Minimal fix for #4243 -- import isn't thread safe

The import function was calling type_loader#import directly so that it could
pass in the current file name, but by doing so it was thwarting the thread-
safety locking level.  This patch rearanges things so that all imports go
through the same (thread safe) code path while retaining the current_file
passing, error handling, etc. from the old structure.

2 files changed, 14 insertions, 16 deletions

diff --git a/lib/puppet/parser/parser_support.rb b/lib/puppet/parser/parser_support.rb
index 4f3a4ddff..c0fd37178 100644
--- a/lib/puppet/parser/parser_support.rb
+++ b/lib/puppet/parser/parser_support.rb
@@ -111,7 +111,7 @@ class Puppet::Parser::Parser
   end
 
   def import(file)
-    known_resource_types.loader.import(file, @lexer.file)
+    known_resource_types.loader.import_if_possible(file, @lexer.file)
   end
 
   def initialize(env)
diff --git a/lib/puppet/parser/type_loader.rb b/lib/puppet/parser/type_loader.rb
index cb8657f0c..c33f90d11 100644
--- a/lib/puppet/parser/type_loader.rb
+++ b/lib/puppet/parser/type_loader.rb
@@ -70,7 +70,7 @@ class Puppet::Parser::TypeLoader
 
   def initialize(env)
     self.environment = env
-    @loaded = []
+    @loaded = {}
     @loading = Helper.new
 
     @imported = {}
@@ -79,10 +79,13 @@ class Puppet::Parser::TypeLoader
   def load_until(namespaces, name)
     return nil if name == "" # special-case main.
     name2files(namespaces, name).each do |filename|
-      modname = nil
-      import_if_possible(filename) do
-        modname = import(filename)
-        @loaded << filename
+      modname = begin
+        import_if_possible(filename)
+      rescue Puppet::ImportError => detail
+        # We couldn't load the item
+        # I'm not convienced we should just drop these errors, but this
+        # preserves existing behaviours.
+        nil
       end
       if result = yield(filename)
         Puppet.info "Automatically imported #{name} from #{filename}"
@@ -124,23 +127,18 @@ class Puppet::Parser::TypeLoader
     parser.parse
   end
 
-  private
-
   # Utility method factored out of load for handling thread-safety.
   # This isn't tested in the specs, because that's basically impossible.
-  def import_if_possible(file, &blk)
-    return if @loaded.include?(file)
-    begin
+  def import_if_possible(file, current_file = nil)
+    @loaded[file] || begin
       case @loading.owner_of(file)
       when :this_thread
-        return
+        nil
       when :another_thread
-        return import_if_possible(file, &blk)
+        import_if_possible(file,current_file)
       when :nobody
-        blk.call
+        @loaded[file] = import(file,current_file)
       end
-    rescue Puppet::ImportError => detail
-      # We couldn't load the item
     ensure
       @loading.done_with(file)
     end