src/threading/thread.h

/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "filesys.h"
#include "util/string.h"
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fstream>
#include "log.h"
#include "config.h"

namespace fs
{

#ifdef _WIN32 // WINDOWS

#define _WIN32_WINNT 0x0501
#include <windows.h>

std::vector<DirListNode> GetDirListing(std::string pathstring)
{
	std::vector<DirListNode> listing;

	WIN32_FIND_DATA FindFileData;
	HANDLE hFind = INVALID_HANDLE_VALUE;
	DWORD dwError;

	std::string dirSpec = pathstring + "\\*";
	
	// Find the first file in the directory.
	hFind = FindFirstFile(dirSpec.c_str(), &FindFileData);

	if (hFind == INVALID_HANDLE_VALUE) {
		dwError = GetLastError();
		if (dwError != ERROR_FILE_NOT_FOUND && dwError != ERROR_PATH_NOT_FOUND) {
			errorstream << "GetDirListing: FindFirstFile error."
					<< " Error is " << dwError << std::endl;
		}
	} else {
		// NOTE:
		// Be very sure to not include '..' in the results, it will
		// result in an epic failure when deleting stuff.

		DirListNode node;
		node.name = FindFileData.cFileName;
		node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
		if (node.name != "." && node.name != "..")
			listing.push_back(node);

		// List all the other files in the directory.
		while (FindNextFile(hFind, &FindFileData) != 0) {
			DirListNode node;
			node.name = FindFileData.cFileName;
			node.dir = FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
			if(node.name != "." && node.name != "..")
				listing.push_back(node);
		}

		dwError = GetLastError();
		FindClose(hFind);
		if (dwError != ERROR_NO_MORE_FILES) {
			errorstream << "GetDirListing: FindNextFile error."
					<< " Error is " << dwError << std::endl;
			listing.clear();
			return listing;
 		}
	}
	return listing;
}

bool CreateDir(std::string path)
{
	bool r = CreateDirectory(path.c_str(), NULL);
	if(r == true)
		return true;
	if(GetLastError() == ERROR_ALREADY_EXISTS)
		return true;
	return false;
}

bool PathExists(std::string path)
{
	return (GetFileAttributes(path.c_str()) != INVALID_FILE_ATTRIBUTES);
}

bool IsDir(std::string path)
{
	DWORD attr = GetFileAttributes(path.c_str());
	return (attr != INVALID_FILE_ATTRIBUTES &&
			(attr & FILE_ATTRIBUTE_DIRECTORY));
}

bool IsDirDelimiter(char c)
{
	return c == '/' || c == '\\';
}

bool RecursiveDelete(std::string path)
{
	infostream<<"Recursively deleting \""<<path<<"\""<<std::endl;

	DWORD attr = GetFileAttributes(path.c_str());
	bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
			(attr & FILE_ATTRIBUTE_DIRECTORY));
	if(!is_directory)
	{
		infostream<<"RecursiveDelete: Deleting file "<<path<<std::endl;
		//bool did = DeleteFile(path.c_str());
		bool did = true;
		if(!did){
			errorstream<<"RecursiveDelete: Failed to delete file "
					<<path<<std::endl;
			return false;
		}
	}
	else
	{
		infostream<<"RecursiveDelete: Deleting content of directory "
				<<path<<std::endl;
		std::vector<DirListNode> content = GetDirListing(path);
		for(int i=0; i<content.size(); i++){
			const DirListNode &n = content[i];
			std::string fullpath = path + DIR_DELIM + n.name;
			bool did = RecursiveDelete(fullpath);
			if(!did){
				errorstream<<"RecursiveDelete: Failed to recurse to "
						<<fullpath<<std::endl;
				return false;
			}
		}
		infostream<<"RecursiveDelete: Deleting directory "<<path<<std::endl;
		//bool did = RemoveDirectory(path.c_str();
		bool did = true;
		if(!did){
			errorstream<<"Failed to recursively delete directory "
					<<path<<std::endl;
			return false;
		}
	}
	return true;
}

bool DeleteSingleFileOrEmptyDirectory(std::string path)
{
	DWORD attr = GetFileAttributes(path.c_str());
	bool is_directory = (attr != INVALID_FILE_ATTRIBUTES &&
			(attr & FILE_ATTRIBUTE_DIRECTORY));
	if(!is_directory)
	{
		bool did = DeleteFile(path.c_str());
		return did;
	}
	else
	{
		bool did = RemoveDirectory(path.c_str());
		return did;
	}
}

std::string TempPath()
{
	DWORD bufsize = GetTempPath(0, "");
	if(bufsize == 0){
		errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
		return "";
	}
	std::vector<char> buf(bufsize);
	DWORD len = GetTempPath(bufsize, &buf[0]);
	if(len == 0 || len > bufsize){
		errorstream<<"GetTempPath failed, error = "<<GetLastError()<<std::endl;
		return "";
	}
	return std::string(buf.begin(), buf.begin() + len);
}

#else // POSIX

#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <unistd.h>

std::vector<DirListNode> GetDirListing(std::string pathstring)
{
	std::vector<DirListNode> listing;

	DIR *dp;
	struct dirent *dirp;
	if((dp = opendir(pathstring.c_str())) == NULL) {
		//infostream<<"Error("<<errno<<") opening "<<pathstring<<std::endl;
		return listing;
	}

	while ((dirp = readdir(dp)) != NULL) {
		// NOTE:
		// Be very sure to not include '..' in the results, it will
		// result in an epic failure when deleting stuff.
		if(strcmp(dirp->d_name, ".") == 0 || strcmp(dirp->d_name, "..") == 0)
			continue;

		DirListNode node;
		node.name = dirp->d_name;

		int isdir = -1; // -1 means unknown

		/*
			POSIX doesn't define d_type member of struct dirent and
			certain filesystems on glibc/Linux will only return
			DT_UNKNOWN for the d_type member.

			Also we don't know whether symlinks are directories or not.
		*/
#ifdef _DIRENT_HAVE_D_TYPE
		if(dirp->d_type != DT_UNKNOWN && dirp->d_type != DT_LNK)
			isdir = (dirp->d_type == DT_DIR);
#endif /* _DIRENT_HAVE_D_TYPE */

		/*
			Was d_type DT_UNKNOWN, DT_LNK or nonexistent?
			If so, try stat().
		*/
		if(isdir == -1) {
			struct stat statbuf;
			if (stat((pathstring + "/" + node.name).c_str(), &statbuf))
				continue;
			isdir = ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
		}
		node.dir = isdir;
		listing.push_back(node);
	}
	closedir(dp);

	return listing;
}

bool CreateDir(std::string path)
{
	int r = mkdir(path.c_str(), S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
	if(r == 0)
	{
		return true;
	}
	else
	{
		// If already exists, return true
		if(errno == EEXIST)
			return true;
		return false;
	}
}

bool PathExists(std::string path)
{
	struct stat st;
	return (stat(path.c_str(),&st) == 0);
}

bool IsDir(std::string path)
{
	struct stat statbuf;
	if(stat(path.c_str(), &statbuf))
		return false; // Actually error; but certainly not a directory
	return ((statbuf.st_mode & S_IFDIR) == S_IFDIR);
}

bool IsDirDelimiter(char c)
{
	return c == '/';
}

bool RecursiveDelete(std::string path)
{
	/*
		Execute the 'rm' command directly, by fork() and execve()
	*/
	
	infostream<<"Removing \""<<path<<"\""<<std::endl;

	//return false;
	
	pid_t child_pid = fork();

	if(child_pid == 0)
	{
		// Child
		char argv_data[3][10000];
		strcpy(argv_data[0], "/bin/rm");
		strcpy(argv_data[1], "-rf");
		strncpy(argv_data[2], path.c_str(), 10000);
		char *argv[4];
		argv[0] = argv_data[0];
		argv[1] = argv_data[1];
		argv[2] = argv_data[2];
		argv[3] = NULL;

		verbosestream<<"Executing '"<<argv[0]<<"' '"<<argv[1]<<"' '"
				<<argv[2]<<"'"<<std::endl;
		
		execv(argv[0], argv);
		
		// Execv shouldn't return. Failed.
		_exit(1);
	}
	else
	{
		// Parent
		int child_status;
		pid_t tpid;
		do{
			tpid = wait(&child_status);
			//if(tpid != child_pid) process_terminated(tpid);
		}while(tpid != child_pid);
		return (child_status == 0);
	}
}

bool DeleteSingleFileOrEmptyDirectory(std::string path)
{
	if(IsDir(path)){
		bool did = (rmdir(path.c_str()) == 0);
		if(!did)
			errorstream<<"rmdir errno: "<<errno<<": "<<strerror(errno)
					<<std::endl;
		return did;
	} else {
		bool did = (unlink(path.c_str()) == 0);
		if(!did)
			errorstream<<"unlink errno: "<<errno<<": "<<strerror(errno)
					<<std::endl;
		return did;
	}
}

std::string TempPath()
{
	/*
		Should the environment variables TMPDIR, TMP and TEMP
		and the macro P_tmpdir (if defined by stdio.h) be checked
		before falling back on /tmp?

		Probably not, because this function is intended to be
		compatible with lua's os.tmpname which under the default
		configuration hardcodes mkstemp("/tmp/lua_XXXXXX").
	*/
#ifdef __ANDROID__
	return DIR_DELIM "sdcard" DIR_DELIM PROJECT_NAME DIR_DELIM "tmp";
#else
	return DIR_DELIM "tmp";
#endif
}

#endif

void GetRecursiveSubPaths(std::string path, std::vector<std::string> &dst)
{
	std::vector<DirListNode> content = GetDirListing(path);
	for(unsigned int  i=0; i<content.size(); i++){
		const DirListNode &n = content[i];
		std::string fullpath = path + DIR_DELIM + n.name;
		dst.push_back(fullpath);
		if (n.dir) {
			GetRecursiveSubPaths(fullpath, dst);
		}
	}
}

bool DeletePaths(const std::vector<std::string> &paths)
{
	bool success = true;
	// Go backwards to succesfully delete the output of GetRecursiveSubPaths
	for(int i=paths.size()-1; i>=0; i--){
		const std::string &path = paths[i];
		bool did = DeleteSingleFileOrEmptyDirectory(path);
		if(!did){
			errorstream<<"Failed to delete "<<path<<std::endl;
			success = false;
		}
	}
	return success;
}

bool RecursiveDeleteContent(std::string path)
{
	infostream<<"Removing content of \""<<path<<"\""<<std::endl;
	std::vector<DirListNode> list = GetDirListing(path);
	for(unsigned int i=0; i<list.size(); i++)
	{
		if(trim(list[i].name) == "." || trim(list[i].name) == "..")
			continue;
		std::string childpath = path + DIR_DELIM + list[i].name;
		bool r = RecursiveDelete(childpath);
		if(r == false)
		{
			errorstream<<"Removing \""<<childpath<<"\" failed"<<std::endl;
			return false;
		}
	}
	return true;
}

bool CreateAllDirs(std::string path)
{

	std::vector<std::string> tocreate;
	std::string basepath = path;
	while(!PathExists(basepath))
	{
		tocreate.push_back(basepath);
		basepath = RemoveLastPathComponent(basepath);
		if(basepath.empty())
			break;
	}
	for(int i=tocreate.size()-1;i>=0;i--)
		if(!CreateDir(tocreate[i]))
			return false;
	return true;
}

bool CopyFileContents(std::string source, std::string target)
{
	FILE *sourcefile = fopen(source.c_str(), "rb");
	if(sourcefile == NULL){
		errorstream<<source<<": can't open for reading: "
			<<strerror(errno)<<std::endl;
		return false;
	}

	FILE *targetfile = fopen(target.c_str(), "wb");
	if(targetfile == NULL){
		errorstream<<target<<": can't open for writing: "
			<<strerror(errno)<<std::endl;
		fclose(sourcefile);
		return false;
	}

	size_t total = 0;
	bool retval = true;
	bool done = false;
	char readbuffer[BUFSIZ];
	while(!done){
		size_t readbytes = fread(readbuffer, 1,
				sizeof(readbuffer), sourcefile);
		total += readbytes;
		if(ferror(sourcefile)){
			errorstream<<source<<": IO error: "
				<<strerror(errno)<<std::endl;
			retval = false;
			done = true;
		}
		if(readbytes > 0){
			fwrite(readbuffer, 1, readbytes, targetfile);
		}
		if(feof(sourcefile) || ferror(sourcefile)){
			// flush destination file to catch write errors
			// (e.g. disk full)
			fflush(targetfile);
			done = true;
		}
		if(ferror(targetfile)){
			errorstream<<target<<": IO error: "
					<<strerror(errno)<<std::endl;
			retval = false;
			done = true;
		}
	}
	infostream<<"copied "<<total<<" bytes from "
		<<source<<" to "<<target<<std::endl;
	fclose(sourcefile);
	fclose(targetfile);
	return retval;
}

bool CopyDir(std::string source, std::string target)
{
	if(PathExists(source)){
		if(!PathExists(target)){
			fs::CreateAllDirs(target);
		}
		bool retval = true;
		std::vector<DirListNode> content = fs::GetDirListing(source);

		for(unsigned int i=0; i < content.size(); i++){
			std::string sourcechild = source + DIR_DELIM + content[i].name;
			std::string targetchild = target + DIR_DELIM + content[i].name;
			if(content[i].dir){
				if(!fs::CopyDir(sourcechild, targetchild)){
					retval = false;
				}
			}
			else {
				if(!fs::CopyFileContents(sourcechild, targetchild)){
					retval = false;
				}
			}
		}
		return retval;
	}
	else {
		return false;
	}
}

bool PathStartsWith(std::string path, std::string prefix)
{
	size_t pathsize = path.size();
	size_t pathpos = 0;
	size_t prefixsize = prefix.size();
	size_t prefixpos = 0;
	for(;;){
		bool delim1 = pathpos == pathsize
			|| IsDirDelimiter(path[pathpos]);
		bool delim2 = prefixpos == prefixsize
			|| IsDirDelimiter(prefix[prefixpos]);

		if(delim1 != delim2)
			return false;

		if(delim1){
			while(pathpos < pathsize &&
					IsDirDelimiter(path[pathpos]))
				++pathpos;
			while(prefixpos < prefixsize &&
					IsDirDelimiter(prefix[prefixpos]))
				++prefixpos;
			if(prefixpos == prefixsize)
				return true;
			if(pathpos == pathsize)
				return false;
		}
		else{
			size_t len = 0;
			do{
				char pathchar = path[pathpos+len];
				char prefixchar = prefix[prefixpos+len];
				if(FILESYS_CASE_INSENSITIVE){
					pathchar = tolower(pathchar);
					prefixchar = tolower(prefixchar);
				}
				if(pathchar != prefixchar)
					return false;
				++len;
			} while(pathpos+len < pathsize
					&& !IsDirDelimiter(path[pathpos+len])
					&& prefixpos+len < prefixsize
					&& !IsDirDelimiter(
						prefix[prefixpos+len]));
			pathpos += len;
			prefixpos += len;
		}
	}
}

std::string RemoveLastPathComponent(std::string path,
		std::string *removed, int count)
{
	if(removed)
		*removed = "";

	size_t remaining = path.size();

	for(int i = 0; i < count; ++i){
		// strip a dir delimiter
		while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
			remaining--;
		// strip a path component
		size_t component_end = remaining;
		while(remaining != 0 && !IsDirDelimiter(path[remaining-1]))
			remaining--;
		size_t component_start = remaining;
		// strip a dir delimiter
		while(remaining != 0 && IsDirDelimiter(path[remaining-1]))
			remaining--;
		if(removed){
			std::string component = path.substr(component_start,
					component_end - component_start);
			if(i)
				*removed = component + DIR_DELIM + *removed;
			else
				*removed = component;
		}
	}
	return path.substr(0, remaining);
}

std::string RemoveRelativePathComponents(std::string path)
{
	size_t pos = path.size();
	size_t dotdot_count = 0;
	while(pos != 0){
		size_t component_with_delim_end = pos;
		// skip a dir delimiter
		while(pos != 0 && IsDirDelimiter(path[pos-1]))
			pos--;
		// strip a path component
		size_t component_end = pos;
		while(pos != 0 && !IsDirDelimiter(path[pos-1]))
			pos--;
		size_t component_start = pos;

		std::string component = path.substr(component_start,
				component_end - component_start);
		bool remove_this_component = false;
		if(component == "."){
			remove_this_component = true;
		}
		else if(component == ".."){
			remove_this_component = true;
			dotdot_count += 1;
		}
		else if(dotdot_count != 0){
			remove_this_component = true;
			dotdot_count -= 1;
		}

		if(remove_this_component){
			while(pos != 0 && IsDirDelimiter(path[pos-1]))
				pos--;
			path = path.substr(0, pos) + DIR_DELIM +
				path.substr(component_with_delim_end,
						std::string::npos);
			pos++;
		}
	}

	if(dotdot_count > 0)
		return "";

	// remove trailing dir delimiters
	pos = path.size();
	while(pos != 0 && IsDirDelimiter(path[pos-1]))
		pos--;
	return path.substr(0, pos);
}

bool safeWriteToFile(const std::string &path, const std::string &content)
{
	std::string tmp_file = path + ".~mt";

	// Write to a tmp file
	std::ofstream os(tmp_file.c_str(), std::ios::binary);
	if (!os.good())
		return false;
	os << content;
	os.flush();
	os.close();
	if (os.fail()) {
		remove(tmp_file.c_str());
		return false;
	}

	// Copy file
	remove(path.c_str());
	if(rename(tmp_file.c_str(), path.c_str())) {
		remove(tmp_file.c_str());
		return false;
	} else {
		return true;
	}
}

} // namespace fs
	Commit message (Collapse)	Author	Age
*	Remove Thread::kill() and related unittest (#10317)	Sebastien Marie	2020-09-10
\| \| \| \|	Closes: #6065
*	Complete Haiku platform support. (#10311)	David CARLIER	2020-08-23
\| \| \| \| \|	Fixing linkage/libraries missing issue. Implements missing platform specifics.
*	Fix 5 issues reported by PVS studio	Loic Blot	2018-04-04
\| \| \| \| \| \| \| \|	* src/sky.cpp 146 warn V519 The 'suncolor_f.r' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 142, 146. * src/sky.cpp 147 warn V519 The 'suncolor_f.g' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 143, 147. * src/sky.cpp 148 warn V519 The 'suncolor_f.b' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 144, 148. * src/threading/thread.cpp 63 err V730 Not all members of a class are initialized inside the constructor. Consider inspecting: m_thread_obj. * src/server.cpp 3243 err V595 The 'log' pointer was utilized before it was verified against nullptr. Check lines: 3243, 3258.
*	C++11 cleanup on constructors (#6000)	Vincent Glize	2017-06-19
\| \| \| \|	* C++11 cleanup on constructors dir script
*	Remove threads.h and replace its definitions with their C++11 equivalents ↵	ShadowNinja	2017-06-11
\| \| \| \| \| \|	(#5957) This also changes threadProc's signature, since C++11 supports arbitrary thread function signatures.
*	C++11 patchset 5: use std::threads and remove old compat layer (#5928)	Loïc Blot	2017-06-08
\| \| \| \| \| \| \|	* C++11 patchset 5: use std::threads and remove old compat layer * use pragma once in modified headers * use C++11 function delete for object copy
*	Use C++11 mutexes only (remove compat code) (#5922)	Loïc Blot	2017-06-06
\| \| \| \|	* Fix event LINT & remove default constructor/destructors * remove compat code & modernize autolock header
*	C++11 patchset 3: remove Atomic/GenericAtomic and use std::atomic (#5906)	Loïc Blot	2017-06-06
\|
*	Fix synchronization issue at thread start	ShadowNinja	2017-01-28
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	If a newly spawned thread called getThreadId or getThreadHandle before the spawning thread finished saving the thread handle, then the handle/id would be used uninitialized. This would cause the threading tests to fail since isCurrentThread would return false, and if Minetest is built with C++11 support the std::thread object pointer would be dereferenced while ininitialized, causing a segmentation fault. This fixes the issue by using a mutex to force the spawned thread to wait for the spawning thread to finish initializing the thread object. An alternative way to handle this would be to also set the thread handle/id in the started thread but this wouldn't work for C++11 builds because there's no way to get the partially constructed object.
*	Fix C++11 Windows build of threading code	sfan5	2016-10-06
\| \| \| \| \| \| \|	The initial problem was that mutex_auto_lock.h tries to use std::unique_lock<std::mutex> despite mutex.h not using C++11's std::mutex on Windows. The problem here is the mismatch between C++11 usage conditions of the two headers. This commit moves the decision logic to threads.h and makes sure mutex.h, mutex_auto_lock.h and event.h all use the same features.
*	Fix prepreprocessor error in thread.h (related to C++11 threads)	Craig Robbins	2016-04-30
\|
*	Fix race on thread creation	ShadowNinja	2016-04-28
\| \| \| \|	This often broke the threading tests on OSX.
*	Rename and move basicmacros.h to util/basic_macros.h	est31	2015-11-02
\|
*	Fix C++11 compatibility	kwolekr	2015-10-31
\|
*	Add DISABLE_CLASS_COPY macro (and use it)	kwolekr	2015-10-27
\| \| \| \| \| \| \| \| \|	Use this macro to disallow copying of an object using the assignment operator or copy constructor. This catches otherwise silent-but-deadly mistakes such as "ServerMap map = env->getMap();" at compile time. If so desired, it is still possible to copy a class, but it now requires an explicit call to memcpy or std::copy.
*	Fix some threading things and add additional thread unittests	kwolekr	2015-10-24
\| \| \| \| \| \|	- Fix thread name reset on start() - Fully reset thread state on kill() - Add unittests to check for correct object states under various circumstances
*	Fix missing include on AIX	kwolekr	2015-10-17
\|
*	Refactor Thread class to improve readability and portability	kwolekr	2015-10-16
\| \| \| \| \| \| \| \| \|	- Fix some incompatibilities with obscure platforms (AIX and WinCE) - Clean up Thread class interface - Add m_ prefix to private member variables - Simplify platform-dependent logic, reducing preprocessor conditional clauses and improving readibility - Add Thread class documentation
*	Clean up threading	ShadowNinja	2015-08-23
	* Rename everything. * Strip J prefix. * Change UpperCamelCase functions to lowerCamelCase. * Remove global (!) semaphore count mutex on OSX. * Remove semaphore count getter (unused, unsafe, depended on internal API functions on Windows, and used a hack on OSX). * Add `Atomic<type>`. * Make `Thread` handle thread names. * Add support for C++11 multi-threading. * Combine pthread and win32 sources. * Remove `ThreadStarted` (unused, unneeded). * Move some includes from the headers to the sources. * Move all of `Event` into its header (allows inlining with no new includes). * Make `Event` use `Semaphore` (except on Windows). * Move some porting functions into `Thread`. * Integrate logging with `Thread`. * Add threading test.