simplify the way we account for different jobs:

- have a simple variable "sequential" that counts  whether we are
running more than one job (for the expensive heuristics)
- don't expose various things globally, just have a set_noparallel() for
the parser
- preallocate exactly enough job structures and record them in availableJobs
- keep one job on the side for .INTERRUPT

7 files changed, 76 insertions, 50 deletions

diff --git a/usr.bin/make/engine.c b/usr.bin/make/engine.c
index 9a87799b9b5..45cd390d33f 100644
--- a/usr.bin/make/engine.c
+++ b/usr.bin/make/engine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: engine.c,v 1.62 2020/01/13 14:15:21 espie Exp $ */
+/*	$OpenBSD: engine.c,v 1.63 2020/01/13 14:51:50 espie Exp $ */
 /*
  * Copyright (c) 2012 Marc Espie.
  *
@@ -603,8 +603,6 @@ run_command(const char *cmd, bool errCheck)
 	_exit(1);
 }
 
-static Job myjob;
-
 void
 job_attach_node(Job *job, GNode *node)
 {
@@ -680,7 +678,7 @@ job_handle_status(Job *job, int status)
 			 * JOB_IS_EXPENSIVE, perform the computation for
 			 * sequential make to figure out whether to display the
 			 * command or not.  */
-			if ((job->flags & JOB_SILENT) && job == &myjob)
+			if ((job->flags & JOB_SILENT) && sequential)
 				determine_expensive_job(job);
 			if ((job->flags & (JOB_SILENT | JOB_IS_EXPENSIVE)) 
 			    == JOB_SILENT)
@@ -702,17 +700,23 @@ job_handle_status(Job *job, int status)
 int
 run_gnode(GNode *gn)
 {
+	Job *j;
 	if (!gn || (gn->type & OP_DUMMY))
 		return NOSUCHNODE;
 
-	job_attach_node(&myjob, gn);
-	while (myjob.exit_type == JOB_EXIT_OKAY) {
-		bool finished = job_run_next(&myjob);
+	assert(availableJobs != NULL);
+	j = availableJobs;
+	availableJobs = availableJobs->next;
+	job_attach_node(j, gn);
+	while (j->exit_type == JOB_EXIT_OKAY) {
+		bool finished = job_run_next(j);
 		if (finished)
 			break;
-		handle_one_job(&myjob);
+		handle_one_job(j);
 	}
 
+	j->next = availableJobs;
+	availableJobs = j;
 	return gn->built_status;
 }
 
diff --git a/usr.bin/make/extern.h b/usr.bin/make/extern.h
index 89797d685b9..2fcafa1fbf6 100644
--- a/usr.bin/make/extern.h
+++ b/usr.bin/make/extern.h
@@ -1,7 +1,7 @@
 #ifndef EXTERN_H
 #define EXTERN_H
 
-/*	$OpenBSD: extern.h,v 1.43 2010/07/19 19:46:44 espie Exp $	*/
+/*	$OpenBSD: extern.h,v 1.44 2020/01/13 14:51:50 espie Exp $	*/
 /*	$NetBSD: nonints.h,v 1.12 1996/11/06 17:59:19 christos Exp $	*/
 
 /*-
@@ -40,7 +40,6 @@
  *	from: @(#)nonints.h	8.3 (Berkeley) 3/19/94
  */
 
-extern bool	compatMake;	/* True if we are make compatible */
 extern bool	ignoreErrors;	/* True if should ignore all errors */
 extern bool	beSilent;	/* True if should print no commands */
 extern bool	noExecute;	/* True if should execute nothing */
diff --git a/usr.bin/make/job.c b/usr.bin/make/job.c
index cf2828aeff8..ece5b323c5d 100644
--- a/usr.bin/make/job.c
+++ b/usr.bin/make/job.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: job.c,v 1.147 2020/01/13 14:14:24 espie Exp $	*/
+/*	$OpenBSD: job.c,v 1.148 2020/01/13 14:51:50 espie Exp $	*/
 /*	$NetBSD: job.c,v 1.16 1996/11/06 17:59:08 christos Exp $	*/
 
 /*
@@ -121,15 +121,16 @@ static int	aborting = 0;	    /* why is the make aborting? */
 #define ABORT_INTERRUPT 2	    /* Because it was interrupted */
 #define ABORT_WAIT	3	    /* Waiting for jobs to finish */
 
-static int	maxJobs;	/* The most children we can run at once */
-static int	nJobs;		/* Number of jobs already allocated */
 static bool	no_new_jobs;	/* Mark recursive shit so we shouldn't start
 				 * something else at the same time
 				 */
+bool sequential;
 Job *runningJobs;		/* Jobs currently running a process */
 Job *errorJobs;			/* Jobs in error at end */
+Job *availableJobs;		/* Pool of available jobs */
 static Job *heldJobs;		/* Jobs not running yet because of expensive */
 static pid_t mypid;		/* Used for printing debugging messages */
+static Job *extra_job;		/* Needed for .INTERRUPT */
 
 static volatile sig_atomic_t got_fatal;
 
@@ -538,14 +539,19 @@ postprocess_job(Job *job)
 	if (job->exit_type == JOB_EXIT_OKAY &&
 	    aborting != ABORT_ERROR &&
 	    aborting != ABORT_INTERRUPT) {
+		job->next = availableJobs;
+		availableJobs = job;
 		/* As long as we aren't aborting and the job didn't return a
 		 * non-zero status that we shouldn't ignore, we call
 		 * Make_Update to update the parents. */
 		job->node->built_status = REBUILT;
 		Make_Update(job->node);
-		free(job);
-	} else if (job->exit_type != JOB_EXIT_OKAY && keepgoing)
-		free(job);
+		job->next = availableJobs;
+		availableJobs = job;
+	} else if (job->exit_type != JOB_EXIT_OKAY && keepgoing) {
+		job->next = availableJobs;
+		availableJobs = job;
+	}
 
 	if (errorJobs != NULL && aborting != ABORT_INTERRUPT)
 		aborting = ABORT_ERROR;
@@ -662,12 +668,10 @@ prepare_job(GNode *gn)
 			Job_Touch(gn);
 			return NULL;
 		} else {
-			Job *job;       	
-
-			job = emalloc(sizeof(Job));
-			if (job == NULL)
-				Punt("can't create job: out of memory");
+			Job *job = availableJobs;       	
 
+			assert(job != NULL);
+			availableJobs = availableJobs->next;
 			job_attach_node(job, gn);
 			return job;
 		}
@@ -696,7 +700,7 @@ continue_job(Job *job)
 	bool finished = job_run_next(job);
 	if (finished)
 		remove_job(job);
-	else
+	else if (!sequential)
 		determine_expensive_job(job);
 }
 
@@ -719,7 +723,6 @@ Job_Make(GNode *gn)
 	job = prepare_job(gn);
 	if (!job)
 		return;
-	nJobs++;
 	may_continue_job(job);
 }
 
@@ -745,7 +748,6 @@ determine_job_next_step(Job *job)
 static void
 remove_job(Job *job)
 {
-	nJobs--;
 	postprocess_job(job);
 }
 
@@ -876,16 +878,27 @@ loop_handle_running_jobs()
 }
 
 void
-Job_Init(int maxproc)
+Job_Init(int maxJobs)
 {
+	Job *j;
+	int i;
+
 	runningJobs = NULL;
 	heldJobs = NULL;
 	errorJobs = NULL;
-	maxJobs = maxproc;
+	availableJobs = NULL;
+	sequential = maxJobs == 1;
+
+	/* we allocate n+1 jobs, since we may need an extra job for
+	 * running .INTERRUPT.  */
+	j = ereallocarray(NULL, sizeof(Job), maxJobs+1);
+	for (i = 0; i != maxJobs; i++) {
+		j[i].next = availableJobs;
+		availableJobs = &j[i];
+	}
+	extra_job = &j[maxJobs];
 	mypid = getpid();
 
-	nJobs = 0;
-
 	aborting = 0;
 	setup_all_signals();
 }
@@ -893,7 +906,7 @@ Job_Init(int maxproc)
 bool
 can_start_job(void)
 {
-	if (aborting || nJobs >= maxJobs)
+	if (aborting || availableJobs == NULL)
 		return false;
 	else
 		return true;
@@ -933,7 +946,8 @@ handle_fatal_signal(int signo)
 	if (signo == SIGINT && !touchFlag) {
 		if ((interrupt_node->type & OP_DUMMY) == 0) {
 			ignoreErrors = false;
-
+			extra_job->next = availableJobs;
+			availableJobs = extra_job;
 			Job_Make(interrupt_node);
 		}
 	}
diff --git a/usr.bin/make/job.h b/usr.bin/make/job.h
index e8152d18fd0..8c0d9aa1fe9 100644
--- a/usr.bin/make/job.h
+++ b/usr.bin/make/job.h
@@ -1,7 +1,7 @@
 #ifndef _JOB_H_
 #define _JOB_H_
 
-/*	$OpenBSD: job.h,v 1.31 2012/12/14 11:10:03 espie Exp $	*/
+/*	$OpenBSD: job.h,v 1.32 2020/01/13 14:51:50 espie Exp $	*/
 /*	$NetBSD: job.h,v 1.5 1996/11/06 17:59:10 christos Exp $ */
 
 /*
@@ -93,11 +93,13 @@ extern void handle_running_jobs(void);
 extern void handle_all_signals(void);
 
 extern void determine_expensive_job(Job *);
-extern Job *runningJobs, *errorJobs;
+extern Job *runningJobs, *errorJobs, *availableJobs;
 extern void debug_job_printf(const char *, ...);
 extern void handle_one_job(Job *);
 extern int check_dying_signal(void);
 
 extern const char *basedirectory;
 
+extern bool	sequential;	/* True if we are running one single-job */
+
 #endif /* _JOB_H_ */
diff --git a/usr.bin/make/main.c b/usr.bin/make/main.c
index 4d8a038ef43..8757e51f304 100644
--- a/usr.bin/make/main.c
+++ b/usr.bin/make/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.124 2020/01/08 14:09:29 espie Exp $ */
+/*	$OpenBSD: main.c,v 1.125 2020/01/13 14:51:50 espie Exp $ */
 /*	$NetBSD: main.c,v 1.34 1997/03/24 20:56:36 gwr Exp $	*/
 
 /*
@@ -73,12 +73,12 @@ static LIST		to_create; 	/* Targets to be made */
 Lst create = &to_create;
 bool 		allPrecious;	/* .PRECIOUS given on line by itself */
 
-static bool		noBuiltins;	/* -r flag */
-static LIST		makefiles;	/* ordered list of makefiles to read */
-static LIST		varstoprint;	/* list of variables to print */
-int			maxJobs;	/* -j argument */
-bool 		compatMake;	/* -B argument */
-static bool		forceJobs = false;
+static bool	noBuiltins;	/* -r flag */
+static LIST	makefiles;	/* ordered list of makefiles to read */
+static LIST	varstoprint;	/* list of variables to print */
+static int	optj;		/* -j argument */
+static bool 	compatMake;	/* -B argument */
+static bool	forceJobs = false;
 int 		debug;		/* -d flag */
 bool 		noExecute;	/* -n flag */
 bool 		keepgoing;	/* -k flag */
@@ -126,6 +126,12 @@ record_option(int c, const char *arg)
 		Var_Append(MAKEFLAGS, arg);
 }
 
+void
+set_notparallel()
+{
+	compatMake = true;
+}
+
 static void
 posixParseOptLetter(int c)
 {
@@ -313,7 +319,7 @@ MainParseArgs(int argc, char **argv)
 			const char *errstr;
 
 			forceJobs = true;
-			maxJobs = strtonum(optarg, 1, INT_MAX, &errstr);
+			optj = strtonum(optarg, 1, INT_MAX, &errstr);
 			if (errstr != NULL) {
 				fprintf(stderr,
 				    "make: illegal argument to -j option"
@@ -676,7 +682,7 @@ main(int argc, char **argv)
 	touchFlag = false;		/* Actually update targets */
 	debug = 0;			/* No debug verbosity, please. */
 
-	maxJobs = DEFMAXJOBS;
+	optj = DEFMAXJOBS;
 	compatMake = false;		/* No compat mode */
 
 
@@ -757,6 +763,9 @@ main(int argc, char **argv)
 
 	read_all_make_rules(noBuiltins, read_depend, &makefiles, &d);
 
+	if (compatMake)
+		optj = 1;
+
 	Var_Append("MFLAGS", Var_Value(MAKEFLAGS));
 
 	/* Install all the flags into the MAKEFLAGS env variable. */
@@ -796,7 +805,7 @@ main(int argc, char **argv)
 		else
 			Targ_FindList(&targs, create);
 
-		Job_Init(maxJobs);
+		Job_Init(optj);
 		/* If the user has defined a .BEGIN target, execute the commands
 		 * attached to it.  */
 		if (!queryFlag)
diff --git a/usr.bin/make/main.h b/usr.bin/make/main.h
index 469487ee058..035de86e602 100644
--- a/usr.bin/make/main.h
+++ b/usr.bin/make/main.h
@@ -1,6 +1,6 @@
 #ifndef MAIN_H
 #define MAIN_H
-/*	$OpenBSD: main.h,v 1.5 2010/07/19 19:46:44 espie Exp $ */
+/*	$OpenBSD: main.h,v 1.6 2020/01/13 14:51:50 espie Exp $ */
 
 /*
  * Copyright (c) 2001 Marc Espie.
@@ -38,4 +38,7 @@ extern void Main_ParseArgLine(const char *);
  * .if make(...) statements. */
 extern Lst	create;
 
+/* set_notparallel(): used to influence running mode from parse.c */
+extern void set_notparallel(void);
+
 #endif
diff --git a/usr.bin/make/parse.c b/usr.bin/make/parse.c
index 2dfae983d67..4c8a8fa7de2 100644
--- a/usr.bin/make/parse.c
+++ b/usr.bin/make/parse.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.c,v 1.129 2020/01/13 14:07:35 espie Exp $	*/
+/*	$OpenBSD: parse.c,v 1.130 2020/01/13 14:51:50 espie Exp $	*/
 /*	$NetBSD: parse.c,v 1.29 1997/03/10 21:20:04 christos Exp $	*/
 
 /*
@@ -739,13 +739,8 @@ handle_special_targets(Lst paths)
 			}
 			break;
 		case SPECIAL_NOTPARALLEL:
-		{
-			extern int  maxJobs;
-
-			maxJobs = 1;
-			compatMake = 1;
+			set_notparallel();
 			break;
-		}
 		case SPECIAL_ORDER:
 			predecessor = NULL;
 			break;