sim/common/sim-events.h

   1 /* The common simulator framework for GDB, the GNU Debugger.
   2
   3    Copyright 2002-2020 Free Software Foundation, Inc.
   4
   5    Contributed by Andrew Cagney and Red Hat.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #ifndef SIM_EVENTS_H
  24 #define SIM_EVENTS_H
  25
  26
  27 /* Notes:
  28
  29    When scheduling an event, the a delta of zero/one refers to the
  30    timeline as follows:
  31
  32    epoch   0|1              1|2              2|3              3|
  33    **queue**|--insn--|*queue*|--insn--|*queue*|--insn--|*queue*|
  34      |   ^               ^        |       ^                ^
  35      `- +0 ------------ +1 --..   `----- +0 ------------- +1 --..
  36
  37    When the queue is initialized, the time is set to zero with a
  38    number of initialization events scheduled.  Consequently, as also
  39    illustrated above, the event queue should be processed before the
  40    first instruction.  That instruction being executed during tick 1.
  41
  42    The simulator main loop may take a form similar to:
  43
  44        if (halt-/restart-setjmp)
  45          {
  46
  47            .... // Determine who should go next
  48            last-cpu-nr = get-last-cpu-nr (sd);
  49            next-cpu-nr = get-next-cpu-nr (sd);
  50            events-were-last? = (last-cpu-nr >= nr-cpus);
  51            events-were-next? = (next-cpu-nr >= nr-cpus);
  52
  53            .... // process any outstanding events
  54            sim_events_preprocess (sd, events-were-last?, events-were-next?);
  55            if (events-were-next)
  56              next-cpu-nr = 0;
  57
  58            .... // prime main loop
  59
  60            while (1)
  61              {
  62                 .... // model one insn of next-cpu-nr .. nr-cpus
  63                 if (sim_events_tick (sd))
  64                   sim_events_process (sd);
  65                 next-cpu-nr = 0
  66              }
  67          }
  68
  69    NB.  In the above pseudo code it is assumed that any cpu-nr >=
  70    nr-cpus is a marker for the event queue. */
  71
  72
  73 typedef void sim_event_handler(SIM_DESC sd, void *data);
  74
  75 typedef struct _sim_event sim_event;
  76
  77 typedef struct _sim_events sim_events;
  78 struct _sim_events {
  79   int nr_ticks_to_process;
  80   sim_event *queue;
  81   sim_event *watchpoints;
  82   sim_event *watchedpoints;
  83   sim_event *free_list;
  84   /* flag additional work needed */
  85   volatile int work_pending;
  86   /* the asynchronous event queue */
  87 #ifndef MAX_NR_SIGNAL_SIM_EVENTS
  88 #define MAX_NR_SIGNAL_SIM_EVENTS 2
  89 #endif
  90   sim_event *held;
  91   volatile int nr_held;
  92   /* timekeeping */
  93   unsigned long elapsed_wallclock;
  94   SIM_ELAPSED_TIME resume_wallclock;
  95   signed64 time_of_event;
  96   signed64 time_from_event;
  97 };
  98
  99
 100
 101 /* Install the "events" module.  */
 102
 103 extern SIM_RC sim_events_install (SIM_DESC sd);
 104
 105
 106 /* Schedule an event DELTA_TIME ticks into the future */
 107
 108 extern sim_event *sim_events_schedule
 109 (SIM_DESC sd,
 110  signed64 delta_time,
 111  sim_event_handler *handler,
 112  void *data);
 113
 114 extern sim_event *sim_events_schedule_tracef
 115 (SIM_DESC sd,
 116  signed64 delta_time,
 117  sim_event_handler *handler,
 118  void *data,
 119  const char *fmt,
 120  ...) __attribute__ ((format (printf, 5, 6)));
 121
 122 extern sim_event *sim_events_schedule_vtracef
 123 (SIM_DESC sd,
 124  signed64 delta_time,
 125  sim_event_handler *handler,
 126  void *data,
 127  const char *fmt,
 128  va_list ap);
 129
 130
 131 extern void sim_events_schedule_after_signal
 132 (SIM_DESC sd,
 133  signed64 delta_time,
 134  sim_event_handler *handler,
 135  void *data);
 136
 137 /* NB: signal level events can't have trace strings as malloc isn't
 138    available */
 139
 140
 141
 142 /* Schedule an event milli-seconds from NOW.  The exact interpretation
 143    of wallclock is host dependant. */
 144
 145 extern sim_event *sim_events_watch_clock
 146 (SIM_DESC sd,
 147  unsigned delta_ms_time,
 148  sim_event_handler *handler,
 149  void *data);
 150
 151
 152 /* Schedule an event when the test (IS_WITHIN == (VAL >= LB && VAL <=
 153    UB)) of the NR_BYTES value at HOST_ADDR with BYTE_ORDER endian is
 154    true.
 155
 156    HOST_ADDR: pointer into the host address space.
 157    BYTE_ORDER: BFD_ENDIAN_UNKNOWN - host endian; BFD_ENDIAN_BIG;
 158                BFD_ENDIAN_LITTLE.  */
 159
 160 extern sim_event *sim_events_watch_sim
 161 (SIM_DESC sd,
 162  void *host_addr,
 163  int nr_bytes,
 164  int byte_order,
 165  int is_within,
 166  unsigned64 lb,
 167  unsigned64 ub,
 168  sim_event_handler *handler,
 169  void *data);
 170
 171
 172 /* Schedule an event when the test (IS_WITHIN == (VAL >= LB && VAL <=
 173    UB)) of the NR_BYTES value at CORE_ADDR in BYTE_ORDER endian is
 174    true.
 175
 176    CORE_ADDR/MAP: pointer into the target address space.
 177    BYTE_ORDER: BFD_ENDIAN_UNKNOWN - host endian; BFD_ENDIAN_BIG;
 178                BFD_ENDIAN_LITTLE.  */
 179
 180 extern sim_event *sim_events_watch_core
 181 (SIM_DESC sd,
 182  address_word core_addr,
 183  unsigned map,
 184  int nr_bytes,
 185  int byte_order,
 186  int is_within,
 187  unsigned64 lb,
 188  unsigned64 ub,
 189  sim_event_handler *handler,
 190  void *data);
 191
 192 /* Deschedule the specified event */
 193
 194 extern void sim_events_deschedule
 195 (SIM_DESC sd,
 196  sim_event *event_to_remove);
 197
 198
 199 /* Prepare for main simulator loop.  Ensure that the next thing to do
 200    is not event processing.
 201
 202    If the simulator halted part way through event processing then both
 203    EVENTS_WERE_LAST and EVENTS_WERE_NEXT shall be true.
 204
 205    If the simulator halted after processing the last cpu, then only
 206    EVENTS_WERE_NEXT shall be true. */
 207
 208 INLINE_SIM_EVENTS\
 209 (void) sim_events_preprocess
 210 (SIM_DESC sd,
 211  int events_were_last,
 212  int events_were_next);
 213
 214
 215 /* Progress time.
 216
 217    Separated into two parts so that the main loop can save its context
 218    before the event queue is processed.  When sim_events_tick*()
 219    returns true, any simulation context should be saved and
 220    sim_events_process() called.
 221
 222    SIM_EVENTS_TICK advances the clock by 1 cycle.
 223
 224    SIM_EVENTS_TICKN advances the clock by N cycles (1..MAXINT). */
 225
 226 INLINE_SIM_EVENTS\
 227 (int) sim_events_tick
 228 (SIM_DESC sd);
 229
 230 INLINE_SIM_EVENTS\
 231 (int) sim_events_tickn
 232 (SIM_DESC sd,
 233  int n);
 234
 235 INLINE_SIM_EVENTS\
 236 (void) sim_events_process
 237 (SIM_DESC sd);
 238
 239
 240 /* Advance the clock by an additional SLIP cycles at the next call to
 241    sim_events_tick*().  For multiple calls, the effect is
 242    accumulative. */
 243
 244 INLINE_SIM_EVENTS\
 245 (void) sim_events_slip
 246 (SIM_DESC sd,
 247  int slip);
 248
 249
 250 /* Progress time such that an event shall occur upon the next call to
 251    sim_events tick */
 252
 253 #if 0
 254 INLINE_SIM_EVENTS\
 255 (void) sim_events_timewarp
 256 (SIM_DESC sd);
 257 #endif
 258
 259
 260 /* local concept of elapsed target time */
 261
 262 INLINE_SIM_EVENTS\
 263 (signed64) sim_events_time
 264 (SIM_DESC sd);
 265
 266
 267 /* local concept of elapsed host time (milliseconds) */
 268
 269 INLINE_SIM_EVENTS\
 270 (unsigned long) sim_events_elapsed_time
 271 (SIM_DESC sd);
 272
 273 /* Returns the time that remains before the event is raised. */
 274 INLINE_SIM_EVENTS\
 275 (signed64) sim_events_remain_time
 276 (SIM_DESC sd, sim_event *event);
 277
 278
 279 #endif