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   struct rusage cpu;
  30   struct timeval real;
  31 };
  32 #define RUSAGE_T        struct rusage_t
  33
  34 #define GETRUSAGE(X) thread_getrusage(X)
  35
  36 /* Linked list of thread. */
  37 struct thread_list
  38 {
  39   struct thread *head;
  40   struct thread *tail;
  41   int count;
  42 };
  43
  44 struct pqueue;
  45
  46 /*
  47  * Abstract it so we can use different methodologies to
  48  * select on data.
  49  */
  50 typedef fd_set thread_fd_set;
  51
  52 #if defined(HAVE_POLL)
  53 #include <poll.h>
  54 struct fd_handler
  55 {
  56   /* number of pfd stored in pfds */
  57   nfds_t pfdcount;
  58   /* number of pfd stored in pfds + number of snmp pfd */
  59   nfds_t pfdcountsnmp;
  60   /* number of pfd that fit in the allocated space of pfds */
  61   nfds_t pfdsize;
  62   struct pollfd *pfds;
  63 };
  64 #else
  65 struct fd_handler
  66 {
  67   fd_set readfd;
  68   fd_set writefd;
  69   fd_set exceptfd;
  70 };
  71 #endif
  72
  73 /* Master of the theads. */
  74 struct thread_master
  75 {
  76   struct thread **read;
  77   struct thread **write;
  78   struct pqueue *timer;
  79   struct thread_list event;
  80   struct thread_list ready;
  81   struct thread_list unuse;
  82   struct pqueue *background;
  83   int fd_limit;
  84   struct fd_handler handler;
  85   unsigned long alloc;
  86 };
  87
  88 typedef unsigned char thread_type;
  89
  90 /* Thread itself. */
  91 struct thread
  92 {
  93   thread_type type;             /* thread type */
  94   thread_type add_type;         /* thread type */
  95   struct thread *next;          /* next pointer of the thread */
  96   struct thread *prev;          /* previous pointer of the thread */
  97   struct thread_master *master; /* pointer to the struct thread_master. */
  98   int (*func) (struct thread *); /* event function */
  99   void *arg;                    /* event argument */
 100   union {
 101     int val;                    /* second argument of the event. */
 102     int fd;                     /* file descriptor in case of read/write. */
 103     struct timeval sands;       /* rest of time sands value. */
 104   } u;
 105   int index;                    /* used for timers to store position in queue */
 106   struct timeval real;
 107   struct cpu_thread_history *hist; /* cache pointer to cpu_history */
 108   unsigned long yield; /* yield time in us */
 109   const char *funcname;
 110   const char *schedfrom;
 111   int schedfrom_line;
 112 };
 113
 114 struct cpu_thread_history
 115 {
 116   int (*func)(struct thread *);
 117   unsigned int total_calls;
 118   struct time_stats
 119   {
 120     unsigned long total, max;
 121   } real;
 122   struct time_stats cpu;
 123   thread_type types;
 124   const char *funcname;
 125 };
 126
 127 /* Clocks supported by Quagga */
 128 enum quagga_clkid {
 129   QUAGGA_CLK_MONOTONIC = 1,     /* monotonic, against an indeterminate base */
 130 };
 131
 132 /* Struct timeval's tv_usec one second value.  */
 133 #define TIMER_SECOND_MICRO 1000000L
 134
 135 /* Thread types. */
 136 #define THREAD_READ           0
 137 #define THREAD_WRITE          1
 138 #define THREAD_TIMER          2
 139 #define THREAD_EVENT          3
 140 #define THREAD_READY          4
 141 #define THREAD_BACKGROUND     5
 142 #define THREAD_UNUSED         6
 143 #define THREAD_EXECUTE        7
 144
 145 /* Thread yield time.  */
 146 #define THREAD_YIELD_TIME_SLOT     10 * 1000L /* 10ms */
 147
 148 /* Macros. */
 149 #define THREAD_ARG(X) ((X)->arg)
 150 #define THREAD_FD(X)  ((X)->u.fd)
 151 #define THREAD_VAL(X) ((X)->u.val)
 152
 153 #define THREAD_READ_ON(master,thread,func,arg,sock) \
 154   do { \
 155     if (! thread) \
 156       thread = thread_add_read (master, func, arg, sock); \
 157   } while (0)
 158
 159 #define THREAD_WRITE_ON(master,thread,func,arg,sock) \
 160   do { \
 161     if (! thread) \
 162       thread = thread_add_write (master, func, arg, sock); \
 163   } while (0)
 164
 165 #define THREAD_TIMER_ON(master,thread,func,arg,time) \
 166   do { \
 167     if (! thread) \
 168       thread = thread_add_timer (master, func, arg, time); \
 169   } while (0)
 170
 171 #define THREAD_TIMER_MSEC_ON(master,thread,func,arg,time) \
 172   do { \
 173     if (! thread) \
 174       thread = thread_add_timer_msec (master, func, arg, time); \
 175   } while (0)
 176
 177 #define THREAD_OFF(thread) \
 178   do { \
 179     if (thread) \
 180       { \
 181         thread_cancel (thread); \
 182         thread = NULL; \
 183       } \
 184   } while (0)
 185
 186 #define THREAD_READ_OFF(thread)  THREAD_OFF(thread)
 187 #define THREAD_WRITE_OFF(thread)  THREAD_OFF(thread)
 188 #define THREAD_TIMER_OFF(thread)  THREAD_OFF(thread)
 189
 190 #define debugargdef  const char *funcname, const char *schedfrom, int fromln
 191
 192 #define thread_add_read(m,f,a,v) funcname_thread_add_read_write(THREAD_READ,m,f,a,v,#f,__FILE__,__LINE__)
 193 #define thread_add_write(m,f,a,v) funcname_thread_add_read_write(THREAD_WRITE,m,f,a,v,#f,__FILE__,__LINE__)
 194 #define thread_add_timer(m,f,a,v) funcname_thread_add_timer(m,f,a,v,#f,__FILE__,__LINE__)
 195 #define thread_add_timer_msec(m,f,a,v) funcname_thread_add_timer_msec(m,f,a,v,#f,__FILE__,__LINE__)
 196 #define thread_add_timer_tv(m,f,a,v) funcname_thread_add_timer_tv(m,f,a,v,#f,__FILE__,__LINE__)
 197 #define thread_add_event(m,f,a,v) funcname_thread_add_event(m,f,a,v,#f,__FILE__,__LINE__)
 198 #define thread_execute(m,f,a,v) funcname_thread_execute(m,f,a,v,#f,__FILE__,__LINE__)
 199
 200 /* The 4th arg to thread_add_background is the # of milliseconds to delay. */
 201 #define thread_add_background(m,f,a,v) funcname_thread_add_background(m,f,a,v,#f,__FILE__,__LINE__)
 202
 203 /* Prototypes. */
 204 extern struct thread_master *thread_master_create (void);
 205 extern void thread_master_free (struct thread_master *);
 206 extern void thread_master_free_unused(struct thread_master *);
 207
 208 extern struct thread *funcname_thread_add_read_write (int dir, struct thread_master *,
 209                                                 int (*)(struct thread *),
 210                                                 void *, int, debugargdef);
 211 extern struct thread *funcname_thread_add_timer (struct thread_master *,
 212                                                  int (*)(struct thread *),
 213                                                  void *, long, debugargdef);
 214 extern struct thread *funcname_thread_add_timer_msec (struct thread_master *,
 215                                                       int (*)(struct thread *),
 216                                                       void *, long, debugargdef);
 217 extern struct thread *funcname_thread_add_timer_tv (struct thread_master *,
 218                                                     int (*)(struct thread *),
 219                                                     void *, struct timeval *,
 220                                                     debugargdef);
 221 extern struct thread *funcname_thread_add_event (struct thread_master *,
 222                                                  int (*)(struct thread *),
 223                                                  void *, int, debugargdef);
 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                                                debugargdef);
 229 extern struct thread *funcname_thread_execute (struct thread_master *,
 230                                                int (*)(struct thread *),
 231                                                void *, int, debugargdef);
 232 #undef debugargdef
 233
 234 extern void thread_cancel (struct thread *);
 235 extern unsigned int thread_cancel_event (struct thread_master *, void *);
 236 extern struct thread *thread_fetch (struct thread_master *, struct thread *);
 237 extern void thread_call (struct thread *);
 238 extern unsigned long thread_timer_remain_second (struct thread *);
 239 extern struct timeval thread_timer_remain(struct thread*);
 240 extern int thread_should_yield (struct thread *);
 241 extern unsigned long timeval_elapsed (struct timeval a, struct timeval b);
 242 /* set yield time for thread */
 243 extern void thread_set_yield_time (struct thread *, unsigned long);
 244
 245 /* Internal libzebra exports */
 246 extern void thread_getrusage (RUSAGE_T *);
 247 extern struct cmd_element show_thread_cpu_cmd;
 248 extern struct cmd_element clear_thread_cpu_cmd;
 249
 250 /* replacements for the system gettimeofday(), clock_gettime() and
 251  * time() functions, providing support for non-decrementing clock on
 252  * all systems, and fully monotonic on /some/ systems.
 253  */
 254 extern int quagga_gettime (enum quagga_clkid, struct timeval *);
 255 extern time_t quagga_monotime (void);
 256
 257 /* Returns elapsed real (wall clock) time. */
 258 extern unsigned long thread_consumed_time(RUSAGE_T *after, RUSAGE_T *before,
 259                                           unsigned long *cpu_time_elapsed);
 260
 261 /* Global variable containing a recent result from gettimeofday.  This can
 262    be used instead of calling gettimeofday if a recent value is sufficient.
 263    This is guaranteed to be refreshed before a thread is called. */
 264 extern struct timeval recent_time;
 265 /* Similar to recent_time, but a monotonically increasing time value */
 266 extern struct timeval recent_relative_time (void);
 267
 268 /* only for use in logging functions! */
 269 extern struct thread *thread_current;
 270
 271 #endif /* _ZEBRA_THREAD_H */