Add support for asynchronous child processes on Windows.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_1_3_X@9843 a592a061-630c-0410-9148-cb99ea01b6c8

src/support/ChangeLog

@@ -1,3 +1,27 @@
+2005-04-19  Angus Leeming  <leeming@lyx.org>
+
+	* forkedcall.C: protect system-specific headers with preprocessor
+	guards.
+	(running): don't call waitpid() on Windows.
+	(waitForChild): add Windows-specific code to wait for a child process
+	to finish.
+	(generateChild): add Windows-specific code to spawn the child in the
+	first place.
+
+	* forkedcontr.[Ch]: remove cruft from the days of the dialog to kill
+	child processes. Class no longer derives from trackable, no longer
+	emits a global signal when a child process is reaped.
+	(getPIDs, getCommand): removed.
+
+	* forkedcontr.C: protect system-specific headers with preprocessor
+	guards. Add Windows-specific code to wait for a child process
+	asynchronously.
+	(getChildErrorMessage): new function, wrapping the Windows native API.
+	(timer): use WaitForSingleObject and GetExitCodeProcess on Windows.
+
+	* kill.C (kill): add Ruurd's Windows-specific code to terminate
+	a child process.
+
 2005-04-19  Angus Leeming  <leeming@lyx.org>
 
 	* package.C (get_temp_dir): call GetLongPathName on Windows.
@@ -40,7 +64,7 @@
 	* filetools.[Ch] (LibScriptSearch): backport the 1.4.x code so
 	that the function now substitutes the $$s placeholder for the
 	path to the appropriate LyX support directory.
-	
+
 	* forkedcall.C (generateChild): backport the 1.4.x code to split
 	the input command up into an array of words and to strip any quotes.
 
@@ -81,7 +105,7 @@
 
 	* FileInfo.h:
 	* chdir.C:
-	* forkedcall.C: 
+	* forkedcall.C:
 	* forkedcontr.C:
 	* getcwd.C:
 	* lyxsum.C:
@@ -191,7 +215,7 @@
 	file using mktemp and open.
 
 2004-12-14  Angus Leeming  <leeming@lyx.org>
- 
+
 	* os.h, os_os2.C, os_unix.C, os_win32.C:
 	(binpath, binname, getTmpDir): return a const reference rather than
 	a copy of the data.
@@ -213,7 +237,7 @@
 2004-12-14  Angus Leeming  <leeming@lyx.org>
 
 	* os.C: Add _WIN32 to the #define.
- 
+
 	* systemcall.C (startscript): remove trailing '/n' from request to
 	start the command in a minimized window under DOS.
 
@@ -257,9 +281,9 @@
 
 2003-03-06  Alfredo Braunstein <abraunst@libero.it>
 
-	* forkedcontr.C (timer): reworked the loop to allow running changes 
+	* forkedcontr.C (timer): reworked the loop to allow running changes
 	on the list.
-	
+
 2003-02-27  Ling Li  <ling@caltech.edu>
 
 	* lyxalgo.h (eliminate_duplicates): re-written to avoid the initial

src/support/forkedcall.C

@@ -30,19 +30,27 @@
 #include "lyxlib.h"
 #include "filetools.h"
 #include "os.h"
+
 #include "debug.h"
 #include "frontends/Timeout.h"
 
 #include <boost/bind.hpp>
 
 #include <vector>
-#include <cerrno>
+
-#include <sys/types.h>
+#ifdef _WIN32
-#include <sys/wait.h>
+# define SIGHUP 1
-#include <csignal>
+# define SIGKILL 9
-#include <cstdlib>
+# include <process.h>
-#ifdef HAVE_UNISTD_H
+# include <windows.h>
-#include <unistd.h>
+
+#else
+# include <cerrno>
+# include <csignal>
+# include <cstdlib>
+# include <unistd.h>
+# include <sys/types.h>
+# include <sys/wait.h>
 #endif
 
 using std::endl;
@@ -153,10 +161,12 @@ bool ForkedProcess::running() const
 	if (!pid())
 		return false;
 
+#if !defined (_WIN32)
 	// Un-UNIX like, but we don't have much use for
 	// knowing if a zombie exists, so just reap it first.
 	int waitstatus;
 	waitpid(pid(), &waitstatus, WNOHANG);
+#endif
 
 	// Racy of course, but it will do.
 	if (lyx::kill(pid(), 0) && errno == ESRCH)
@@ -196,6 +206,29 @@ int ForkedProcess::waitForChild()
 {
 	// We'll pretend that the child returns 1 on all error conditions.
 	retval_ = 1;
+
+#if defined (_WIN32)
+	HANDLE const hProcess = HANDLE(pid_);
+
+	DWORD const wait_status = ::WaitForSingleObject(hProcess, INFINITE);
+
+	switch (wait_status) {
+	case WAIT_OBJECT_0: {
+		DWORD exit_code = 0;
+		if (!GetExitCodeProcess(hProcess, &exit_code)) {
+			lyxerr << "GetExitCodeProcess failed waiting for child\n"
+			       << getChildErrorMessage() << std::endl;
+		} else
+			retval_ = exit_code;
+		break;
+	}
+	case WAIT_FAILED:
+		lyxerr << "WaitForSingleObject failed waiting for child\n"
+		       << getChildErrorMessage() << std::endl;
+		break;
+	}
+
+#else
 	int status;
 	bool wait = true;
 	while (wait) {
@@ -224,6 +257,7 @@ int ForkedProcess::waitForChild()
 			wait = false;
 		}
 	}
+#endif
 	return retval_;
 }
 
@@ -327,7 +361,12 @@ int Forkedcall::generateChild()
 		lyxerr << "</command>" << std::endl;
 	}
 
-#ifndef __EMX__
+#if defined (__EMX__)
+	pid_t const cpid = spawnvp(P_SESSION|P_DEFAULT|P_MINIMIZE|P_BACKGROUND,
+				   argv[0], &*argv.begin());
+#elif defined (_WIN32)
+ 	pid_t const cpid = spawnvp(_P_NOWAIT, argv[0], &*argv.begin());
+#else // POSIX
 	pid_t const cpid = ::fork();
 	if (cpid == 0) {
 		// Child
@@ -338,9 +377,6 @@ int Forkedcall::generateChild()
 		       << strerror(errno) << endl;
 		_exit(1);
 	}
-#else
-	pid_t const cpid = spawnvp(P_SESSION|P_DEFAULT|P_MINIMIZE|P_BACKGROUND,
-				   argv[0], &*argv.begin());
 #endif
 
 	if (cpid < 0) {

src/support/forkedcontr.C

@@ -19,25 +19,59 @@
 #include "lyxfunctional.h"
 #include "debug.h"
 
+#ifdef _WIN32
+# include <sstream>
+# include <windows.h>
+
+#else
+# include <cerrno>
+# include <cstdlib>
+# include <unistd.h>
+# include <sys/wait.h>
+
+# ifndef CXX_GLOBAL_CSTD
+  using std::strerror;
+# endif
+#endif
+
 #include "frontends/Timeout.h"
 
 #include <boost/bind.hpp>
 
-#include <cerrno>
-#include <cstdlib>
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-#include <sys/wait.h>
 
 using std::vector;
 using std::endl;
 using std::find_if;
 
-#ifndef CXX_GLOBAL_CSTD
+
-using std::strerror;
+#if defined(_WIN32)
+string const getChildErrorMessage()
+{
+	DWORD const error_code = ::GetLastError();
+
+	HLOCAL t_message = 0;
+	bool const ok = ::FormatMessage(
+		FORMAT_MESSAGE_ALLOCATE_BUFFER |
+		FORMAT_MESSAGE_FROM_SYSTEM,
+		0, error_code,
+		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+		(LPTSTR) &t_message, 0, 0
+		) != 0;
+
+	std::ostringstream ss;
+	ss << "LyX: Error waiting for child: " << error_code;
+
+	if (ok) {
+		ss << ": " << (LPTSTR)t_message;
+		::LocalFree(t_message);
+	} else
+		ss << ": Error unknown.";
+
+	return STRCONV(ss.str());
+}
 #endif
 
+
 // Ensure, that only one controller exists inside process
 ForkedcallsController & ForkedcallsController::get()
 {
@@ -75,7 +109,6 @@ void ForkedcallsController::addCall(ForkedProcess const & newcall)
 		timeout_->start();
 
 	forkedCalls.push_back(newcall.clone());
-	childrenChanged();
 }
 
 
@@ -83,17 +116,45 @@ void ForkedcallsController::addCall(ForkedProcess const & newcall)
 // Check the list and, if there is a stopped child, emit the signal.
 void ForkedcallsController::timer()
 {
-	ListType::size_type start_size = forkedCalls.size();
-
 	ListType::iterator it  = forkedCalls.begin();
 	ListType::iterator end = forkedCalls.end();
 	while (it != end) {
 		ForkedProcess * actCall = *it;
+		bool remove_it = false;
 
+#if defined(_WIN32)
+		HANDLE const hProcess = HANDLE(actCall->pid());
+
+		DWORD const wait_status = ::WaitForSingleObject(hProcess, 0);
+
+		switch (wait_status) {
+		case WAIT_TIMEOUT:
+			// Still running
+			break;
+		case WAIT_OBJECT_0: {
+			DWORD exit_code = 0;
+			if (!GetExitCodeProcess(hProcess, &exit_code)) {
+				lyxerr << "GetExitCodeProcess failed waiting for child\n"
+				       << getChildErrorMessage() << std::endl;
+				// Child died, so pretend it returned 1
+				actCall->setRetValue(1);
+			} else {
+				actCall->setRetValue(exit_code);
+			}
+			remove_it = true;
+			break;
+		}
+		case WAIT_FAILED:
+			lyxerr << "WaitForSingleObject failed waiting for child\n"
+			       << getChildErrorMessage() << std::endl;
+			actCall->setRetValue(1);
+			remove_it = true;
+			break;
+		}
+#else
 		pid_t pid = actCall->pid();
 		int stat_loc;
 		pid_t const waitrpid = waitpid(pid, &stat_loc, WNOHANG);
-		bool remove_it = false;
 
 		if (waitrpid == -1) {
 			lyxerr << "LyX: Error waiting for child: "
@@ -130,6 +191,7 @@ void ForkedcallsController::timer()
 			actCall->setRetValue(1);
 			remove_it = true;
 		}
+#endif
 
 		if (remove_it) {
 			forkedCalls.erase(it);
@@ -149,44 +211,6 @@ void ForkedcallsController::timer()
 	if (!forkedCalls.empty() && !timeout_->running()) {
 		timeout_->start();
 	}
-
-	if (start_size != forkedCalls.size())
-		childrenChanged();
-}
-
-
-// Return a vector of the pids of all the controlled processes.
-vector<pid_t> const ForkedcallsController::getPIDs() const
-{
-	vector<pid_t> pids;
-
-	if (forkedCalls.empty())
-		return pids;
-
-	pids.resize(forkedCalls.size());
-
-	vector<pid_t>::iterator vit = pids.begin();
-	for (ListType::const_iterator lit = forkedCalls.begin();
-	     lit != forkedCalls.end(); ++lit, ++vit) {
-		*vit = (*lit)->pid();
-	}
-
-	std::sort(pids.begin(), pids.end());
-	return pids;
-}
-
-
-// Get the command string of the process.
-string const ForkedcallsController::getCommand(pid_t pid) const
-{
-	ListType::const_iterator it =
-		find_if(forkedCalls.begin(), forkedCalls.end(),
-			lyx::compare_memfun(&Forkedcall::pid, pid));
-
-	if (it == forkedCalls.end())
-		return string();
-
-	return (*it)->command();
 }
 
 

src/support/forkedcontr.h

@@ -18,9 +18,6 @@
 
 #include "LString.h"
 
-#include <boost/signals/signal0.hpp>
-#include <boost/signals/trackable.hpp>
-
 #include <sys/types.h> // needed for pid_t
 
 #include <list>
@@ -29,7 +26,7 @@
 class ForkedProcess;
 class Timeout;
 
-class ForkedcallsController : public boost::signals::trackable {
+class ForkedcallsController {
 public:
 	/// We need this to avoid warnings.
 	ForkedcallsController();
@@ -51,21 +48,12 @@ public:
 	 */
 	void timer();
 
-	/// Return a vector of the pids of all the controlled processes.
-	std::vector<pid_t> const getPIDs() const;
-
-	/// Get the command string of the process.
-	string const getCommand(pid_t) const;
-
 	/** Kill this process prematurely and remove it from the list.
 	 *  The process is killed within tolerance secs.
 	 *  See forkedcall.[Ch] for details.
 	 */
 	void kill(pid_t, int tolerance = 5);
 
-	/// Signal emitted when the list of current child processes changes.
-	boost::signal0<void> childrenChanged;
-
 private:
 	///
 	ForkedcallsController(ForkedcallsController const &);
@@ -81,4 +69,9 @@ private:
 	Timeout * timeout_;
 };
 
+#if defined(_WIN32)
+// a wrapper for GetLastError() and FormatMessage().
+string const getChildErrorMessage();
+#endif
+
 #endif // FORKEDCONTR_H

src/support/kill.C

@@ -5,7 +5,40 @@
 #include <sys/types.h>
 #include <csignal>
 
+#ifdef _WIN32
+#include "debug.h"
+#include "os.h"
+
+#include <windows.h>
+#include <errno.h>
+
+using std::endl;
+#endif //_WIN32
+
 int lyx::kill(int pid, int sig)
 {
+#ifdef _WIN32 && 0
+	if (pid == (int)GetCurrentProcessId())
+		return -(raise(sig));
+	else{
+		HANDLE hProcess;
+		if (!(hProcess =
+		OpenProcess(PROCESS_ALL_ACCESS, TRUE, pid))) {
+			lyxerr << "kill OpenProcess failed!" << endl;
+			return -1;
+		}
+		else {
+			if (!TerminateProcess(hProcess, sig)){
+				lyxerr << "kill process failed!" << endl;
+				CloseHandle(hProcess);
+				return -1;
+			}
+		CloseHandle(hProcess);
+		}
+	}
+	return 0;
+
+#else
 	return ::kill(pid, sig);
+#endif	
 }