Cooperative multitasking added.

client/client.pro

@@ -44,6 +44,7 @@ INCLUDEPATH += \
 HEADERS = \
 	$$LINUX_HEADERS \
 	src/gui/button.h \
+	src/gui/task.h \
 	src/thirdparty/stb_ds.h \
 	src/thirdparty/stb_leakcheck.h \
 	src/thirdparty/stb_image.h \
@@ -67,6 +68,7 @@ SOURCES = \
 	src/gui/font.c \
 	src/gui/desktop.c \
 	src/gui/gui.c \
+	src/gui/task.c \
 	src/gui/widget.c \
 	src/gui/window.c \
 	src/gui/image.c \

client/src/dos/vesa.c

@@ -377,7 +377,7 @@ static uint8_t vbeIsDesiredMode(void) {
 		// Packed or Direct Color mode.
 		if (_vbeModeInfo.memoryModel == VBE_MM_PACKED || _vbeModeInfo.memoryModel == VBE_MM_DCOLOR) {
 			// Resolution minimum of 640x480.
-			if (_vbeModeInfo.xResolution >= 640 && _vbeModeInfo.yResolution >= 480) {
+			if (_vbeModeInfo.xResolution >= 800 && _vbeModeInfo.yResolution >= 600) {
 				// Multiple of 8
 				if (DIVISIBLE_BY_EIGHT(_vbeModeInfo.xResolution) && DIVISIBLE_BY_EIGHT(_vbeModeInfo.yResolution)) {
 					// Valid mode!
@@ -601,8 +601,8 @@ uint16_t vbeSetScanlineLength(uint16_t pixelLength) {
 	r.x.bx = 0x0000;
 	r.x.cx = pixelLength;
 	__dpmi_int(0x10, &r);
-	if(r.h.ah != 0) return(0);
+	if (r.h.ah != 0) return(0);
-	if(r.x.cx != pixelLength) return(0);
+	if (r.x.cx != pixelLength) return(0);
 
 	_vbeSurface.virtualXResolution = pixelLength;
 
@@ -615,11 +615,11 @@ int16_t vbeShowInfo(void) {
 
 	//    0        1         2         3         4         5         6         7         8
 	//    12345678901234567890123456789012345678901234567890123456789012345678901234567890
-	printf("VBE 2.0 driver v1.0 (c) 2021, Scott Duensing <scott@kangaroopunch.com>\n");
+	//printf("VBE 2.0 driver v1.0 (c) 2021, Scott Duensing <scott@kangaroopunch.com>\n");
-	printf("Based on:  VBE 2.0 driver v1.0 (c) 1999, Tobias Koch <tobias.koch@gmail.com>\n\n");
+	//printf("Based on:  VBE 2.0 driver v1.0 (c) 1999, Tobias Koch <tobias.koch@gmail.com>\n\n");
 
 	if (vbeGetInfo() == NULL) {
-		printf("No VESA BIOS Extensions found.\n\n");
+		printf("No VESA BIOS Extensions found.\n");
 		return(1);
 	}
 	printf(
@@ -643,7 +643,7 @@ int16_t vbeShowInfo(void) {
 			_vbeInfo.oemProductRevPtr,
 			vbeGetPmodeInterface() ? "Found" : "Missing");
 	} else {
-		printf("VESA BIOS Extension 2.0 or better required!\n\n");
+		printf("VESA BIOS Extension 2.0 or better required!\n");
 		return(1);
 	}
 

client/src/gui/gui.c

@@ -18,6 +18,9 @@
  */
 
 
+// Inspired by https://github.com/JMarlin/wsbe
+
+
 #include "gui.h"
 #include "widget.h"
 #include "desktop.h"

client/src/gui/gui.h

@@ -22,9 +22,6 @@
 #define GUI_H
 
 
-// Inspired by https://github.com/JMarlin/wsbe
-
-
 #include "os.h"
 #include "vesa.h"
 #include "array.h"

client/src/gui/task.c

@@ -0,0 +1,222 @@
+/*
+ * Kangaroo Punch Multi Player Game Server Mark II
+ * Copyright (C) 2020-2021  Scott Duensing
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+
+// Based on https://brennan.io/2020/05/24/userspace-cooperative-multitasking/
+
+
+// https://sourceforge.net/p/predef/wiki/Home/
+#if !defined(__i386__) && !defined(__i486__) && !defined(__i586__) && !defined(__i686__) && !defined(__x86_64__)
+#error "Only Intel 386 and later processors are supported."
+#endif
+
+#if !defined(__DJGPP__) && !defined(__GNUC__)
+#error "Requires GCC or DJGPP."
+#endif
+
+
+#include <setjmp.h>
+
+#include "os.h"
+#include "task.h"
+#include "array.h"
+
+
+typedef struct TaskS {
+	enum {
+		STATE_CREATED,
+		STATE_RUNNING,
+		STATE_WAITING
+	}              status;
+	uint32_t       id;
+	jmp_buf        buf;
+	void         (*function)(void *);
+	void          *data;
+	void          *stackBottom;
+	void          *stackTop;
+	uint32_t       stackSize;
+} TaskT;
+
+enum {
+	INIT = 0,
+	SCHEDULE,
+	EXIT_TASK,
+};
+
+typedef struct PrivateS {
+	jmp_buf   buf;
+	TaskT    *current;
+	TaskT   **taskList;
+} PrivateT;
+
+
+static PrivateT _private;
+static uint16_t _stackSizeInK;
+
+
+static TaskT *taskChoose(void);
+static void   taskFree(void);
+static void   taskSchedule(void);
+
+
+static TaskT *taskChoose(void) {
+	TaskT    *task = NULL;
+	uint32_t  len  = arrlenu(_private.taskList);
+	uint32_t  x;
+
+	// Find the next task to run.
+	for (x=0; x<len; x++) {
+		task = _private.taskList[x];
+		if (task->status == STATE_CREATED || task->status == STATE_RUNNING) {
+			// Move it to the end of the list.
+			arrdel(_private.taskList, x);
+			arrput(_private.taskList, task);
+			break;
+		}
+	}
+
+	return task;
+}
+
+
+void taskCreate(void (*function)(void *), void *data) {
+	static uint32_t  id = 1;
+	TaskT           *task = (TaskT *)malloc(sizeof(TaskT));
+
+	task->status      = STATE_CREATED;
+	task->function    = function;
+	task->data        = data;
+	task->id          = id++;
+	task->stackSize   = _stackSizeInK * 1024;
+	task->stackBottom = malloc(task->stackSize);
+	task->stackTop    = task->stackBottom + task->stackSize;
+
+	arrput(_private.taskList, task);
+}
+
+
+void taskExit(void) {
+	TaskT    *task = _private.current;
+	uint32_t  len  = arrlenu(_private.taskList);
+	uint32_t  x;
+
+	// Find our task.
+	for (x=0; x<len; x++) {
+		if (task == _private.taskList[x]) {
+			// Remove us from the list.
+			arrdel(_private.taskList, x);
+		}
+	}
+
+	// Don't free the task or we won't have a stack.
+	// Defer until we longjmp back into the old stack.
+	longjmp(_private.buf, EXIT_TASK);
+
+	// Execution doesn't get to here.
+}
+
+
+static void taskFree(void) {
+	TaskT *task = _private.current;
+
+	_private.current = NULL;
+	free(task->stackBottom);
+	free(task);
+}
+
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+void taskRun(void) {
+	// This is the exit path for the scheduler!
+	switch (setjmp(_private.buf)) {
+		case EXIT_TASK:
+			taskFree();
+
+		case INIT:
+		case SCHEDULE:
+			taskSchedule();
+			// If we get here, there's nothing else to do so exit
+			return;
+
+		default:
+			fprintf(stderr, "Task scheduler error!\n");
+			return;
+	}
+}
+#pragma GCC diagnostic pop
+
+
+static void taskSchedule(void) {
+	TaskT *next = taskChoose();
+
+	if (!next) return;
+
+	_private.current = next;
+
+	if (next->status == STATE_CREATED) {
+		// This task has not been started yet.
+		// Assign a new stack pointer, run the task, and exit it at the end.
+		register void *top = next->stackTop;
+#ifdef __x86_64__
+		// 64 bit.
+		asm volatile(
+			"mov %[rs], %%rsp \n"
+			: [ rs ] "+r" (top) ::
+		);
+#else
+		// 32 bit.
+		asm volatile(
+			"mov %[rs], %%esp \n"
+			: [ rs ] "+r" (top) ::
+		);
+#endif
+		// Run the task.
+		next->status = STATE_RUNNING;
+		next->function(next->data);
+
+		// The stack pointer should be back where we set it. Returning would be a very, very bad idea. Let's instead exit.
+		taskExit();
+	} else {
+		longjmp(next->buf, 1);
+	}
+
+	// Execution doesn't get to here.
+}
+
+
+void taskShutdown(void) {
+	// Nothing yet.
+}
+
+
+void taskStartup(uint16_t stackInK) {
+	_stackSizeInK     = stackInK;
+	_private.current  = NULL;
+	_private.taskList = NULL;
+}
+
+
+void taskYield(void) {
+	if (setjmp(_private.current->buf)) {
+		return;
+	} else {
+		longjmp(_private.buf, SCHEDULE);
+	}
+}

client/src/gui/task.h

@@ -0,0 +1,36 @@
+/*
+ * Kangaroo Punch Multi Player Game Server Mark II
+ * Copyright (C) 2020-2021  Scott Duensing
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+
+#ifndef TASK_H
+#define TASK_H
+
+
+#include "os.h"
+
+
+void taskCreate(void (*function)(void *), void *data);
+void taskExit(void);
+void taskRun(void);
+void taskShutdown(void);
+void taskStartup(uint16_t stackInK);
+void taskYield(void);
+
+
+#endif // TASK_H

client/src/main.c

@@ -18,8 +18,10 @@
  */
 
 
+#include "os.h"
 #include "vesa.h"
 #include "mouse.h"
+#include "task.h"
 #include "image.h"
 #include "font.h"
 #include "gui.h"
@@ -34,19 +36,17 @@ void buttonClick(WidgetT *widget) {
 }
 
 
-void test(void) {
+void test(void *data) {
 	MouseT   *mouse   = NULL;
 	ImageT   *pointer = NULL;
 	PixelT    alpha;
-	DesktopT *desktop = NULL;
+	DesktopT *desktop = (DesktopT *)guiRootGet();
 	WindowT  *w1      = NULL;
 	WindowT  *w2      = NULL;
 	WindowT  *w3      = NULL;
 	ButtonT  *b1      = NULL;
 
-	vbeStartup(800, 600, 16);
+	(void)data;
-	mouseStartup();
-	desktop = guiStartup();
 
 	pointer = imageLoad("mouse.png");
 	alpha   = imagePixelGet(pointer, 5, 0);
@@ -71,30 +71,69 @@ void test(void) {
 	} while (!(!mouse->buttonRight && mouse->buttonRightWasDown));  // Exit on release of right-click.
 
 	imageUnload(&pointer);
-
-	guiShutdown();
-	mouseShutdown();
-	vbeShutdown();
 }
 
 
 int main(int argc, char *argv[]) {
-	(void)argv;
 
-	if (argc > 1) {
+	uint16_t  xResolution = 0;
+	uint16_t  yResolution = 0;
+	uint16_t  colorDepth  = 0;
+	char      logName[32] = { "log.log" };
+	char     *c           = NULL;
+	int16_t   x           = strlen(argv[0]);
+
+	//      0        1         2         3         4         5         6         7         8
+	//      12345678901234567890123456789012345678901234567890123456789012345678901234567890
+	printf("Kangaroo Punch Multi Player DOS Game Client Mark II\n");
+	printf("Copyright (C) 2020-2021  Scott Duensing  scott@kangaroopunch.com\n\n");
+
+	// Find last portion of filename.
+	while (x > 0) {
+		if (argv[0][x] == '/' || argv[0][x] == '\\') break;
+		x--;
+	}
+	if (strlen(argv[0]) - x < 32) {
+		// Replace any extension with ".log"
+		strncpy(logName, &argv[0][x + 1], 31);
+		c = strstr(logName, ".");
+		if (c) *c = 0;
+		strncat(logName, ".log", 31);
+	}
+
+	logOpen(logName, 0);
+
+	// Command line needs to have the desired resolution and color depth on it.
+	if (argc != 4) {
 		vbeShowInfo();
 		return 0;
 	}
+	xResolution = atoi(argv[1]);
+	yResolution = atoi(argv[2]);
+	colorDepth  = atoi(argv[3]);
 
-	logOpen("test.log", 0);
+	// Do we have the video mode they asked for?
+	if (vbeStartup(xResolution, yResolution, colorDepth)) {
+		return 1;
+	}
 
-	test();
+	mouseStartup();
+	guiStartup();
+	taskStartup(64);
 
-	logClose();
+	taskCreate(test, NULL);
+	taskRun();
+
+	taskShutdown();
+	guiShutdown();
+	mouseShutdown();
+	vbeShutdown();
 
 #ifdef memoryLeakShow
 	memoryLeaksShow();
 #endif
 
+	logClose();
+
 	return 0;
 }