lib/thread.h

   1 /* Thread management routine header.
   2  * Copyright (C) 1998 Kunihiro Ishiguro
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef _ZEBRA_THREAD_H
  22 #define _ZEBRA_THREAD_H
  23
  24 #include <zebra.h>
  25 #include <pthread.h>
  26 #include <poll.h>
  27 #include "monotime.h"
  28 #include "frratomic.h"
  29 #include "typesafe.h"
  30 #include "xref.h"
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 extern bool cputime_enabled;
  37 extern unsigned long cputime_threshold;
  38 /* capturing wallclock time is always enabled since it is fast (reading
  39  * hardware TSC w/o syscalls)
  40  */
  41 extern unsigned long walltime_threshold;
  42
  43 struct rusage_t {
  44 #ifdef HAVE_CLOCK_THREAD_CPUTIME_ID
  45         struct timespec cpu;
  46 #else
  47         struct rusage cpu;
  48 #endif
  49         struct timeval real;
  50 };
  51 #define RUSAGE_T        struct rusage_t
  52
  53 #define GETRUSAGE(X) thread_getrusage(X)
  54
  55 PREDECL_LIST(thread_list);
  56 PREDECL_HEAP(thread_timer_list);
  57
  58 struct fd_handler {
  59         /* number of pfd that fit in the allocated space of pfds. This is a
  60          * constant and is the same for both pfds and copy.
  61          */
  62         nfds_t pfdsize;
  63
  64         /* file descriptors to monitor for i/o */
  65         struct pollfd *pfds;
  66         /* number of pollfds stored in pfds */
  67         nfds_t pfdcount;
  68
  69         /* chunk used for temp copy of pollfds */
  70         struct pollfd *copy;
  71         /* number of pollfds stored in copy */
  72         nfds_t copycount;
  73 };
  74
  75 struct xref_threadsched {
  76         struct xref xref;
  77
  78         const char *funcname;
  79         const char *dest;
  80         uint32_t thread_type;
  81 };
  82
  83 /* Master of the theads. */
  84 struct thread_master {
  85         char *name;
  86
  87         struct thread **read;
  88         struct thread **write;
  89         struct thread_timer_list_head timer;
  90         struct thread_list_head event, ready, unuse;
  91         struct list *cancel_req;
  92         bool canceled;
  93         pthread_cond_t cancel_cond;
  94         struct hash *cpu_record;
  95         int io_pipe[2];
  96         int fd_limit;
  97         struct fd_handler handler;
  98         unsigned long alloc;
  99         long selectpoll_timeout;
 100         bool spin;
 101         bool handle_signals;
 102         pthread_mutex_t mtx;
 103         pthread_t owner;
 104
 105         bool ready_run_loop;
 106         RUSAGE_T last_getrusage;
 107 };
 108
 109 /* Thread itself. */
 110 struct thread {
 111         uint8_t type;             /* thread type */
 112         uint8_t add_type;         /* thread type */
 113         struct thread_list_item threaditem;
 114         struct thread_timer_list_item timeritem;
 115         struct thread **ref;      /* external reference (if given) */
 116         struct thread_master *master; /* pointer to the struct thread_master */
 117         void (*func)(struct thread *); /* event function */
 118         void *arg;                    /* event argument */
 119         union {
 120                 int val;              /* second argument of the event. */
 121                 int fd;               /* file descriptor in case of r/w */
 122                 struct timeval sands; /* rest of time sands value. */
 123         } u;
 124         struct timeval real;
 125         struct cpu_thread_history *hist; /* cache pointer to cpu_history */
 126         unsigned long yield;             /* yield time in microseconds */
 127         const struct xref_threadsched *xref;   /* origin location */
 128         pthread_mutex_t mtx;   /* mutex for thread.c functions */
 129         bool ignore_timer_late;
 130 };
 131
 132 #ifdef _FRR_ATTRIBUTE_PRINTFRR
 133 #pragma FRR printfrr_ext "%pTH" (struct thread *)
 134 #endif
 135
 136 struct cpu_thread_history {
 137         void (*func)(struct thread *);
 138         atomic_size_t total_cpu_warn;
 139         atomic_size_t total_wall_warn;
 140         atomic_size_t total_starv_warn;
 141         atomic_size_t total_calls;
 142         atomic_size_t total_active;
 143         struct time_stats {
 144                 atomic_size_t total, max;
 145         } real;
 146         struct time_stats cpu;
 147         atomic_uint_fast32_t types;
 148         const char *funcname;
 149 };
 150
 151 /* Struct timeval's tv_usec one second value.  */
 152 #define TIMER_SECOND_MICRO 1000000L
 153
 154 /* Thread types. */
 155 #define THREAD_READ           0
 156 #define THREAD_WRITE          1
 157 #define THREAD_TIMER          2
 158 #define THREAD_EVENT          3
 159 #define THREAD_READY          4
 160 #define THREAD_UNUSED         5
 161 #define THREAD_EXECUTE        6
 162
 163 /* Thread yield time.  */
 164 #define THREAD_YIELD_TIME_SLOT     10 * 1000L /* 10ms */
 165
 166 #define THREAD_TIMER_STRLEN 12
 167
 168 /* Macros. */
 169 #define THREAD_ARG(X) ((X)->arg)
 170 #define THREAD_FD(X)  ((X)->u.fd)
 171 #define THREAD_VAL(X) ((X)->u.val)
 172
 173 /*
 174  * Please consider this macro deprecated, and do not use it in new code.
 175  */
 176 #define THREAD_OFF(thread)                                             \
 177         do {                                                           \
 178                 if ((thread))                                          \
 179                         thread_cancel(&(thread));                      \
 180         } while (0)
 181
 182 /*
 183  * Macro wrappers to generate xrefs for all thread add calls.  Includes
 184  * file/line/function info for debugging/tracing.
 185  */
 186 #include "lib/xref.h"
 187
 188 #define _xref_t_a(addfn, type, m, f, a, v, t)                                  \
 189         ({                                                                     \
 190                 static const struct xref_threadsched _xref                     \
 191                                 __attribute__((used)) = {                      \
 192                         .xref = XREF_INIT(XREFT_THREADSCHED, NULL, __func__),  \
 193                         .funcname = #f,                                        \
 194                         .dest = #t,                                            \
 195                         .thread_type = THREAD_ ## type,                        \
 196                 };                                                             \
 197                 XREF_LINK(_xref.xref);                                         \
 198                 _thread_add_ ## addfn(&_xref, m, f, a, v, t);                  \
 199         })                                                                     \
 200         /* end */
 201
 202 #define thread_add_read(m,f,a,v,t)       _xref_t_a(read_write, READ,  m,f,a,v,t)
 203 #define thread_add_write(m,f,a,v,t)      _xref_t_a(read_write, WRITE, m,f,a,v,t)
 204 #define thread_add_timer(m,f,a,v,t)      _xref_t_a(timer,      TIMER, m,f,a,v,t)
 205 #define thread_add_timer_msec(m,f,a,v,t) _xref_t_a(timer_msec, TIMER, m,f,a,v,t)
 206 #define thread_add_timer_tv(m,f,a,v,t)   _xref_t_a(timer_tv,   TIMER, m,f,a,v,t)
 207 #define thread_add_event(m,f,a,v,t)      _xref_t_a(event,      EVENT, m,f,a,v,t)
 208
 209 #define thread_execute(m,f,a,v)                                                \
 210         ({                                                                     \
 211                 static const struct xref_threadsched _xref                     \
 212                                 __attribute__((used)) = {                      \
 213                         .xref = XREF_INIT(XREFT_THREADSCHED, NULL, __func__),  \
 214                         .funcname = #f,                                        \
 215                         .dest = NULL,                                          \
 216                         .thread_type = THREAD_EXECUTE,                         \
 217                 };                                                             \
 218                 XREF_LINK(_xref.xref);                                         \
 219                 _thread_execute(&_xref, m, f, a, v);                           \
 220         }) /* end */
 221
 222 /* Prototypes. */
 223 extern struct thread_master *thread_master_create(const char *);
 224 void thread_master_set_name(struct thread_master *master, const char *name);
 225 extern void thread_master_free(struct thread_master *);
 226 extern void thread_master_free_unused(struct thread_master *);
 227
 228 extern void _thread_add_read_write(const struct xref_threadsched *xref,
 229                                    struct thread_master *master,
 230                                    void (*fn)(struct thread *), void *arg,
 231                                    int fd, struct thread **tref);
 232
 233 extern void _thread_add_timer(const struct xref_threadsched *xref,
 234                               struct thread_master *master,
 235                               void (*fn)(struct thread *), void *arg, long t,
 236                               struct thread **tref);
 237
 238 extern void _thread_add_timer_msec(const struct xref_threadsched *xref,
 239                                    struct thread_master *master,
 240                                    void (*fn)(struct thread *), void *arg,
 241                                    long t, struct thread **tref);
 242
 243 extern void _thread_add_timer_tv(const struct xref_threadsched *xref,
 244                                  struct thread_master *master,
 245                                  void (*fn)(struct thread *), void *arg,
 246                                  struct timeval *tv, struct thread **tref);
 247
 248 extern void _thread_add_event(const struct xref_threadsched *xref,
 249                               struct thread_master *master,
 250                               void (*fn)(struct thread *), void *arg, int val,
 251                               struct thread **tref);
 252
 253 extern void _thread_execute(const struct xref_threadsched *xref,
 254                             struct thread_master *master,
 255                             void (*fn)(struct thread *), void *arg, int val);
 256
 257 extern void thread_cancel(struct thread **event);
 258 extern void thread_cancel_async(struct thread_master *, struct thread **,
 259                                 void *);
 260 /* Cancel ready tasks with an arg matching 'arg' */
 261 extern void thread_cancel_event_ready(struct thread_master *m, void *arg);
 262 /* Cancel all tasks with an arg matching 'arg', including timers and io */
 263 extern void thread_cancel_event(struct thread_master *m, void *arg);
 264 extern struct thread *thread_fetch(struct thread_master *, struct thread *);
 265 extern void thread_call(struct thread *);
 266 extern unsigned long thread_timer_remain_second(struct thread *);
 267 extern struct timeval thread_timer_remain(struct thread *);
 268 extern unsigned long thread_timer_remain_msec(struct thread *);
 269 extern int thread_should_yield(struct thread *);
 270 /* set yield time for thread */
 271 extern void thread_set_yield_time(struct thread *, unsigned long);
 272
 273 /* Internal libfrr exports */
 274 extern void thread_getrusage(RUSAGE_T *);
 275 extern void thread_cmd_init(void);
 276
 277 /* Returns elapsed real (wall clock) time. */
 278 extern unsigned long thread_consumed_time(RUSAGE_T *after, RUSAGE_T *before,
 279                                           unsigned long *cpu_time_elapsed);
 280
 281 /* only for use in logging functions! */
 282 extern pthread_key_t thread_current;
 283 extern char *thread_timer_to_hhmmss(char *buf, int buf_size,
 284                 struct thread *t_timer);
 285
 286 static inline bool thread_is_scheduled(struct thread *thread)
 287 {
 288         if (thread)
 289                 return true;
 290
 291         return false;
 292 }
 293
 294 /* Debug signal mask */
 295 void debug_signals(const sigset_t *sigs);
 296
 297 static inline void thread_ignore_late_timer(struct thread *thread)
 298 {
 299         thread->ignore_timer_late = true;
 300 }
 301
 302 #ifdef __cplusplus
 303 }
 304 #endif
 305
 306 #endif /* _ZEBRA_THREAD_H */