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 struct rusage_t
  26 {
  27 #ifdef HAVE_RUSAGE
  28   struct rusage cpu;
  29 #endif
  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 /* Master of the theads. */
  45 struct thread_master
  46 {
  47   struct thread_list read;
  48   struct thread_list write;
  49   struct thread_list timer;
  50   struct thread_list event;
  51   struct thread_list ready;
  52   struct thread_list unuse;
  53   struct thread_list background;
  54   fd_set readfd;
  55   fd_set writefd;
  56   fd_set exceptfd;
  57   unsigned long alloc;
  58 };
  59
  60 typedef unsigned char thread_type;
  61
  62 /* Thread itself. */
  63 struct thread
  64 {
  65   thread_type type;             /* thread type */
  66   thread_type add_type;         /* thread type */
  67   struct thread *next;          /* next pointer of the thread */
  68   struct thread *prev;          /* previous pointer of the thread */
  69   struct thread_master *master; /* pointer to the struct thread_master. */
  70   int (*func) (struct thread *); /* event function */
  71   void *arg;                    /* event argument */
  72   union {
  73     int val;                    /* second argument of the event. */
  74     int fd;                     /* file descriptor in case of read/write. */
  75     struct timeval sands;       /* rest of time sands value. */
  76   } u;
  77   RUSAGE_T ru;                  /* Indepth usage info.  */
  78   struct cpu_thread_history *hist; /* cache pointer to cpu_history */
  79   char* funcname;
  80 };
  81
  82 struct cpu_thread_history
  83 {
  84   int (*func)(struct thread *);
  85   const char *funcname;
  86   unsigned int total_calls;
  87   struct time_stats
  88   {
  89     unsigned long total, max;
  90   } real;
  91 #ifdef HAVE_RUSAGE
  92   struct time_stats cpu;
  93 #endif
  94   thread_type types;
  95 };
  96
  97 /* Clocks supported by Quagga */
  98 enum quagga_clkid {
  99   QUAGGA_CLK_REALTIME = 0,      /* ala gettimeofday() */
 100   QUAGGA_CLK_MONOTONIC,         /* monotonic, against an indeterminate base */
 101   QUAGGA_CLK_REALTIME_STABILISED, /* like realtime, but non-decrementing */
 102 };
 103
 104 /* Thread types. */
 105 #define THREAD_READ           0
 106 #define THREAD_WRITE          1
 107 #define THREAD_TIMER          2
 108 #define THREAD_EVENT          3
 109 #define THREAD_READY          4
 110 #define THREAD_BACKGROUND     5
 111 #define THREAD_UNUSED         6
 112 #define THREAD_EXECUTE        7
 113
 114 /* Thread yield time.  */
 115 #define THREAD_YIELD_TIME_SLOT     10 * 1000L /* 10ms */
 116
 117 /* Macros. */
 118 #define THREAD_ARG(X) ((X)->arg)
 119 #define THREAD_FD(X)  ((X)->u.fd)
 120 #define THREAD_VAL(X) ((X)->u.val)
 121
 122 #define THREAD_READ_ON(master,thread,func,arg,sock) \
 123   do { \
 124     if (! thread) \
 125       thread = thread_add_read (master, func, arg, sock); \
 126   } while (0)
 127
 128 #define THREAD_WRITE_ON(master,thread,func,arg,sock) \
 129   do { \
 130     if (! thread) \
 131       thread = thread_add_write (master, func, arg, sock); \
 132   } while (0)
 133
 134 #define THREAD_TIMER_ON(master,thread,func,arg,time) \
 135   do { \
 136     if (! thread) \
 137       thread = thread_add_timer (master, func, arg, time); \
 138   } while (0)
 139
 140 #define THREAD_OFF(thread) \
 141   do { \
 142     if (thread) \
 143       { \
 144         thread_cancel (thread); \
 145         thread = NULL; \
 146       } \
 147   } while (0)
 148
 149 #define THREAD_READ_OFF(thread)  THREAD_OFF(thread)
 150 #define THREAD_WRITE_OFF(thread)  THREAD_OFF(thread)
 151 #define THREAD_TIMER_OFF(thread)  THREAD_OFF(thread)
 152
 153 #define thread_add_read(m,f,a,v) funcname_thread_add_read(m,f,a,v,#f)
 154 #define thread_add_write(m,f,a,v) funcname_thread_add_write(m,f,a,v,#f)
 155 #define thread_add_timer(m,f,a,v) funcname_thread_add_timer(m,f,a,v,#f)
 156 #define thread_add_timer_msec(m,f,a,v) funcname_thread_add_timer_msec(m,f,a,v,#f)
 157 #define thread_add_event(m,f,a,v) funcname_thread_add_event(m,f,a,v,#f)
 158 #define thread_execute(m,f,a,v) funcname_thread_execute(m,f,a,v,#f)
 159
 160 /* The 4th arg to thread_add_background is the # of milliseconds to delay. */
 161 #define thread_add_background(m,f,a,v) funcname_thread_add_background(m,f,a,v,#f)
 162
 163 /* Prototypes. */
 164 extern struct thread_master *thread_master_create (void);
 165 extern void thread_master_free (struct thread_master *);
 166
 167 extern struct thread *funcname_thread_add_read (struct thread_master *,
 168                                                 int (*)(struct thread *),
 169                                                 void *, int, const char*);
 170 extern struct thread *funcname_thread_add_write (struct thread_master *,
 171                                                  int (*)(struct thread *),
 172                                                  void *, int, const char*);
 173 extern struct thread *funcname_thread_add_timer (struct thread_master *,
 174                                                  int (*)(struct thread *),
 175                                                  void *, long, const char*);
 176 extern struct thread *funcname_thread_add_timer_msec (struct thread_master *,
 177                                                       int (*)(struct thread *),
 178                                                       void *, long, const char*);
 179 extern struct thread *funcname_thread_add_event (struct thread_master *,
 180                                                  int (*)(struct thread *),
 181                                                  void *, int, const char*);
 182 extern struct thread *funcname_thread_add_background (struct thread_master *,
 183                                                int (*func)(struct thread *),
 184                                                void *arg,
 185                                                long milliseconds_to_delay,
 186                                                const char *funcname);
 187 extern struct thread *funcname_thread_execute (struct thread_master *,
 188                                                int (*)(struct thread *),
 189                                                void *, int, const char *);
 190 extern void thread_cancel (struct thread *);
 191 extern unsigned int thread_cancel_event (struct thread_master *, void *);
 192 extern struct thread *thread_fetch (struct thread_master *, struct thread *);
 193 extern void thread_call (struct thread *);
 194 extern unsigned long thread_timer_remain_second (struct thread *);
 195 extern int thread_should_yield (struct thread *);
 196
 197 /* Internal libzebra exports */
 198 extern void thread_getrusage (RUSAGE_T *);
 199 extern struct cmd_element show_thread_cpu_cmd;
 200
 201 /* replacements for the system gettimeofday(), clock_gettime() and
 202  * time() functions, providing support for non-decrementing clock on
 203  * all systems, and fully monotonic on /some/ systems.
 204  */
 205 extern int quagga_gettime (enum quagga_clkid, struct timeval *);
 206 extern time_t quagga_time (time_t *);
 207
 208 /* Returns elapsed real (wall clock) time. */
 209 extern unsigned long thread_consumed_time(RUSAGE_T *after, RUSAGE_T *before,
 210                                           unsigned long *cpu_time_elapsed);
 211
 212 /* Global variable containing a recent result from gettimeofday.  This can
 213    be used instead of calling gettimeofday if a recent value is sufficient.
 214    This is guaranteed to be refreshed before a thread is called. */
 215 extern struct timeval recent_time;
 216 /* Similar to recent_time, but a monotonically increasing time value */
 217 extern struct timeval recent_relative_time (void);
 218 #endif /* _ZEBRA_THREAD_H */