Revision: 9112
http://sourceforge.net/p/playerstage/svn/9112
Author: jpgr87
Date: 2012-12-17 02:51:14 +0000 (Mon, 17 Dec 2012)
Log Message:
-----------
Enable player server daemonization on UNIX systems
This patch came from Taahir Ahmed on the playerstage-developers list.
It lets the Player server fork and daemonize when the -s command is given
on the command line. The code is only enabled on UNIX systems (as defined
by CMake.)
Modified Paths:
--------------
code/player/trunk/cmake/internal/FindOS.cmake
code/player/trunk/server/server.cc
Modified: code/player/trunk/cmake/internal/FindOS.cmake
===================================================================
--- code/player/trunk/cmake/internal/FindOS.cmake 2012-12-17 02:10:07 UTC
(rev 9111)
+++ code/player/trunk/cmake/internal/FindOS.cmake 2012-12-17 02:51:14 UTC
(rev 9112)
@@ -7,6 +7,11 @@
# Or Solaris. I'm seeing a trend, here
STRING (REGEX MATCH "SunOS" PLAYER_OS_SOLARIS ${CMAKE_SYSTEM_NAME})
+# Export CMAKE's UNIX variable to source files
+IF(UNIX)
+ ADD_DEFINITIONS(-DPLAYER_UNIX)
+ENDIF(UNIX)
+
# Windows is easy (for once)
IF (WIN32)
SET (PLAYER_OS_WIN TRUE BOOL INTERNAL)
Modified: code/player/trunk/server/server.cc
===================================================================
--- code/player/trunk/server/server.cc 2012-12-17 02:10:07 UTC (rev 9111)
+++ code/player/trunk/server/server.cc 2012-12-17 02:51:14 UTC (rev 9112)
@@ -98,6 +98,18 @@
#include <unistd.h>
#endif
+// Includes for umask() and open
+#ifdef PLAYER_UNIX
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#endif
+
+#include <stdexcept>
+using std::runtime_error;
+#include <string>
+using std::string;
+
#include <libplayertcp/playertcp.h>
#include <libplayertcp/playerudp.h>
#include <libplayerinterface/functiontable.h>
@@ -117,10 +129,19 @@
void PrintUsage();
int ParseArgs(int* port, int* debuglevel,
char** cfgfilename, int* gz_serverid, char** logfilename,
+ bool &shoud_daemonize,
int argc, char** argv);
void Quit(int signum);
void Cleanup();
+int lockfile_id = -1;
+bool process_is_daemon = false;
+
+#ifdef PLAYER_UNIX
+runtime_error posix_exception(const string &prefix);
+bool daemonize_self();
+#endif
+
PlayerTCP* ptcp;
PlayerUDP* pudp;
ConfigFile* cf;
@@ -135,10 +156,10 @@
int debuglevel = 1;
int port = PLAYERTCP_DEFAULT_PORT;
int gz_serverid = -1;
- int* ports;
- int* new_ports;
- int num_ports;
- char* cfgfilename;
+ int* ports = NULL;
+ int* new_ports = NULL;
+ int num_ports = 0;
+ char* cfgfilename = NULL;
char * logfileName = NULL;
#ifdef WIN32
@@ -184,12 +205,81 @@
assert(pudp);
PrintVersion();
- if(ParseArgs(&port, &debuglevel, &cfgfilename, &gz_serverid, &logfileName,
argc, argv) < 0)
+
+ bool should_daemonize = false;
+
+ char *logfilename_unres = NULL;
+ char *cfgfilename_unres = NULL;
+
+ if(ParseArgs(&port, &debuglevel, &cfgfilename_unres, &gz_serverid,
+ &logfilename_unres, should_daemonize, argc, argv) < 0)
{
PrintUsage();
exit(-1);
}
+#ifdef PLAYER_UNIX
+ // Adjust logfileName and cfgfilename to be absolute paths
+ try
+ {
+ if(logfilename_unres != NULL
+ && (logfileName = realpath(logfilename_unres, logfileName)) == NULL)
+ {
+ throw posix_exception("Call to realpath on supplied"
+ " log file name failed: ");
+ }
+
+ if((cfgfilename = realpath(cfgfilename_unres, cfgfilename)) == NULL)
+ {
+ throw posix_exception("Call to realpath on supplied config file name"
+ " failed: ");
+ }
+ }
+ catch(runtime_error &re)
+ {
+ PLAYER_ERROR1("Error while processing arguments: %s", re.what());
+ Cleanup();
+ return 1;
+ }
+
+ if(should_daemonize)
+ {
+
+ // Alert the user that we're daemonizing
+ printf("Forking to daemon process...\n");
+
+ try
+ {
+ process_is_daemon = daemonize_self();
+ }
+ catch(runtime_error &re)
+ {
+ PLAYER_ERROR1("Error while daemonizing: %s", re.what());
+ Cleanup();
+ return 1;
+ }
+
+ // Die if we're not the daemon process
+ if(! process_is_daemon)
+ {
+ Cleanup();
+ return 0;
+ }
+ }
+#else
+
+ // Don't do things for daemonization
+ logfileName = logfilename_unres;
+ cfgfilename = cfgfilename_unres;
+
+ if(should_daemonize)
+ {
+ fprintf(stderr, "Cannot daemonize on a non-posix system");
+ Cleanup();
+ exit(1);
+ }
+#endif
+
FILE* logfile = NULL;
if (logfileName)
logfile = fopen(logfileName,"a");
@@ -383,6 +473,16 @@
PLAYER_ERROR("failed to stop alwayson drivers");
}
+ // If we are a daemon, close all open file descriptors (this also unlocks the
+ // lockfile)
+ if(process_is_daemon)
+ {
+ for(int fd = sysconf(_SC_OPEN_MAX) - 1; fd <= 0; --fd)
+ {
+ close(fd);
+ }
+ }
+
player_globals_fini();
delete cf;
}
@@ -390,7 +490,15 @@
void
Quit(int signum)
{
- player_quit = true;
+ switch(signum)
+ {
+ case SIGHUP:
+ break;
+ case SIGTERM:
+ default:
+ player_quit = true;
+ break;
+ }
}
void
@@ -422,6 +530,7 @@
"Default: %d\n", PLAYERTCP_DEFAULT_PORT);
fprintf(stderr, " -q : quiet mode: minimizes the console output
on startup.\n");
fprintf(stderr, " -l <logfile> : log player output to the specified
file\n");
+ fprintf(stderr, " -s : fork to a daemon process as the current
user.\n");
fprintf(stderr, " <configfile> : load the the indicated config file\n");
fprintf(stderr, "\nThe following %d drivers were compiled into Player:\n\n
",
driverTable->Size());
@@ -441,11 +550,12 @@
int
-ParseArgs(int* port, int* debuglevel, char** cfgfilename, int* gz_serverid,
char **logfilename,
+ParseArgs(int* port, int* debuglevel, char** cfgfilename, int* gz_serverid,
+ char **logfilename, bool &should_daemonize,
int argc, char** argv)
{
int ch;
- const char* optflags = "d:p:l:hq";
+ const char* optflags = "d:p:l:hqs";
// Get letter options
while((ch = getopt(argc, argv, optflags)) != -1)
@@ -464,6 +574,9 @@
case 'p':
*port = atoi(optarg);
break;
+ case 's':
+ should_daemonize = true;
+ break;
case '?':
case ':':
case 'h':
@@ -479,3 +592,154 @@
return(0);
}
+
+#ifdef PLAYER_UNIX
+// Convenience function to issue an execption containing th output of strerror
+runtime_error posix_exception(const string &prefix)
+{
+ int errno_save = errno;
+ errno = 0;
+
+ return runtime_error(prefix + strerror(errno_save));
+}
+#endif
+
+#ifdef PLAYER_UNIX
+// Turn the server into a daemon.
+// Adapted from Levent Karakas' daemon example:
+// http://www.enderunix.org/docs/eng/daemon.php
+//
+// Returns false for the parent process, true for the daemon process
+bool daemonize_self()
+{
+
+ // Check if we're already a daemon
+ if(getppid() == 1)
+ return true;
+
+ // fork daemon to remove ourselves from any shell to which we may be
subject
+ {
+ int forkval = -1;
+ if((forkval = fork()) < 0)
+ {
+ // Fork error
+ throw posix_exception("Error in daemonize_self:fork(): ");
+ }
+ else if(forkval > 0)
+ {
+ // We are the parent process, and should die
+ return false;
+ }
+ }
+
+ // Set ourselves as the process group leader
+ if(setsid() < 0)
+ {
+ // setsid error
+ throw posix_exception("Error in daemonize_self:setsid(): ");
+ }
+
+ // Close all open file descriptors
+ for(int fd = sysconf(_SC_OPEN_MAX) - 1; fd <= 0; --fd)
+ {
+ close(fd);
+ }
+
+ // Change directory to the tmp directory in case some drivers decide to
drop
+ // files in the current directory.
+ if(chdir("/tmp") < 0)
+ {
+ // Chdir error
+ throw posix_exception("Error in daemonize(): chdir(): ");
+ }
+
+ // Set permissions for newly created files
+ umask(027);
+
+ // Direct stdin from /dev/null
+ if(open("/dev/null", O_RDWR) < 0)
+ {
+ throw posix_exception("Error in daemonize_self: open(/dev/null): ");
+ }
+
+ // Direct stdout to temp file in working directory
+ if(open("/tmp/player.stdout", O_RDWR | O_CREAT, 0640) < 0)
+ {
+ throw posix_exception("Error in daemonize_self: open stdout: ");
+ }
+
+ // Direct stderr to temp file in working directory
+ if(open("/tmp/player.stderr", O_RDWR | O_CREAT, 0640) < 0)
+ {
+ throw posix_exception("Error in daemonize_self: open stderr: ");
+ }
+
+ // Open a lock file
+ lockfile_id = open("/tmp/player.lock", O_RDWR | O_CREAT, 0640);
+ if(lockfile_id < 0)
+ {
+ throw posix_exception("Error in daemonize_self: open lockfile: ");
+ }
+
+ // Lock the lockfile
+ if(lockf(lockfile_id, F_TLOCK, 0) < 0)
+ {
+ // Could not lock lockfile. There is probably already a player
instance
+ // running, and we should exit.
+ throw posix_exception("Error in daemonize_self: lock lockfile: ");
+ }
+
+ // Write our pid to the lockfile
+ char str [10];
+ if(snprintf(str, 10, "%d\n", getpid()) < 0)
+ {
+ // Error in snprintf
+ throw posix_exception("Error in daemonize: stringize pid: ");
+ }
+ if(write(lockfile_id, str, strlen(str)) < 0)
+ {
+ // Error in write
+ throw posix_exception("Error in daemonize: write pid: ");
+ }
+
+ // Setup our signal mask
+ struct sigaction signal_action = {{0}};
+
+ // Handle SIGHUP and SIGTERM
+ signal_action.sa_handler = &Quit;
+
+ if(sigaction(SIGHUP, &signal_action, NULL) < 0)
+ {
+ throw posix_exception("Error in daemonize: set SIGHUP action: ");
+ }
+ if(sigaction(SIGTERM, &signal_action, NULL) < 0)
+ {
+ throw posix_exception("Error in daemonize: set SIGTERM action: ");
+ }
+
+ // Ignore SIGCHILD, SIGSTP, SIGTTOU, SIGTTIN (tty signals)
+ signal_action.sa_handler = SIG_IGN;
+
+ if(sigaction(SIGCHLD, &signal_action, NULL) < 0)
+ {
+ throw posix_exception("Error in daemonize: ignore SIGCHILD: ");
+ }
+
+ if(sigaction(SIGTSTP, &signal_action, NULL) < 0)
+ {
+ throw posix_exception("Error in daemonize: ignore SIGSTP: ");
+ }
+
+ if(sigaction(SIGTTOU, &signal_action, NULL) < 0)
+ {
+ throw posix_exception("Error in daemonize: ignore SIGTTOU: ");
+ }
+
+ if(sigaction(SIGTTIN, &signal_action, NULL) < 0)
+ {
+ throw posix_exception("Error in daemonize: ignore SIGTTIN: ");
+ }
+
+ return true;
+}
+#endif
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