mem.zip_内存分配

struct telnetd_line { char line[TELNETD_CONF_LINELEN]; }; MEMB(linemem, struct telnetd_line, TELNETD_CONF_NUMLINES); memb_init(&linemem); /*---------------------------------------------------------------------------*/ void memb_init(struct memb_blocks *m) { memset(m->count, 0, m->num); memset(m->mem, 0, m->size * m->num); } /*---------------------------------------------------------------------------*/ void * memb_alloc(struct memb_blocks *m) { int i; for(i = 0; i < m->num; ++i) { if(m->count[i] == 0) { /* If this block was unused, we increase the reference count to indicate that it now is used and return a pointer to the memory block. */ ++(m->count[i]); return (void *)((char *)m->mem + (i * m->size)); } } /* No free block was found, so we return NULL to indicate failure to allocate block. */ return NULL; } /*---------------------------------------------------------------------------*/ char memb_free(struct memb_blocks *m, void *ptr) { int i; char *ptr2; /* Walk through the list of blocks and try to find the block to which the pointer "ptr" points to. */ ptr2 = (char *)m->mem; for(i = 0; i < m->num; ++i) { if(ptr2 == (char *)ptr) { /* We've found to block to which "ptr" points so we decrease the reference count and return the new value of it. */ if(m->count[i] > 0) { /* Make sure that we don't deallocate free memory. */ --(m->count[i]); } return m->count[i]; } ptr2 += m->size; } return -1; } static void acked(void) { static unsigned int i; while(s.numsent > 0) { dealloc_line(s.lines[0]); for(i = 1; i < TELNETD_CONF_NUMLINES; ++i) { s.lines[i - 1] = s.lines[i]; } s.lines[TELNETD_CONF_NUMLINES - 1] = NULL; --s.numsent; } udp_dadt_len=0; } void senddata(void)//static { /*static char *bufptr, *lineptr; static int buflen, linelen; bufptr = uip_appdata; buflen = 0; for(s.numsent = 0; s.numsent < 1300 && s.lines[s.numsent] != NULL ; ++s.numsent) { lineptr = s.lines[s.numsent]; linelen = strlen(lineptr); if(linelen > 1300) { linelen = 1300; } if(buflen + linelen < uip_mss()) { memcpy(bufptr, lineptr, linelen); bufptr += linelen; buflen += linelen; } else { break; } } uip_send(uip_appdata, buflen);*/ static char *bufptr, *lineptr; static int buflen, linelen; bufptr = uip_appdata; buflen = 0; linelen =udp_dadt_len+1; for(s.numsent = 0; s.numsent < 1300&&s.numsent<udp_dadt_len ;//&& s.lines[s.numsent] != NULL ; ++s.numsent) { lineptr = s.lines[s.numsent]; // linelen = strlen(lineptr); linelen--; if(linelen > 1300) { linelen = 1300; } if(buflen + linelen < uip_mss()) { memcpy(bufptr, lineptr, linelen); bufptr += linelen; buflen += linelen; } else { break; } } uip_send(uip_appdata, udp_dadt_len); /*static char *lineptr; lineptr = s.lines[0]; //s.numsent获取数据最后的指针地址 uip_send(lineptr,udp_dadt_len);// buflen udp_dadt_len=0;*/ } /*---------------------------------------------------------------------------*/ static void closed(void) { static unsigned int i; for(i = 0; i < TELNETD_CONF_NUMLINES; ++i) { if(s.lines[i] != NULL) { dealloc_line(s.lines[i]); } } } static void sendline(char *line) { static unsigned int i; for(i = 0; i < TELNETD_CONF_NUMLINES; ++i) { if(s.lines[i] == NULL) { s.lines[i] = line; break; } } if(i == TELNETD_CONF_NUMLINES) { dealloc_line(line); } } void shell_output(char *str1, int out_len) { static unsigned len; char *line; udp_dadt_len=out_len; line = alloc_line();//分配内存 if(line != NULL) { memcpy(line, str1,out_len); } sendline(line);//释放内存 #define MEMB_CONCAT2(s1, s2) s1##s2#define MEMB_CONCAT(s1, s2) MEMB_CONCAT2(s1, s2) } #define MEMB(name, structure, num) \ //第一个 参数是分配内存块起名字 //第2个参数是分配 内存的块大小子块的数据结构 //第3个参数是分配内存的块数量 static char MEMB_CONCAT(name,_memb_count)[num]; \ static structure MEMB_CONCAT(name,_memb_mem)[num]; \ static struct memb_blocks name = {sizeof(structure), num, \ MEMB_CONCAT(name,_memb_count), \ (void *)MEMB_CONCAT(name,_memb_mem)} struct memb_blocks { unsigned short size;//子块的大小 unsigned short num;//子块的数目 char *count;//每个子块引用计数，表示正在使用还是未被使用 void *mem;//内存块首地址 };