Commit 88bacc49 authored by Chase Douglas's avatar Chase Douglas Committed by Peter Hutterer

os: Add -displayfd option

This option specifies a file descriptor in the launching process.  X
will scan for an available display number and write that number back to
the launching process, at the same time as SIGUSR1 generation.  This
means display managers don't need to guess at available display numbers.
As a consequence, if X fails to start when using -displayfd, it's not
because the display was in use, so there's no point in retrying the X
launch on a higher display number.
Signed-off-by: Adam Jackson's avatarAdam Jackson <ajax@redhat.com>
Signed-off-by: default avatarChase Douglas <chase.douglas@canonical.com>
Reviewed-by: Julien Cristau's avatarJulien Cristau <jcristau@debian.org>
Tested-by: Julien Cristau's avatarJulien Cristau <jcristau@debian.org>
Reviewed-by: Alan Coopersmith's avatarAlan Coopersmith <alan.coopersmith@oracle.com>
Signed-off-by: Peter Hutterer's avatarPeter Hutterer <peter.hutterer@who-t.net>
parent 1d82ec95
......@@ -128,6 +128,7 @@ int defaultColorVisualClass = -1;
int monitorResolution = 0;
char *display;
int displayfd;
char *ConnectionInfo;
CARD32 TimeOutValue = DEFAULT_TIMEOUT * MILLI_PER_SECOND;
......@@ -50,6 +50,7 @@ extern _X_EXPORT int ScreenSaverAllowExposures;
extern _X_EXPORT int defaultScreenSaverBlanking;
extern _X_EXPORT int defaultScreenSaverAllowExposures;
extern _X_EXPORT char *display;
extern _X_EXPORT int displayfd;
extern _X_EXPORT int defaultBackingStore;
extern _X_EXPORT Bool disableBackingStore;
......
......@@ -127,6 +127,13 @@ Not obeyed by all servers.
.B \-core
causes the server to generate a core dump on fatal errors.
.TP 8
.B \-displayfd \fIfd\fP
specifies a file descriptor in the launching process. Rather than specify
a display number, the X server will attempt to listen on successively higher
display numbers, and upon finding a free one, will write the port number back
on this file descriptor as a newline-terminated string. The \-pn option is
ignored when using \-displayfd.
.TP 8
.B \-deferglyphs \fIwhichfonts\fP
specifies the types of fonts for which the server should attempt to use
deferred glyph loading. \fIwhichfonts\fP can be all (all fonts),
......
......@@ -142,6 +142,7 @@ Bool AnyClientsWriteBlocked; /* true if some client blocked on write */
static Bool RunFromSmartParent; /* send SIGUSR1 to parent process */
Bool RunFromSigStopParent; /* send SIGSTOP to our own process; Upstart (or
equivalent) will send SIGCONT back. */
static char dynamic_display[7]; /* display name */
Bool PartialNetwork; /* continue even if unable to bind all addrs */
static Pid_t ParentProcess;
......@@ -350,6 +351,10 @@ void
NotifyParentProcess(void)
{
#if !defined(WIN32)
if (dynamic_display[0]) {
write(displayfd, dynamic_display, strlen(dynamic_display));
close(displayfd);
}
if (RunFromSmartParent) {
if (ParentProcess > 1) {
kill(ParentProcess, SIGUSR1);
......@@ -360,6 +365,18 @@ NotifyParentProcess(void)
#endif
}
static Bool
TryCreateSocket(int num, int *partial)
{
char port[20];
snprintf(port, sizeof(port), "%d", num);
return (_XSERVTransMakeAllCOTSServerListeners(port, partial,
&ListenTransCount,
&ListenTransConns) >= 0);
}
/*****************
* CreateWellKnownSockets
* At initialization, create the sockets to listen on for new clients.
......@@ -370,7 +387,6 @@ CreateWellKnownSockets(void)
{
int i;
int partial;
char port[20];
FD_ZERO(&AllSockets);
FD_ZERO(&AllClients);
......@@ -386,29 +402,41 @@ CreateWellKnownSockets(void)
FD_ZERO(&WellKnownConnections);
snprintf(port, sizeof(port), "%d", atoi(display));
if ((_XSERVTransMakeAllCOTSServerListeners(port, &partial,
&ListenTransCount,
&ListenTransConns) >= 0) &&
(ListenTransCount >= 1)) {
if (!PartialNetwork && partial) {
FatalError("Failed to establish all listening sockets");
/* display is initialized to "0" by main(). It is then set to the display
* number if specified on the command line, or to NULL when the -displayfd
* option is used. */
if (display) {
if (TryCreateSocket(atoi(display), &partial) &&
ListenTransCount >= 1)
if (!PartialNetwork && partial)
FatalError ("Failed to establish all listening sockets");
}
else { /* -displayfd */
Bool found = 0;
for (i = 0; i < 65535 - X_TCP_PORT; i++) {
if (TryCreateSocket(i, &partial) && !partial) {
found = 1;
break;
}
else
CloseWellKnownConnections();
}
else {
ListenTransFds = malloc(ListenTransCount * sizeof(int));
if (!found)
FatalError("Failed to find a socket to listen on");
snprintf(dynamic_display, sizeof(dynamic_display), "%d", i);
display = dynamic_display;
}
for (i = 0; i < ListenTransCount; i++) {
int fd = _XSERVTransGetConnectionNumber(ListenTransConns[i]);
ListenTransFds = malloc(ListenTransCount * sizeof (int));
ListenTransFds[i] = fd;
FD_SET(fd, &WellKnownConnections);
for (i = 0; i < ListenTransCount; i++) {
int fd = _XSERVTransGetConnectionNumber(ListenTransConns[i]);
if (!_XSERVTransIsLocal(ListenTransConns[i])) {
DefineSelf(fd);
}
}
}
ListenTransFds[i] = fd;
FD_SET(fd, &WellKnownConnections);
if (!_XSERVTransIsLocal(ListenTransConns[i]))
DefineSelf (fd);
}
if (!XFD_ANYSET(&WellKnownConnections))
......
......@@ -659,6 +659,15 @@ ProcessCommandLine(int argc, char *argv[])
else
UseMsg();
}
else if (strcmp(argv[i], "-displayfd") == 0) {
if (++i < argc) {
displayfd = atoi(argv[i]);
display = NULL;
nolock = TRUE;
}
else
UseMsg();
}
#ifdef DPMSExtension
else if (strcmp(argv[i], "dpms") == 0)
/* ignored for compatibility */ ;
......
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