伙伴系统算法

9109bfb9 · 王晓庆 · 6d428cb0 · 9109bfb9 · 9109bfb9 · 9109bfb9
--- a/.gitignore
+++ b/.gitignore
+*.exe
+*.o
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "(gdb) Launch",
+            "type": "cppdbg",
+            "request": "launch",
+            "program": "${workspaceFolder}/partnersystem.exe",
+            "targetArchitecture": "x86",
+            "args": [],
+            "stopAtEntry": false,
+            "cwd": "${workspaceFolder}",
+            "environment": [],
+            "externalConsole": true,
+            "preLaunchTask": "生成项目(make)",
+            "MIMode": "gdb",
+            "miDebuggerPath": "${execPath}.toolchain\\bin\\gdb.exe",
+            "setupCommands": [
+                {
+                    "description": "Enable pretty-printing for gdb",
+                    "text": "-enable-pretty-printing",
+                    "ignoreFailures": true
+                }
+            ]
+        }
+    ]
+}
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
+{
+    "files.exclude": {
+    }
+}
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "生成项目(make)",
+            "type": "shell",
+            "windows": {
+                "command": "cmd.exe /c echo VSCode安装路径-${execPath} ; echo ''; echo 正在使用makefile文件生成项目 ; echo ''; make",
+                "options": {
+                    "env": {
+                        "PATH": "${execPath}.toolchain\\bin;${execPath}.mingw64\\bin;${env:PATH}"
+                    }
+                }
+            },
+            "args": [],
+            "group": "build",
+            "presentation": {
+                "reveal": "always",
+                "group": "make"
+            },
+            "problemMatcher": "$gcc"
+        },
+        {
+            "label": "清理项目(make clean)",
+            "type": "shell",
+            "windows": {
+                "command": "cmd.exe /c echo VSCode安装路径-${execPath} ; echo ''; echo 正在使用makefile文件清理项目 ; echo ''; make clean",
+                    "options": {
+                        "env": {
+                            "PATH": "${execPath}.toolchain\\bin;${execPath}.mingw64\\bin;${env:PATH}"
+                        }
+                    }
+            },
+            "args": [],
+            "group": "build",
+            "presentation": {
+                "reveal": "always",
+                "group": "clean"
+            },
+            "problemMatcher": "$gcc"
+        }
+    ]
+}
--- a/main.c
+++ b/main.c
+#include <stdio.h>
+#include <math.h>
+#include <windows.h>
+
+#define RED FOREGROUND_RED
+#define GREEN FOREGROUND_GREEN
+#define BLUE FOREGROUND_BLUE
+
+#define M 10	/* 可利用空间总容量(2的幂次)，子表的个数为M+1 */
+#define N 100	/* 占用块个数的最大值 */
+
+//伙伴系统可利用空间表的结构
+typedef struct _Node{
+	struct _Node *llink;	//指向前驱节点
+	int bflag;				//块标志，0：空闲，1：占用
+	int bsize;				//块大小，值为2的幂次k
+	struct _Node *rlink;	//头部域，指向后继节点
+}Node;
+
+//可利用空间表的头结点
+typedef struct HeadNode{
+	int nodesize;		//链表的空闲块大小
+	Node *first;		//链表的表头指针
+}FreeList[M+1];
+
+Node* AllocBuddy(FreeList *avail, unsigned long n);
+Node* buddy(Node* n);
+void Reclaim(FreeList *pav,Node* *p);
+void SetColor(int color);
+void print_free(FreeList p);
+void print_used(Node* p[]);
+
+Node* start;   // 全局变量start为整个生成空间的首地址
+
+int main(int argc, char* argv[])
+{
+	int i, j, item;
+	unsigned long joblength;
+	FreeList avail;
+	Node* used_block[N] = {NULL};	//used_block数组为占用块的首地址
+	
+	//初始化可利用空间
+	for(i = 0; i <= M; i++)
+	{
+		avail[i].nodesize = (int)pow(2,i);
+		avail[i].first = NULL;
+	}
+	
+	// 在最大链表中生成一个结点 
+	start = avail[M].first = (Node*)malloc(avail[M].nodesize * sizeof(Node));
+	if(start) // 生成结点成功 
+	{
+		start->llink = start->rlink = start; // 初始化该结点 
+		start->bflag = 0;
+		start->bsize = M;
+		int color = 8;
+		i = 0;
+		while(1)
+		{
+			//设置字体颜色为白色
+			SetColor(RED|BLUE|GREEN);
+			printf("选择功能项：(0-退出  1-分配主存  2-回收主存  3-显示主存):");
+			scanf("%d",&item);
+			switch(item)
+			{
+				case 0:
+					exit(0);
+				case 1:
+					SetColor(RED|GREEN);
+					printf("输入作业所需长度：");
+					scanf("%ld",&joblength);
+					if(avail[M].first && (int)pow(2, avail[M].first->bsize) == 1024)
+					{
+						i = 0;
+					}
+					used_block[i] = AllocBuddy(&avail,joblength);
+					++i;
+					break;
+				case 2:
+					SetColor(RED|BLUE);
+					printf("输入要回收块的块号：");
+					scanf("%d",&j);
+					if(i > 0 && j < i)
+					{
+						Reclaim(&avail,&used_block[j]);
+					}
+					else
+					{
+						SetColor(RED);
+						if(i == 0)
+						{
+							printf("没有可回收的内存块,请分配后，再进行回收!\n");
+						}
+						else
+						{
+							printf("输入的块号不合法\n");
+						}		
+					}	
+					break;
+				case 3:	
+					print_free(avail);
+					print_used(used_block);
+					break;
+				default:
+					printf("没有该选项\n");
+			}
+		}
+	}	
+}
+
+
+/* avail[0...M]为可利用空间表，n为申请分配量。若有不小于n的空闲块，
+则分配相应的存储块，并返回首地址；否则，返回NULL */
+Node* AllocBuddy(FreeList *avail, unsigned long n)
+{
+	int i, k;
+	Node *pa, *pi, *pre, *suc;
+	//查找满足分配要求的子表即空闲块大小大于n的表
+	for(k = 0; k <= M && ((*avail)[k].nodesize <= n  || !(*avail)[k].first); ++k)
+		;
+
+	if(k>M) 	//	分配失败返回NULL
+	{
+		printf("内存分配失败！\n");
+		return NULL;
+	}
+	else{		//进行分配
+		pa = (*avail)[k].first;			//指向可分配表的第一个节点
+		pre = pa->llink;				//分别指向前驱和后继
+		suc = pa->rlink;				
+		
+		if(pa == suc)					//分配后该子表变成空表
+			(*avail)[k].first = NULL;
+			
+		else{							//从子表删去*pa节点
+			pre->rlink = suc;
+			suc->llink = pre;
+			(*avail)[k].first = suc;
+		}
+		
+		/* 将剩余块插入相应子表 */
+		for(i = 1; (*avail)[k-i].nodesize >= n+1; ++i)
+		{
+			pi = pa + (int)pow(2,k-i);
+			pi->rlink = pi;
+			pi->llink = pi;
+			pi->bflag = 0;
+			pi->bsize = k-i;
+			(*avail)[k-i].first = pi;
+			
+		}
+		pa->bflag = 1;
+		pa->bsize = k - (--i);
+	}
+	return pa;
+}
+
+//返回相对起始地址为p，块大小为pow(2,k)的块的伙伴地址
+Node* buddy(Node* n)
+{	
+	if((n-start)%(int)pow(2,n->bsize+1)==0)		//p为前块
+		return n + (int)pow(2,n->bsize);
+	else										//p为后块
+		return n - (int)pow(2,n->bsize);
+}
+
+// 伙伴系统的回收算法 将p所指的释放块回收到可利用空间表pav中
+void Reclaim(FreeList *pav,Node* *p)
+{ 
+	
+	//
+	//	TODO: 在此添加代码
+	//
+
+}
+
+/* 设置字体颜色 */
+void SetColor(int color)
+{
+	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), 
+		FOREGROUND_INTENSITY | color);
+}
+
+//输出所有可用空间表
+void print_free(FreeList p)
+{
+	int i;
+	Node* head;
+	//设置字体颜色为白色
+	SetColor(RED|BLUE|GREEN);
+									
+	printf("可利用空间：\n");
+	printf("      块的大小    块的首地址\t块标志(0:空闲 1:占用)  前驱地址  后继地址\n");
+	
+	SetColor(GREEN);
+											
+	for(i = 0; i <= M; i++)
+	{
+		if(p[i].first)		//第i个可利用空间表不同
+		{
+			head = p[i].first;	//head指向链表的第一个节点的头部域（首地址）
+			do
+			{
+				printf("\t%d\t   0x%x\t    %10d         0x%x  0x%x\n",(int)pow(2,head->bsize), head, head->bflag, head->llink, head->rlink);
+				head = head->rlink;
+			}while(head != p[i].first);
+		}
+	}
+	printf("\n");
+}
+
+// 输出p数组所指的已分配空间
+void print_used(Node* p[])
+{ 
+	int i;
+	//设置字体颜色为白色
+	SetColor(RED|BLUE|GREEN);
+									
+	printf("已利用空间：\n");
+	printf("     占用块块号\t占用块的首地址\t块大小\t块标志(0:空闲 1:占用)\n");
+	
+	SetColor(RED);
+											
+	for(i = 0; i < N; i++)
+		if(p[i]) // 指针不为0(指向一个占用块) 
+			printf("\t  %d\t   0x%x\t %d\t  %d\n",i, p[i],(int)pow(2,p[i]->bsize), p[i]->bflag); 
+	printf("\n");
+}
--- a/makefile
+++ b/makefile
+DIR_INC = .
+DIR_SRC = .
+DIR_OBJ = .
+DIR_BIN = .
+
+SRC = $(wildcard ${DIR_SRC}/*.c)  
+OBJ = $(patsubst %.c,${DIR_OBJ}/%.o,$(notdir ${SRC})) 
+
+TARGET = partnersystem.exe
+
+BIN_TARGET = ${DIR_BIN}/${TARGET}
+
+CC = gcc
+CFLAGS = -g -w -std=c99 -fsigned-char -I${DIR_INC}
+
+${BIN_TARGET}:${OBJ}
+	@echo --- build executable file: $@
+	$(CC) $(OBJ) -o $@
+    
+${DIR_OBJ}/%.o:${DIR_SRC}/%.c
+	@echo --- build object file: $@
+	$(CC) $(CFLAGS) -c  $< -o $@
+
+clean:
+	del /Q *.exe *.o