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
  17  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19  * 02111-1307, USA.
  20  */
  21
  22 #ifndef _ZEBRA_THREAD_H
  23 #define _ZEBRA_THREAD_H
  24
  25 #include <zebra.h>
  26
  27 struct rusage_t
  28 {
  29 #ifdef HAVE_RUSAGE
  30   struct rusage cpu;
  31 #endif
  32   struct timeval real;
  33 };
  34 #define RUSAGE_T        struct rusage_t
  35
  36 #define GETRUSAGE(X) thread_getrusage(X)
  37
  38 /* Linked list of thread. */
  39 struct thread_list
  40 {
  41   struct thread *head;
  42   struct thread *tail;
  43   int count;
  44 };
  45
  46 struct pqueue;
  47
  48 /*
  49  * Abstract it so we can use different methodologies to
  50  * select on data.
  51  */
  52 typedef fd_set thread_fd_set;
  53
  54 #if defined(HAVE_POLL)
  55 #include <poll.h>
  56 struct fd_handler
  57 {
  58   /* number of pfd stored in pfds */
  59   nfds_t pfdcount;
  60   /* number of pfd stored in pfds + number of snmp pfd */
  61   nfds_t pfdcountsnmp;
  62   /* number of pfd that fit in the allocated space of pfds */
  63   nfds_t pfdsize;
  64   struct pollfd *pfds;
  65 };
  66 #else
  67 struct fd_handler
  68 {
  69   fd_set readfd;
  70   fd_set writefd;
  71   fd_set exceptfd;
  72 };
  73 #endif
  74
  75 /* Master of the theads. */
  76 struct thread_master
  77 {
  78   struct thread **read;
  79   struct thread **write;
  80   struct pqueue *timer;
  81   struct thread_list event;
  82   struct thread_list ready;
  83   struct thread_list unuse;
  84   struct pqueue *background;
  85   int fd_limit;
  86   struct fd_handler handler;
  87   unsigned long alloc;
  88 };
  89
  90 typedef unsigned char thread_type;
  91
  92 /* ISO C99 maximum function name length is 63 */
  93 #define FUNCNAME_LEN    64
  94
  95 /* Thread itself. */
  96 struct thread
  97 {
  98   thread_type type;             /* thread type */
  99   thread_type add_type;         /* thread type */
 100   struct thread *next;          /* next pointer of the thread */
 101   struct thread *prev;          /* previous pointer of the thread */
 102   struct thread_master *master; /* pointer to the struct thread_master. */
 103   int (*func) (struct thread *); /* event function */
 104   void *arg;                    /* event argument */
 105   union {
 106     int val;                    /* second argument of the event. */
 107     int fd;                     /* file descriptor in case of read/write. */
 108     struct timeval sands;       /* rest of time sands value. */
 109   } u;
 110   int index;                    /* used for timers to store position in queue */
 111   struct timeval real;
 112   struct cpu_thread_history *hist; /* cache pointer to cpu_history */
 113   unsigned long yield; /* yield time in us */
 114   char funcname[FUNCNAME_LEN];
 115 };
 116
 117 struct cpu_thread_history
 118 {
 119   int (*func)(struct thread *);
 120   unsigned int total_calls;
 121   struct time_stats
 122   {
 123     unsigned long total, max;
 124   } real;
 125 #ifdef HAVE_RUSAGE
 126   struct time_stats cpu;
 127 #endif
 128   thread_type types;
 129   char funcname[FUNCNAME_LEN];
 130 };
 131
 132 /* Clocks supported by Quagga */
 133 enum quagga_clkid {
 134   QUAGGA_CLK_REALTIME = 0,      /* ala gettimeofday() */
 135   QUAGGA_CLK_MONOTONIC,         /* monotonic, against an indeterminate base */
 136   QUAGGA_CLK_REALTIME_STABILISED, /* like realtime, but non-decrementing */
 137 };
 138
 139 /* Struct timeval's tv_usec one second value.  */
 140 #define TIMER_SECOND_MICRO 1000000L
 141
 142 /* Thread types. */
 143 #define THREAD_READ           0
 144 #define THREAD_WRITE          1
 145 #define THREAD_TIMER          2
 146 #define THREAD_EVENT          3
 147 #define THREAD_READY          4
 148 #define THREAD_BACKGROUND     5
 149 #define THREAD_UNUSED         6
 150 #define THREAD_EXECUTE        7
 151
 152 /* Thread yield time.  */
 153 #define THREAD_YIELD_TIME_SLOT     10 * 1000L /* 10ms */
 154
 155 /* Macros. */
 156 #define THREAD_ARG(X) ((X)->arg)
 157 #define THREAD_FD(X)  ((X)->u.fd)
 158 #define THREAD_VAL(X) ((X)->u.val)
 159
 160 #define THREAD_READ_ON(master,thread,func,arg,sock) \
 161   do { \
 162     if (! thread) \
 163       thread = thread_add_read (master, func, arg, sock); \
 164   } while (0)
 165
 166 #define THREAD_WRITE_ON(master,thread,func,arg,sock) \
 167   do { \
 168     if (! thread) \
 169       thread = thread_add_write (master, func, arg, sock); \
 170   } while (0)
 171
 172 #define THREAD_TIMER_ON(master,thread,func,arg,time) \
 173   do { \
 174     if (! thread) \
 175       thread = thread_add_timer (master, func, arg, time); \
 176   } while (0)
 177
 178 #define THREAD_TIMER_MSEC_ON(master,thread,func,arg,time) \
 179   do { \
 180     if (! thread) \
 181       thread = thread_add_timer_msec (master, func, arg, time); \
 182   } while (0)
 183
 184 #define THREAD_OFF(thread) \
 185   do { \
 186     if (thread) \
 187       { \
 188         thread_cancel (thread); \
 189         thread = NULL; \
 190       } \
 191   } while (0)
 192
 193 #define THREAD_READ_OFF(thread)  THREAD_OFF(thread)
 194 #define THREAD_WRITE_OFF(thread)  THREAD_OFF(thread)
 195 #define THREAD_TIMER_OFF(thread)  THREAD_OFF(thread)
 196
 197 #define thread_add_read(m,f,a,v) funcname_thread_add_read_write(THREAD_READ,m,f,a,v,#f)
 198 #define thread_add_write(m,f,a,v) funcname_thread_add_read_write(THREAD_WRITE,m,f,a,v,#f)
 199 #define thread_add_timer(m,f,a,v) funcname_thread_add_timer(m,f,a,v,#f)
 200 #define thread_add_timer_msec(m,f,a,v) funcname_thread_add_timer_msec(m,f,a,v,#f)
 201 #define thread_add_event(m,f,a,v) funcname_thread_add_event(m,f,a,v,#f)
 202 #define thread_execute(m,f,a,v) funcname_thread_execute(m,f,a,v,#f)
 203
 204 /* The 4th arg to thread_add_background is the # of milliseconds to delay. */
 205 #define thread_add_background(m,f,a,v) funcname_thread_add_background(m,f,a,v,#f)
 206
 207 /* Prototypes. */
 208 extern struct thread_master *thread_master_create (void);
 209 extern void thread_master_free (struct thread_master *);
 210 extern void thread_master_free_unused(struct thread_master *);
 211
 212 extern struct thread *funcname_thread_add_read_write (int dir, struct thread_master *,
 213                                                 int (*)(struct thread *),
 214                                                 void *, int, const char*);
 215 extern struct thread *funcname_thread_add_timer (struct thread_master *,
 216                                                  int (*)(struct thread *),
 217                                                  void *, long, const char*);
 218 extern struct thread *funcname_thread_add_timer_msec (struct thread_master *,
 219                                                       int (*)(struct thread *),
 220                                                       void *, long, const char*);
 221 extern struct thread *funcname_thread_add_event (struct thread_master *,
 222                                                  int (*)(struct thread *),
 223                                                  void *, int, const char*);
 224 extern struct thread *funcname_thread_add_background (struct thread_master *,
 225                                                int (*func)(struct thread *),
 226                                                void *arg,
 227                                                long milliseconds_to_delay,
 228                                                const char *funcname);
 229 extern struct thread *funcname_thread_execute (struct thread_master *,
 230                                                int (*)(struct thread *),
 231                                                void *, int, const char *);
 232 extern void thread_cancel (struct thread *);
 233 extern unsigned int thread_cancel_event (struct thread_master *, void *);
 234 extern struct thread *thread_fetch (struct thread_master *, struct thread *);
 235 extern void thread_call (struct thread *);
 236 extern unsigned long thread_timer_remain_second (struct thread *);
 237 extern struct timeval thread_timer_remain(struct thread*);
 238 extern int thread_should_yield (struct thread *);
 239 extern unsigned long timeval_elapsed (struct timeval a, struct timeval b);
 240 /* set yield time for thread */
 241 extern void thread_set_yield_time (struct thread *, unsigned long);
 242
 243 /* Internal libzebra exports */
 244 extern void thread_getrusage (RUSAGE_T *);
 245 extern struct cmd_element show_thread_cpu_cmd;
 246 extern struct cmd_element clear_thread_cpu_cmd;
 247
 248 /* replacements for the system gettimeofday(), clock_gettime() and
 249  * time() functions, providing support for non-decrementing clock on
 250  * all systems, and fully monotonic on /some/ systems.
 251  */
 252 extern int quagga_gettime (enum quagga_clkid, struct timeval *);
 253 extern time_t quagga_time (time_t *);
 254
 255 /* Returns elapsed real (wall clock) time. */
 256 extern unsigned long thread_consumed_time(RUSAGE_T *after, RUSAGE_T *before,
 257                                           unsigned long *cpu_time_elapsed);
 258
 259 /* Global variable containing a recent result from gettimeofday.  This can
 260    be used instead of calling gettimeofday if a recent value is sufficient.
 261    This is guaranteed to be refreshed before a thread is called. */
 262 extern struct timeval recent_time;
 263 /* Similar to recent_time, but a monotonically increasing time value */
 264 extern struct timeval recent_relative_time (void);
 265 #endif /* _ZEBRA_THREAD_H */