/* The following macros process structure members: to determine the */
/* offset of a structure member from the beginning of the structure, and */
/* to detemine the size of a member of a structure. */
#define DEFS_OFFSET(s,m) (DEFS_UI16)&(((s *)0)->m)
#define DEFS_MEMBER_SIZE(s,m) sizeof(((s *)0)->m)
/* The following macros make it easier to specify binary numbers. For */
/* example, to specify a byte in binary: DEFS_BINARY(01100001) or to */
/* specify a word in binary: DEFS_BINARY_WORD(00111101,11001010) */
#define DEFS_BINARY_CONVERT(byte) (((byte & 0x10000000L) / 0x200000L) + \
((byte & 0x01000000L) / 0x040000L) + \
((byte & 0x00100000L) / 0x008000L) + \
((byte & 0x00010000L) / 0x001000L) + \
((byte & 0x00001000L) / 0x000200L) + \
((byte & 0x00000100L) / 0x000040L) + \
((byte & 0x00000010L) / 0x000008L) + \
((byte & 0x00000001L) / 0x000001L))
#define DEFS_BINARY(byte) DEFS_BINARY_CONVERT(0x##byte)
#define DEFS_BINARY_WORD(high,low) (DEFS_BINARY_CONVERT(0x##high) * 256) + \
2006.1.7 字節(jié)交換順序
/* This is a set of routines for demonstrating the effects of
byte ordering between little endian and big endian machines
Big Endian (B_ENDIAN == TRUE):
MSB [ n | n+1 | n+2 | n+3 ] LSB
Little Endian (B_ENDIAN == FALSE):
MSB [ n+3 | n+2 | n+1 | n] LSB
little/big-endian is bitness as well. For example,
struct {
short b:5, --- we _want_ signed for the example ---
c:11;
};
is stored in little-endian (gint32el) ['+' denotes sign bit]:
tf_Bitstream view -->
0123456789A BCDEF
|-----c----+|--b-+|
Whereas bigendian (Motorola) stores it thus:
tf_Bitstream view -->
FEDCB A9876543210
|+-b--|+----c-----|
So, you have to invert bits as well to convert endianness.
#define Gettf_Bit(Val,Idx) ( ( (Val) & (1<<(Idx)) ) )
#define Settf_Bit(Val,Idx,tf_Bit) ( ( (Val) & (~(1<<Idx)) ) | ((tf_Bit)<<(Idx)) )
for ( i = 0; i < sizeof(Val)*8; i++)
NewVal = Settf_Bit(NewVal,sizeof(Val)*8-i-1, Gettf_Bit(Val,i));
*/
DNP
DnpMasterStart
--> taskSpawn ("tDnpMaster", priority, VX_FP_TASK, 0x8000,
(FUNCPTR) DnpMasterTask,
(int) ini_name, 0, 0, 0, 0, 0, 0, 0, 0, 0)
dnpMasterTask ---> dnp_init()
---> ca_task_initialize()
---> ca_add_fd_registration()
---> 從配置文件中得到dnp的配置信息
---> pdpdvrs_initDNP()
---> addr_init()
---> dnp_loop()
DnpMasterAddDevice
DnpMasterAdd8550
DnpMasterAddText
DNP PEER TO PEER
一些debug信息
物理層
．利用查表法來確定鏈路層的長(zhǎng)度
--->． pdpphys_initPhysRecMgr 物理層初始化，分配內(nèi)存
． valid_address()
． pdpphys_parseDNPframe()
DnpMasterTask
========================================================
串口：從溫舊夢(mèng)
非重疊模式優(yōu)點(diǎn) ．直接
．易移植
缺點(diǎn) ．線程中讀、寫相互堵塞
．線程間相互堵塞（包括讀之間，寫之間，讀寫之間）
單片機(jī)，嵌入式如vxworks，任務(wù)中相對(duì)簡(jiǎn)單的程序中常用
重疊模式 優(yōu)點(diǎn) ．靈活，效率高（后臺(tái)執(zhí)行操作）
．多線程間，線程中，讀寫操作不會(huì)相互堵塞
缺點(diǎn) ．不那么直接
．不易于移植
EV_RXCHAR：事件通知模式用在非重疊模是一個(gè)比較好的方式，因?yàn)槌绦虿挥幂喸兇冢怨?jié)省CPU的thread quantum
方式如下：
DWORD dwCommEvent;
DWORD dwRead;
char chRead;
if (!SetCommMask(hComm, EV_RXCHAR))
// Error setting communications event mask.
for ( ; ; ) {
if (WaitCommEvent(hComm, &dwCommEvent, NULL)) {
if (ReadFile(hComm, &chRead, 1, &dwRead, NULL))
// A byte has been read; process it.
else
// An error occurred in the ReadFile call.
break;
}
else
// Error in WaitCommEvent.
break;
}
問題出現(xiàn)在：當(dāng)多個(gè)字節(jié)連續(xù)的發(fā)送，第１個(gè)byte到，引起EV_RXCHAR 事件發(fā)生，
WaitCommEvent指示可讀．第２個(gè)byte緊接著到，EV_RXCHAR只是在內(nèi)部置位，
當(dāng)?shù)冢眰€(gè)byte讀完，調(diào)用WaitCommEvent時(shí)，系統(tǒng)再次指示EV_RXCHAR 事件發(fā)生，
可讀第２個(gè)byte,問題出現(xiàn)在當(dāng)?shù)冢矀€(gè)字符到達(dá)，而沒有被讀出時(shí)，第３個(gè)字符到
達(dá)了，此時(shí)系統(tǒng)也期望將對(duì)應(yīng)于第３個(gè)字符的EV_RXCHAR置位，但是系統(tǒng)中的
EV_RXCHAR標(biāo)志位已經(jīng)被第２個(gè)已經(jīng)置位了，于是就被忽略，當(dāng)?shù)冢矀€(gè)自負(fù)讀出
后，只能在系統(tǒng)緩沖區(qū)，等待第４個(gè)字符到，而讀出第３個(gè)字符，這樣代碼和系統(tǒng)
就失去同步。
（我覺得這種情況在一般情況下不會(huì)出現(xiàn),在單片機(jī)、
嵌入式應(yīng)該是一個(gè)一個(gè)字符往外蹦，）
而且WaitCommEvent會(huì)導(dǎo)致很多其它事件丟失，在高速情況下。
解決辦法是：利用ClearCommError判斷緩沖中的字符個(gè)數(shù)，一次性讀完所有到達(dá)字符