/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2020 Cppcheck team.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "threadexecutor.h"

#include "config.h"
#include "cppcheck.h"
#include "cppcheckexecutor.h"
#include "importproject.h"
#include "settings.h"
#include "suppressions.h"

#include <algorithm>
#include <cerrno>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <utility>

#ifdef __SVR4 // Solaris
#include <sys/loadavg.h>
#endif
#ifdef THREADING_MODEL_FORK
#if defined(__linux__)
#include <sys/prctl.h>
#endif
#include <sys/select.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>
#endif
#ifdef THREADING_MODEL_WIN
#include <process.h>
#include <windows.h>
#endif

// required for FD_ZERO
using std::memset;

ThreadExecutor::ThreadExecutor(const std::map<std::string, std::size_t> &files, Settings &settings, ErrorLogger &errorLogger)
 : mFiles(files), mSettings(settings), mErrorLogger(errorLogger), mFileCount(0)
 // Not initialized mFileSync, mErrorSync, mReportSync
{
#if defined(THREADING_MODEL_FORK)
 mWpipe = 0;
#elif defined(THREADING_MODEL_WIN)
 mProcessedFiles = 0;
 mTotalFiles = 0;
 mProcessedSize = 0;
 mTotalFileSize = 0;
#endif
}

ThreadExecutor::~ThreadExecutor()
{
 //dtor
}


///////////////////////////////////////////////////////////////////////////////
////// This code is for platforms that support fork() only ////////////////////
///////////////////////////////////////////////////////////////////////////////

#if defined(THREADING_MODEL_FORK)

void ThreadExecutor::addFileContent(const std::string &path, const std::string &content)
{
 mFileContents[ path ] = content;
}

int ThreadExecutor::handleRead(int rpipe, unsigned int &result)
{
 char type = 0;
 if (read(rpipe, &type, 1) <= 0) {
 if (errno == EAGAIN)
 return 0;

 return -1;
 }

 if (type != REPORT_OUT && type != REPORT_ERROR && type != REPORT_INFO && type != CHILD_END) {
 std::cerr << "#### ThreadExecutor::handleRead error, type was:" << type << std::endl;
 std::exit(0);
 }

 unsigned int len = 0;
 if (read(rpipe, &len, sizeof(len)) <= 0) {
 std::cerr << "#### ThreadExecutor::handleRead error, type was:" << type << std::endl;
 std::exit(0);
 }

 // Don't rely on incoming data being null-terminated.
 // Allocate +1 element and null-terminate the buffer.
 char *buf = new char[len + 1];
 const ssize_t readIntoBuf = read(rpipe, buf, len);
 if (readIntoBuf <= 0) {
 std::cerr << "#### ThreadExecutor::handleRead error, type was:" << type << std::endl;
 std::exit(0);
 }
 buf[readIntoBuf] = 0;

 if (type == REPORT_OUT) {
 mErrorLogger.reportOut(buf);
 } else if (type == REPORT_ERROR || type == REPORT_INFO) {
 ErrorMessage msg;
 msg.deserialize(buf);

 if (!mSettings.nomsg.isSuppressed(msg.toSuppressionsErrorMessage())) {
 // Alert only about unique errors
 std::string errmsg = msg.toString(mSettings.verbose);
 if (std::find(mErrorList.begin(), mErrorList.end(), errmsg) == mErrorList.end()) {
 mErrorList.emplace_back(errmsg);
 if (type == REPORT_ERROR)
 mErrorLogger.reportErr(msg);
 else
 mErrorLogger.reportInfo(msg);
 }
 }
 } else if (type == CHILD_END) {
 std::istringstream iss(buf);
 unsigned int fileResult = 0;
 iss >> fileResult;
 result += fileResult;
 delete [] buf;
 return -1;
 }

 delete [] buf;
 return 1;
}

bool ThreadExecutor::checkLoadAverage(size_t nchildren)
{
#if defined(__CYGWIN__) || defined(__QNX__) // getloadavg() is unsupported on Cygwin, Qnx.
 return true;
#else
 if (!nchildren || !mSettings.loadAverage) {
 return true;
 }

 double sample(0);
 if (getloadavg(&sample, 1) != 1) {
 // disable load average checking on getloadavg error
 return true;
 } else if (sample < mSettings.loadAverage) {
 return true;
 }
 return false;
#endif
}

unsigned int ThreadExecutor::check()
{
 mFileCount = 0;
 unsigned int result = 0;

 std::size_t totalfilesize = 0;
 for (std::map<std::string, std::size_t>::const_iterator i = mFiles.begin(); i != mFiles.end(); ++i) {
 totalfilesize += i->second;
 }

 std::list<int> rpipes;
 std::map<pid_t, std::string> childFile;
 std::map<int, std::string> pipeFile;
 std::size_t processedsize = 0;
 std::map<std::string, std::size_t>::const_iterator iFile = mFiles.begin();
 std::list<ImportProject::FileSettings>::const_iterator iFileSettings = mSettings.project.fileSettings.begin();
 for (;;) {
 // Start a new child
 size_t nchildren = rpipes.size();
 if ((iFile != mFiles.end() || iFileSettings != mSettings.project.fileSettings.end()) && nchildren < mSettings.jobs && checkLoadAverage(nchildren)) {
 int pipes[2];
 if (pipe(pipes) == -1) {
 std::cerr << "#### ThreadExecutor::check, pipe() failed: "<< std::strerror(errno) << std::endl;
 std::exit(EXIT_FAILURE);
 }

 int flags = 0;
 if ((flags = fcntl(pipes[0], F_GETFL, 0)) < 0) {
 std::cerr << "#### ThreadExecutor::check, fcntl(F_GETFL) failed: "<< std::strerror(errno) << std::endl;
 std::exit(EXIT_FAILURE);
 }

 if (fcntl(pipes[0], F_SETFL, flags | O_NONBLOCK) < 0) {
 std::cerr << "#### ThreadExecutor::check, fcntl(F_SETFL) failed: "<< std::strerror(errno) << std::endl;
 std::exit(EXIT_FAILURE);
 }

 pid_t pid = fork();
 if (pid < 0) {
 // Error
 std::cerr << "#### ThreadExecutor::check, Failed to create child process: "<< std::strerror(errno) << std::endl;
 std::exit(EXIT_FAILURE);
 } else if (pid == 0) {
#if defined(__linux__)
 prctl(PR_SET_PDEATHSIG, SIGHUP);
#endif
 close(pipes[0]);
 mWpipe = pipes[1];

 CppCheck fileChecker(*this, false, CppCheckExecutor::executeCommand);
 fileChecker.settings() = mSettings;
 unsigned int resultOfCheck = 0;

 if (iFileSettings != mSettings.project.fileSettings.end()) {
 resultOfCheck = fileChecker.check(*iFileSettings);
 } else if (!mFileContents.empty() && mFileContents.find(iFile->first) != mFileContents.end()) {
 // File content was given as a string
 resultOfCheck = fileChecker.check(iFile->first, mFileContents[ iFile->first ]);
 } else {
 // Read file from a file
 resultOfCheck = fileChecker.check(iFile->first);
 }

 std::ostringstream oss;
 oss << resultOfCheck;
 writeToPipe(CHILD_END, oss.str());
 std::exit(0);
 }

 close(pipes[1]);
 rpipes.push_back(pipes[0]);
 if (iFileSettings != mSettings.project.fileSettings.end()) {
 childFile[pid] = iFileSettings->filename + ' ' + iFileSettings->cfg;
 pipeFile[pipes[0]] = iFileSettings->filename + ' ' + iFileSettings->cfg;
 ++iFileSettings;
 } else {
 childFile[pid] = iFile->first;
 pipeFile[pipes[0]] = iFile->first;
 ++iFile;
 }
 } else if (!rpipes.empty()) {
 fd_set rfds;
 FD_ZERO(&rfds);
 for (std::list<int>::const_iterator rp = rpipes.begin(); rp != rpipes.end(); ++rp)
 FD_SET(*rp, &rfds);
 struct timeval tv; // for every second polling of load average condition
 tv.tv_sec = 1;
 tv.tv_usec = 0;
 int r = select(*std::max_element(rpipes.begin(), rpipes.end()) + 1, &rfds, nullptr, nullptr, &tv);

 if (r > 0) {
 std::list<int>::iterator rp = rpipes.begin();
 while (rp != rpipes.end()) {
 if (FD_ISSET(*rp, &rfds)) {
 int readRes = handleRead(*rp, result);
 if (readRes == -1) {
 std::size_t size = 0;
 std::map<int, std::string>::iterator p = pipeFile.find(*rp);
 if (p != pipeFile.end()) {
 std::string name = p->second;
 pipeFile.erase(p);
 std::map<std::string, std::size_t>::const_iterator fs = mFiles.find(name);
 if (fs != mFiles.end()) {
 size = fs->second;
 }
 }

 mFileCount++;
 processedsize += size;
 if (!mSettings.quiet)
 CppCheckExecutor::reportStatus(mFileCount, mFiles.size() + mSettings.project.fileSettings.size(), processedsize, totalfilesize);

 close(*rp);
 rp = rpipes.erase(rp);
 } else
 ++rp;
 } else
 ++rp;
 }
 }

 int stat = 0;
 pid_t child = waitpid(0, &stat, WNOHANG);
 if (child > 0) {
 std::string childname;
 std::map<pid_t, std::string>::iterator c = childFile.find(child);
 if (c != childFile.end()) {
 childname = c->second;
 childFile.erase(c);
 }

 if (WIFSIGNALED(stat)) {
 std::ostringstream oss;
 oss << "Internal error: Child process crashed with signal " << WTERMSIG(stat);

 std::list<ErrorMessage::FileLocation> locations;
 locations.emplace_back(childname, 0, 0);
 const ErrorMessage errmsg(locations,
 emptyString,
 Severity::error,
 oss.str(),
 "cppcheckError",
 false);

 if (!mSettings.nomsg.isSuppressed(errmsg.toSuppressionsErrorMessage()))
 mErrorLogger.reportErr(errmsg);
 }
 }
 } else {
 // All done
 break;
 }
 }


 return result;
}

void ThreadExecutor::writeToPipe(PipeSignal type, const std::string &data)
{
 unsigned int len = static_cast<unsigned int>(data.length() + 1);
 char *out = new char[ len + 1 + sizeof(len)];
 out[0] = static_cast<char>(type);
 std::memcpy(&(out[1]), &len, sizeof(len));
 std::memcpy(&(out[1+sizeof(len)]), data.c_str(), len);
 if (write(mWpipe, out, len + 1 + sizeof(len)) <= 0) {
 delete [] out;
 out = nullptr;
 std::cerr << "#### ThreadExecutor::writeToPipe, Failed to write to pipe" << std::endl;
 std::exit(0);
 }

 delete [] out;
}

void ThreadExecutor::reportOut(const std::string &outmsg)
{
 writeToPipe(REPORT_OUT, outmsg);
}

void ThreadExecutor::reportErr(const ErrorMessage &msg)
{
 writeToPipe(REPORT_ERROR, msg.serialize());
}

void ThreadExecutor::reportInfo(const ErrorMessage &msg)
{
 writeToPipe(REPORT_INFO, msg.serialize());
}

void ThreadExecutor::bughuntingReport(const std::string &str)
{
 writeToPipe(REPORT_VERIFICATION, str.c_str());
}

#elif defined(THREADING_MODEL_WIN)

void ThreadExecutor::addFileContent(const std::string &path, const std::string &content)
{
 mFileContents[path] = content;
}

unsigned int ThreadExecutor::check()
{
 HANDLE *threadHandles = new HANDLE[mSettings.jobs];

 mItNextFile = mFiles.begin();
 mItNextFileSettings = mSettings.project.fileSettings.begin();

 mProcessedFiles = 0;
 mProcessedSize = 0;
 mTotalFiles = mFiles.size() + mSettings.project.fileSettings.size();
 mTotalFileSize = 0;
 for (std::map<std::string, std::size_t>::const_iterator i = mFiles.begin(); i != mFiles.end(); ++i) {
 mTotalFileSize += i->second;
 }

 InitializeCriticalSection(&mFileSync);
 InitializeCriticalSection(&mErrorSync);
 InitializeCriticalSection(&mReportSync);

 for (unsigned int i = 0; i < mSettings.jobs; ++i) {
 threadHandles[i] = (HANDLE)_beginthreadex(nullptr, 0, threadProc, this, 0, nullptr);
 if (!threadHandles[i]) {
 std::cerr << "#### ThreadExecutor::check error, errno :" << errno << std::endl;
 exit(EXIT_FAILURE);
 }
 }

 const DWORD waitResult = WaitForMultipleObjects(mSettings.jobs, threadHandles, TRUE, INFINITE);
 if (waitResult != WAIT_OBJECT_0) {
 if (waitResult == WAIT_FAILED) {
 std::cerr << "#### ThreadExecutor::check wait failed, result: " << waitResult << " error: " << GetLastError() << std::endl;
 exit(EXIT_FAILURE);
 } else {
 std::cerr << "#### ThreadExecutor::check wait failed, result: " << waitResult << std::endl;
 exit(EXIT_FAILURE);
 }
 }

 unsigned int result = 0;
 for (unsigned int i = 0; i < mSettings.jobs; ++i) {
 DWORD exitCode;

 if (!GetExitCodeThread(threadHandles[i], &exitCode)) {
 std::cerr << "#### ThreadExecutor::check get exit code failed, error:" << GetLastError() << std::endl;
 exit(EXIT_FAILURE);
 }

 result += exitCode;

 if (!CloseHandle(threadHandles[i])) {
 std::cerr << "#### ThreadExecutor::check close handle failed, error:" << GetLastError() << std::endl;
 exit(EXIT_FAILURE);
 }
 }

 DeleteCriticalSection(&mFileSync);
 DeleteCriticalSection(&mErrorSync);
 DeleteCriticalSection(&mReportSync);

 delete[] threadHandles;

 return result;
}

unsigned int __stdcall ThreadExecutor::threadProc(void *args)
{
 unsigned int result = 0;

 ThreadExecutor *threadExecutor = static_cast<ThreadExecutor*>(args);
 std::map<std::string, std::size_t>::const_iterator &itFile = threadExecutor->mItNextFile;
 std::list<ImportProject::FileSettings>::const_iterator &itFileSettings = threadExecutor->mItNextFileSettings;

 // guard static members of CppCheck against concurrent access
 EnterCriticalSection(&threadExecutor->mFileSync);

 CppCheck fileChecker(*threadExecutor, false, CppCheckExecutor::executeCommand);
 fileChecker.settings() = threadExecutor->mSettings;

 for (;;) {
 if (itFile == threadExecutor->mFiles.end() && itFileSettings == threadExecutor->mSettings.project.fileSettings.end()) {
 LeaveCriticalSection(&threadExecutor->mFileSync);
 break;
 }

 std::size_t fileSize = 0;
 if (itFile != threadExecutor->mFiles.end()) {
 const std::string &file = itFile->first;
 fileSize = itFile->second;
 ++itFile;

 LeaveCriticalSection(&threadExecutor->mFileSync);

 const std::map<std::string, std::string>::const_iterator fileContent = threadExecutor->mFileContents.find(file);
 if (fileContent != threadExecutor->mFileContents.end()) {
 // File content was given as a string
 result += fileChecker.check(file, fileContent->second);
 } else {
 // Read file from a file
 result += fileChecker.check(file);
 }
 } else { // file settings..
 const ImportProject::FileSettings &fs = *itFileSettings;
 ++itFileSettings;
 LeaveCriticalSection(&threadExecutor->mFileSync);
 result += fileChecker.check(fs);
 if (threadExecutor->mSettings.clangTidy)
 fileChecker.analyseClangTidy(fs);
 }

 EnterCriticalSection(&threadExecutor->mFileSync);

 threadExecutor->mProcessedSize += fileSize;
 threadExecutor->mProcessedFiles++;
 if (!threadExecutor->mSettings.quiet) {
 EnterCriticalSection(&threadExecutor->mReportSync);
 CppCheckExecutor::reportStatus(threadExecutor->mProcessedFiles, threadExecutor->mTotalFiles, threadExecutor->mProcessedSize, threadExecutor->mTotalFileSize);
 LeaveCriticalSection(&threadExecutor->mReportSync);
 }
 }
 return result;
}

void ThreadExecutor::reportOut(const std::string &outmsg)
{
 EnterCriticalSection(&mReportSync);

 mErrorLogger.reportOut(outmsg);

 LeaveCriticalSection(&mReportSync);
}
void ThreadExecutor::reportErr(const ErrorMessage &msg)
{
 report(msg, MessageType::REPORT_ERROR);
}

void ThreadExecutor::reportInfo(const ErrorMessage &msg)
{

}

void ThreadExecutor::bughuntingReport(const std::string &/*str*/)
{
 // TODO
}

void ThreadExecutor::report(const ErrorMessage &msg, MessageType msgType)
{
 if (mSettings.nomsg.isSuppressed(msg.toSuppressionsErrorMessage()))
 return;

 // Alert only about unique errors
 bool reportError = false;
 const std::string errmsg = msg.toString(mSettings.verbose);

 EnterCriticalSection(&mErrorSync);
 if (std::find(mErrorList.begin(), mErrorList.end(), errmsg) == mErrorList.end()) {
 mErrorList.emplace_back(errmsg);
 reportError = true;
 }
 LeaveCriticalSection(&mErrorSync);

 if (reportError) {
 EnterCriticalSection(&mReportSync);

 switch (msgType) {
 case MessageType::REPORT_ERROR:
 mErrorLogger.reportErr(msg);
 break;
 case MessageType::REPORT_INFO:
 mErrorLogger.reportInfo(msg);
 break;
 }

 LeaveCriticalSection(&mReportSync);
 }
}

#else

void ThreadExecutor::addFileContent(const std::string &/*path*/, const std::string &/*content*/)
{

}

unsigned int ThreadExecutor::check()
{
 return 0;
}

void ThreadExecutor::reportOut(const std::string &/*outmsg*/)
{

}
void ThreadExecutor::reportErr(const ErrorMessage &/*msg*/)
{

}

void ThreadExecutor::reportInfo(const ErrorMessage &/*msg*/)
{

}

void ThreadExecutor::bughuntingReport(const std::string &/*str*/)
{
}

#endif