job.c

早期freebsd实现

 *	A new Job node is created and added to the list of running
 *	jobs. PMake is forked and a child shell created.
 *-----------------------------------------------------------------------
 */
static int
JobStart (gn, flags, previous)
    GNode         *gn;	      /* target to create */
    short	  flags;      /* flags for the job to override normal ones.
			       * e.g. JOB_SPECIAL or JOB_IGNDOTS */
    Job 	  *previous;  /* The previous Job structure for this node,
			       * if any. */
{
    register Job  *job;       /* new job descriptor */
    char	  *argv[4];   /* Argument vector to shell */
    static int    jobno = 0;  /* job number of catching output in a file */
    Boolean	  cmdsOK;     /* true if the nodes commands were all right */
    Boolean 	  local;      /* Set true if the job was run locally */
    Boolean 	  noExec;     /* Set true if we decide not to run the job */

    if (previous != (Job *)NULL) {
	previous->flags &= ~ (JOB_FIRST|JOB_IGNERR|JOB_SILENT|JOB_REMOTE);
	job = previous;
    } else {
	job = (Job *) emalloc (sizeof (Job));
	if (job == (Job *)NULL) {
	    Punt("JobStart out of memory");
	}
	flags |= JOB_FIRST;
    }

    job->node = gn;
    job->tailCmds = NILLNODE;

    /*
     * Set the initial value of the flags for this job based on the global
     * ones and the node's attributes... Any flags supplied by the caller
     * are also added to the field.
     */
    job->flags = 0;
    if (Targ_Ignore (gn)) {
	job->flags |= JOB_IGNERR;
    }
    if (Targ_Silent (gn)) {
	job->flags |= JOB_SILENT;
    }
    job->flags |= flags;

    /*
     * Check the commands now so any attributes from .DEFAULT have a chance
     * to migrate to the node
     */
    if (job->flags & JOB_FIRST) {
	cmdsOK = Job_CheckCommands(gn, Error);
    } else {
	cmdsOK = TRUE;
    }
    
    /*
     * If the -n flag wasn't given, we open up OUR (not the child's)
     * temporary file to stuff commands in it. The thing is rd/wr so we don't
     * need to reopen it to feed it to the shell. If the -n flag *was* given,
     * we just set the file to be stdout. Cute, huh?
     */
    if ((gn->type & OP_MAKE) || (!noExecute && !touchFlag)) {
	/*
	 * We're serious here, but if the commands were bogus, we're
	 * also dead...
	 */
	if (!cmdsOK) {
	    DieHorribly();
	}
	
	job->cmdFILE = fopen (tfile, "w+");
	if (job->cmdFILE == (FILE *) NULL) {
	    Punt ("Could not open %s", tfile);
	}
	fcntl(fileno(job->cmdFILE), F_SETFD, 1);
	/*
	 * Send the commands to the command file, flush all its buffers then
	 * rewind and remove the thing.
	 */
	noExec = FALSE;

	/*
	 * used to be backwards; replace when start doing multiple commands
	 * per shell.
	 */
	if (compatMake) {
	    /*
	     * Be compatible: If this is the first time for this node,
	     * verify its commands are ok and open the commands list for
	     * sequential access by later invocations of JobStart.
	     * Once that is done, we take the next command off the list
	     * and print it to the command file. If the command was an
	     * ellipsis, note that there's nothing more to execute.
	     */
	    if ((job->flags&JOB_FIRST) && (Lst_Open(gn->commands) != SUCCESS)){
		cmdsOK = FALSE;
	    } else {
		LstNode	ln = Lst_Next (gn->commands);
		    
		if ((ln == NILLNODE) ||
		    JobPrintCommand ((char *)Lst_Datum (ln), job))
		{
		    noExec = TRUE;
		    Lst_Close (gn->commands);
		}
		if (noExec && !(job->flags & JOB_FIRST)) {
		    /*
		     * If we're not going to execute anything, the job
		     * is done and we need to close down the various
		     * file descriptors we've opened for output, then
		     * call JobDoOutput to catch the final characters or
		     * send the file to the screen... Note that the i/o streams
		     * are only open if this isn't the first job.
		     * Note also that this could not be done in
		     * Job_CatchChildren b/c it wasn't clear if there were
		     * more commands to execute or not...
		     */
		    if (usePipes) {
#ifdef RMT_WILL_WATCH
			Rmt_Ignore(job->inPipe);
#else
			FD_CLR(job->inPipe, &outputs);
#endif
			if (job->outPipe != job->inPipe) {
			    (void)close (job->outPipe);
			}
			JobDoOutput (job, TRUE);
			(void)close (job->inPipe);
		    } else {
			(void)close (job->outFd);
			JobDoOutput (job, TRUE);
		    }
		}
	    }
	} else {
	    /*
	     * We can do all the commands at once. hooray for sanity
	     */
	    numCommands = 0;
	    Lst_ForEach (gn->commands, JobPrintCommand, (ClientData)job);
	    
	    /*
	     * If we didn't print out any commands to the shell script,
	     * there's not much point in executing the shell, is there?
	     */
	    if (numCommands == 0) {
		noExec = TRUE;
	    }
	}
    } else if (noExecute) {
	/*
	 * Not executing anything -- just print all the commands to stdout
	 * in one fell swoop. This will still set up job->tailCmds correctly.
	 */
	if (lastNode != gn) {
	    printf (targFmt, gn->name);
	    lastNode = gn;
	}
	job->cmdFILE = stdout;
	/*
	 * Only print the commands if they're ok, but don't die if they're
	 * not -- just let the user know they're bad and keep going. It
	 * doesn't do any harm in this case and may do some good.
	 */
	if (cmdsOK) {
	    Lst_ForEach(gn->commands, JobPrintCommand, (ClientData)job);
	}
	/*
	 * Don't execute the shell, thank you.
	 */
	noExec = TRUE;
    } else {
	/*
	 * Just touch the target and note that no shell should be executed.
	 * Set cmdFILE to stdout to make life easier. Check the commands, too,
	 * but don't die if they're no good -- it does no harm to keep working
	 * up the graph.
	 */
	job->cmdFILE = stdout;
    	Job_Touch (gn, job->flags&JOB_SILENT);
	noExec = TRUE;
    }

    /*
     * If we're not supposed to execute a shell, don't. 
     */
    if (noExec) {
	/*
	 * Unlink and close the command file if we opened one
	 */
	if (job->cmdFILE != stdout) {
	    (void) unlink (tfile);
	    fclose(job->cmdFILE);
	} else {
	    fflush (stdout);
	}

	/*
	 * We only want to work our way up the graph if we aren't here because
	 * the commands for the job were no good.
	 */
	if (cmdsOK) {
	    if (aborting == 0) {
		if (job->tailCmds != NILLNODE) {
		    Lst_ForEachFrom(job->node->commands, job->tailCmds,
				    JobSaveCommand,
				    (ClientData)job->node);
		}
		Make_Update(job->node);
	    }
	    free((Address)job);
	    return(JOB_FINISHED);
	} else {
	    free((Address)job);
	    return(JOB_ERROR);
	}
    } else {
	fflush (job->cmdFILE);
	(void) unlink (tfile);
    }

    /*
     * Set up the control arguments to the shell. This is based on the flags
     * set earlier for this job.
     */
    JobMakeArgv(job, argv);

    /*
     * If we're using pipes to catch output, create the pipe by which we'll
     * get the shell's output. If we're using files, print out that we're
     * starting a job and then set up its temporary-file name. This is just
     * tfile with two extra digits tacked on -- jobno.
     */
    if (job->flags & JOB_FIRST) {
	if (usePipes) {
	    int fd[2];
	    (void) pipe(fd); 
	    job->inPipe = fd[0];
	    job->outPipe = fd[1];
	    (void)fcntl (job->inPipe, F_SETFD, 1);
	    (void)fcntl (job->outPipe, F_SETFD, 1);
	} else {
	    printf ("Remaking `%s'\n", gn->name);
	    fflush (stdout);
	    sprintf (job->outFile, "%s%02d", tfile, jobno);
	    jobno = (jobno + 1) % 100;
	    job->outFd = open(job->outFile,O_WRONLY|O_CREAT|O_APPEND,0600);
	    (void)fcntl (job->outFd, F_SETFD, 1);
	}
    }

    local = TRUE;

    if (local && (((nLocal >= maxLocal) &&
	 !(job->flags & JOB_SPECIAL) &&
	 (maxLocal != 0))))
    {
	/*
	 * The job can only be run locally, but we've hit the limit of
	 * local concurrency, so put the job on hold until some other job
	 * finishes. Note that the special jobs (.BEGIN, .INTERRUPT and .END)
	 * may be run locally even when the local limit has been reached
	 * (e.g. when maxLocal == 0), though they will be exported if at
	 * all possible. 
	 */
	jobFull = TRUE;
	
	if (DEBUG(JOB)) {
	    printf("Can only run job locally.\n");
	}
	job->flags |= JOB_RESTART;
	(void)Lst_AtEnd(stoppedJobs, (ClientData)job);
    } else {
	if ((nLocal >= maxLocal) && local) {
	    /*
	     * If we're running this job locally as a special case (see above),
	     * at least say the table is full.
	     */
	    jobFull = TRUE;
	    if (DEBUG(JOB)) {
		printf("Local job queue is full.\n");
	    }
	}
	JobExec(job, argv);
    }
    return(JOB_RUNNING);
}

/*-
 *-----------------------------------------------------------------------
 * JobDoOutput  --
 *	This function is called at different times depending on
 *	whether the user has specified that output is to be collected
 *	via pipes or temporary files. In the former case, we are called
 *	whenever there is something to read on the pipe. We collect more
 *	output from the given job and store it in the job's outBuf. If
 *	this makes up a line, we print it tagged by the job's identifier,
 *	as necessary.
 *	If output has been collected in a temporary file, we open the
 *	file and read it line by line, transfering it to our own
 *	output channel until the file is empty. At which point we
 *	remove the temporary file.
 *	In both cases, however, we keep our figurative eye out for the
 *	'noPrint' line for the shell from which the output came. If
 *	we recognize a line, we don't print it. If the command is not
 *	alone on the line (the character after it is not \0 or \n), we
 *	do print whatever follows it.
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	curPos may be shifted as may the contents of outBuf.
 *-----------------------------------------------------------------------
 */
static void
JobDoOutput (job, finish)
    register Job   *job;	  /* the job whose output needs printing */
    Boolean	   finish;	  /* TRUE if this is the last time we'll be
				   * called for this job */
{
    Boolean       gotNL = FALSE;  /* true if got a newline */
    register int  nr;	      	  /* number of bytes read */
    register int  i;	      	  /* auxiliary index into outBuf */
    register int  max;	      	  /* limit for i (end of current data) */
    int		  nRead;      	  /* (Temporary) number of bytes read */

    FILE      	  *oFILE;	  /* Stream pointer to shell's output file */
    char          inLine[132];

    
    if (usePipes) {
	/*
	 * Read as many bytes as will fit in the buffer.
	 */
end_loop:
	
	nRead = read (job->inPipe, &job->outBuf[job->curPos],
			 JOB_BUFSIZE - job->curPos);
	if (nRead < 0) {
	    if (DEBUG(JOB)) {
		perror("JobDoOutput(piperead)");
	    }
	    nr = 0;
	} else {
	    nr = nRead;
	}

	/*
	 * If we hit the end-of-file (the job is dead), we must flush its
	 * remaining output, so pretend we read a newline if there's any
	 * output remaining in the buffer.
	 * Also clear the 'finish' flag so we stop looping.
	 */
	if ((nr == 0) && (job->curPos != 0)) {
	    job->outBuf[job->curPos] = '\n';
	    nr = 1;
	    finish = FALSE;
	} else if (nr == 0) {
	    finish = FALSE;
	}
	
	/*
	 * Look for the last newline in the bytes we just got. If there is
	 * one, break out of the loop with 'i' as its index and gotNL set
	 * TRUE. 
	 */
	max = job->curPos + nr;
	for (i = job->curPos + nr - 1; i >= job->curPos; i--) {
	    if (job->outBuf[i] == '\n') {
		gotNL = TRUE;
		break;
	    } else if (job->outBuf[i] == '\0') {
		/*
		 * Why?
		 */
		job->outBuf[i] = ' ';
	    }
	}
	
	if (!gotNL) {
	    job->curPos += nr;
	    if (job->curPos == JOB_BUFSIZE) {
		/*
		 * If we've run out of buffer space, we have no choice
		 * but to print the stuff. sigh. 
		 */
		gotNL = TRUE;
		i = job->curPos;
	    }
	}
	if (gotNL) {
	    /*
	     * Need to send the output to the screen. Null terminate it
	     * first, overwriting the newline character if there was one.
	     * So long as the line isn't one we should filter (according
	     * to the shell description), we print the line, preceeded
	     * by a target banner if this target isn't the same as the
	     * one for which we last printed something.
	     * The rest of the data in the buffer are then shifted down
	     * to the start of the buffer and curPos is set accordingly. 
	     */
	    job->outBuf[i] = '\0';
	    if (i >= job->curPos) {
		register char	*cp, *ecp;

		cp = job->outBuf;
		if (commandShell->noPrint) {
		    ecp = Str_FindSubstring(job->outBuf,
					    commandShell->noPrint);
		    while (ecp != (char *)NULL) {
			if (cp != ecp) {
			    *ecp = '\0';
			    if (job->node != lastNode) {
				printf (targFmt, job->node->name);
				lastNode = job->node;
			    }
			    /*
			     * The only way there wouldn't be a newline after
			     * this line is if it were the last in the buffer.
			     * however, since the non-printable comes after it,
			     * there must be a newline, so we don't print one.
			     */
			    printf ("%s", cp);
			}
			cp = ecp + commandShell->noPLen;
			if (cp != &job->outBuf[i]) {
			    /*
			     * Still more to print, look again after skipping
			     * the whitespace following the non-printable
			     * command....
			     */
			    cp++;
			    while (*cp == ' ' || *cp == '\t' || *cp == '\n') {
				cp++;
			    }
			    ecp = Str_FindSubstring (cp,
						     commandShell->noPrint);
			} else {
			    break;
			}
		    }
		}

		/*
		 * There's still more in that thar buffer. This time, though,
		 * we know there's no newline at the end, so we add one of
		 * our own free will.
		 */
		if (*cp != '\0') {