2 * \file ForkedCalls.cpp
3 * This file is part of LyX, the document processor.
4 * Licence details can be found in the file COPYING.
6 * \author Asger Alstrup
7 * \author Angus Leeming
8 * \author Alfredo Braunstein
10 * Full author contact details are available in file CREDITS.
15 #include "support/ForkedCalls.h"
17 #include "support/debug.h"
18 #include "support/filetools.h"
19 #include "support/lstrings.h"
20 #include "support/lyxlib.h"
21 #include "support/os.h"
22 #include "support/Timeout.h"
24 #include "support/bind.h"
44 # include <sys/wait.h>
56 /////////////////////////////////////////////////////////////////////
60 /////////////////////////////////////////////////////////////////////
62 class Murder : public boost::signals::trackable {
65 static void killItDead(int secs, pid_t pid)
68 new Murder(secs, pid);
70 support::kill(pid, SIGKILL);
77 support::kill(pid_, SIGKILL);
78 lyxerr << "Killed " << pid_ << endl;
84 Murder(int secs, pid_t pid)
85 : timeout_(1000*secs, Timeout::ONETIME), pid_(pid)
87 timeout_.timeout.connect(lyx::bind(&Murder::kill, this));
100 /////////////////////////////////////////////////////////////////////
104 /////////////////////////////////////////////////////////////////////
106 ForkedProcess::ForkedProcess()
107 : pid_(0), retval_(0)
111 bool ForkedProcess::IAmAChild = false;
114 void ForkedProcess::emitSignal()
117 signal_->operator()(pid_, retval_);
122 // Spawn the child process
123 int ForkedProcess::run(Starttype type)
126 pid_ = generateChild();
127 if (pid_ <= 0) { // child or fork failed.
130 //we also do this in fork(), too, but maybe someone will try
138 retval_ = waitForChild();
141 // Integrate into the Controller
142 ForkedCallsController::addCall(*this);
151 bool ForkedProcess::running() const
156 #if !defined (_WIN32)
157 // Un-UNIX like, but we don't have much use for
158 // knowing if a zombie exists, so just reap it first.
160 waitpid(pid(), &waitstatus, WNOHANG);
163 // Racy of course, but it will do.
164 if (support::kill(pid(), 0) && errno == ESRCH)
170 void ForkedProcess::kill(int tol)
172 lyxerr << "ForkedProcess::kill(" << tol << ')' << endl;
174 lyxerr << "Can't kill non-existent process!" << endl;
178 int const tolerance = max(0, tol);
179 if (tolerance == 0) {
181 Murder::killItDead(0, pid());
183 int ret = support::kill(pid(), SIGHUP);
185 // The process is already dead if wait_for_death is false
186 bool const wait_for_death = (ret == 0 && errno != ESRCH);
189 Murder::killItDead(tolerance, pid());
194 pid_t ForkedProcess::fork() {
195 #if !defined (HAVE_FORK)
198 pid_t pid = ::fork();
206 // Wait for child process to finish. Returns returncode from child.
207 int ForkedProcess::waitForChild()
209 // We'll pretend that the child returns 1 on all error conditions.
213 HANDLE const hProcess = HANDLE(pid_);
215 DWORD const wait_status = ::WaitForSingleObject(hProcess, INFINITE);
217 switch (wait_status) {
218 case WAIT_OBJECT_0: {
220 if (!GetExitCodeProcess(hProcess, &exit_code)) {
221 lyxerr << "GetExitCodeProcess failed waiting for child\n"
222 << getChildErrorMessage() << endl;
228 lyxerr << "WaitForSingleObject failed waiting for child\n"
229 << getChildErrorMessage() << endl;
237 pid_t waitrpid = waitpid(pid_, &status, WUNTRACED);
238 if (waitrpid == -1) {
239 lyxerr << "LyX: Error waiting for child:"
240 << strerror(errno) << endl;
242 } else if (WIFEXITED(status)) {
243 // Child exited normally. Update return value.
244 retval_ = WEXITSTATUS(status);
246 } else if (WIFSIGNALED(status)) {
247 lyxerr << "LyX: Child didn't catch signal "
249 << "and died. Too bad." << endl;
251 } else if (WIFSTOPPED(status)) {
252 lyxerr << "LyX: Child (pid: " << pid_
253 << ") stopped on signal "
255 << ". Waiting for child to finish." << endl;
257 lyxerr << "LyX: Something rotten happened while "
258 "waiting for child " << pid_ << endl;
267 /////////////////////////////////////////////////////////////////////
271 /////////////////////////////////////////////////////////////////////
273 ForkedCall::ForkedCall(string const & path)
274 : cmd_prefix_(to_filesystem8bit(from_utf8(latexEnvCmdPrefix(path))))
278 int ForkedCall::startScript(Starttype wait, string const & what)
281 retval_ = startScript(what, SignalTypePtr());
291 int ForkedCall::startScript(string const & what, SignalTypePtr signal)
296 return run(DontWait);
300 // generate child in background
301 int ForkedCall::generateChild()
303 string const line = trim(cmd_prefix_ + command_);
307 #if !defined (_WIN32)
310 // Split the input command up into an array of words stored
311 // in a contiguous block of memory. The array contains pointers
313 // Don't forget the terminating `\0' character.
314 char const * const c_str = line.c_str();
315 vector<char> vec(c_str, c_str + line.size() + 1);
317 // Splitting the command up into an array of words means replacing
318 // the whitespace between words with '\0'. Life is complicated
319 // however, because words protected by quotes can contain whitespace.
321 // The strategy we adopt is:
322 // 1. If we're not inside quotes, then replace white space with '\0'.
323 // 2. If we are inside quotes, then don't replace the white space
324 // but do remove the quotes themselves. We do this naively by
325 // replacing the quote with '\0' which is fine if quotes
326 // delimit the entire word.
327 char inside_quote = 0;
328 vector<char>::iterator it = vec.begin();
329 vector<char>::iterator const end = vec.end();
330 for (; it != end; ++it) {
335 else if (c == '\'' || c == '"') {
339 } else if (c == inside_quote) {
345 // Build an array of pointers to each word.
349 for (; it != end; ++it) {
350 if (*it != '\0' && prev == '\0')
351 argv.push_back(&*it);
357 if (lyxerr.debugging(Debug::FILES)) {
358 vector<char *>::iterator ait = argv.begin();
359 vector<char *>::iterator const aend = argv.end();
360 lyxerr << "<command>\n\t" << line
361 << "\n\tInterpretted as:\n\n";
362 for (; ait != aend; ++ait)
364 lyxerr << '\t'<< *ait << '\n';
365 lyxerr << "</command>" << endl;
368 pid_t const cpid = ::fork();
371 execvp(argv[0], &*argv.begin());
373 // If something goes wrong, we end up here
374 lyxerr << "execvp of \"" << command_ << "\" failed: "
375 << strerror(errno) << endl;
384 PROCESS_INFORMATION process;
386 memset(&startup, 0, sizeof(STARTUPINFO));
387 memset(&process, 0, sizeof(PROCESS_INFORMATION));
389 startup.cb = sizeof(STARTUPINFO);
391 if (CreateProcess(0, (LPSTR)line.c_str(), 0, 0, FALSE,
392 CREATE_NO_WINDOW, 0, 0, &startup, &process)) {
393 CloseHandle(process.hThread);
394 cpid = (pid_t)process.hProcess;
400 lyxerr << "Could not fork: " << strerror(errno) << endl;
407 /////////////////////////////////////////////////////////////////////
411 /////////////////////////////////////////////////////////////////////
413 namespace ForkedCallQueue {
415 /// A process in the queue
416 typedef pair<string, ForkedCall::SignalTypePtr> Process;
417 /** Add a process to the queue. Processes are forked sequentially
418 * only one is running at a time.
419 * Connect to the returned signal and you'll be informed when
420 * the process has ended.
422 ForkedCall::SignalTypePtr add(string const & process);
424 /// in-progress queue
425 static queue<Process> callQueue_;
427 /// flag whether queue is running
428 static bool running_ = 0;
435 void callback(pid_t, int);
437 ForkedCall::SignalTypePtr add(string const & process)
439 ForkedCall::SignalTypePtr ptr;
440 ptr.reset(new ForkedCall::SignalType);
441 callQueue_.push(Process(process, ptr));
450 if (callQueue_.empty())
452 Process pro = callQueue_.front();
454 // Bind our chain caller
455 pro.second->connect(lyx::bind(&ForkedCallQueue::callback, _1, _2));
457 //If we fail to fork the process, then emit the signal
458 //to tell the outside world that it failed.
459 if (call.startScript(pro.first, pro.second) > 0)
460 pro.second->operator()(0,1);
464 void callback(pid_t, int)
466 if (callQueue_.empty())
475 LYXERR(Debug::GRAPHICS, "ForkedCallQueue: waking up");
484 LYXERR(Debug::GRAPHICS, "ForkedCallQueue: I'm going to sleep");
493 } // namespace ForkedCallsQueue
497 /////////////////////////////////////////////////////////////////////
499 // ForkedCallsController
501 /////////////////////////////////////////////////////////////////////
504 string const getChildErrorMessage()
506 DWORD const error_code = ::GetLastError();
508 HLOCAL t_message = 0;
509 bool const ok = ::FormatMessage(
510 FORMAT_MESSAGE_ALLOCATE_BUFFER |
511 FORMAT_MESSAGE_FROM_SYSTEM,
513 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
514 (LPTSTR) &t_message, 0, 0
518 ss << "LyX: Error waiting for child: " << error_code;
521 ss << ": " << (LPTSTR)t_message;
522 ::LocalFree(t_message);
524 ss << ": Error unknown.";
531 namespace ForkedCallsController {
533 typedef shared_ptr<ForkedProcess> ForkedProcessPtr;
534 typedef list<ForkedProcessPtr> ListType;
535 typedef ListType::iterator iterator;
538 /// The child processes
539 static ListType forkedCalls;
541 iterator find_pid(pid_t pid)
543 return find_if(forkedCalls.begin(), forkedCalls.end(),
544 lyx::bind(equal_to<pid_t>(),
545 lyx::bind(&ForkedCall::pid, _1),
550 void addCall(ForkedProcess const & newcall)
552 forkedCalls.push_back(newcall.clone());
556 // Check the list of dead children and emit any associated signals.
557 void handleCompletedProcesses()
559 ListType::iterator it = forkedCalls.begin();
560 ListType::iterator end = forkedCalls.end();
562 ForkedProcessPtr actCall = *it;
563 bool remove_it = false;
566 HANDLE const hProcess = HANDLE(actCall->pid());
568 DWORD const wait_status = ::WaitForSingleObject(hProcess, 0);
570 switch (wait_status) {
574 case WAIT_OBJECT_0: {
576 if (!GetExitCodeProcess(hProcess, &exit_code)) {
577 lyxerr << "GetExitCodeProcess failed waiting for child\n"
578 << getChildErrorMessage() << endl;
579 // Child died, so pretend it returned 1
580 actCall->setRetValue(1);
582 actCall->setRetValue(exit_code);
584 CloseHandle(hProcess);
589 lyxerr << "WaitForSingleObject failed waiting for child\n"
590 << getChildErrorMessage() << endl;
591 actCall->setRetValue(1);
592 CloseHandle(hProcess);
597 pid_t pid = actCall->pid();
599 pid_t const waitrpid = waitpid(pid, &stat_loc, WNOHANG);
601 if (waitrpid == -1) {
602 lyxerr << "LyX: Error waiting for child: "
603 << strerror(errno) << endl;
605 // Child died, so pretend it returned 1
606 actCall->setRetValue(1);
609 } else if (waitrpid == 0) {
610 // Still running. Move on to the next child.
612 } else if (WIFEXITED(stat_loc)) {
613 // Ok, the return value goes into retval.
614 actCall->setRetValue(WEXITSTATUS(stat_loc));
617 } else if (WIFSIGNALED(stat_loc)) {
618 // Child died, so pretend it returned 1
619 actCall->setRetValue(1);
622 } else if (WIFSTOPPED(stat_loc)) {
623 lyxerr << "LyX: Child (pid: " << pid
624 << ") stopped on signal "
625 << WSTOPSIG(stat_loc)
626 << ". Waiting for child to finish." << endl;
629 lyxerr << "LyX: Something rotten happened while "
630 "waiting for child " << pid << endl;
632 // Child died, so pretend it returned 1
633 actCall->setRetValue(1);
639 forkedCalls.erase(it);
640 actCall->emitSignal();
642 /* start all over: emiting the signal can result
643 * in changing the list (Ab)
645 it = forkedCalls.begin();
653 // Kill the process prematurely and remove it from the list
654 // within tolerance secs
655 void kill(pid_t pid, int tolerance)
657 ListType::iterator it = find_pid(pid);
658 if (it == forkedCalls.end())
661 (*it)->kill(tolerance);
662 forkedCalls.erase(it);
665 } // namespace ForkedCallsController
667 } // namespace support