Resolve #11166 by mitigating (i.e. reducing the likelihood of) a possible external file system race in remove(), using a slight refinement of the patch supplied by Jeff Epler. Made no attempt to fix or mitigate the thread data race in the test program provided.

doc/release_history.html

@@ -40,7 +40,7 @@
 
 <h2>1.60.0</h2>
 <ul>
-  <li>Fix a race condition <code>unique_path</code> by applying
+  <li>Fix a race condition in <code>unique_path</code> by applying
   <a href="https://github.com/boostorg/filesystem/pull/15">pull request #15</a> 
   from Sebastian Redl. Also fixes
   <a href="unique_path%20Fails%20on%20Windows%20for%20Temporary%20User%20Profiles">
@@ -60,9 +60,12 @@
   <p dir="ltr">Fix <a href="https://svn.boost.org/trac/boost/ticket/11288">#11288</a>, <i>
   <font face="Arial">A patch to avoid redundant string allocations</font></i>, 
   by applying a patch submitted by Yevhen Ivannikov.</li>
-  <li>Fix #<a href="https://svn.boost.org/trac/boost/ticket/11175">11175</a>, 
+  <li>Fix <a href="https://svn.boost.org/trac/boost/ticket/11175">#11175</a>, 
   out-of-date documentation causing users to incorrectly expect that the library 
-  could be used with exceptions disabled.<br>
+  could be used with exceptions disabled.</li>
+  <li>Resolve <a href="https://svn.boost.org/trac/boost/ticket/11175">#11166</a> 
+  by mitigating (i.e. reducing the likelihood of) a possible external file 
+  system race in <code>remove()</code>.<br>
 &nbsp;</li>
 </ul>
 
@@ -319,7 +322,7 @@
 </ul>
 <hr>
 <p>Revised
-<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->31 August, 2015<!--webbot bot="Timestamp" endspan i-checksum="34633" --></p>
+<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->01 September, 2015<!--webbot bot="Timestamp" endspan i-checksum="39338" --></p>
 <p>&copy; Copyright Beman Dawes, 2011</p>
 <p> Use, modification, and distribution are subject to the Boost Software 
 License, Version 1.0. See <a href="http://www.boost.org/LICENSE_1_0.txt">

src/operations.cpp

@@ -333,11 +333,21 @@ namespace
     return fs::directory_iterator(p)== end_dir_itr;
   }
 
-  bool remove_directory(const path& p) // true if succeeds
-    { return BOOST_REMOVE_DIRECTORY(p.c_str()); }
+  bool not_found_error(int errval); // forward declaration
+
+  // only called if directory exists
+  bool remove_directory(const path& p) // true if succeeds or not found
+  { 
+    return BOOST_REMOVE_DIRECTORY(p.c_str())
+      || not_found_error(BOOST_ERRNO);  // mitigate possible file system race. See #11166
+  }
   
-  bool remove_file(const path& p) // true if succeeds
-    { return BOOST_DELETE_FILE(p.c_str()); }
+  // only called if file exists
+  bool remove_file(const path& p) // true if succeeds or not found
+  {
+    return BOOST_DELETE_FILE(p.c_str())
+      || not_found_error(BOOST_ERRNO);  // mitigate possible file system race. See #11166
+  }
   
   // called by remove and remove_all_aux
   bool remove_file_or_directory(const path& p, fs::file_type type, error_code* ec)
@@ -1534,7 +1544,7 @@ namespace detail
     // Since POSIX remove() is specified to work with either files or directories, in a
     // perfect world it could just be called. But some important real-world operating
     // systems (Windows, Mac OS X, for example) don't implement the POSIX spec. So
-    // remove_file_or_directory() is always called to kep it simple.
+    // remove_file_or_directory() is always called to keep it simple.
     return remove_file_or_directory(p, type, ec);
   }
 

test/issues/11166-remove-race.cpp

@@ -0,0 +1,38 @@
+#include <boost/filesystem.hpp>
+#include <boost/thread.hpp>
+#include <fstream>
+
+boost::condition_variable cond;
+boost::mutex mut;
+
+#define FNAME ("remove-test")
+void remover()
+{
+    while(1)
+    {
+        boost::filesystem::remove(FNAME);
+    }
+}
+
+void creater()
+{
+    for(int i=0; i<100000; i++) std::fstream(FNAME, std::fstream::out);
+}
+
+int main()
+{
+    boost::filesystem::remove(FNAME);
+    boost::filesystem::remove(FNAME);
+
+    std::cout <<
+        "If you got this far, it's OK to remove a file that doesn't exist\n"
+        "Now trying with one creator thread and two remover threads.\n"
+        "This is likely to crash after just a few seconds at most." <<
+        std::endl;
+
+    boost::thread c(creater), r1(remover), r2(remover);
+
+    c.join();
+    r1.interrupt(); r1.join();
+    r2.interrupt(); r2.join();
+}

test/issues/11228--filtered-recursive_directory_iterator-range.cpp

@@ -0,0 +1,25 @@
+#include <boost/filesystem.hpp>
+#include <boost/range.hpp>
+#include <boost/range/algorithm.hpp>
+#include <boost/range/adaptors.hpp>
+#include <vector>
+#include <iostream>
+
+namespace fs = boost::filesystem;
+using namespace boost::adaptors;
+
+int main() {
+    fs::recursive_directory_iterator beg("."), end;
+
+    auto fileFilter = [](fs::path const & path)
+    { 
+      return is_regular_file(path);
+    };
+
+    std::vector<fs::path> paths;
+    copy(boost::make_iterator_range(beg, end) | filtered(fileFilter),
+      std::back_inserter(paths));
+
+    for(auto& p : paths)
+        std::cout << p << "\n";
+}

test/msvc/common.props

@@ -12,7 +12,7 @@
       <WarningLevel>Level4</WarningLevel>
     </ClCompile>
     <Link>
-      <AdditionalLibraryDirectories>%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalLibraryDirectories>C:\boost\develop\stage\lib;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
     </Link>
   </ItemDefinitionGroup>
 </Project>

test/msvc/issue_test/issue_test.vcxproj

@@ -95,7 +95,7 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="..\..\issues\6638-global-init-fails-3.cpp" />
+    <ClCompile Include="..\..\issues\11166-remove-race.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

test/msvc/issues_test_static/issues_test_static.vcxproj

@@ -87,14 +87,14 @@
       </PrecompiledHeader>
       <WarningLevel>Level3</WarningLevel>
       <Optimization>Disabled</Optimization>
-      <PreprocessorDefinitions>BOOST_ALL_NO_LIB;BOOST_ALL_STATIC_LINK;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>BOOST_ALL_STATIC_LINK;WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <SDLCheck>true</SDLCheck>
       <AdditionalIncludeDirectories>../../../../..</AdditionalIncludeDirectories>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
-      <AdditionalLibraryDirectories />
+      <AdditionalLibraryDirectories>C:\boost\develop\stage\lib;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
     </Link>
     <PostBuildEvent>
       <Command>"$(TargetDir)\$(TargetName).exe"</Command>
@@ -154,9 +154,6 @@
       <OptimizeReferences>true</OptimizeReferences>
     </Link>
   </ItemDefinitionGroup>
-  <ItemGroup>
-    <ClCompile Include="..\..\issues\6638-global-init-fails-3.cpp" />
-  </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\filesystem_lib\filesystem_lib.vcxproj">
       <Project>{2c1770a4-4ac3-4102-9d36-e652dbb686d8}</Project>
@@ -165,6 +162,9 @@
       <Project>{3640605d-6f82-493d-879f-8f30762da554}</Project>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\issues\11166-remove-race.cpp" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>