |
6 files changed, 282 insertions, 69 deletions
diff --git a/sysdep/unix/Makefile b/sysdep/unix/Makefile index 51ab98a9..a01e8f46 100644 --- a/sysdep/unix/Makefile +++ b/sysdep/unix/Makefile @@ -1,4 +1,4 @@ -src := alloc.c io.c krt.c log.c main.c random.c +src := alloc.c io.c krt.c log.c main.c random.c coroutine.c obj := $(src-o-files) $(all-daemon) $(cf-local) diff --git a/sysdep/unix/coroutine.c b/sysdep/unix/coroutine.c new file mode 100644 index 00000000..2eba142c --- /dev/null +++ b/sysdep/unix/coroutine.c @@ -0,0 +1,179 @@ +/* + * BIRD Coroutines + * + * (c) 2017 Martin Mares <mj@ucw.cz> + * (c) 2020 Maria Matejka <mq@jmq.cz> + * + * Can be freely distributed and used under the terms of the GNU GPL. + */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#undef LOCAL_DEBUG + +#undef DEBUG_LOCKING + +#include "lib/birdlib.h" +#include "lib/locking.h" +#include "lib/coro.h" +#include "lib/resource.h" +#include "lib/timer.h" + +/* Using a rather big stack for coroutines to allow for stack-local allocations. + * In real world, the kernel doesn't alloc this memory until it is used. + * */ +#define CORO_STACK_SIZE 1048576 + +/* + * Implementation of coroutines based on POSIX threads + */ + +#include <errno.h> +#include <fcntl.h> +#include <poll.h> +#include <pthread.h> +#include <semaphore.h> +#include <stdatomic.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +/* + * Locking subsystem + */ + +_Thread_local struct lock_order locking_stack = {}; +_Thread_local struct domain_generic **last_locked = NULL; + +#define ASSERT_NO_LOCK ASSERT_DIE(last_locked == NULL) + +struct domain_generic { + pthread_mutex_t mutex; + uint order; + struct domain_generic **prev; + struct lock_order *locked_by; + const char *name; +}; + +#define DOMAIN_INIT(_name, _order) { .mutex = PTHREAD_MUTEX_INITIALIZER, .name = _name, .order = _order } + +static struct domain_generic the_bird_domain_gen = DOMAIN_INIT("The BIRD", OFFSETOF(struct lock_order, the_bird)); + +DOMAIN(the_bird) the_bird_domain = { .the_bird = &the_bird_domain_gen }; + +struct domain_generic * +domain_new(const char *name, uint order) +{ + ASSERT_DIE(order < sizeof(struct lock_order)); + struct domain_generic *dg = xmalloc(sizeof(struct domain_generic)); + *dg = (struct domain_generic) DOMAIN_INIT(name, order); + return dg; +} + +void +domain_free(struct domain_generic *dg) +{ + pthread_mutex_destroy(&dg->mutex); + xfree(dg); +} + +void do_lock(struct domain_generic *dg, struct domain_generic **lsp) +{ + if ((char *) lsp - (char *) &locking_stack != dg->order) + bug("Trying to lock on bad position: order=%u, lsp=%p, base=%p", dg->order, lsp, &locking_stack); + + if (lsp <= last_locked) + bug("Trying to lock in a bad order"); + if (*lsp) + bug("Inconsistent locking stack state on lock"); + + pthread_mutex_lock(&dg->mutex); + + if (dg->prev || dg->locked_by) + bug("Previous unlock not finished correctly"); + dg->prev = last_locked; + *lsp = dg; + last_locked = lsp; + dg->locked_by = &locking_stack; +} + +void do_unlock(struct domain_generic *dg, struct domain_generic **lsp) +{ + if ((char *) lsp - (char *) &locking_stack != dg->order) + bug("Trying to unlock on bad position: order=%u, lsp=%p, base=%p", dg->order, lsp, &locking_stack); + + if (dg->locked_by != &locking_stack) + bug("Inconsistent domain state on unlock"); + if ((last_locked != lsp) || (*lsp != dg)) + bug("Inconsistent locking stack state on unlock"); + dg->locked_by = NULL; + last_locked = dg->prev; + *lsp = NULL; + dg->prev = NULL; + pthread_mutex_unlock(&dg->mutex); +} + +/* Coroutines */ +struct coroutine { + resource r; + pthread_t id; + pthread_attr_t attr; + void (*entry)(void *); + void *data; +}; + +static _Thread_local _Bool coro_cleaned_up = 0; + +static void coro_free(resource *r) +{ + struct coroutine *c = (void *) r; + ASSERT_DIE(pthread_equal(pthread_self(), c->id)); + pthread_attr_destroy(&c->attr); + coro_cleaned_up = 1; +} + +static struct resclass coro_class = { + .name = "Coroutine", + .size = sizeof(struct coroutine), + .free = coro_free, +}; + +static void *coro_entry(void *p) +{ + struct coroutine *c = p; + ASSERT_DIE(c->entry); + + c->entry(c->data); + ASSERT_DIE(coro_cleaned_up); + + return NULL; +} + +struct coroutine *coro_run(pool *p, void (*entry)(void *), void *data) +{ + ASSERT_DIE(entry); + ASSERT_DIE(p); + + struct coroutine *c = ralloc(p, &coro_class); + + c->entry = entry; + c->data = data; + + int e = 0; + + if (e = pthread_attr_init(&c->attr)) + die("pthread_attr_init() failed: %M", e); + + if (e = pthread_attr_setstacksize(&c->attr, CORO_STACK_SIZE)) + die("pthread_attr_setstacksize(%u) failed: %M", CORO_STACK_SIZE, e); + + if (e = pthread_attr_setdetachstate(&c->attr, PTHREAD_CREATE_DETACHED)) + die("pthread_attr_setdetachstate(PTHREAD_CREATE_DETACHED) failed: %M", e); + + if (e = pthread_create(&c->id, &c->attr, coro_entry, c)) + die("pthread_create() failed: %M", e); + + return c; +} diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c index 810e782d..a3f1491a 100644 --- a/sysdep/unix/io.c +++ b/sysdep/unix/io.c @@ -36,6 +36,7 @@ #include "lib/resource.h" #include "lib/socket.h" #include "lib/event.h" +#include "lib/locking.h" #include "lib/timer.h" #include "lib/string.h" #include "nest/iface.h" @@ -122,55 +123,50 @@ rf_fileno(struct rfile *f) btime boot_time; + void -times_init(struct timeloop *loop) +times_update(void) { struct timespec ts; int rv; + btime old_time = current_time(); + btime old_real_time = current_real_time(); + rv = clock_gettime(CLOCK_MONOTONIC, &ts); if (rv < 0) die("Monotonic clock is missing"); if ((ts.tv_sec < 0) || (((u64) ts.tv_sec) > ((u64) 1 << 40))) log(L_WARN "Monotonic clock is crazy"); - - loop->last_time = ts.tv_sec S + ts.tv_nsec NS; - loop->real_time = 0; -} - -void -times_update(struct timeloop *loop) -{ - struct timespec ts; - int rv; - - rv = clock_gettime(CLOCK_MONOTONIC, &ts); - if (rv < 0) - die("clock_gettime: %m"); - + btime new_time = ts.tv_sec S + ts.tv_nsec NS; - if (new_time < loop->last_time) + if (new_time < old_time) log(L_ERR "Monotonic clock is broken"); - loop->last_time = new_time; - loop->real_time = 0; -} - -void -times_update_real_time(struct timeloop *loop) -{ - struct timespec ts; - int rv; - rv = clock_gettime(CLOCK_REALTIME, &ts); if (rv < 0) die("clock_gettime: %m"); - loop->real_time = ts.tv_sec S + ts.tv_nsec NS; -} + btime new_real_time = ts.tv_sec S + ts.tv_nsec NS; + + if (!atomic_compare_exchange_strong_explicit( + &last_time, + &old_time, + new_time, + memory_order_acq_rel, + memory_order_relaxed)) + DBG("Time update collision: last_time"); + if (!atomic_compare_exchange_strong_explicit( + &real_time, + &old_real_time, + new_real_time, + memory_order_acq_rel, + memory_order_relaxed)) + DBG("Time update collision: real_time"); +} /** * DOC: Sockets @@ -2037,30 +2033,17 @@ struct event_log_entry static struct event_log_entry event_log[EVENT_LOG_LENGTH]; static struct event_log_entry *event_open; static int event_log_pos, event_log_num, watchdog_active; -static btime last_time; +static btime last_io_time; static btime loop_time; static void io_update_time(void) { - struct timespec ts; - int rv; - - /* - * This is third time-tracking procedure (after update_times() above and - * times_update() in BFD), dedicated to internal event log and latency - * tracking. Hopefully, we consolidate these sometimes. - */ - - rv = clock_gettime(CLOCK_MONOTONIC, &ts); - if (rv < 0) - die("clock_gettime: %m"); - - last_time = ts.tv_sec S + ts.tv_nsec NS; + last_io_time = current_time(); if (event_open) { - event_open->duration = last_time - event_open->timestamp; + event_open->duration = last_io_time - event_open->timestamp; if (event_open->duration > config->latency_limit) log(L_WARN "Event 0x%p 0x%p took %u.%03u ms", @@ -2089,7 +2072,7 @@ io_log_event(void *hook, void *data) en->hook = hook; en->data = data; - en->timestamp = last_time; + en->timestamp = last_io_time; en->duration = 0; event_log_num++; @@ -2117,14 +2100,14 @@ io_log_dump(void) struct event_log_entry *en = event_log + (event_log_pos + i) % EVENT_LOG_LENGTH; if (en->hook) log(L_DEBUG " Event 0x%p 0x%p at %8d for %d ms", en->hook, en->data, - (int) ((last_time - en->timestamp) TO_MS), (int) (en->duration TO_MS)); + (int) ((last_io_time - en->timestamp) TO_MS), (int) (en->duration TO_MS)); } } void watchdog_sigalrm(int sig UNUSED) { - /* Update last_time and duration, but skip latency check */ + /* Update last_io_time and duration, but skip latency check */ config->latency_limit = 0xffffffff; io_update_time(); @@ -2137,7 +2120,7 @@ watchdog_start1(void) { io_update_time(); - loop_time = last_time; + loop_time = last_io_time; } static inline void @@ -2145,7 +2128,7 @@ watchdog_start(void) { io_update_time(); - loop_time = last_time; + loop_time = last_io_time; event_log_num = 0; if (config->watchdog_timeout) @@ -2166,7 +2149,7 @@ watchdog_stop(void) watchdog_active = 0; } - btime duration = last_time - loop_time; + btime duration = last_io_time - loop_time; if (duration > config->watchdog_warning) log(L_WARN "I/O loop cycle took %u.%03u ms for %d events", (uint) (duration TO_MS), (uint) (duration % 1000), event_log_num); @@ -2196,6 +2179,15 @@ static int short_loops = 0; #define SHORT_LOOP_MAX 10 #define WORK_EVENTS_MAX 10 +static int poll_reload_pipe[2]; + +void +io_loop_reload(void) +{ + char b; + write(poll_reload_pipe[1], &b, 1); +} + void io_loop(void) { @@ -2207,10 +2199,13 @@ io_loop(void) int fdmax = 256; struct pollfd *pfd = xmalloc(fdmax * sizeof(struct pollfd)); + if (pipe(poll_reload_pipe) < 0) + die("pipe(poll_reload_pipe) failed: %m"); + watchdog_start1(); for(;;) { - times_update(&main_timeloop); + times_update(); events = ev_run_list(&global_event_list); events = ev_run_list_limited(&global_work_list, WORK_EVENTS_MAX) || events; timers_fire(&main_timeloop); @@ -2220,12 +2215,17 @@ io_loop(void) poll_tout = (events ? 0 : 3000); /* Time in milliseconds */ if (t = timers_first(&main_timeloop)) { - times_update(&main_timeloop); + times_update(); timeout = (tm_remains(t) TO_MS) + 1; poll_tout = MIN(poll_tout, timeout); } - nfds = 0; + /* A hack to reload main io_loop() when something has changed asynchronously. */ + pfd[0].fd = poll_reload_pipe[0]; + pfd[0].events = POLLIN; + + nfds = 1; + WALK_LIST(n, sock_list) { pfd[nfds] = (struct pollfd) { .fd = -1 }; /* everything other set to 0 by this */ @@ -2284,7 +2284,9 @@ io_loop(void) /* And finally enter poll() to find active sockets */ watchdog_stop(); + the_bird_unlock(); pout = poll(pfd, nfds, poll_tout); + the_bird_lock(); watchdog_start(); if (pout < 0) @@ -2295,7 +2297,15 @@ io_loop(void) } if (pout) { - times_update(&main_timeloop); + if (pfd[0].revents & POLLIN) + { + /* IO loop reload requested */ + char b; + read(poll_reload_pipe[0], &b, 1); + continue; + } + + times_update(); /* guaranteed to be non-empty */ current_sock = SKIP_BACK(sock, n, HEAD(sock_list)); diff --git a/sysdep/unix/log.c b/sysdep/unix/log.c index 4e9df069..f48588b6 100644 --- a/sysdep/unix/log.c +++ b/sysdep/unix/log.c @@ -15,6 +15,7 @@ * user's manual. */ +#include <stdatomic.h> #include <stdio.h> #include <stdlib.h> #include <stdarg.h> @@ -35,8 +36,10 @@ static FILE *dbgf; static list *current_log_list; static char *current_syslog_name; /* NULL -> syslog closed */ +static _Atomic uint max_coro_id = ATOMIC_VAR_INIT(1); +static _Thread_local uint this_coro_id; -#ifdef USE_PTHREADS +#define THIS_CORO_ID (this_coro_id ?: (this_coro_id = atomic_fetch_add_explicit(&max_coro_id, 1, memory_order_acq_rel))) #include <pthread.h> @@ -48,15 +51,6 @@ static pthread_t main_thread; void main_thread_init(void) { main_thread = pthread_self(); } static int main_thread_self(void) { return pthread_equal(pthread_self(), main_thread); } -#else - -static inline void log_lock(void) { } -static inline void log_unlock(void) { } -void main_thread_init(void) { } -static int main_thread_self(void) { return 1; } - -#endif - #ifdef HAVE_SYSLOG_H #include <sys/syslog.h> @@ -189,7 +183,7 @@ log_commit(int class, buffer *buf) l->pos += msg_len; } - fprintf(l->fh, "%s <%s> ", tbuf, class_names[class]); + fprintf(l->fh, "%s [%04x] <%s> ", tbuf, THIS_CORO_ID, class_names[class]); } fputs(buf->start, l->fh); fputc('\n', l->fh); @@ -299,6 +293,8 @@ die(const char *msg, ...) exit(1); } +static struct timespec dbg_time_start; + /** * debug - write to debug output * @msg: a printf-like message @@ -311,12 +307,33 @@ debug(const char *msg, ...) { #define MAX_DEBUG_BUFSIZE 16384 va_list args; - char buf[MAX_DEBUG_BUFSIZE]; + char buf[MAX_DEBUG_BUFSIZE], *pos = buf; + int max = MAX_DEBUG_BUFSIZE; va_start(args, msg); if (dbgf) { - if (bvsnprintf(buf, MAX_DEBUG_BUFSIZE, msg, args) < 0) + struct timespec dbg_time; + clock_gettime(CLOCK_MONOTONIC, &dbg_time); + uint nsec; + uint sec; + + if (dbg_time.tv_nsec > dbg_time_start.tv_nsec) + { + nsec = dbg_time.tv_nsec - dbg_time_start.tv_nsec; + sec = dbg_time.tv_sec - dbg_time_start.tv_sec; + } + else + { + nsec = 1000000000 + dbg_time.tv_nsec - dbg_time_start.tv_nsec; + sec = dbg_time.tv_sec - dbg_time_start.tv_sec - 1; + } + + int n = bsnprintf(pos, max, "%u.%09u: [%04x] ", sec, nsec, THIS_CORO_ID); + pos += n; + max -= n; + + if (bvsnprintf(pos, max, msg, args) < 0) bug("Extremely long debug output, split it."); fputs(buf, dbgf); @@ -422,6 +439,8 @@ done: void log_init_debug(char *f) { + clock_gettime(CLOCK_MONOTONIC, &dbg_time_start); + if (dbgf && dbgf != stderr) fclose(dbgf); if (!f) diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c index 07d6c691..8bc07d94 100644 --- a/sysdep/unix/main.c +++ b/sysdep/unix/main.c @@ -28,6 +28,7 @@ #include "lib/resource.h" #include "lib/socket.h" #include "lib/event.h" +#include "lib/locking.h" #include "lib/timer.h" #include "lib/string.h" #include "nest/rt.h" @@ -873,6 +874,7 @@ main(int argc, char **argv) dmalloc_debug(0x2f03d00); #endif + times_update(); parse_args(argc, argv); log_switch(1, NULL, NULL); @@ -927,6 +929,8 @@ main(int argc, char **argv) dup2(0, 2); } + the_bird_lock(); + main_thread_init(); write_pid_file(); diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h index ad85d1ea..313c97c3 100644 --- a/sysdep/unix/unix.h +++ b/sysdep/unix/unix.h @@ -106,6 +106,7 @@ extern volatile sig_atomic_t async_shutdown_flag; void io_init(void); void io_loop(void); +void io_loop_reload(void); void io_log_dump(void); int sk_open_unix(struct birdsock *s, char *name); struct rfile *rf_open(struct pool *, const char *name, const char *mode); |