job.c

早期freebsd实现

    GNode          *gn;	    	    /* The target whose commands need
				     * verifying */
    void    	  (*abortProc) __P((const char *, ...));   
			/* Function to abort with message */
{
    if (OP_NOP(gn->type) && Lst_IsEmpty (gn->commands) &&
	(gn->type & OP_LIB) == 0) {
	/*
	 * No commands. Look for .DEFAULT rule from which we might infer
	 * commands 
	 */
	if ((DEFAULT != NILGNODE) && !Lst_IsEmpty(DEFAULT->commands)) {
	    /*
	     * Make only looks for a .DEFAULT if the node was never the
	     * target of an operator, so that's what we do too. If
	     * a .DEFAULT was given, we substitute its commands for gn's
	     * commands and set the IMPSRC variable to be the target's name
	     * The DEFAULT node acts like a transformation rule, in that
	     * gn also inherits any attributes or sources attached to
	     * .DEFAULT itself.
	     */
	    Make_HandleUse(DEFAULT, gn);
	    Var_Set (IMPSRC, Var_Value (TARGET, gn), gn);
	} else if (Dir_MTime (gn) == 0) {
	    /*
	     * The node wasn't the target of an operator we have no .DEFAULT
	     * rule to go on and the target doesn't already exist. There's
	     * nothing more we can do for this branch. If the -k flag wasn't
	     * given, we stop in our tracks, otherwise we just don't update
	     * this node's parents so they never get examined. 
	     */
	    if (gn->type & OP_OPTIONAL) {
		printf ("make: don't know how to make %s (ignored)\n",
			gn->name);
	    } else if (keepgoing) {
		printf ("make: don't know how to make %s (continuing)\n",
			gn->name);
		return (FALSE);
	    } else {
		(*abortProc) ("make: don't know how to make %s. Stop",
			     gn->name);
		return(FALSE);
	    }
	}
    }
    return (TRUE);
}
#ifdef RMT_WILL_WATCH
/*-
 *-----------------------------------------------------------------------
 * JobLocalInput --
 *	Handle a pipe becoming readable. Callback function for Rmt_Watch
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	JobDoOutput is called.
 *	
 *-----------------------------------------------------------------------
 */
/*ARGSUSED*/
static void
JobLocalInput(stream, job)
    int	    stream; 	/* Stream that's ready (ignored) */
    Job	    *job;   	/* Job to which the stream belongs */
{
    JobDoOutput(job, FALSE);
}
#endif /* RMT_WILL_WATCH */

/*-
 *-----------------------------------------------------------------------
 * JobExec --
 *	Execute the shell for the given job. Called from JobStart and
 *	JobRestart.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	A shell is executed, outputs is altered and the Job structure added
 *	to the job table.
 *
 *-----------------------------------------------------------------------
 */
static void
JobExec(job, argv)
    Job	    	  *job; 	/* Job to execute */
    char    	  **argv;
{
    int	    	  cpid;	    	/* ID of new child */
    
    if (DEBUG(JOB)) {
	int 	  i;
	
	printf("Running %s %sly\n", job->node->name,
	       job->flags&JOB_REMOTE?"remote":"local");
	printf("\tCommand: ");
	for (i = 0; argv[i] != (char *)NULL; i++) {
	    printf("%s ", argv[i]);
	}
	printf("\n");
    }
    
    /*
     * Some jobs produce no output and it's disconcerting to have
     * no feedback of their running (since they produce no output, the
     * banner with their name in it never appears). This is an attempt to
     * provide that feedback, even if nothing follows it.
     */
    if ((lastNode != job->node) && (job->flags & JOB_FIRST) &&
	!(job->flags & JOB_SILENT))
    {
	printf(targFmt, job->node->name);
	lastNode = job->node;
    }
    
#ifdef RMT_NO_EXEC
    if (job->flags & JOB_REMOTE) {
	goto jobExecFinish;
    }
#endif /* RMT_NO_EXEC */

    if ((cpid =  vfork()) == -1) {
	Punt ("Cannot fork");
    } else if (cpid == 0) {

	/*
	 * Must duplicate the input stream down to the child's input and
	 * reset it to the beginning (again). Since the stream was marked
	 * close-on-exec, we must clear that bit in the new input.
	 */
	(void) dup2(fileno(job->cmdFILE), 0);
	fcntl(0, F_SETFD, 0);
	lseek(0, 0, L_SET);
	
	if (usePipes) {
	    /*
	     * Set up the child's output to be routed through the pipe
	     * we've created for it.
	     */
	    (void) dup2 (job->outPipe, 1);
	} else {
	    /*
	     * We're capturing output in a file, so we duplicate the
	     * descriptor to the temporary file into the standard
	     * output.
	     */
	    (void) dup2 (job->outFd, 1);
	}
	/*
	 * The output channels are marked close on exec. This bit was
	 * duplicated by the dup2 (on some systems), so we have to clear
	 * it before routing the shell's error output to the same place as
	 * its standard output.
	 */
	fcntl(1, F_SETFD, 0);
	(void) dup2 (1, 2);

#ifdef USE_PGRP
	/*
	 * We want to switch the child into a different process family so
	 * we can kill it and all its descendants in one fell swoop,
	 * by killing its process family, but not commit suicide.
	 */
	
	(void) setpgrp(0, getpid());
#endif USE_PGRP

	(void) execv (shellPath, argv);
	(void) write (2, "Could not execute shell\n",
		 sizeof ("Could not execute shell"));
	_exit (1);
    } else {
	job->pid = cpid;

	if (usePipes && (job->flags & JOB_FIRST) ) {
	    /*
	     * The first time a job is run for a node, we set the current
	     * position in the buffer to the beginning and mark another
	     * stream to watch in the outputs mask
	     */
	    job->curPos = 0;
	    
#ifdef RMT_WILL_WATCH
	    Rmt_Watch(job->inPipe, JobLocalInput, job);
#else
	    FD_SET(job->inPipe, &outputs);
#endif /* RMT_WILL_WATCH */
	}

	if (job->flags & JOB_REMOTE) {
	    job->rmtID = 0;
	} else {
	    nLocal += 1;
	    /*
	     * XXX: Used to not happen if CUSTOMS. Why?
	     */
	    if (job->cmdFILE != stdout) {
		fclose(job->cmdFILE);
		job->cmdFILE = NULL;
	    }
	}
    }

#ifdef RMT_NO_EXEC
jobExecFinish:    
#endif
    /*
     * Now the job is actually running, add it to the table.
     */
    nJobs += 1;
    (void)Lst_AtEnd (jobs, (ClientData)job);
    if (nJobs == maxJobs) {
	jobFull = TRUE;
    }
}

/*-
 *-----------------------------------------------------------------------
 * JobMakeArgv --
 *	Create the argv needed to execute the shell for a given job.
 *	
 *
 * Results:
 *
 * Side Effects:
 *
 *-----------------------------------------------------------------------
 */
static void
JobMakeArgv(job, argv)
    Job	    	  *job;
    char	  **argv;
{
    int	    	  argc;
    static char	  args[10]; 	/* For merged arguments */
    
    argv[0] = shellName;
    argc = 1;

    if ((commandShell->exit && (*commandShell->exit != '-')) ||
	(commandShell->echo && (*commandShell->echo != '-')))
    {
	/*
	 * At least one of the flags doesn't have a minus before it, so
	 * merge them together. Have to do this because the *(&(@*#*&#$#
	 * Bourne shell thinks its second argument is a file to source.
	 * Grrrr. Note the ten-character limitation on the combined arguments.
	 */
	(void)sprintf(args, "-%s%s",
		      ((job->flags & JOB_IGNERR) ? "" :
		       (commandShell->exit ? commandShell->exit : "")),
		      ((job->flags & JOB_SILENT) ? "" :
		       (commandShell->echo ? commandShell->echo : "")));

	if (args[1]) {
	    argv[argc] = args;
	    argc++;
	}
    } else {
	if (!(job->flags & JOB_IGNERR) && commandShell->exit) {
	    argv[argc] = commandShell->exit;
	    argc++;
	}
	if (!(job->flags & JOB_SILENT) && commandShell->echo) {
	    argv[argc] = commandShell->echo;
	    argc++;
	}
    }
    argv[argc] = (char *)NULL;
}

/*-
 *-----------------------------------------------------------------------
 * JobRestart --
 *	Restart a job that stopped for some reason. 
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	jobFull will be set if the job couldn't be run.
 *
 *-----------------------------------------------------------------------
 */
static void
JobRestart(job)
    Job 	  *job;    	/* Job to restart */
{
    if (job->flags & JOB_REMIGRATE) {
	if (DEBUG(JOB)) {
	    printf("Remigrating %x\n", job->pid);
	}
	if (nLocal != maxLocal) {
		/*
		 * Job cannot be remigrated, but there's room on the local
		 * machine, so resume the job and note that another
		 * local job has started.
		 */
		if (DEBUG(JOB)) {
		    printf("resuming on local machine\n");
	        }
		KILL(job->pid, SIGCONT);
		nLocal +=1;
		job->flags &= ~(JOB_REMIGRATE|JOB_RESUME);
	} else {
		/*
		 * Job cannot be restarted. Mark the table as full and
		 * place the job back on the list of stopped jobs.
		 */
		if (DEBUG(JOB)) {
		    printf("holding\n");
		}
		(void)Lst_AtFront(stoppedJobs, (ClientData)job);
		jobFull = TRUE;
		if (DEBUG(JOB)) {
		    printf("Job queue is full.\n");
		}
		return;
	}
	
	(void)Lst_AtEnd(jobs, (ClientData)job);
	nJobs += 1;
	if (nJobs == maxJobs) {
	    jobFull = TRUE;
	    if (DEBUG(JOB)) {
		printf("Job queue is full.\n");
	    }
	}
    } else if (job->flags & JOB_RESTART) {
	/*
	 * Set up the control arguments to the shell. This is based on the
	 * flags set earlier for this job. If the JOB_IGNERR flag is clear,
	 * the 'exit' flag of the commandShell is used to cause it to exit
	 * upon receiving an error. If the JOB_SILENT flag is clear, the
	 * 'echo' flag of the commandShell is used to get it to start echoing
	 * as soon as it starts processing commands. 
	 */
	char	  *argv[4];
	
	JobMakeArgv(job, argv);
	
	if (DEBUG(JOB)) {
	    printf("Restarting %s...", job->node->name);
	}
	if (((nLocal >= maxLocal) && ! (job->flags & JOB_SPECIAL))) {
		/*
		 * Can't be exported and not allowed to run locally -- put it
		 * back on the hold queue and mark the table full
		 */
		if (DEBUG(JOB)) {
		    printf("holding\n");
		}
		(void)Lst_AtFront(stoppedJobs, (ClientData)job);
		jobFull = TRUE;
		if (DEBUG(JOB)) {
		    printf("Job queue is full.\n");
		}
		return;
	} else {
		/*
		 * Job may be run locally.
		 */
		if (DEBUG(JOB)) {
		    printf("running locally\n");
		}
		job->flags &= ~JOB_REMOTE;
	}
	JobExec(job, argv);
    } else {
	/*
	 * The job has stopped and needs to be restarted. Why it stopped,
	 * we don't know...
	 */
	if (DEBUG(JOB)) {
	    printf("Resuming %s...", job->node->name);
	}
	if (((job->flags & JOB_REMOTE) ||
	     (nLocal < maxLocal) ||
	     (((job->flags & JOB_SPECIAL)) &&
	      (maxLocal == 0))) &&
	    (nJobs != maxJobs))
	{
	    /*
	     * If the job is remote, it's ok to resume it as long as the
	     * maximum concurrency won't be exceeded. If it's local and
	     * we haven't reached the local concurrency limit already (or the
	     * job must be run locally and maxLocal is 0), it's also ok to
	     * resume it.
	     */
	    Boolean error;
	    extern int errno;
	    union wait status;
	    
#ifdef RMT_WANTS_SIGNALS
	    if (job->flags & JOB_REMOTE) {
		error = !Rmt_Signal(job, SIGCONT);
	    } else
#endif	/* RMT_WANTS_SIGNALS */
		error = (KILL(job->pid, SIGCONT) != 0);

	    if (!error) {
		/*
		 * Make sure the user knows we've continued the beast and
		 * actually put the thing in the job table.
		 */
		job->flags |= JOB_CONTINUING;
		status.w_termsig = SIGCONT;
		JobFinish(job, status);
		
		job->flags &= ~(JOB_RESUME|JOB_CONTINUING);
		if (DEBUG(JOB)) {
		    printf("done\n");
		}
	    } else {
		Error("couldn't resume %s: %s",
		    job->node->name, strerror(errno));
		status.w_status = 0;
		status.w_retcode = 1;
		JobFinish(job, status);
	    }
	} else {
	    /*
	     * Job cannot be restarted. Mark the table as full and
	     * place the job back on the list of stopped jobs.
	     */
	    if (DEBUG(JOB)) {
		printf("table full\n");
	    }
	    (void)Lst_AtFront(stoppedJobs, (ClientData)job);
	    jobFull = TRUE;
	    if (DEBUG(JOB)) {
		printf("Job queue is full.\n");
	    }
	}
    }
}

/*-
 *-----------------------------------------------------------------------
 * JobStart  --
 *	Start a target-creation process going for the target described
 *	by the graph node gn. 
 *
 * Results:
 *	JOB_ERROR if there was an error in the commands, JOB_FINISHED
 *	if there isn't actually anything left to do for the job and
 *	JOB_RUNNING if the job has been started.
 *
 * Side Effects: