1 files changed, 32 insertions, 14 deletions
diff --git a/src/util.cpp b/src/util.cpp
index a3e4b0acfb..6738bbc6e4 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -1,9 +1,10 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2016 The Bitcoin Core developers
+// Copyright (c) 2009-2017 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <util.h>
+#include <fs.h>
 
 #include <chainparamsbase.h>
 #include <random.h>
@@ -72,6 +73,7 @@
 
 #include <boost/algorithm/string/case_conv.hpp> // for to_lower()
 #include <boost/algorithm/string/predicate.hpp> // for startswith() and endswith()
+#include <boost/interprocess/sync/file_lock.hpp>
 #include <boost/program_options/detail/config_file.hpp>
 #include <boost/thread.hpp>
 #include <openssl/crypto.h>
@@ -187,11 +189,7 @@ static void DebugPrintInit()
 fs::path GetDebugLogPath()
 {
     fs::path logfile(gArgs.GetArg("-debuglogfile", DEFAULT_DEBUGLOGFILE));
-    if (logfile.is_absolute()) {
-        return logfile;
-    } else {
-        return GetDataDir() / logfile;
-    }
+    return AbsPathForConfigVal(logfile);
 }
 
 bool OpenDebugLog()
@@ -375,6 +373,27 @@ int LogPrintStr(const std::string &str)
     return ret;
 }
 
+bool LockDirectory(const fs::path& directory, const std::string lockfile_name, bool probe_only)
+{
+    fs::path pathLockFile = directory / lockfile_name;
+    FILE* file = fsbridge::fopen(pathLockFile, "a"); // empty lock file; created if it doesn't exist.
+    if (file) fclose(file);
+
+    try {
+        static std::map<std::string, boost::interprocess::file_lock> locks;
+        boost::interprocess::file_lock& lock = locks.emplace(pathLockFile.string(), pathLockFile.string().c_str()).first->second;
+        if (!lock.try_lock()) {
+            return false;
+        }
+        if (probe_only) {
+            lock.unlock();
+        }
+    } catch (const boost::interprocess::interprocess_exception& e) {
+        return error("Error while attempting to lock directory %s: %s", directory.string(), e.what());
+    }
+    return true;
+}
+
 /** Interpret string as boolean, for argument parsing */
 static bool InterpretBool(const std::string& strValue)
 {
@@ -602,11 +621,7 @@ void ClearDatadirCache()
 
 fs::path GetConfigFile(const std::string& confPath)
 {
-    fs::path pathConfigFile(confPath);
-    if (!pathConfigFile.is_complete())
-        pathConfigFile = GetDataDir(false) / pathConfigFile;
-
-    return pathConfigFile;
+    return AbsPathForConfigVal(fs::path(confPath), false);
 }
 
 void ArgsManager::ReadConfigFile(const std::string& confPath)
@@ -641,9 +656,7 @@ void ArgsManager::ReadConfigFile(const std::string& confPath)
 #ifndef WIN32
 fs::path GetPidFile()
 {
-    fs::path pathPidFile(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME));
-    if (!pathPidFile.is_complete()) pathPidFile = GetDataDir() / pathPidFile;
-    return pathPidFile;
+    return AbsPathForConfigVal(fs::path(gArgs.GetArg("-pid", BITCOIN_PID_FILENAME)));
 }
 
 void CreatePidFile(const fs::path &path, pid_t pid)
@@ -914,3 +927,8 @@ int64_t GetStartupTime()
 {
     return nStartupTime;
 }
+
+fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific)
+{
+    return fs::absolute(path, GetDataDir(net_specific));
+}