* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
- * \author Lars Gullik Bjønnes
+ * \author Lars Gullik Bjønnes
* \author Jean-Marc Lasgouttes
* \author Angus Leeming
* \author John Levon
#include <config.h>
#include "Server.h"
-#include "support/debug.h"
#include "FuncRequest.h"
#include "LyXAction.h"
#include "LyXFunc.h"
+
#include "frontends/Application.h"
+#include "support/debug.h"
#include "support/FileName.h"
#include "support/lstrings.h"
-#include "support/lyxlib.h"
#include <boost/bind.hpp>
int LyXComm::startPipe(string const & file, bool write)
{
+ static bool stalepipe = false;
FileName const filename(file);
- if (::access(filename.toFilesystemEncoding().c_str(), F_OK) == 0) {
- lyxerr << "LyXComm: Pipe " << filename << " already exists.\n"
- << "If no other LyX program is active, please delete"
- " the pipe by hand and try again." << endl;
- pipename_.erase();
- return -1;
+ if (filename.exists()) {
+ if (!write) {
+ // Let's see whether we have a stale pipe.
+ int fd = ::open(filename.toFilesystemEncoding().c_str(),
+ O_WRONLY | O_NONBLOCK);
+ if (fd >= 0) {
+ // Another LyX instance is using it.
+ ::close(fd);
+ } else if (errno == ENXIO) {
+ // No process is reading from the other end.
+ stalepipe = true;
+ LYXERR(Debug::LYXSERVER,
+ "LyXComm: trying to remove "
+ << filename);
+ filename.removeFile();
+ }
+ } else if (stalepipe) {
+ LYXERR(Debug::LYXSERVER, "LyXComm: trying to remove "
+ << filename);
+ filename.removeFile();
+ stalepipe = false;
+ }
+ if (filename.exists()) {
+ lyxerr << "LyXComm: Pipe " << filename
+ << " already exists.\nIf no other LyX program"
+ " is active, please delete the pipe by hand"
+ " and try again."
+ << endl;
+ pipename_.erase();
+ return -1;
+ }
}
if (::mkfifo(filename.toFilesystemEncoding().c_str(), 0600) < 0) {
int const charbuf_size = 100;
char charbuf[charbuf_size];
+ // As O_NONBLOCK is set, until no data is available for reading,
+ // read() doesn't block but returns -1 and set errno to EAGAIN.
+ // After a client that opened the pipe for writing, closes it
+ // (and no other client is using the pipe), read() would always
+ // return 0 and thus the connection has to be reset.
+
errno = 0;
int status;
// the single = is intended here.
clientcb_(client_, cmd);
//\n or not \n?
}
- }
- if (errno == EAGAIN) {
- errno = 0;
- return;
- }
- if (errno != 0) {
+ } else {
+ if (errno == EAGAIN) {
+ // Nothing to read, continue
+ errno = 0;
+ return;
+ }
+ // An error occurred, better bailing out
LYXERR0("LyXComm: " << strerror(errno));
if (!read_buffer_.empty()) {
LYXERR0("LyXComm: truncated command: " << read_buffer_);
}
}
- // The connection gets reset in errno != EAGAIN
- // Why does it need to be reset if errno == 0?
+ // The connection gets reset when read() returns 0 (meaning that the
+ // last client closed the pipe) or an error occurred, in which case
+ // read() returns -1 and errno != EAGAIN.
closeConnection();
openConnection();
errno = 0;
}
-// Send a notify messge to a client, called by WorkAreaKeyPress
+// Send a notify message to a client, called by WorkAreaKeyPress
void Server::notifyClient(string const & s)
{
pipes_.send("NOTIFY:" + s + "\n");