Add model mutex, make var_pool const by default

4 files changed, 49 insertions, 25 deletions

diff --git a/build2/config/init.cxx b/build2/config/init.cxx
index d6cbe74..1f0b391 100644
--- a/build2/config/init.cxx
+++ b/build2/config/init.cxx
@@ -38,6 +38,8 @@ namespace build2
       rs.meta_operations.insert (configure_id, configure);
       rs.meta_operations.insert (disfigure_id, disfigure);
 
+      auto& vp (var_pool.rw (rs));
+
       // Load config.build if one exists.
       //
       // Note that we have to do this during bootstrap since the order in
@@ -45,7 +47,7 @@ namespace build2
       // possible that some module which needs the configuration will get
       // called first.
       //
-      const variable& c_v (var_pool.insert<uint64_t> ("config.version"));
+      const variable& c_v (vp.insert<uint64_t> ("config.version"));
 
       // Don't load it if we are disfiguring. This is a bit tricky since the
       // build2 core may not yet know it is disfiguring. But we know.
@@ -68,7 +70,7 @@ namespace build2
           {
             // Assume missing version is 0.
             //
-            auto p (extract_variable (f, c_v.name.c_str ()));
+            auto p (extract_variable (f, c_v));
             uint64_t v (p.second ? cast<uint64_t> (p.first) : 0);
 
             if (v != module::version)
@@ -80,7 +82,7 @@ namespace build2
                          << out_root;
           }
 
-          source (f, rs, rs);
+          source (rs, rs, f);
         }
       }
     }
diff --git a/build2/config/operation.cxx b/build2/config/operation.cxx
index f74136c..175338a 100644
--- a/build2/config/operation.cxx
+++ b/build2/config/operation.cxx
@@ -82,7 +82,7 @@ namespace build2
 
         ofs << "config.version = " << module::version << endl;
 
-        if (auto l = root.vars["amalgamation"])
+        if (auto l = root.vars[var_amalgamation])
         {
           const dir_path& d (cast<dir_path> (l));
 
@@ -325,7 +325,7 @@ namespace build2
 
       // Configure subprojects that have been loaded.
       //
-      if (auto l = root.vars["subprojects"])
+      if (auto l = root.vars[var_subprojects])
       {
         for (auto p: cast<subprojects> (l))
         {
@@ -345,13 +345,13 @@ namespace build2
     }
 
     static void
-    configure_match (action, action_targets&)
+    configure_match (ulock&, action, action_targets&)
     {
       // Don't match anything -- see execute ().
     }
 
     static void
-    configure_execute (action a, const action_targets& ts, bool)
+    configure_execute (ulock& ml, action a, const action_targets& ts, bool)
     {
       // Match rules to configure every operation supported by each
       // project. Note that we are not calling operation_pre/post()
@@ -360,6 +360,10 @@ namespace build2
       //
       set<scope*> projects;
 
+      // Relock for shared access.
+      //
+      ml.unlock ();
+
       for (void* v: ts)
       {
         target& t (*static_cast<target*> (v));
@@ -368,6 +372,9 @@ namespace build2
         if (rs == nullptr)
           fail << "out of project target " << t;
 
+        slock sl (*ml.mutex ());
+        model_lock = &sl; // @@ Guard?
+
         for (operations::size_type id (default_id + 1); // Skip default_id
              id < rs->operations.size ();
              ++id)
@@ -379,11 +386,15 @@ namespace build2
           set_current_oif (*oif);
           dependency_count = 0;
 
-          match (action (configure_id, id), t);
+          match (sl, action (configure_id, id), t);
         }
 
+        model_lock = nullptr;
+
         configure_project (a, *rs, projects);
       }
+
+      ml.lock ();
     }
 
     const meta_operation_info configure {
@@ -414,8 +425,9 @@ namespace build2
     }
 
     static void
-    disfigure_load (const path& bf,
+    disfigure_load (ulock&,
                     scope&,
+                    const path& bf,
                     const dir_path&,
                     const dir_path&,
                     const location&)
@@ -425,7 +437,8 @@ namespace build2
     }
 
     static void
-    disfigure_search (scope& root,
+    disfigure_search (ulock&,
+                      scope& root,
                       const target_key&,
                       const location&,
                       action_targets& ts)
@@ -436,7 +449,9 @@ namespace build2
     }
 
     static void
-    disfigure_match (action, action_targets&) {}
+    disfigure_match (ulock&, action, action_targets&)
+    {
+    }
 
     static bool
     disfigure_project (action a, scope& root, set<scope*>& projects)
@@ -457,7 +472,7 @@ namespace build2
       // Disfigure subprojects. Since we don't load buildfiles during
       // disfigure, we do it for all known subprojects.
       //
-      if (auto l = root.vars["subprojects"])
+      if (auto l = root.vars[var_subprojects])
       {
         for (auto p: cast<subprojects> (l))
         {
@@ -475,7 +490,7 @@ namespace build2
           {
             bootstrap_out (nroot);
 
-            value& val (nroot.assign ("src_root"));
+            value& val (nroot.assign (var_src_root));
 
             if (!val)
               val = is_src_root (out_nroot) ? out_nroot : (src_root / pd);
@@ -550,7 +565,7 @@ namespace build2
     }
 
     static void
-    disfigure_execute (action a, const action_targets& ts, bool quiet)
+    disfigure_execute (ulock&, action a, const action_targets& ts, bool quiet)
     {
       tracer trace ("disfigure_execute");
 
diff --git a/build2/config/utility b/build2/config/utility
index 6c18715..e4e463d 100644
--- a/build2/config/utility
+++ b/build2/config/utility
@@ -44,6 +44,8 @@ namespace build2
               bool override = false,
               uint64_t save_flags = 0);
 
+    // Note that the variable is expected to have already been registered.
+    //
     template <typename T>
     inline pair<lookup, bool>
     required (scope& root,
@@ -76,6 +78,8 @@ namespace build2
     pair<lookup, bool>
     omitted (scope& root, const variable&);
 
+    // Note that the variable is expected to have already been registered.
+    //
     inline pair<lookup, bool>
     omitted (scope& root, const string& name)
     {
@@ -91,10 +95,12 @@ namespace build2
     lookup
     optional (scope& root, const variable&);
 
+    // Note that the variable is expected to have already been registered.
+    //
     inline lookup
-    optional (scope& root, const string& var)
+    optional (scope& root, const string& name)
     {
-      return optional (root, var_pool[var]);
+      return optional (root, var_pool[name]);
     }
 
     // Check whether there are any variables specified from the config
diff --git a/build2/config/utility.cxx b/build2/config/utility.cxx
index 7a3fa9c..7db4555 100644
--- a/build2/config/utility.cxx
+++ b/build2/config/utility.cxx
@@ -72,9 +72,10 @@ namespace build2
       // any original values, they will be "visible"; see find_override() for
       // details.
       //
+      const variable& vns (var_pool.rw (r).insert (ns));
       for (scope* s (&r); s != nullptr; s = s->parent_scope ())
       {
-        for (auto p (s->vars.find_namespace (ns));
+        for (auto p (s->vars.find_namespace (vns));
              p.first != p.second;
              ++p.first)
         {
@@ -92,30 +93,30 @@ namespace build2
     }
 
     bool
-    unconfigured (scope& root, const string& ns)
+    unconfigured (scope& rs, const string& ns)
     {
       // Note: not overridable.
       //
-      const variable& var (var_pool.insert<bool> (ns + ".configured"));
+      const variable& var (var_pool.rw (rs).insert<bool> (ns + ".configured"));
 
       if (current_mif->id == configure_id)
-        save_variable (root, var);
+        save_variable (rs, var);
 
-      auto l (root[var]); // Include inherited values.
+      auto l (rs[var]); // Include inherited values.
       return l && !cast<bool> (l);
     }
 
     bool
-    unconfigured (scope& root, const string& ns, bool v)
+    unconfigured (scope& rs, const string& ns, bool v)
     {
       // Note: not overridable.
       //
-      const variable& var (var_pool.insert<bool> (ns + ".configured"));
+      const variable& var (var_pool.rw (rs).insert<bool> (ns + ".configured"));
 
       if (current_mif->id == configure_id)
-        save_variable (root, var);
+        save_variable (rs, var);
 
-      value& x (root.assign (var));
+      value& x (rs.assign (var));
 
       if (x.null || cast<bool> (x) != !v)
       {