Synchronization problem stubs and drivers.

kern/conf/conf.kern

@@ -438,3 +438,8 @@ file		test/semunit.c
 file		test/kmalloctest.c
 file		test/fstest.c
 optfile net	test/nettest.c
+
+defoption synchprobs
+optfile   synchprobs  synchprobs/whalemating.c
+optfile   synchprobs  synchprobs/stoplight.c
+optfile   synchprobs  test/synchprobs.c

kern/include/synchprobs.h

@@ -0,0 +1,28 @@
+#ifndef _SYNCHPROBS_H_
+#define _SYNCHPROBS_H_
+
+/*
+ * Synchronization problem primitives.
+ */
+
+/*
+ * whalemating.c.
+ */
+
+void whalemating_init(void);
+void whalemating_cleanup(void);
+void male(void *, unsigned long);
+void female(void *, unsigned long);
+void matchmaker(void *, unsigned long);
+ 
+/*
+ * stoplight.c.
+ */
+
+void gostraight(void *, unsigned long);
+void turnleft(void *, unsigned long);
+void turnright(void *, unsigned long);
+void stoplight_init(void);
+void stoplight_cleanup(void);
+
+#endif /* _SYNCHPROBS_H_ */

kern/include/test.h

@@ -30,6 +30,8 @@
 #ifndef _TEST_H_
 #define _TEST_H_
 
+#include "opt-synchprobs.h"
+
 /*
  * Declarations for test code and other miscellaneous high-level
  * functions.
@@ -105,5 +107,24 @@ void menu(char *argstr);
 /* The main function, called from start.S. */
 void kmain(char *bootstring);
 
+#if OPT_SYNCHPROBS
+
+/*
+ * Synchronization driver primitives.
+ */
+
+void male_start(void);
+void male_end(void);
+void female_start(void);
+void female_end(void);
+void matchmaker_start(void);
+void matchmaker_end(void);
+int whalemating(int, char **);
+
+void inQuadrant(int);
+void leaveIntersection(void);
+int stoplight(int, char **);
+
+#endif
 
 #endif /* _TEST_H_ */

kern/main/menu.c

@@ -44,6 +44,7 @@
 #include <prompt.h>
 #include "opt-sfs.h"
 #include "opt-net.h"
+#include "opt-synchprobs.h"
 
 /*
  * In-kernel menu and command dispatcher.
@@ -478,6 +479,10 @@ static const char *testmenu[] = {
 	"[sy3] CV test               (1)     ",
 	"[sy4] CV test #2            (1)     ",
 	"[sy5] RW lock test          (1)     ",
+#if OPT_SYNCHPROBS
+	"[sp1] Whalemating test      (1)     ",
+	"[sp2] Stoplight test        (1)     ",
+#endif
 	"[semu1-22] Semaphore unit tests     ",
 	"[fs1] Filesystem test               ",
 	"[fs2] FS read stress                ",
@@ -581,6 +586,10 @@ static struct {
 	{ "sy3",	cvtest },
 	{ "sy4",	cvtest2 },
 	{ "sy5",	rwtest },
+#if OPT_SYNCHPROBS
+	{ "sp1",	whalemating },
+	{ "sp2",	stoplight },
+#endif
 
 	/* semaphore unit tests */
 	{ "semu1",	semu1 },

kern/synchprobs/stoplight.c

@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2001, 2002, 2009
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Driver code is in kern/tests/synchprobs.c We will
+ * replace that file. This file is yours to modify as you see fit.
+ *
+ * You should implement your solution to the stoplight problem below. The
+ * quadrant and direction mappings for reference: (although the problem is,
+ * of course, stable under rotation)
+ *
+ *   | 0 |
+ * --     --
+ *    0 1
+ * 3       1
+ *    3 2
+ * --     --
+ *   | 2 | 
+ *
+ * As way to think about it, assuming cars drive on the right: a car entering
+ * the intersection from direction X will enter intersection quadrant X
+ * first.
+ *
+ * You will probably want to write some helper functions to assist
+ * with the mappings. Modular arithmetic can help, e.g. a car passing
+ * straight through the intersection entering from direction X will leave to
+ * direction (X + 2) % 4 and pass through quadrants X and (X + 3) % 4.
+ * Boo-yah.
+ *
+ * Your solutions below should call the inQuadrant() and leaveIntersection()
+ * functions in synchprobs.c to record their progress.
+ */
+
+#include <types.h>
+#include <lib.h>
+#include <thread.h>
+#include <test.h>
+#include <synch.h>
+#include <synchprobs.h>
+
+/*
+ * Called by the driver during initialization.
+ */
+
+void
+stoplight_init() {
+	return;
+}
+
+/*
+ * Called by the driver during teardown.
+ */
+
+void stoplight_cleanup() {
+	return;
+}
+
+void
+gostraight(void *p, unsigned long direction)
+{
+	struct semaphore * stoplightMenuSemaphore = (struct semaphore *)p;
+	(void)direction;
+	
+	/*
+	 * Implement this function.
+	 */
+
+	/*
+	 * This code allows the test to return to the menu cleanly.
+	 */
+	V(stoplightMenuSemaphore);
+	return;
+}
+
+void
+turnleft(void *p, unsigned long direction)
+{
+	struct semaphore * stoplightMenuSemaphore = (struct semaphore *)p;
+	(void)direction;
+	
+	/*
+	 * Implement this function.
+	 */
+
+	/*
+	 * This code allows the test to return to the menu cleanly.
+	 */
+	V(stoplightMenuSemaphore);
+	return;
+}
+
+void
+turnright(void *p, unsigned long direction)
+{
+	struct semaphore * stoplightMenuSemaphore = (struct semaphore *)p;
+	(void)direction;
+	
+	/*
+	 * Implement this function.
+	 */
+
+	/*
+	 * This code allows the test to return to the menu cleanly.
+	 */
+	V(stoplightMenuSemaphore);
+	return;
+}

kern/synchprobs/whalemating.c

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2001, 2002, 2009
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Driver code is in kern/tests/synchprobs.c We will
+ * replace that file. This file is yours to modify as you see fit.
+ *
+ * You should implement your solution to the whalemating problem below.
+ */
+
+#include <types.h>
+#include <lib.h>
+#include <thread.h>
+#include <test.h>
+#include <synch.h>
+#include <synchprobs.h>
+
+/*
+ * Called by the driver during initialization.
+ */
+
+void whalemating_init() {
+	return;
+}
+
+/*
+ * Called by the driver during teardown.
+ */
+
+void
+whalemating_cleanup() {
+	return;
+}
+
+void
+male(void *p, unsigned long which)
+{
+	struct semaphore * whalematingMenuSemaphore = (struct semaphore *)p;
+	(void)which;
+
+	male_start();
+	/*
+	 * Implement this function.
+	 */
+	male_end();
+
+	/*
+	 * This code allows the test to return to the menu cleanly.
+	 */
+	V(whalematingMenuSemaphore);
+	return;
+}
+
+void
+female(void *p, unsigned long which)
+{
+	struct semaphore * whalematingMenuSemaphore = (struct semaphore *)p;
+	(void)which;
+
+	female_start();
+	/*
+	 * Implement this function.
+	 */
+	female_end();
+
+	/*
+	 * This code allows the test to return to the menu cleanly.
+	 */
+	V(whalematingMenuSemaphore);
+	return;
+}
+
+void
+matchmaker(void *p, unsigned long which)
+{
+	struct semaphore * whalematingMenuSemaphore = (struct semaphore *)p;
+	(void)which;
+
+	matchmaker_start();
+	/*
+	 * Implement this function.
+	 */
+	matchmaker_end();
+
+	/*
+	 * This code allows the test to return to the menu cleanly.
+	 */
+	V(whalematingMenuSemaphore);
+	return;
+}

kern/test/synchprobs.c

@@ -0,0 +1,202 @@
+/*
+ * 08 Feb 2012 : GWA : Please make any changes necessary to test your code to
+ * the drivers in this file. However, the automated testing suite *will
+ * replace this file in its entirety* with driver code intented to stress
+ * test your synchronization problem solutions.
+ */
+
+#include <types.h>
+#include <lib.h>
+#include <thread.h>
+#include <test.h>
+#include <current.h>
+#include <synch.h>
+#include <synchprobs.h>
+
+#define PROBLEMS_MAX_YIELDER 16
+#define PROBLEMS_MAX_SPINNER 8192
+
+/*
+ * 08 Feb 2012 : GWA : Driver code for the whalemating problem.
+ */
+
+/*
+ * 08 Feb 2012 : GWA : The following functions are for you to use when each
+ * whale starts and completes either mating (if it is a male or female) or
+ * matchmaking. We will use the output from these functions to verify the to
+ * verify the correctness of your solution. These functions may spin for
+ * arbitrary periods of time or yield.
+ */
+
+inline void male_start(void) {
+	random_yielder(PROBLEMS_MAX_YIELDER);
+	kprintf("%s starting\n", curthread->t_name);
+}
+
+inline void male_end(void) {
+	kprintf("%s ending\n", curthread->t_name);
+}
+
+inline void female_start(void) {
+	random_spinner(PROBLEMS_MAX_SPINNER);
+	kprintf("%s starting\n", curthread->t_name);
+}
+
+inline void female_end(void) {
+	kprintf("%s ending\n", curthread->t_name);
+}
+
+inline void matchmaker_start(void) {
+	random_yielder(PROBLEMS_MAX_YIELDER);
+	kprintf("%s starting\n", curthread->t_name);
+}
+
+inline void matchmaker_end(void) {
+	kprintf("%s ending\n", curthread->t_name);
+}
+
+/*
+ * 08 Feb 2012 : GWA : The following function drives the entire whalemating
+ * process. Feel free to modify at will, but make no assumptions about the
+ * order or timing of threads launched by our testing suite.
+ */
+
+#define NMATING 10
+
+struct semaphore * whalematingMenuSemaphore;
+
+int whalemating(int nargs, char **args) {
+	(void) nargs;
+	(void) args;
+
+	int i, j, err = 0;
+	char name[32];
+
+	whalematingMenuSemaphore = sem_create("Whalemating Driver Semaphore",
+			0);
+	if (whalematingMenuSemaphore == NULL ) {
+		panic("whalemating: sem_create failed.\n");
+	}
+
+	whalemating_init();
+
+	for (i = 0; i < 3; i++) {
+		for (j = 0; j < NMATING; j++) {
+
+			random_yielder(PROBLEMS_MAX_YIELDER);
+
+			switch (i) {
+				case 0:
+					snprintf(name, sizeof(name), "Male Whale Thread %d", (i * 3) + j);
+					err = thread_fork(name, NULL, male, whalematingMenuSemaphore, j);
+					break;
+				case 1:
+					snprintf(name, sizeof(name), "Female Whale Thread %d", (i * 3) + j);
+					err = thread_fork(name, NULL, female, whalematingMenuSemaphore, j);
+					break;
+				case 2:
+					snprintf(name, sizeof(name), "Matchmaker Whale Thread %d", (i * 3) + j);
+					err = thread_fork(name, NULL, matchmaker, whalematingMenuSemaphore, j);
+					break;
+			}
+			if (err) {
+				panic("whalemating: thread_fork failed: (%s)\n", strerror(err));
+			}
+		}
+	}
+
+	for (i = 0; i < 3; i++) {
+		for (j = 0; j < NMATING; j++) {
+			P(whalematingMenuSemaphore);
+		}
+	}
+
+	sem_destroy(whalematingMenuSemaphore);
+	whalemating_cleanup();
+
+	return 0;
+}
+
+/*
+ * 08 Feb 2012 : GWA : Driver code for the stoplight problem.
+ */
+
+/*
+ * 08 Feb 2012 : GWA : The following functions should be called by your
+ * stoplight solution when a car is in an intersection quadrant. The
+ * semantics of the problem are that once a car enters any quadrant it has to
+ * be somewhere in the intersection until it call leaveIntersection(), which
+ * it should call while in the final quadrant.
+ *
+ * As an example, let's say a car approaches the intersection and needs to
+ * pass through quadrants 0, 3 and 2. Once you call inQuadrant(0), the car is
+ * considered in quadrant 0 until you call inQuadrant(3). After you call
+ * inQuadrant(2), the car is considered in quadrant 2 until you call
+ * leaveIntersection().
+ * 
+ * As in the whalemating example, we will use the output from these functions
+ * to verify the correctness of your solution. These functions may spin for
+ * arbitrary periods of time or yield.
+ */
+
+inline void inQuadrant(int quadrant) {
+	random_spinner(PROBLEMS_MAX_SPINNER);
+	kprintf("%s in quadrant %d\n", curthread->t_name, quadrant);
+}
+
+inline void leaveIntersection() {
+	kprintf("%s left the intersection\n", curthread->t_name);
+}
+
+#define NCARS 99
+
+struct semaphore * stoplightMenuSemaphore;
+
+int stoplight(int nargs, char **args) {
+	(void) nargs;
+	(void) args;
+	int i, direction, turn, err = 0;
+	char name[32];
+
+	stoplightMenuSemaphore = sem_create("Stoplight Driver Semaphore", 0);
+	if (stoplightMenuSemaphore == NULL ) {
+		panic("stoplight: sem_create failed.\n");
+	}
+
+	stoplight_init();
+
+	for (i = 0; i < NCARS; i++) {
+
+		direction = random() % 4;
+		turn = random() % 3;
+
+		snprintf(name, sizeof(name), "Car Thread %d", i);
+
+		switch (turn) {
+
+			random_yielder(PROBLEMS_MAX_YIELDER);
+
+			case 0:
+			err = thread_fork(name, NULL, gostraight, stoplightMenuSemaphore, direction);
+			break;
+			case 1:
+			err = thread_fork(name, NULL, turnleft, stoplightMenuSemaphore, direction);
+			break;
+			case 2:
+			err = thread_fork(name, NULL, turnright, stoplightMenuSemaphore, direction);
+			break;
+		}
+		if (err) {
+			panic("stoplight: thread_fork failed: (%s)\n", strerror(err));
+		}
+	}
+
+	for (i = 0; i < NCARS; i++) {
+		P(stoplightMenuSemaphore);
+	}
+
+	sem_destroy(stoplightMenuSemaphore);
+	stoplight_cleanup();
+
+	return 0;
+}