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 #include "monotime.h"
  27
  28 struct rusage_t
  29 {
  30   struct rusage cpu;
  31   struct timeval real;
  32 };
  33 #define RUSAGE_T        struct rusage_t
  34
  35 #define GETRUSAGE(X) thread_getrusage(X)
  36
  37 /* Linked list of thread. */
  38 struct thread_list
  39 {
  40   struct thread *head;
  41   struct thread *tail;
  42   int count;
  43 };
  44
  45 struct pqueue;
  46
  47 /*
  48  * Abstract it so we can use different methodologies to
  49  * select on data.
  50  */
  51 typedef fd_set thread_fd_set;
  52
  53 #if defined(HAVE_POLL)
  54 #include <poll.h>
  55 struct fd_handler
  56 {
  57   /* number of pfd stored in pfds */
  58   nfds_t pfdcount;
  59   /* number of pfd stored in pfds + number of snmp pfd */
  60   nfds_t pfdcountsnmp;
  61   /* number of pfd that fit in the allocated space of pfds */
  62   nfds_t pfdsize;
  63   struct pollfd *pfds;
  64 };
  65 #else
  66 struct fd_handler
  67 {
  68   fd_set readfd;
  69   fd_set writefd;
  70   fd_set exceptfd;
  71 };
  72 #endif
  73
  74 /* Master of the theads. */
  75 struct thread_master
  76 {
  77   struct thread **read;
  78   struct thread **write;
  79   struct pqueue *timer;
  80   struct thread_list event;
  81   struct thread_list ready;
  82   struct thread_list unuse;
  83   struct pqueue *background;
  84   int fd_limit;
  85   struct fd_handler handler;
  86   unsigned long alloc;
  87 };
  88
  89 typedef unsigned char thread_type;
  90
  91 /* Thread itself. */
  92 struct thread
  93 {
  94   thread_type type;             /* thread type */
  95   thread_type add_type;         /* thread type */
  96   struct thread *next;          /* next pointer of the thread */
  97   struct thread *prev;          /* previous pointer of the thread */
  98   struct thread_master *master; /* pointer to the struct thread_master. */
  99   int (*func) (struct thread *); /* event function */
 100   void *arg;                    /* event argument */
 101   union {
 102     int val;                    /* second argument of the event. */
 103     int fd;                     /* file descriptor in case of read/write. */
 104     struct timeval sands;       /* rest of time sands value. */
 105   } u;
 106   int index;                    /* used for timers to store position in queue */
 107   struct timeval real;
 108   struct cpu_thread_history *hist; /* cache pointer to cpu_history */
 109   unsigned long yield; /* yield time in us */
 110   const char *funcname;
 111   const char *schedfrom;
 112   int schedfrom_line;
 113 };
 114
 115 struct cpu_thread_history
 116 {
 117   int (*func)(struct thread *);
 118   unsigned int total_calls;
 119   unsigned int total_active;
 120   struct time_stats
 121   {
 122     unsigned long total, max;
 123   } real;
 124   struct time_stats cpu;
 125   thread_type types;
 126   const char *funcname;
 127 };
 128
 129 /* Struct timeval's tv_usec one second value.  */
 130 #define TIMER_SECOND_MICRO 1000000L
 131
 132 /* Thread types. */
 133 #define THREAD_READ           0
 134 #define THREAD_WRITE          1
 135 #define THREAD_TIMER          2
 136 #define THREAD_EVENT          3
 137 #define THREAD_READY          4
 138 #define THREAD_BACKGROUND     5
 139 #define THREAD_UNUSED         6
 140 #define THREAD_EXECUTE        7
 141
 142 /* Thread yield time.  */
 143 #define THREAD_YIELD_TIME_SLOT     10 * 1000L /* 10ms */
 144
 145 /* Macros. */
 146 #define THREAD_ARG(X) ((X)->arg)
 147 #define THREAD_FD(X)  ((X)->u.fd)
 148 #define THREAD_VAL(X) ((X)->u.val)
 149
 150 #define THREAD_READ_ON(master,thread,func,arg,sock) \
 151   do { \
 152     if (! thread) \
 153       thread = thread_add_read (master, func, arg, sock); \
 154   } while (0)
 155
 156 #define THREAD_WRITE_ON(master,thread,func,arg,sock) \
 157   do { \
 158     if (! thread) \
 159       thread = thread_add_write (master, func, arg, sock); \
 160   } while (0)
 161
 162 #define THREAD_TIMER_ON(master,thread,func,arg,time) \
 163   do { \
 164     if (! thread) \
 165       thread = thread_add_timer (master, func, arg, time); \
 166   } while (0)
 167
 168 #define THREAD_TIMER_MSEC_ON(master,thread,func,arg,time) \
 169   do { \
 170     if (! thread) \
 171       thread = thread_add_timer_msec (master, func, arg, time); \
 172   } while (0)
 173
 174 #define THREAD_OFF(thread) \
 175   do { \
 176     if (thread) \
 177       { \
 178         thread_cancel (thread); \
 179         thread = NULL; \
 180       } \
 181   } while (0)
 182
 183 #define THREAD_READ_OFF(thread)  THREAD_OFF(thread)
 184 #define THREAD_WRITE_OFF(thread)  THREAD_OFF(thread)
 185 #define THREAD_TIMER_OFF(thread)  THREAD_OFF(thread)
 186
 187 #define debugargdef  const char *funcname, const char *schedfrom, int fromln
 188
 189 #define thread_add_read(m,f,a,v) funcname_thread_add_read_write(THREAD_READ,m,f,a,v,#f,__FILE__,__LINE__)
 190 #define thread_add_write(m,f,a,v) funcname_thread_add_read_write(THREAD_WRITE,m,f,a,v,#f,__FILE__,__LINE__)
 191 #define thread_add_timer(m,f,a,v) funcname_thread_add_timer(m,f,a,v,#f,__FILE__,__LINE__)
 192 #define thread_add_timer_msec(m,f,a,v) funcname_thread_add_timer_msec(m,f,a,v,#f,__FILE__,__LINE__)
 193 #define thread_add_timer_tv(m,f,a,v) funcname_thread_add_timer_tv(m,f,a,v,#f,__FILE__,__LINE__)
 194 #define thread_add_event(m,f,a,v) funcname_thread_add_event(m,f,a,v,#f,__FILE__,__LINE__)
 195 #define thread_execute(m,f,a,v) funcname_thread_execute(m,f,a,v,#f,__FILE__,__LINE__)
 196
 197 /* The 4th arg to thread_add_background is the # of milliseconds to delay. */
 198 #define thread_add_background(m,f,a,v) funcname_thread_add_background(m,f,a,v,#f,__FILE__,__LINE__)
 199
 200 /* Prototypes. */
 201 extern struct thread_master *thread_master_create (void);
 202 extern void thread_master_free (struct thread_master *);
 203 extern void thread_master_free_unused(struct thread_master *);
 204
 205 extern struct thread *funcname_thread_add_read_write (int dir, struct thread_master *,
 206                                                 int (*)(struct thread *),
 207                                                 void *, int, debugargdef);
 208 extern struct thread *funcname_thread_add_timer (struct thread_master *,
 209                                                  int (*)(struct thread *),
 210                                                  void *, long, debugargdef);
 211 extern struct thread *funcname_thread_add_timer_msec (struct thread_master *,
 212                                                       int (*)(struct thread *),
 213                                                       void *, long, debugargdef);
 214 extern struct thread *funcname_thread_add_timer_tv (struct thread_master *,
 215                                                     int (*)(struct thread *),
 216                                                     void *, struct timeval *,
 217                                                     debugargdef);
 218 extern struct thread *funcname_thread_add_event (struct thread_master *,
 219                                                  int (*)(struct thread *),
 220                                                  void *, int, debugargdef);
 221 extern struct thread *funcname_thread_add_background (struct thread_master *,
 222                                                int (*func)(struct thread *),
 223                                                void *arg,
 224                                                long milliseconds_to_delay,
 225                                                debugargdef);
 226 extern struct thread *funcname_thread_execute (struct thread_master *,
 227                                                int (*)(struct thread *),
 228                                                void *, int, debugargdef);
 229 #undef debugargdef
 230
 231 extern void thread_cancel (struct thread *);
 232 extern unsigned int thread_cancel_event (struct thread_master *, void *);
 233 extern struct thread *thread_fetch (struct thread_master *, struct thread *);
 234 extern void thread_call (struct thread *);
 235 extern unsigned long thread_timer_remain_second (struct thread *);
 236 extern struct timeval thread_timer_remain(struct thread*);
 237 extern int thread_should_yield (struct thread *);
 238 /* set yield time for thread */
 239 extern void thread_set_yield_time (struct thread *, unsigned long);
 240
 241 /* Internal libfrr exports */
 242 extern void thread_getrusage (RUSAGE_T *);
 243 extern void thread_cmd_init (void);
 244
 245 /* Returns elapsed real (wall clock) time. */
 246 extern unsigned long thread_consumed_time(RUSAGE_T *after, RUSAGE_T *before,
 247                                           unsigned long *cpu_time_elapsed);
 248
 249 /* Global variable containing a recent result from gettimeofday.  This can
 250    be used instead of calling gettimeofday if a recent value is sufficient.
 251    This is guaranteed to be refreshed before a thread is called. */
 252 extern struct timeval recent_time;
 253
 254 /* only for use in logging functions! */
 255 extern struct thread *thread_current;
 256
 257 #endif /* _ZEBRA_THREAD_H */