Also create pid file in non-daemon mode

Always make a pid file, not only when `-daemon` specified.

This is useful for troubleshooting, for attaching debuggers and loggers
and such.

- Write the pid file only after the datadir lock was acquired
- Don't create or remove a pid file on WIN32, and also don't show the option

src/bitcoind.cpp

@@ -129,7 +129,6 @@ bool AppInit(int argc, char* argv[])
             }
             if (pid > 0) // Parent process, pid is child process id
             {
-                CreatePidFile(GetPidFile(), pid);
                 return true;
             }
             // Child process falls through to rest of initialization

src/init.cpp

@@ -160,7 +160,9 @@ void Shutdown()
     if (pwalletMain)
         bitdb.Flush(true);
 #endif
+#ifndef WIN32
     boost::filesystem::remove(GetPidFile());
+#endif
     UnregisterAllWallets();
 #ifdef ENABLE_WALLET
     if (pwalletMain)
@@ -228,7 +230,9 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += "  -maxorphanblocks=<n>   " + strprintf(_("Keep at most <n> unconnectable blocks in memory (default: %u)"), DEFAULT_MAX_ORPHAN_BLOCKS) + "\n";
     strUsage += "  -maxorphantx=<n>       " + strprintf(_("Keep at most <n> unconnectable transactions in memory (default: %u)"), DEFAULT_MAX_ORPHAN_TRANSACTIONS) + "\n";
     strUsage += "  -par=<n>               " + strprintf(_("Set the number of script verification threads (%u to %d, 0 = auto, <0 = leave that many cores free, default: %d)"), -(int)boost::thread::hardware_concurrency(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS) + "\n";
+#ifndef WIN32
     strUsage += "  -pid=<file>            " + _("Specify pid file (default: bitcoind.pid)") + "\n";
+#endif
     strUsage += "  -reindex               " + _("Rebuild block chain index from current blk000??.dat files") + " " + _("on startup") + "\n";
 #if !defined(WIN32)
     strUsage += "  -sysperms              " + _("Create new files with system default permissions, instead of umask 077 (only effective with disabled wallet functionality)") + "\n";
@@ -714,7 +718,9 @@ bool AppInit2(boost::thread_group& threadGroup)
     static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
     if (!lock.try_lock())
         return InitError(strprintf(_("Cannot obtain a lock on data directory %s. Bitcoin Core is probably already running."), strDataDir));
-
+#ifndef WIN32
+    CreatePidFile(GetPidFile(), getpid());
+#endif
     if (GetBoolArg("-shrinkdebugfile", !fDebug))
         ShrinkDebugFile();
     LogPrintf("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");

src/util.cpp

@@ -472,6 +472,7 @@ void ReadConfigFile(map<string, string>& mapSettingsRet,
     ClearDatadirCache();
 }
 
+#ifndef WIN32
 boost::filesystem::path GetPidFile()
 {
     boost::filesystem::path pathPidFile(GetArg("-pid", "bitcoind.pid"));
@@ -479,7 +480,6 @@ boost::filesystem::path GetPidFile()
     return pathPidFile;
 }
 
-#ifndef WIN32
 void CreatePidFile(const boost::filesystem::path &path, pid_t pid)
 {
     FILE* file = fopen(path.string().c_str(), "w");

src/util.h

@@ -93,8 +93,8 @@ bool TryCreateDirectory(const boost::filesystem::path& p);
 boost::filesystem::path GetDefaultDataDir();
 const boost::filesystem::path &GetDataDir(bool fNetSpecific = true);
 boost::filesystem::path GetConfigFile();
-boost::filesystem::path GetPidFile();
 #ifndef WIN32
+boost::filesystem::path GetPidFile();
 void CreatePidFile(const boost::filesystem::path &path, pid_t pid);
 #endif
 void ReadConfigFile(std::map<std::string, std::string>& mapSettingsRet, std::map<std::string, std::vector<std::string> >& mapMultiSettingsRet);