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 xbt_dynar_t MC_smx_process_info_list_new(void)
  17 {
  18   return xbt_dynar_new(
  19     sizeof(s_mc_smx_process_info_t), NULL);
  20 }
  21
  22 static inline
  23 bool is_in_dynar(smx_process_t p, xbt_dynar_t dynar)
  24 {
  25   return (uintptr_t) p >= (uintptr_t) dynar->data
  26     && (uintptr_t) p < ((uintptr_t) dynar->data + dynar->used * dynar->elmsize);
  27 }
  28
  29 static inline
  30 mc_smx_process_info_t MC_smx_process_get_info(smx_process_t p)
  31 {
  32   assert(is_in_dynar(p, mc_model_checker->process.smx_process_infos)
  33     || is_in_dynar(p, mc_model_checker->process.smx_old_process_infos));
  34   mc_smx_process_info_t process_info =
  35     (mc_smx_process_info_t)
  36       ((char*) p - offsetof(s_mc_smx_process_info_t, copy));
  37   return process_info;
  38 }
  39
  40 /** Load the remote swag of processes into a dynar
  41  *
  42  *  @param process     MCed process
  43  *  @param target      Local dynar (to be filled with copies of `s_smx_process_t`)
  44  *  @param remote_swag Address of the process SWAG in the remote list
  45  */
  46 static void MC_process_refresh_simix_process_list(
  47   mc_process_t process,
  48   xbt_dynar_t target, xbt_swag_t remote_swag)
  49 {
  50   // swag = REMOTE(*simix_global->process_list)
  51   s_xbt_swag_t swag;
  52   MC_process_read(process, MC_PROCESS_NO_FLAG, &swag, remote_swag, sizeof(swag),
  53     MC_PROCESS_INDEX_ANY);
  54
  55   smx_process_t p;
  56   xbt_dynar_reset(target);
  57
  58   // Load each element of the dynar from the MCed process:
  59   int i = 0;
  60   for (p = swag.head; p; ++i) {
  61
  62     s_mc_smx_process_info_t info;
  63     info.address = p;
  64     info.hostname = NULL;
  65     MC_process_read(process, MC_PROCESS_NO_FLAG,
  66       &info.copy, p, sizeof(info.copy), MC_PROCESS_INDEX_ANY);
  67     xbt_dynar_push(target, &info);
  68
  69     // Lookup next process address:
  70     p = xbt_swag_getNext(&info.copy, swag.offset);
  71   }
  72   assert(i == swag.count);
  73 }
  74
  75 void MC_process_smx_refresh(mc_process_t process)
  76 {
  77   if (process->cache_flags & MC_PROCESS_CACHE_FLAG_SIMIX_PROCESSES)
  78     return;
  79
  80   xbt_mheap_t heap = mmalloc_set_current_heap(mc_heap);
  81
  82   // TODO, avoid to reload `&simix_global`, `simix_global`, `*simix_global`
  83
  84   // simix_global_p = REMOTE(simix_global);
  85   smx_global_t simix_global_p;
  86   MC_process_read_variable(process, "simix_global", &simix_global_p, sizeof(simix_global_p));
  87
  88   // simix_global = REMOTE(*simix_global)
  89   s_smx_global_t simix_global;
  90   MC_process_read(process, MC_PROCESS_NO_FLAG, &simix_global, simix_global_p, sizeof(simix_global),
  91     MC_PROCESS_INDEX_ANY);
  92
  93   MC_process_refresh_simix_process_list(
  94     process, process->smx_process_infos, simix_global.process_list);
  95   MC_process_refresh_simix_process_list(
  96     process, process->smx_old_process_infos, simix_global.process_to_destroy);
  97
  98   process->cache_flags |= MC_PROCESS_CACHE_FLAG_SIMIX_PROCESSES;
  99   mmalloc_set_current_heap(heap);
 100 }
 101
 102 /** Get the issuer of a simcall (`req->issuer`)
 103  *
 104  *  In split-process mode, it does the black magic necessary to get an address
 105  *  of a (shallow) copy of the data structure the issuer SIMIX process in the local
 106  *  address space.
 107  *
 108  *  @param process the MCed process
 109  *  @param req     the simcall (copied in the local process)
 110  */
 111 smx_process_t MC_smx_simcall_get_issuer(smx_simcall_t req)
 112 {
 113   if (MC_process_is_self(&mc_model_checker->process))
 114     return req->issuer;
 115
 116   MC_process_smx_refresh(&mc_model_checker->process);
 117
 118   // This is the address of the smx_process in the MCed process:
 119   void* address = req->issuer;
 120
 121   unsigned i;
 122   mc_smx_process_info_t p;
 123
 124   // Lookup by address:
 125   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, i, p)
 126     if (p->address == address)
 127       return &p->copy;
 128   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_old_process_infos, i, p)
 129     if (p->address == address)
 130       return &p->copy;
 131
 132   xbt_die("Issuer not found");
 133 }
 134
 135 smx_process_t MC_smx_resolve_process(smx_process_t process_remote_address)
 136 {
 137   if (MC_process_is_self(&mc_model_checker->process))
 138     return process_remote_address;
 139
 140   mc_smx_process_info_t process_info = MC_smx_resolve_process_info(process_remote_address);
 141   if (process_info)
 142     return &process_info->copy;
 143   else
 144     return NULL;
 145 }
 146
 147 mc_smx_process_info_t MC_smx_resolve_process_info(smx_process_t process_remote_address)
 148 {
 149   if (MC_process_is_self(&mc_model_checker->process))
 150     xbt_die("No process_info for local process is not enabled.");
 151
 152   unsigned index;
 153   mc_smx_process_info_t process_info;
 154   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_process_infos, index, process_info)
 155     if (process_info->address == process_remote_address)
 156       return process_info;
 157   xbt_dynar_foreach_ptr(mc_model_checker->process.smx_old_process_infos, index, process_info)
 158     if (process_info->address == process_remote_address)
 159       return process_info;
 160   xbt_die("Process info not found");
 161 }
 162
 163 const char* MC_smx_process_get_host_name(smx_process_t p)
 164 {
 165   if (MC_process_is_self(&mc_model_checker->process))
 166     return SIMIX_host_get_name(p->smx_host);
 167
 168   mc_process_t process = &mc_model_checker->process;
 169
 170   // Currently, smx_host_t = xbt_dictelm_t.
 171   // TODO, add an static_assert on this if switching to C++
 172   // The host name is host->key and the host->key_len==strlen(host->key).
 173   s_xbt_dictelm_t host_copy;
 174   mc_smx_process_info_t info = MC_smx_process_get_info(p);
 175   if (!info->hostname) {
 176
 177     // Read the hostname from the MCed process:
 178     MC_process_read_simple(process, &host_copy, p->smx_host, sizeof(host_copy));
 179     int len = host_copy.key_len + 1;
 180     char hostname[len];
 181     MC_process_read_simple(process, hostname, host_copy.key, len);
 182
 183     // Lookup the host name in the dictionary (or create it):
 184     xbt_dictelm_t elt = xbt_dict_get_elm_or_null(mc_model_checker->hosts, hostname);
 185     if (!elt) {
 186       xbt_mheap_t heap = mmalloc_set_current_heap(mc_heap);
 187       xbt_dict_set(mc_model_checker->hosts, hostname, NULL, NULL);
 188       elt = xbt_dict_get_elm_or_null(mc_model_checker->hosts, hostname);
 189       assert(elt);
 190       mmalloc_set_current_heap(heap);
 191     }
 192
 193     info->hostname = elt->key;
 194   }
 195   return info->hostname;
 196 }