From 89496d987dc6a21250c9fdda2cd3668516061f5c Mon Sep 17 00:00:00 2001 From: Chase Douglas Date: Wed, 15 Mar 2017 14:10:24 +0000 Subject: os: Add -displayfd option commit 88bacc49f06da5927f716869f5a32672a8297ed0 Author: Chase Douglas Date: Wed Apr 4 15:29:42 2012 -0700 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 Signed-off-by: Chase Douglas Reviewed-by: Julien Cristau Tested-by: Julien Cristau Reviewed-by: Alan Coopersmith Signed-off-by: Peter Hutterer Backported-to-NX-by: Mike Gabriel --- nx-X11/programs/Xserver/dix/globals.c | 1 + nx-X11/programs/Xserver/hw/nxagent/man/nxagent.1 | 7 +++ nx-X11/programs/Xserver/include/opaque.h | 1 + nx-X11/programs/Xserver/os/connection.c | 76 ++++++++++++++++-------- nx-X11/programs/Xserver/os/utils.c | 10 ++++ 5 files changed, 69 insertions(+), 26 deletions(-) diff --git a/nx-X11/programs/Xserver/dix/globals.c b/nx-X11/programs/Xserver/dix/globals.c index a0af50fa8..5a3e22c26 100644 --- a/nx-X11/programs/Xserver/dix/globals.c +++ b/nx-X11/programs/Xserver/dix/globals.c @@ -149,6 +149,7 @@ int defaultColorVisualClass = -1; int monitorResolution = 0; char *display; +int displayfd; CARD32 TimeOutValue = DEFAULT_TIMEOUT * MILLI_PER_SECOND; int argcGlobal; diff --git a/nx-X11/programs/Xserver/hw/nxagent/man/nxagent.1 b/nx-X11/programs/Xserver/hw/nxagent/man/nxagent.1 index af5fc88f8..66f25b438 100644 --- a/nx-X11/programs/Xserver/hw/nxagent/man/nxagent.1 +++ b/nx-X11/programs/Xserver/hw/nxagent/man/nxagent.1 @@ -178,6 +178,13 @@ different from the user's real uid. .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), diff --git a/nx-X11/programs/Xserver/include/opaque.h b/nx-X11/programs/Xserver/include/opaque.h index bd286ba12..8f98bf1be 100644 --- a/nx-X11/programs/Xserver/include/opaque.h +++ b/nx-X11/programs/Xserver/include/opaque.h @@ -52,6 +52,7 @@ extern int defaultScreenSaverAllowExposures; extern int argcGlobal; extern char **argvGlobal; extern char *display; +extern int displayfd; extern int defaultBackingStore; extern Bool disableBackingStore; diff --git a/nx-X11/programs/Xserver/os/connection.c b/nx-X11/programs/Xserver/os/connection.c index 2fa8ad12d..6dc0ff64d 100644 --- a/nx-X11/programs/Xserver/os/connection.c +++ b/nx-X11/programs/Xserver/os/connection.c @@ -138,6 +138,7 @@ int NumNotifyWriteFd; /* Number of NotifyFd members with write set */ Bool NewOutputPending; /* not yet attempted to write some new output */ Bool AnyWritesPending; /* true if some client blocked on write or NotifyFd with write */ Bool RunFromSmartParent; /* send SIGUSR1 to parent process */ +static char dynamic_display[7]; /* display name */ Bool PartialNetwork; /* continue even if unable to bind all addrs */ static Pid_t ParentProcess; @@ -359,6 +360,10 @@ 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); @@ -367,6 +372,18 @@ 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. @@ -377,7 +394,6 @@ CreateWellKnownSockets(void) { int i; int partial; - char port[20]; FD_ZERO(&AllSockets); FD_ZERO(&AllClients); @@ -392,33 +408,41 @@ CreateWellKnownSockets(void) FD_ZERO (&WellKnownConnections); - sprintf (port, "%d", atoi (display)); - - if ((_XSERVTransMakeAllCOTSServerListeners (port, &partial, - &ListenTransCount, &ListenTransConns) >= 0) && - (ListenTransCount >= 1)) - { - if (!PartialNetwork && partial) - { - FatalError ("Failed to establish all listening sockets"); - } - else - { - ListenTransFds = (int *) malloc (ListenTransCount * sizeof (int)); - - for (i = 0; i < ListenTransCount; i++) - { - int fd = _XSERVTransGetConnectionNumber (ListenTransConns[i]); - - ListenTransFds[i] = fd; - FD_SET (fd, &WellKnownConnections); - - if (!_XSERVTransIsLocal (ListenTransConns[i])) - { - DefineSelf (fd); - } + /* 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(); } + if (!found) + FatalError("Failed to find a socket to listen on"); + snprintf(dynamic_display, sizeof(dynamic_display), "%d", i); + display = dynamic_display; + } + + ListenTransFds = malloc(ListenTransCount * sizeof (int)); + + for (i = 0; i < ListenTransCount; i++) { + int fd = _XSERVTransGetConnectionNumber(ListenTransConns[i]); + + ListenTransFds[i] = fd; + FD_SET(fd, &WellKnownConnections); + + if (!_XSERVTransIsLocal(ListenTransConns[i])) + DefineSelf (fd); } if (!XFD_ANYSET (&WellKnownConnections)) diff --git a/nx-X11/programs/Xserver/os/utils.c b/nx-X11/programs/Xserver/os/utils.c index 25cbb1e87..929549168 100644 --- a/nx-X11/programs/Xserver/os/utils.c +++ b/nx-X11/programs/Xserver/os/utils.c @@ -780,6 +780,16 @@ 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) DPMSEnabledSwitch = TRUE; -- cgit v1.2.3