Import backup from 2003-09-29

desc.txt

@@ -0,0 +1 @@
+mm_palloc() and mm_pfree() working, coalescing successfully!!

k_defines.h

@@ -30,6 +30,8 @@
 
 #define FREERAM_START	0x268000
 
+#define KERNEL_PID	0x02
+
 typedef	unsigned char	byte;
 typedef	unsigned short	word;
 typedef	unsigned int	dword;

kernel.c

@@ -23,8 +23,10 @@ void k_init();
 #include "functions.c"
 #include "video.c"
 
-dword timer = 0;
-dword addresses[256];
+dword	timer = 0;
+dword	index = 0;
+dword	keepgoing = 1;
+dword	addresses[256];
 
 void k_init()
 {
@@ -45,14 +47,6 @@ void k_init()
 	enable_ints();
 	console_cls();
 	printf("Memory available to OS: %d MB (Bytes: %d)\n", mm_totalmem/0x100000, mm_totalmem);
-	int a = 0;
-	for (;;)
-	{
-		addresses[a] = (dword)mm_palloc(256);
-		printf("%x\t", addresses[a]);
-		if (addresses[a++] == 0)
-			break;
-	}
 	dword key = 0;
 	for (;;)
 	{
@@ -68,6 +62,32 @@ void isr(dword num)
 	case 0x20:         		// IRQ0 - timer interrupt
 		timer++;
 		(*(byte *)0xb8000)++;
+		if ((timer%25)==0)
+		{
+			if (keepgoing)
+			{
+				addresses[index] = (dword) mm_palloc(256, KERNEL_PID);
+				printf("Addr: 0x%x\tEntries:\t%d\n", addresses[index], mm_freeentries());
+				if (addresses[index] == 0)
+				{
+					index = -1;
+					keepgoing = 0;
+				}
+				index++;
+			}
+			else
+			{
+				printf("Freeing %x\t", addresses[index]);
+				addresses[index] = mm_pfree((void *)addresses[index]);
+				printf("Free:\t%d\tEntries:\t%d\n", addresses[index], mm_freeentries());
+				if (addresses[index] != 0)
+				{
+					index = -1;
+					keepgoing = 1;
+				}
+				index++;
+			}
+		}
 		eoi();
 		break;
 	case 0x21:  			// IRQ1 - keyboard interrupt

mm.c

@@ -32,21 +32,21 @@ void	mm_init()
 					mm_init_pageblockpage(first_pageblock);
 					first_pageblock->base = maps[a].base.lowdword;
 					first_pageblock->length = maps[a].limit.lowdword / 4096;
-					first_pageblock->flags = MM_PB_AVAIL;
+					first_pageblock->pid = MM_PB_AVAIL;
 				}
 				else				//first_pageblock already set up, add on segment
 				{
 					pageblock *pb = first_pageblock;
 					for (;;)
 					{
-						if (pb->flags == MM_PB_NP)
+						if (pb->pid == MM_PB_NP)
 							break;
 						else
 							pb++;
 					}
 					pb->base = maps[a].base.lowdword;
 					pb->length = maps[a].limit.lowdword / 4096;
-					pb->flags = MM_PB_AVAIL;
+					pb->pid = MM_PB_AVAIL;
 				}
 			}
 		}
@@ -71,7 +71,7 @@ void	mm_init_pageblockpage(pageblock *pbp)
 	{
 		pbp[a].base = 0;
 		pbp[a].length = 0;
-		pbp[a].flags = MM_PB_NP;
+		pbp[a].pid = MM_PB_NP;
 		if (a<255)
 			pbp[a].link = (dword)(&pbp[a+1]);
 		else
@@ -80,8 +80,10 @@ void	mm_init_pageblockpage(pageblock *pbp)
 }
 
 
-void   *mm_palloc(dword numpages)
+void   *mm_palloc(dword numpages, dword proc_pid)
 {
+ 	if (proc_pid < KERNEL_PID)
+ 		return 0;
 	pageblock *pb = first_pageblock;
 	if (mm_freeentries() < 2)
 	{
@@ -91,7 +93,7 @@ void   *mm_palloc(dword numpages)
 	pageblock *newentry = mm_nextpageblockentry();
 	for (;;)
 	{
-		if ((pb->flags == MM_PB_AVAIL) && (pb->length >= numpages))
+		if ((pb->pid == MM_PB_AVAIL) && (pb->length >= numpages))
 			break;
 		if (pb->link == 0)
 			return 0;
@@ -99,14 +101,14 @@ void   *mm_palloc(dword numpages)
 	}
 	if (pb->length == numpages)		//dont need a new entry, just mark this one as used :)
 	{
-		pb->flags = MM_PB_USED;
-		return pb;
+		pb->pid = proc_pid;
+		return (void *)pb->base;
 	}
 	else					//subtract out allocated number of pages from length
 	{
 		newentry->base = pb->base;
 		newentry->length = numpages;
-		newentry->flags = MM_PB_USED;
+		newentry->pid = proc_pid;
 		pb->base += (numpages * 4096);
 		pb->length -= numpages;
 		return (void *)newentry->base;
@@ -120,7 +122,7 @@ dword	mm_freeentries()
 	dword counter = 0;
 	for (;;)
 	{
-		if (pb->flags == MM_PB_NP)
+		if (pb->pid == MM_PB_NP)
 			counter++;
 		if (pb->link == 0)
 			return counter;
@@ -134,7 +136,7 @@ pageblock *mm_new_pageblock_page()  	//as of 09/26/03 this method leaks 4kb main
 	pageblock *pb = first_pageblock;
 	for (;;)
 	{
-		if ((pb->flags == MM_PB_AVAIL) && (pb->length > 1))
+		if ((pb->pid == MM_PB_AVAIL) && (pb->length > 1))
 		{
 			pageblock *retval = (pageblock *)pb->base;
 			pb->base += 4096;
@@ -158,31 +160,11 @@ int	mm_pfree(void *ptr)
 	dword tofree = (dword) ptr;
 	for (;;)
 	{
-		if (pb->base == tofree)		// && (pb->flags == MM_PB_USED))
+		if (pb->base == tofree)		// && (pb->pid == MM_PB_USED))
 		{
-			pb->flags = MM_PB_AVAIL;		//found block, mark available / coalesce it
-			pageblock *pbc = first_pageblock;
-			for (;;)
-			{
-			    	if (pbc->flags == MM_PB_AVAIL)
-			    	{
-			    		if ((pbc->base + (pbc->length * 4096)) == pb->base)	//pbc ends where pb starts
-					{
-						pbc->length += pb->length;	//extend pbc's length by pb's length
-						pb->flags = MM_PB_NP;		//mark pb as an unused entry
-						return 0;
-					}
-					if ((pb->base + (pb->length * 4096)) == pbc->base)	//pb ends where pb starts
-					{
-						pb->length += pbc->length;
-						pbc->flags = MM_PB_NP;
-						return 0;
-					}
-				 }
-				if (pbc->link == 0)			//no entry found to consolidate...
-					return 0;
-				pbc = (pageblock *) pbc->link;		//next entry to test
-			}
+			pb->pid = MM_PB_AVAIL;		//found block, mark available / coalesce it
+			mm_coalesce(pb);
+			return 0;
 		}
 		if (pb->link == 0)
 			return 1;
@@ -208,7 +190,7 @@ pageblock *mm_nextpageblockentry()
 	pageblock *pb = first_pageblock;
 	for (;;)
 	{
-		if (pb->flags == MM_PB_NP)
+		if (pb->pid == MM_PB_NP)
 			return pb;
 		if (pb->link == 0)
 			return 0;
@@ -223,7 +205,7 @@ dword mm_freemem()
 	pageblock *pb = first_pageblock;
 	for (;;)
 	{
-		if (pb->flags == MM_PB_AVAIL)
+		if (pb->pid == MM_PB_AVAIL)
 			amount += (pb->length)*4096;
 		if (pb->link == 0)
 			return amount;
@@ -232,6 +214,35 @@ dword mm_freemem()
 }
 
 
+void	mm_coalesce(pageblock *pb)
+{
+	pageblock *pbc = first_pageblock;
+	for (;;)
+	{
+		if (pbc->pid == pb->pid)	//pid fields must match, both same process, both avail, or both not present
+		{
+			if ((pbc->base + (pbc->length * 4096)) == pb->base)	//pbc ends where pb starts
+			{
+				pbc->length += pb->length;
+				pb->pid = MM_PB_NP;
+				mm_coalesce(pbc);			//recursion: checks for any more page blocks to coalesce if one found
+				return;					//exit this recursion...
+			}
+			if ((pb->base + (pb->length * 4096)) == pbc->base)	//pb ends where pbc starts
+			{
+				pb->length += pbc->length;
+				pbc->pid = MM_PB_NP;
+				mm_coalesce(pb);
+				return;
+			}
+		}
+		if (pbc->link == 0)
+			return;
+		pbc = (pageblock *)pbc->link;
+	}
+}
+
+
 
 
 

mm.h

@@ -10,14 +10,15 @@ typedef struct {
 typedef struct {
 	dword	base;
 	dword	length;				//in pages
-	dword	flags;
+	dword	pid;                            //normally PID of process, use NP, AVAIL for special flags
 	dword	link;				//leave dword instead of pointer so i dont have to worry about pointer arithmetic
 } __attribute__ ((packed)) pageblock;		//16 byte pageblock entry - 256 entries = 1 page
 
 
 void	mm_init();
 void	mm_init_pageblockpage(pageblock *pbp);
-void   *mm_palloc(dword numpages);
+void   *mm_palloc(dword numpages, dword proc_pid);
+void	mm_coalesce(pageblock *pb);
 int	mm_pfree(void *ptr);
 dword	mm_freeentries();
 dword	mm_freemem();
@@ -26,10 +27,8 @@ pageblock *mm_lastpageblockentry();
 pageblock *mm_nextpageblockentry();
 
 
-#define MM_PB_FLAGMASK 0x03	//00000011
 #define MM_PB_NP 0x00		//00000000
 #define MM_PB_AVAIL 0x01	//00000001
-#define MM_PB_USED 0x02		//00000010