From: Gabriel Corona <gabriel.corona@loria.fr>
Date: Fri, 19 Dec 2014 10:56:52 +0000 (+0100)
Subject: [mc] Add some FIXMEs for cross-process support
X-Git-Tag: v3_12~732^2~146
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/d63e6e420e35b2df639d3a774abb79d004608627

[mc] Add some FIXMEs for cross-process support
---

diff --git a/src/mc/mc_checkpoint.c b/src/mc/mc_checkpoint.c
index 1825cdc498..a4a83fea77 100644
--- a/src/mc/mc_checkpoint.c
+++ b/src/mc/mc_checkpoint.c
@@ -187,6 +187,8 @@ static void MC_region_restore(mc_mem_region_t region, mc_mem_region_t ref_region
   }
 }
 
+// FIXME, multiple privatisation regions
+// FIXME, cross-process
 static inline
 void* MC_privatization_address(mc_process_t process, int process_index)
 {
@@ -272,6 +274,7 @@ static void MC_get_memory_regions(mc_process_t process, mc_snapshot_t snapshot)
 
 #ifdef HAVE_SMPI
   if (smpi_privatize_global_variables && smpi_process_count()) {
+    // FIXME, cross-process
     snapshot->privatization_index = smpi_loaded_page;
   } else
 #endif
@@ -282,7 +285,7 @@ static void MC_get_memory_regions(mc_process_t process, mc_snapshot_t snapshot)
 
 /** \brief Fills the position of the segments (executable, read-only, read/write).
  *
- * TODO, use dl_iterate_phdr to be more robust
+ *  `dl_iterate_phdr` would be more robust but would not work in cross-process.
  * */
 void MC_find_object_address(memory_map_t maps, mc_object_info_t result)
 {
@@ -378,6 +381,7 @@ static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
       continue;
 
     int region_type;
+    // FIXME, get rid of `region_type`
     if ((long) stack_frame->ip > (long) process->libsimgrid_info->start_exec)
       region_type = 1;
     else
@@ -394,6 +398,7 @@ static void mc_fill_local_variables_values(mc_stack_frame_t stack_frame,
       new_var->address = current_variable->address;
     } else if (current_variable->locations.size != 0) {
       s_mc_location_t location;
+      // FIXME, cross-process support
       mc_dwarf_resolve_locations(&location, &current_variable->locations,
                                               current_variable->object_info,
                                               &(stack_frame->unw_cursor),
@@ -456,6 +461,7 @@ static xbt_dynar_t MC_unwind_stack_frames(void *stack_context)
   unw_cursor_t c;
 
   // TODO, check condition check (unw_init_local==0 means end of frame)
+  // FIXME, cross-process support
   if (unw_init_local(&c, (unw_context_t *) stack_context) != 0) {
 
     xbt_die("Could not initialize stack unwinding");
@@ -521,6 +527,7 @@ static xbt_dynar_t MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
   unsigned int cursor = 0;
   stack_region_t current_stack;
 
+  // FIXME, cross-process support (stack_areas)
   xbt_dynar_foreach(stacks_areas, cursor, current_stack) {
     mc_snapshot_stack_t st = xbt_new(s_mc_snapshot_stack_t, 1);
     st->stack_frames = MC_unwind_stack_frames(current_stack->context);
@@ -540,6 +547,7 @@ static xbt_dynar_t MC_take_snapshot_stacks(mc_snapshot_t * snapshot)
 
 }
 
+// FIXME, cross-process support (mc_heap_comparison_ignore)
 static xbt_dynar_t MC_take_snapshot_ignore()
 {
 
@@ -580,6 +588,7 @@ static void MC_snapshot_handle_ignore(mc_snapshot_t snapshot)
   // Copy the memory:
   unsigned int cursor = 0;
   mc_checkpoint_ignore_region_t region;
+  // FIXME, cross-process support (mc_checkpoint_ignore)
   xbt_dynar_foreach (mc_checkpoint_ignore, cursor, region) {
     s_mc_snapshot_ignored_data_t ignored_data;
     ignored_data.start = region->addr;
@@ -628,17 +637,18 @@ int mc_important_snapshot(mc_snapshot_t snapshot)
   return false;
 }
 
-static void MC_get_current_fd(mc_snapshot_t snapshot){
+static void MC_get_current_fd(mc_snapshot_t snapshot)
+{
 
   snapshot->total_fd = 0;
 
   const size_t fd_dir_path_size = 20;
   char fd_dir_path[fd_dir_path_size];
   if (snprintf(fd_dir_path, fd_dir_path_size,
-    "/proc/%lli/fd", (long long int) getpid()) > fd_dir_path_size)
+    "/proc/%lli/fd", (long long int) snapshot->process->pid) > fd_dir_path_size)
     xbt_die("Unexpected buffer is too small for fd_dir_path");
 
-  DIR* fd_dir = opendir (fd_dir_path);
+  DIR* fd_dir = opendir(fd_dir_path);
   if (fd_dir == NULL)
     xbt_die("Cannot open directory '/proc/self/fd'\n");
 
@@ -653,7 +663,8 @@ static void MC_get_current_fd(mc_snapshot_t snapshot){
 
     const size_t source_size = 25;
     char source[25];
-    if (snprintf(source, source_size, "/proc/self/fd/%s", fd_number->d_name) > source_size)
+    if (snprintf(source, source_size, "/proc/%lli/fd/%s",
+        (long long int) snapshot->process->pid, fd_number->d_name) > source_size)
       xbt_die("Unexpected buffer is too small for fd %s", fd_number->d_name);
 
     const size_t link_size = 200;
@@ -712,6 +723,7 @@ mc_snapshot_t MC_take_snapshot(int num_state)
 
   snapshot->enabled_processes = xbt_dynar_new(sizeof(int), NULL);
   smx_process_t process;
+  // FIXME, cross-process support (simix_global->process_list)
   xbt_swag_foreach(process, simix_global->process_list) {
     xbt_dynar_push_as(snapshot->enabled_processes, int, (int)process->pid);
   }
@@ -775,6 +787,9 @@ void MC_restore_snapshot_regions(mc_snapshot_t snapshot)
 #endif
 }
 
+// FIXME, cross-process support ~ we need to implement this on the app side
+// or use some form of [remote syscall execution](http://criu.org/Remote_syscall_execution)
+// based on [parasite code execution](http://criu.org/Parasite_code).
 static inline
 void MC_restore_snapshot_fds(mc_snapshot_t snapshot)
 {
diff --git a/src/mc/mc_global.c b/src/mc/mc_global.c
index e283c52d8d..fabab0ae63 100644
--- a/src/mc/mc_global.c
+++ b/src/mc/mc_global.c
@@ -181,6 +181,7 @@ void MC_init()
     MC_ignore_heap(mc_time, simix_process_maxpid * sizeof(double));
 
     smx_process_t process;
+    // FIXME, cross-process support (simix_global->process_list)
     xbt_swag_foreach(process, simix_global->process_list) {
       MC_ignore_heap(&(process->process_hookup),
                      sizeof(process->process_hookup));
diff --git a/src/mc/mc_ignore.c b/src/mc/mc_ignore.c
index 372bee5158..e16383a23e 100644
--- a/src/mc/mc_ignore.c
+++ b/src/mc/mc_ignore.c
@@ -61,6 +61,7 @@ static void checkpoint_ignore_region_free_voidp(void *r)
 
 /***********************************************************************/
 
+// FIXME, cross-process support? (or make this it is used on the app-side)
 void MC_ignore_heap(void *address, size_t size)
 {
   if(!std_heap)
@@ -175,6 +176,7 @@ void MC_remove_ignore_heap(void *address, size_t size)
 
 }
 
+// FIXME, cross-process support?
 void MC_ignore_global_variable(const char *name)
 {
   mc_process_t process = &mc_model_checker->process;
@@ -223,6 +225,7 @@ void MC_ignore_global_variable(const char *name)
  *  \param subprogram      (possibly inlined) Subprogram of the scope
  *  \param scope           Current scope
  */
+ // FIXME, cross-process support (messaging?)
 static void mc_ignore_local_variable_in_scope(const char *var_name,
                                               const char *subprogram_name,
                                               dw_frame_t subprogram,
@@ -230,7 +233,7 @@ static void mc_ignore_local_variable_in_scope(const char *var_name,
 {
   // Processing of direct variables:
 
-  // If the current subprogram matche the given name:
+  // If the current subprogram matches the given name:
   if (!subprogram_name ||
       (subprogram->name && strcmp(subprogram_name, subprogram->name) == 0)) {
 
@@ -314,7 +317,7 @@ void MC_ignore_local_variable(const char *var_name, const char *frame_name)
 /** @brief Register a stack in the model checker
  *
  *  The stacks are allocated in the heap. The MC handle them especially
- *  when we analyse/compare the content of theap so it must be told where
+ *  when we analyse/compare the content of the heap so it must be told where
  *  they are with this function.
  *
  *  @param stack
@@ -361,6 +364,7 @@ void MC_ignore(void *addr, size_t size)
 
   MC_SET_MC_HEAP;
 
+  // FIXME, cross-process support
   if (mc_checkpoint_ignore == NULL)
     mc_checkpoint_ignore =
         xbt_dynar_new(sizeof(mc_checkpoint_ignore_region_t),
diff --git a/src/mc/mc_liveness.c b/src/mc/mc_liveness.c
index 1b8c3dd163..f927f2fb56 100644
--- a/src/mc/mc_liveness.c
+++ b/src/mc/mc_liveness.c
@@ -33,7 +33,7 @@ static xbt_dynar_t get_atomic_propositions_values()
   unsigned int cursor = 0;
   xbt_automaton_propositional_symbol_t ps = NULL;
   xbt_dynar_t values = xbt_dynar_new(sizeof(int), NULL);
-
+  // FIXME, cross-process support
   xbt_dynar_foreach(_mc_property_automaton->propositional_symbols, cursor, ps) {
     f = (int_f_void_t) ps->function;
     res = f();
diff --git a/src/smpi/smpi_bench.c b/src/smpi/smpi_bench.c
index 72230dba95..7028ea3960 100644
--- a/src/smpi/smpi_bench.c
+++ b/src/smpi/smpi_bench.c
@@ -638,6 +638,7 @@ void smpi_really_switch_data_segment(int dest) {
     }
   }
 
+  // FIXME, cross-process support (mmap across process when necessary)
   int current = smpi_privatisation_regions[dest].file_descriptor;
   XBT_DEBUG("Switching data frame to the one of process %d", dest);
   void* tmp = mmap (TOPAGE(start_data_exe), size_data_exe, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, current, 0);