The 6.0 release of Visual C++ shows Microsoft s continued focus on Internet technologies and COM, which are key components of the new Windows Distributed interNet Application Architecture (DNA). In addition to supporting these platform initiatives, Visual C++ 6.0 also adds an amazing number of productivity-boosting features such as Edit And continue, IntelliSense, AutoComplete, and code tips. These features take Visual C++ to a new level. We have tried to make sure that this book keeps you up to speed on the latest technologies being introduced into Visual C++.
标签： technologies Microsoft continued Internet
上传时间： 2017-09-07
上传用户：wsf950131
第一章关键字...................................................................................................................................9 1.1，最宽恒大量的关键字----auto..........................................................................................11 1.2，最快的关键字---- register............................................................................................... 11 1.2.1，皇帝身边的小太监----寄存器............................................................................. 11 1.2.2，使用register 修饰符的注意点.............................................................................11 1.3，最名不符实的关键字----static........................................................................................12 1.3.1，修饰变量...............................................................................................................12 1.3.2，修饰函数...............................................................................................................13 1.4，基本数据类型----short、int、long、char、float、double........................................... 13 1.4.1，数据类型与“模子”............................................................................................... 14 1.4.2，变量的命名规则...................................................................................................14 1.5，最冤枉的关键字----sizeof...............................................................................................18 1.5.1，常年被人误认为函数...........................................................................................18 1.5.2，sizeof（int）*p 表示什么意思？........................................................................18 1.4，signed、unsigned 关键字................................................................................................19 1.6，if、else 组合.................................................................................................................... 20 1.6.1，bool 变量与“零值”进行比较...............................................................................20 1.6.2, float 变量与“零值”进行比较.................................................................................21 1.6.3，指针变量与“零值”进行比较...............................................................................21 1.6.4，else 到底与哪个if 配对呢？...............................................................................22 1.6.5，if 语句后面的分号............................................................................................... 23 1.6.6，使用if 语句的其他注意事项.............................................................................. 24 1.7，switch、case 组合........................................................................................................... 24 1.7.1，不要拿青龙偃月刀去削苹果.............................................................................. 24 1.7.2，case 关键字后面的值有什么要求吗？.............................................................. 25 1.7.3，case 语句的排列顺序...........................................................................................25 1.7.4，使用case 语句的其他注意事项..........................................................................27 1.8，do、while、for 关键字................................................................................................... 28 1.8.1，break 与continue 的区别.....................................................................................28 1.8.2，循环语句的注意点...............................................................................................29 1.9，goto 关键字......................................................................................................................30 1.10，void 关键字....................................................................................................................31 1.10.1，void a？............................................................................................................31 1.10，return 关键字................................................................................................................. 34 1.11，const 关键字也许该被替换为readolny....................................................................... 34 1.11.2，节省空间，避免不必要的内存分配，同时提高效率.................................... 35 1.12，最易变的关键字----volatile.......................................................................................... 36 1.13，最会带帽子的关键字----extern.................................................................................... 37 1.14，struct 关键字..................................................................................................................38
标签： c语言深度剖析
上传时间： 2015-05-01
上传用户：cascas
/* ********************************************************************************************************* * uC/TCP-IP V2 * The Embedded TCP/IP Suite * * (c) Copyright 2003-2010; Micrium, Inc.; Weston, FL * * All rights reserved. Protected by international copyright laws. * * uC/TCP-IP is provided in source form to registered licensees ONLY. It is * illegal to distribute this source code to any third party unless you receive * written permission by an authorized Micrium representative. Knowledge of * the source code may NOT be used to develop a similar product. * * Please help us continue to provide the Embedded community with the finest * software available. Your honesty is greatly appreciated. * * You can contact us at www.micrium.com. ********************************************************************************************************* */ /* ********************************************************************************************************* * * NETWORK TCP LAYER * (TRANSMISSION CONTROL PROTOCOL) * * Filename : net_tcp.h * Version : V2.10 * Programmer(s) : ITJ ********************************************************************************************************* * Note(s) : (1) Supports Transmission Control Protocol as described in RFC #793 with the following * restrictions/constraints : * * (a) TCP Security & Precedence NOT supported RFC # 793, Section 3.6 * * (b) TCP Urgent Data NOT supported RFC # 793, Section 3.7 * 'The Communication of * Urgent Information' * * (c) The following TCP options NOT supported : * * (1) Window Scale RFC #1072, Section 2 * RFC #1323, Section 2 * (2) Selective Acknowledgement (SACK) RFC #1072, Section 3 * RFC #2018 * RFC #2883 * (3) TCP Echo RFC #1072, Section 4 * (4) Timestamp RFC #1323, Section 3.2 * (5) Protection Against Wrapped Sequences (PAWS) RFC #1323, Section 4 * * (d) #### IP-Options-to-TCP-Connection RFC #1122, Section 4.2.3.8 * Handling NOT supported * * (e) #### ICMP-Error-Message-to-TCP-Connection RFC #1122, Section 4.2.3.9 * Handling NOT currently supported * * (2) TCP Layer assumes/requires Network Socket Layer (see 'net_sock.h MODULE Note #1a2'). ********************************************************************************************************* */ /*$PAGE*/ /* ********************************************************************************************************* * MODULE * * Note(s) : (1) TCP Layer module is NOT required for UDP-to-Application API configuration. * * See also 'net_cfg.h TRANSPORT LAYER CONFIGURATION' * & 'net_cfg.h USER DATAGRAM PROTOCOL LAYER CONFIGURATION'. * * See also 'net_tcp.h Note #2'. * * (2) The following TCP-module-present configuration value MUST be pre-#define'd in * 'net_cfg_net.h' PRIOR to all other network modules that require TCP Layer * configuration (see 'net_cfg_net.h TCP LAYER CONFIGURATION Note #2b') : * * NET_TCP_MODULE_PRESENT ********************************************************************************************************* */ #ifdef NET_TCP_MODULE_PRESENT /* See Note #2. */ /* ********************************************************************************************************* * EXTERNS ********************************************************************************************************* */ #if ((defined(NET_TCP_MODULE)) && \ (defined(NET_GLOBALS_EXT))) #define NET_TCP_EXT #else #define NET_TCP_EXT extern #endif /*$PAGE*/ /* ********************************************************************************************************* * DEFINES ********************************************************************************************************* */ /* ********************************************************************************************************* * TCP HEADER DEFINES * * Note(s) : (1) The following TCP value MUST be pre-#define'd in 'net_def.h' PRIOR to 'net_buf.h' so that * the Network Buffer Module can configure maximum buffer header size (see 'net_def.h TCP * LAYER DEFINES' & 'net_buf.h NETWORK BUFFER INDEX & SIZE DEFINES Note #1') : * * (a) NET_TCP_HDR_SIZE_MAX 60 (NET_TCP_HDR_LEN_MAX * * NET_TCP_HDR_LEN_WORD_SIZE) * * (2) Urgent pointer & data NOT supported (see 'net_tcp.h Note #1b'). ********************************************************************************************************* */ #define NET_TCP_HDR_LEN_MASK 0xF000u #define NET_TCP_HDR_LEN_SHIFT 12u #define NET_TCP_HDR_LEN_NONE 0u #define NET_TCP_HDR_LEN_MIN 5u #define NET_TCP_HDR_LEN_MAX 15u #define NET_TCP_HDR_LEN_WORD_SIZE CPU_WORD_SIZE_32 #define NET_TCP_HDR_SIZE_MIN (NET_TCP_HDR_LEN_MIN * NET_TCP_HDR_LEN_WORD_SIZE) #if 0 /* See Note #1a. */ #define NET_TCP_HDR_SIZE_MAX (NET_TCP_HDR_LEN_MAX * NET_TCP_HDR_LEN_WORD_SIZE) #endif #define NET_TCP_HDR_SIZE_TOT_MIN (NET_IP_HDR_SIZE_TOT_MIN + NET_TCP_HDR_SIZE_MIN) #define NET_TCP_HDR_SIZE_TOT_MAX (NET_IP_HDR_SIZE_TOT_MAX + NET_TCP_HDR_SIZE_MAX) #define NET_TCP_PSEUDO_HDR_SIZE 12u /* = sizeof(NET_TCP_PSEUDO_HDR) */ #define NET_TCP_PORT_NBR_RESERVED NET_PORT_NBR_RESERVED #define NET_TCP_PORT_NBR_NONE NET_TCP_PORT_NBR_RESERVED #define NET_TCP_HDR_URG_PTR_NONE 0x0000u /* See Note #2. */ /*$PAGE*/ /* ********************************************************************************************************* * TCP HEADER FLAG DEFINES * * Note(s) : (1) See 'TCP HEADER Note #2' for flag fields. * * (2) Urgent pointer & data NOT supported (see 'net_tcp.h Note #1b'). ********************************************************************************************************* */ #define NET_TCP_HDR_FLAG_MASK 0x0FFFu #define NET_TCP_HDR_FLAG_NONE DEF_BIT_NONE #define NET_TCP_HDR_FLAG_RESERVED 0x0FE0u /* MUST be '0'. */ #define NET_TCP_HDR_FLAG_URGENT DEF_BIT_05 /* See Note #2. */ #define NET_TCP_HDR_FLAG_ACK DEF_BIT_04 #define NET_TCP_HDR_FLAG_PUSH DEF_BIT_03 #define NET_TCP_HDR_FLAG_RESET DEF_BIT_02 #define NET_TCP_HDR_FLAG_SYNC DEF_BIT_01 #define NET_TCP_HDR_FLAG_FIN DEF_BIT_00 #define NET_TCP_HDR_FLAG_CLOSE NET_TCP_HDR_FLAG_FIN /* ********************************************************************************************************* * TCP FLAG DEFINES ********************************************************************************************************* */ /* ------------------ NET TCP FLAGS ------------------- */ #define NET_TCP_FLAG_NONE DEF_BIT_NONE #define NET_TCP_FLAG_USED DEF_BIT_00 /* TCP conn cur used; i.e. NOT in free TCP conn pool. */ /* ------------------ TCP TX FLAGS ------------------- */ /* TCP tx flags copied from TCP hdr flags. */ #define NET_TCP_FLAG_TX_FIN NET_TCP_HDR_FLAG_FIN #define NET_TCP_FLAG_TX_CLOSE NET_TCP_FLAG_TX_FIN #define NET_TCP_FLAG_TX_SYNC NET_TCP_HDR_FLAG_SYNC #define NET_TCP_FLAG_TX_RESET NET_TCP_HDR_FLAG_RESET #define NET_TCP_FLAG_TX_PUSH NET_TCP_HDR_FLAG_PUSH #define NET_TCP_FLAG_TX_ACK NET_TCP_HDR_FLAG_ACK #define NET_TCP_FLAG_TX_URGENT NET_TCP_HDR_FLAG_URGENT #define NET_TCP_FLAG_TX_BLOCK DEF_BIT_07 /* ------------------ TCP RX FLAGS ------------------- */ #define NET_TCP_FLAG_RX_DATA_PEEK DEF_BIT_08 #define NET_TCP_FLAG_RX_BLOCK DEF_BIT_15 /*$PAGE*/ /* ********************************************************************************************************* * TCP TYPE DEFINES * * Note(s) : (1) NET_TCP_TYPE_&&& #define values specifically chosen as ASCII representations of the TCP * types. Memory displays of TCP types will display with their chosen ASCII names. ********************************************************************************************************* */ /* ------------------ NET TCP TYPES ------------------- */ #if (CPU_CFG_ENDIAN_TYPE == CPU_ENDIAN_TYPE_BIG) #define NET_TCP_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x54435020u /* "TCP " in ASCII. */ #else #if (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_32) #define NET_TCP_TYPE_NONE 0x454E4F4Eu /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x20504354u /* "TCP " in ASCII. */ #elif (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_16) #define NET_TCP_TYPE_NONE 0x4F4E454Eu /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x43542050u /* "TCP " in ASCII. */ #else /* Dflt CPU_WORD_SIZE_08. */ #define NET_TCP_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_TYPE_CONN 0x54435020u /* "TCP " in ASCII. */ #endif #endif /* ********************************************************************************************************* * TCP SEQUENCE NUMBER DEFINES * * Note(s) : (1) TCP initial transmit sequence number is incremented by a fixed value, preferably a large * prime value or a large value with multiple unique factors. * * (a) One reasonable TCP initial transmit sequence number increment value example : * * 65527 = 37 * 23 * 11 * 7 * * * #### NET_TCP_TX_SEQ_NBR_CTR_INC could be developer-configured in 'net_cfg.h'. * * See also 'NET_TCP_TX_GET_SEQ_NBR() Notes #1b2 & #1c2'. ********************************************************************************************************* */ #define NET_TCP_SEQ_NBR_NONE 0u #define NET_TCP_ACK_NBR_NONE NET_TCP_SEQ_NBR_NONE #define NET_TCP_TX_SEQ_NBR_CTR_INC 65527u /* See Note #1. */ #define NET_TCP_ACK_NBR_DUP_WIN_SIZE_SCALE 4 /*$PAGE*/ /* ********************************************************************************************************* * TCP DATA/TOTAL LENGTH DEFINES * * Note(s) : (1) (a) TCP total length #define's (NET_TCP_TOT_LEN) relate to the total size of a complete * TCP packet, including the packet's TCP header. Note that a complete TCP packet MAY * be fragmented in multiple Internet Protocol packets. * * (b) TCP data length #define's (NET_TCP_DATA_LEN) relate to the data size of a complete * TCP packet, equal to the total TCP packet length minus its TCP header size. Note * that a complete TCP packet MAY be fragmented in multiple Internet Protocol packets. ********************************************************************************************************* */ /* See Notes #1a & #1b. */ #define NET_TCP_DATA_LEN_MIN 0u #define NET_TCP_TOT_LEN_MIN (NET_TCP_HDR_SIZE_MIN + NET_TCP_DATA_LEN_MIN) #define NET_TCP_TOT_LEN_MAX (NET_IP_TOT_LEN_MAX - NET_IP_HDR_SIZE_MIN ) #define NET_TCP_DATA_LEN_MAX (NET_TCP_TOT_LEN_MAX - NET_TCP_HDR_SIZE_MIN) /*$PAGE*/ /* ********************************************************************************************************* * TCP SEGMENT SIZE DEFINES * * Note(s) : (1) (a) RFC # 879, Section 3 states that the TCP Maximum Segment Size "counts only * data octets in the segment, ... not the TCP header or the IP header". * * (b) RFC #1122, Section 4.2.2.6 requires that : * * (1) "The MSS value to be sent in an MSS option must be less than or equal to * * (A) MMS_R - 20 * * where MMS_R is the maximum size for a transport-layer message that can * be received." * * (2) "If an MSS option is not received at connection setup, TCP MUST assume a * default send MSS of 536 (576 - 40)." * * See also 'net_ip.h IP DATA/TOTAL LENGTH DEFINES Note #1'. ********************************************************************************************************* */ /* See Note #1. */ #define NET_TCP_MAX_SEG_SIZE_DFLT (NET_IP_MAX_DATAGRAM_SIZE_DFLT - NET_IP_HDR_SIZE_MIN - NET_TCP_HDR_SIZE_MIN) #define NET_TCP_MAX_SEG_SIZE_DFLT_RX NET_TCP_DATA_LEN_MAX /* See Note #1b1. */ #define NET_TCP_MAX_SEG_SIZE_DFLT_TX NET_TCP_MAX_SEG_SIZE_DFLT /* See Note #1b2. */ #define NET_TCP_MAX_SEG_SIZE_NONE 0u #define NET_TCP_MAX_SEG_SIZE_MIN NET_TCP_MAX_SEG_SIZE_DFLT #define NET_TCP_MAX_SEG_SIZE_MAX NET_TCP_DATA_LEN_MAX #define NET_TCP_SEG_LEN_MIN NET_TCP_DATA_LEN_MIN #define NET_TCP_SEG_LEN_MAX NET_TCP_DATA_LEN_MAX #define NET_TCP_SEG_LEN_SYNC 1u #define NET_TCP_SEG_LEN_FIN 1u #define NET_TCP_SEG_LEN_CLOSE NET_TCP_SEG_LEN_FIN #define NET_TCP_SEG_LEN_ACK 0u #define NET_TCP_SEG_LEN_RESET 0u #define NET_TCP_SEG_LEN_PROBE 0u #define NET_TCP_DATA_LEN_TX_SYNC 0u #define NET_TCP_DATA_LEN_TX_FIN 0u #define NET_TCP_DATA_LEN_TX_CLOSE NET_TCP_DATA_LEN_TX_FIN #define NET_TCP_DATA_LEN_TX_ACK 0u #define NET_TCP_DATA_LEN_TX_PROBE_NO_DATA 0u #define NET_TCP_DATA_LEN_TX_PROBE_DATA 1u #define NET_TCP_DATA_LEN_TX_RESET 0u #define NET_TCP_TX_PROBE_DATA 0x00u /* ********************************************************************************************************* * TCP WINDOW SIZE DEFINES * * Note(s) : (1) Although NO RFC specifies the absolute minimum TCP connection window size value allowed, * RFC #793, Section 3.7 'Data Communication : Managing the Window' states that for "the * window ... there is an assumption that this is related to the currently available data * buffer space available for this connection". ********************************************************************************************************* */ #define NET_TCP_WIN_SIZE_NONE 0u #define NET_TCP_WIN_SIZE_MIN NET_TCP_MAX_SEG_SIZE_MIN #define NET_TCP_WIN_SIZE_MAX DEF_INT_16U_MAX_VAL /*$PAGE*/ /* ********************************************************************************************************* * TCP HEADER OPTIONS DEFINES * * Note(s) : (1) See the following RFC's for TCP options summary : * * (a) RFC # 793, Section 3.1 'Header Format : Options' * (b) RFC #1122; Sections 4.2.2.5, 4.2.2.6 * * (2) TCP option types are encoded in the first octet for each TCP option as follows : * * -------- * | TYPE | * -------- * * The TCP option type value determines the TCP option format : * * (a) The following TCP option types are single-octet TCP options -- i.e. the option type * octet is the ONLY octet for the TCP option. * * (1) TYPE = 0 End of Options List * (2) TYPE = 1 No Operation * * * (b) All other TCP options MUST be multi-octet TCP options (see RFC #1122, Section 4.2.2.5) : * * ------------------------------ * | TYPE | LEN | TCP OPT | * ------------------------------ * * where * TYPE Indicates the specific TCP option type * LEN Indicates the total TCP option length, in octets, including * the option type & the option length octets * TCP OPT Additional TCP option octets, if any, that contain the remaining * TCP option information * * The following TCP option types are multi-octet TCP options where the option's second * octet specify the total TCP option length, in octets, including the option type & the * option length octets : * * (1) TYPE = 2 Maximum Segment Size See RFC # 793, Section 3.1 'Header Format : * Options : Maximum Segment Size'; * RFC #1122, Section 4.2.2.6; * RFC # 879, Section 3 * * (2) TYPE = 3 Window Scale See 'net_tcp.h Note #1c1' * (3) TYPE = 4 SACK Allowed See 'net_tcp.h Note #1c2' * (4) TYPE = 5 SACK Option See 'net_tcp.h Note #1c2' * (5) TYPE = 6 Echo Request See 'net_tcp.h Note #1c3' * (6) TYPE = 7 Echo Reply See 'net_tcp.h Note #1c3' * (7) TYPE = 8 Timestamp See 'net_tcp.h Note #1c4' * * (3) TCP header allows for a maximum option list length of 40 octets : * * NET_TCP_HDR_OPT_SIZE_MAX = NET_TCP_HDR_SIZE_MAX - NET_TCP_HDR_SIZE_MIN * * = 60 - 20 * * = 40 * * (4) 'NET_TCP_OPT_SIZE' MUST be pre-defined PRIOR to all definitions that require TCP option * size data type. ********************************************************************************************************* */ /*$PAGE*/ #define NET_TCP_HDR_OPT_END_LIST 0u #define NET_TCP_HDR_OPT_NOP 1u #define NET_TCP_HDR_OPT_MAX_SEG_SIZE 2u #define NET_TCP_HDR_OPT_WIN_SCALE 3u #define NET_TCP_HDR_OPT_SACK_PERMIT 4u #define NET_TCP_HDR_OPT_SACK 5u #define NET_TCP_HDR_OPT_ECHO_REQ 6u #define NET_TCP_HDR_OPT_ECHO_REPLY 7u #define NET_TCP_HDR_OPT_TS 8u #define NET_TCP_HDR_OPT_PAD NET_TCP_HDR_OPT_END_LIST #define NET_TCP_HDR_OPT_LEN_END_LIST 1u #define NET_TCP_HDR_OPT_LEN_NOP 1u #define NET_TCP_HDR_OPT_LEN_MAX_SEG_SIZE 4u #define NET_TCP_HDR_OPT_LEN_WIN_SCALE 3u #define NET_TCP_HDR_OPT_LEN_SACK_PERMIT 2u #define NET_TCP_HDR_OPT_LEN_ECHO_REQ 6u #define NET_TCP_HDR_OPT_LEN_ECHO_REPLY 6u #define NET_TCP_HDR_OPT_LEN_TS 10u #define NET_TCP_HDR_OPT_LEN_SACK_MIN 6u #define NET_TCP_HDR_OPT_LEN_SACK_MAX 38u #define NET_TCP_HDR_OPT_LEN_MIN 1u #define NET_TCP_HDR_OPT_LEN_MIN_LEN 2u #define NET_TCP_HDR_OPT_LEN_MAX 38u typedef CPU_INT32U NET_TCP_OPT_SIZE; /* TCP opt size data type (see Note #4). */ #define NET_TCP_HDR_OPT_SIZE_WORD (sizeof(NET_TCP_OPT_SIZE)) #define NET_TCP_HDR_OPT_SIZE_MAX (NET_TCP_HDR_SIZE_MAX - NET_TCP_HDR_SIZE_MIN) #define NET_TCP_HDR_OPT_NBR_MIN 0u #define NET_TCP_HDR_OPT_NBR_MAX (NET_TCP_HDR_OPT_SIZE_MAX / NET_TCP_HDR_OPT_SIZE_WORD) #define NET_TCP_HDR_OPT_IX NET_TCP_HDR_SIZE_MIN /*$PAGE*/ /* ********************************************************************************************************* * TCP OPTION CONFIGURATION TYPE DEFINES * * Note(s) : (1) NET_TCP_OPT_CFG_TYPE_&&& #define values specifically chosen as ASCII representations of * the TCP option configuration types. Memory displays of TCP option configuration buffers * will display the TCP option configuration TYPEs with their chosen ASCII names. ********************************************************************************************************* */ /* ---------------- TCP OPT CFG TYPES ----------------- */ #if (CPU_CFG_ENDIAN_TYPE == CPU_ENDIAN_TYPE_BIG) #define NET_TCP_OPT_CFG_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x4D535320u /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x57494E20u /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x53434B50u /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x5341434Bu /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x45524551u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x4543484Fu /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x54532020u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #else #if (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_32) #define NET_TCP_OPT_CFG_TYPE_NONE 0x454E4F4Eu /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x2053534Du /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x204E4957u /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x504B4353u /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x4B434153u /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x51455245u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x4F484345u /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x20205354u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #elif (CPU_CFG_DATA_SIZE == CPU_WORD_SIZE_16) #define NET_TCP_OPT_CFG_TYPE_NONE 0x4F4E454Eu /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x534D2053u /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x4957204Eu /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x4353504Bu /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x41534B43u /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x52455145u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x43454F48u /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x53542020u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #else /* Dflt CPU_WORD_SIZE_08. */ #define NET_TCP_OPT_CFG_TYPE_NONE 0x4E4F4E45u /* "NONE" in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_MAX_SEG_SIZE 0x4D535320u /* "MSS " in ASCII. */ #define NET_TCP_OPT_CFG_TYPE_WIN_SCALE 0x57494E20u /* "WIN " in ASCII (see 'net_tcp.h Note #1c1'). */ #define NET_TCP_OPT_CFG_TYPE_SACK_PERMIT 0x53434B50u /* "SCKP" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_SACK 0x5341434Bu /* "SACK" in ASCII (see 'net_tcp.h Note #1c2'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REQ 0x45524551u /* "EREQ" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_ECHO_REPLY 0x4543484Fu /* "ECHO" in ASCII (see 'net_tcp.h Note #1c3'). */ #define NET_TCP_OPT_CFG_TYPE_TS 0x54532020u /* "TS " in ASCII (see 'net_tcp.h Note #1c4'). */ #endif #endif /*$PAGE*/ /* ********************************************************************************************************* * TCP CONNECTION TIMEOUT DEFINES * * Note(s) : (1) (a) (1) RFC #1122, Section 4.2.2.13 'DISCUSSION' states that "the graceful close algorithm * of TCP requires that the connection state remain defined on (at least) one end of * the connection, for a timeout period of 2xMSL ... During this period, the (remote * socket, local socket) pair that defines the connection is busy and cannot be reused". * * (2) The following sections reiterate that the TIME-WAIT state timeout scalar is two * maximum segment lifetimes (2 MSL) : * * (A) RFC #793, Section 3.9 'Event Processing : SEGMENT ARRIVES : * Check Sequence Number : TIME-WAIT STATE' * (B) RFC #793, Section 3.9 'Event Processing : SEGMENT ARRIVES : * Check FIN Bit : TIME-WAIT STATE' * * (b) (1) RFC #793, Section 3.3 'Sequence Numbers : Knowing When to Keep Quiet' states that * "the Maximum Segment Lifetime (MSL) is ... to be 2 minutes. This is an engineering * choice, and may be changed if experience indicates it is desirable to do so". * * (2) Microsoft Corporation's Windows XP defaults MSL to 15 seconds. ********************************************************************************************************* */ /* Max seg timeout (see Note #1b) : */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_MIN_SEC ( 0u ) /* ... min = 0 seconds */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_MAX_SEC ( 2u * DEF_TIME_NBR_SEC_PER_MIN) /* ... max = 2 minutes */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_DFLT_SEC ( 15u ) /* ... dflt = 15 seconds */ #define NET_TCP_CONN_TIMEOUT_MAX_SEG_SCALAR 2u /* ... scalar (see Note #1a). */ #define NET_TCP_CONN_TIMEOUT_CONN_DFLT_SEC (120u * DEF_TIME_NBR_SEC_PER_MIN) /* Dflt conn timeout = 120 minutes */ #define NET_TCP_CONN_TIMEOUT_USER_DFLT_SEC ( 30u * DEF_TIME_NBR_SEC_PER_MIN) /* Dflt user timeout = 30 minutes */ /*$PAGE*/ /* ********************************************************************************************************* * TCP CONNECTION STATES * * Note(s) : (1) See the following RFC's for TCP state machine summary : * * (a) RFC # 793; Sections 3.2, 3.4, 3.5, 3.9 * (b) RFC #1122; Sections 4.2.2.8, 4.2.2.10, 4.2.2.11, 4.2.2.13, 4.2.2.18, 4.2.2.20 * * (2) (a) #### Additional closing-data-available state used for closing connections to allow the * application layer to receive any remaining data. * * See also 'net_tcp.c NetTCP_RxPktConnHandlerFinWait1() Note #2f5A2', * 'net_tcp.c NetTCP_RxPktConnHandlerFinWait2() Note #2f5B', * 'net_tcp.c NetTCP_RxPktConnHandlerClosing() Note #2d2B2a1B', * & 'net_tcp.c NetTCP_RxPktConnHandlerLastAck() Note #2d2A1b'. ********************************************************************************************************* */ #define NET_TCP_CONN_STATE_NONE 0u #define NET_TCP_CONN_STATE_FREE 1u #define NET_TCP_CONN_STATE_CLOSED 10u #define NET_TCP_CONN_STATE_LISTEN 20u #define NET_TCP_CONN_STATE_SYNC_RXD 30u #define NET_TCP_CONN_STATE_SYNC_RXD_PASSIVE 31u #define NET_TCP_CONN_STATE_SYNC_RXD_ACTIVE 32u #define NET_TCP_CONN_STATE_SYNC_TXD 35u #define NET_TCP_CONN_STATE_CONN 40u #define NET_TCP_CONN_STATE_FIN_WAIT_1 50u #define NET_TCP_CONN_STATE_FIN_WAIT_2 51u #define NET_TCP_CONN_STATE_CLOSING 52u #define NET_TCP_CONN_STATE_TIME_WAIT 53u #define NET_TCP_CONN_STATE_CLOSE_WAIT 55u #define NET_TCP_CONN_STATE_LAST_ACK 56u #define NET_TCP_CONN_STATE_CLOSING_DATA_AVAIL 59u /* See Note #2a. */ /* ********************************************************************************************************* * TCP CONNECTION QUEUE STATES ********************************************************************************************************* */ #define NET_TCP_RX_Q_STATE_NONE 0u #define NET_TCP_RX_Q_STATE_CLOSED 100u #define NET_TCP_RX_Q_STATE_CLOSING 101u #define NET_TCP_RX_Q_STATE_SYNC 110u #define NET_TCP_RX_Q_STATE_CONN 111u #define NET_TCP_TX_Q_STATE_NONE 0u #define NET_TCP_TX_Q_STATE_CLOSED 200u #define NET_TCP_TX_Q_STATE_CLOSING 201u #define NET_TCP_TX_Q_STATE_SYNC 210u #define NET_TCP_TX_Q_STATE_CONN 211u #define NET_TCP_TX_Q_STATE_SUSPEND 215u #define NET_TCP_TX_Q_STATE_CLOSED_SUSPEND 220u #define NET_TCP_TX_Q_STATE_CLOSING_SUSPEND 221u /*$PAGE*/ /* ********************************************************************************************************* * TCP CONNECTION CODE DEFINES **************
上传时间： 2015-11-22
上传用户：the same kong
#include "string.h" #include "ctype.h" #include "stdio.h" search(char pd[]) {FILE *fp; int time=0,i=0,j=0,add[80],k=0,m; char *ch, str[900]; m=strlen(pd); if((fp=fopen("haha.txt","r"))==NULL) { printf("Cannot open this file\n"); exit(0); } for(;!feof(fp);i++) { str[i]=fgetc(fp); if(tolower(str[i])==tolower(pd[k])) {k++; if(k==m) if(!isalpha(i-m)&&!isalpha((str[i++]=fgetc(fp)))) { time++; add[j]=i-m+1; j++; k=0; } else k=0; } } if(time) { printf("The time is:%d\n",time); printf("The adders is:\n"); for(i=0;i<j;i++) printf("%5d",add[i]); if(i%5==0) printf("\n"); getch(); fclose(fp); } else printf("Sorry!Cannot find the word(^_^)"); } main() { char pd[10],choose='y'; int flag=1; while(flag) {printf("In put the word you want to seqarch:"); scanf("%s",pd); search(strlwr(pd)); printf("\nWould you want to continue?(Y/N):"); getchar(); scanf("%c",&choose); if((tolower(choose))=='n') flag=0; else flag=1; } printf("Thanks for your using!Bye-bye!\n"); getch(); }
标签： 学生专用
上传时间： 2016-12-29
上传用户：767483511
由STC89C51单片机来控制DHT11传感器采集的温湿度的转换、1602液晶屏的显示，以及蜂鸣器的报警。
上传时间： 2018-04-27
上传用户：luson
Broadband powerline communication systems are continuing to gain significant market adoption worldwide for applications ranging from IPTV delivery to the Smart Grid. The suite of standards developed by the HomePlug Powerline Alliance plays an important role in the widespread deployment of broadband PLC. To date, more than 100 million HomePlug modems are deployed and these numbers continue to rise.
上传时间： 2020-05-26
上传用户：shancjb
One traditional view of how wireless networks evolve is of a continuous, inevitable progres- sion to higher link speeds, combined with greater mobility over wider areas. This standpoint certainly captures the development from first and second generation cellular systems focused on voice support, and the early short-range wireless data networks, through to today’s 3G cellular and mobile broadband systems; there is every confidence that the trend will continue some way into the future.
上传时间： 2020-05-26
上传用户：shancjb
With the rapid growth of the wireless mobile applications, wireless voice has begun to challenge wireline voice, whereas the desire to access e-mail, surf the Web or download music (e.g., MP3) wirelessly is increasing for wireless data. While second generation (2G) cellular wireless systems, such as cdmaOne1, GSM2 and TDMA3, introduced digital technology to wireless cellular systems to deal with the increasing demand for wireless applications, there is still the need for more spectrally efficient technologies for two reasons. First, wireless voice capacity is expected to continue to grow. Second, the introduction of high-speed wireless data will require more bandwidth.
标签： Wireless Systems Mobile Beyond and 3G
上传时间： 2020-05-30
上传用户：shancjb
Mobile operators must continuously pursue cost‐ effective and efficient solutions to meet the high data demand requirements of their subscribers. Limited spectrum allocations and non‐contiguous spectrum blocks continue to pose challenges for mobile operators supporting large data uploads and downloads across their networks. With the increase in video and social media content, the challenges have increased exponentially.
标签： qorvo-carrier-aggregation-fundame ntals
上传时间： 2020-05-31
上传用户：shancjb
Radio propagation measurements and channel modelling continue to be of fundamental importance to radio system design. As new technology enables dynamic spectrum access and higher data rates, radio propagation effects such as shadowing, the presence of multipath and frequency dispersion are the limiting factors in the design of wireless communication systems. While there are several books covering the topic of radio propagation in various frequency bands, there appears to be no books on radio propagation measurements, which this book addresses at length.
标签： Propagation Measurement Radio
上传时间： 2020-06-01
上传用户：shancjb
