src/mc/mc_smx.c

   1 /* Copyright (c) 2015. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   4 /* This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the license (GNU LGPL) which comes with this package. */
   6
   7 #include <assert.h>
   8
   9 #include <xbt/log.h>
  10
  11 #include "simix/smx_private.h"
  12
  13 #include "mc_smx.h"
  14 #include "mc_model_checker.h"
  15
  16 static
  17 void MC_smx_process_info_clear(mc_smx_process_info_t p)
  18 {
  19   p->hostname = NULL;
  20
  21   xbt_mheap_t heap = mmalloc_set_current_heap(mc_heap);
  22   free(p->name);
  23   mmalloc_set_current_heap(heap);
  24
  25   p->name = NULL;
  26 }
  27
  28 xbt_dynar_t MC_smx_process_info_list_new(void)
  29 {
  30   return xbt_dynar_new(
  31     sizeof(s_mc_smx_process_info_t),
  32     ( void_f_pvoid_t) &MC_smx_process_info_clear);
  33 }
  34
  35 static inline
  36 bool is_in_dynar(smx_process_t p, xbt_dynar_t dynar)
  37 {
  38   return (uintptr_t) p >= (uintptr_t) dynar->data
  39     && (uintptr_t) p < ((uintptr_t) dynar->data + dynar->used * dynar->elmsize);
  40 }
  41
  42 static inline
  43 mc_smx_process_info_t MC_smx_process_get_info(smx_process_t p)
  44 {
  45   assert(is_in_dynar(p, mc_model_checker->process.smx_process_infos)
  46     || is_in_dynar(p, mc_model_checker->process.smx_old_process_infos));
  47   mc_smx_process_info_t process_info =
  48     (mc_smx_process_info_t)
  49       ((char*) p - offsetof(s_mc_smx_process_info_t, copy));
  50   return process_info;
  51 }
  52
  53 /** Load the remote swag of processes into a dynar
  54  *
  55  *  @param process     MCed process
  56  *  @param target      Local dynar (to be filled with copies of `s_smx_process_t`)
  57  *  @param remote_swag Address of the process SWAG in the remote list
  58  */
  59 static void MC_process_refresh_simix_process_list(
  60   mc_process_t process,
  61   xbt_dynar_t target, xbt_swag_t remote_swag)
  62 {
  63   // swag = REMOTE(*simix_global->process_list)
  64   s_xbt_swag_t swag;
  65   MC_process_read(process, MC_PROCESS_NO_FLAG, &swag, remote_swag, sizeof(swag),
  66     MC_PROCESS_INDEX_ANY);
  67
  68   smx_process_t p;
  69   xbt_dynar_reset(target);
  70
  71   // Load each element of the dynar from the MCed process:
  72   int i = 0;
  73   for (p = swag.head; p; ++i) {
  74
  75     s_mc_smx_process_info_t info;
  76     info.address = p;
  77     info.name = NULL;
  78     info.hostname = NULL;
  79     MC_process_read(process, MC_PROCESS_NO_FLAG,
  80       &info.copy, p, sizeof(info.copy), MC_PROCESS_INDEX_ANY);
  81     xbt_dynar_push(target, &info);
  82
  83     // Lookup next process address:
  84     p = xbt_swag_getNext(&info.copy, swag.offset);
  85   }
  86   assert(i == swag.count);
  87 }
  88
  89 void MC_process_smx_refresh(mc_process_t process)
  90 {
  91   if (process->cache_flags & MC_PROCESS_CACHE_FLAG_SIMIX_PROCESSES)
  92     return;
  93
  94   xbt_mheap_t heap = mmalloc_set_current_heap(mc_heap);
  95
  96   // TODO, avoid to reload `&simix_global`, `simix_global`, `*simix_global`
  97
  98   // simix_global_p = REMOTE(simix_global);
  99   smx_global_t simix_global_p;
 100   MC_process_read_variable(process, "simix_global", &simix_global_p, sizeof(simix_global_p));
 101
 102   // simix_global = REMOTE(*simix_global)
 103   s_smx_global_t simix_global;
 104   MC_process_read(process, MC_PROCESS_NO_FLAG, &simix_global, simix_global_p, sizeof(simix_global),
 105     MC_PROCESS_INDEX_ANY);
 106
 107   MC_process_refresh_simix_process_list(
 108     process, process->smx_process_infos, simix_global.process_list);
 109   MC_process_refresh_simix_process_list(
 110     process, process->smx_old_process_infos, simix_global.process_to_destroy);
 111
 112   process->cache_flags |= MC_PROCESS_CACHE_FLAG_SIMIX_PROCESSES;
 113   mmalloc_set_current_heap(heap);
 114 }
 115
 116 /** Get the issuer of a simcall (`req->issuer`)
 117  *
 118  *  In split-process mode, it does the black magic necessary to get an address
 119  *  of a (shallow) copy of the data structure the issuer SIMIX process in the local
 120  *  address space.
 121  *
 122  *  @param process the MCed process
 123  *  @param req     the simcall (copied in the local process)
 124  */
 125 smx_process_t MC_smx_simcall_get_issuer(smx_simcall_t req)
 126 {
 127   if (MC_process_is_self(&mc_model_checker->process))
 128     return req->issuer;
 129
 130   MC_process_smx_refresh(&mc_model_checker->process);
 131
 132   // This is the address of the smx_process in the MCed process:
 133   void* address = req->issuer;
 134
 135   unsigned i;
 136   mc_smx_process_info_t p;
 137
 138   // Lookup by address:
 139   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, i, p)
 140     if (p->address == address)
 141       return &p->copy;
 142   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_old_process_infos, i, p)
 143     if (p->address == address)
 144       return &p->copy;
 145
 146   xbt_die("Issuer not found");
 147 }
 148
 149 smx_process_t MC_smx_resolve_process(smx_process_t process_remote_address)
 150 {
 151   if (!process_remote_address)
 152     return NULL;
 153   if (MC_process_is_self(&mc_model_checker->process))
 154     return process_remote_address;
 155
 156   mc_smx_process_info_t process_info = MC_smx_resolve_process_info(process_remote_address);
 157   if (process_info)
 158     return &process_info->copy;
 159   else
 160     return NULL;
 161 }
 162
 163 mc_smx_process_info_t MC_smx_resolve_process_info(smx_process_t process_remote_address)
 164 {
 165   if (MC_process_is_self(&mc_model_checker->process))
 166     xbt_die("No process_info for local process is not enabled.");
 167
 168   unsigned index;
 169   mc_smx_process_info_t process_info;
 170   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, index, process_info)
 171     if (process_info->address == process_remote_address)
 172       return process_info;
 173   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_old_process_infos, index, process_info)
 174     if (process_info->address == process_remote_address)
 175       return process_info;
 176   xbt_die("Process info not found");
 177 }
 178
 179 const char* MC_smx_process_get_host_name(smx_process_t p)
 180 {
 181   if (MC_process_is_self(&mc_model_checker->process))
 182     return SIMIX_host_get_name(p->smx_host);
 183
 184   mc_process_t process = &mc_model_checker->process;
 185
 186   // Currently, smx_host_t = xbt_dictelm_t.
 187   // TODO, add an static_assert on this if switching to C++
 188   // The host name is host->key and the host->key_len==strlen(host->key).
 189   s_xbt_dictelm_t host_copy;
 190   mc_smx_process_info_t info = MC_smx_process_get_info(p);
 191   if (!info->hostname) {
 192
 193     // Read the hostname from the MCed process:
 194     MC_process_read_simple(process, &host_copy, p->smx_host, sizeof(host_copy));
 195     int len = host_copy.key_len + 1;
 196     char hostname[len];
 197     MC_process_read_simple(process, hostname, host_copy.key, len);
 198
 199     // Lookup the host name in the dictionary (or create it):
 200     xbt_dictelm_t elt = xbt_dict_get_elm_or_null(mc_model_checker->hosts, hostname);
 201     if (!elt) {
 202       xbt_mheap_t heap = mmalloc_set_current_heap(mc_heap);
 203       xbt_dict_set(mc_model_checker->hosts, hostname, NULL, NULL);
 204       elt = xbt_dict_get_elm_or_null(mc_model_checker->hosts, hostname);
 205       assert(elt);
 206       mmalloc_set_current_heap(heap);
 207     }
 208
 209     info->hostname = elt->key;
 210   }
 211   return info->hostname;
 212 }
 213
 214 const char* MC_smx_process_get_name(smx_process_t p)
 215 {
 216   mc_process_t process = &mc_model_checker->process;
 217   if (MC_process_is_self(process))
 218     return p->name;
 219   if (!p->name)
 220     return NULL;
 221
 222   mc_smx_process_info_t info = MC_smx_process_get_info(p);
 223   if (!info->name) {
 224     size_t size = 128;
 225     char buffer[size];
 226
 227     size_t off = 0;
 228     while (1) {
 229       ssize_t n = pread(process->memory_file, buffer+off, size-off, (off_t)p->name + off);
 230       if (n==-1) {
 231         if (errno == EINTR)
 232           continue;
 233         else {
 234           perror("MC_smx_process_get_name");
 235           xbt_die("Could not read memory");
 236         }
 237       }
 238       if (n==0)
 239         return "?";
 240       void* end = memchr(buffer+off, '\0', n);
 241       if (end)
 242         break;
 243       off += n;
 244       if (off == size)
 245         return "?";
 246     }
 247     xbt_mheap_t heap = mmalloc_set_current_heap(mc_heap);
 248     info->name = strdup(buffer);
 249     mmalloc_set_current_heap(heap);
 250   }
 251   return info->name;
 252 }