Files
epics-base/src/libCom/fdManager.cc

416 lines
8.3 KiB
C++

//
// $Id$
//
//
// $Log$
// Revision 1.13 1998/05/29 20:22:44 jhill
// made hashing routine portable
//
// Revision 1.12 1998/02/05 21:12:09 jhill
// removed questionable inline
//
// Revision 1.11 1997/08/05 00:37:00 jhill
// removed warnings
//
// Revision 1.10 1997/06/25 05:45:49 jhill
// cleaned up pc port
//
// Revision 1.9 1997/06/13 09:39:09 jhill
// fixed warnings
//
// Revision 1.8 1997/05/29 21:37:38 tang
// add ifdef for select call to support HP-UX
//
// Revision 1.7 1997/05/27 14:53:11 tang
// fd_set cast in select for both Hp and Sun
//
// Revision 1.6 1997/05/08 19:49:12 tang
// added int * cast in select for HP port compatibility
//
// Revision 1.5 1997/04/23 17:22:57 jhill
// fixed WIN32 DLL symbol exports
//
// Revision 1.4 1997/04/10 19:45:33 jhill
// API changes and include with not <>
//
// Revision 1.3 1996/11/02 02:04:42 jhill
// fixed several subtle bugs
//
// Revision 1.2 1996/09/04 21:50:16 jhill
// added hashed fd to fdi convert
//
// Revision 1.1 1996/08/13 22:48:23 jhill
// dfMgr =>fdManager
//
//
//
//
// NOTES:
// 1) This library is not thread safe
//
//
//
// ANSI C
//
#include <assert.h>
#include <errno.h>
#include <string.h>
// Both the functions in osiTimer and fdManager are
// implemented in this DLL -> define epicsExportSharesSymbols
#define epicsExportSharedSymbols
#define instantiateRecourceLib
#include "osiTimer.h"
#include "fdManager.h"
#include "osiSleep.h"
#include "bsdSocketResource.h"
//
// if the compiler supports explicit instantiation of
// template member functions
//
#if defined(EXPL_TEMPL)
//
// From Stroustrups's "The C++ Programming Language"
// Appendix A: r.14.9
//
// This explicitly instantiates the template class's member
// functions used by fdManager
//
//
// instantiated by "fdManager fileDescriptorManager;" statement below?
// (according to ms vis C++)
//
template class resTable <fdReg, fdRegId>;
#endif
epicsShareDef fdManager fileDescriptorManager;
//
// fdManager::fdManager()
//
epicsShareFunc fdManager::fdManager()
{
size_t i;
assert (bsdSockAttach());
for (i=0u; i<sizeof(this->fdSets)/sizeof(this->fdSets[0u]); i++) {
FD_ZERO(&this->fdSets[i]);
}
this->maxFD = 0;
this->processInProg = 0u;
this->pCBReg = 0;
//
// should throw an exception here
// when most compilers are implementing
// exceptions
//
assert (this->fdTbl.init(0x100)>=0);
}
//
// fdManager::~fdManager()
//
epicsShareFunc fdManager::~fdManager()
{
fdReg *pReg;
while ( (pReg = this->regList.get()) ) {
pReg->state = fdrLimbo;
pReg->destroy();
}
while ( (pReg = this->activeList.get()) ) {
pReg->state = fdrLimbo;
pReg->destroy();
}
bsdSockRelease();
}
//
// fdManager::process()
//
epicsShareFunc void fdManager::process (const osiTime &delay)
{
static const tsDLIterBD<fdReg> eol; // end of list
tsDLIterBD<fdReg> iter;
tsDLIterBD<fdReg> tmp;
osiTime minDelay;
osiTime zeroDelay;
fdReg *pReg;
struct timeval tv;
int status;
int ioPending = 0;
//
// no recursion
//
if (this->processInProg) {
return;
}
this->processInProg = 1;
//
// One shot at expired timers prior to going into
// select. This allows zero delay timers to arm
// fd writes. We will never process the timer queue
// more than once here so that fd activity get serviced
// in a reasonable length of time.
//
minDelay = staticTimerQueue.delayToFirstExpire();
if (zeroDelay>=minDelay) {
staticTimerQueue.process();
minDelay = staticTimerQueue.delayToFirstExpire();
}
if (minDelay>=delay) {
minDelay = delay;
}
for (iter=this->regList.first(); iter!=eol; ++iter) {
FD_SET(iter->getFD(), &this->fdSets[iter->getType()]);
ioPending = 1;
}
tv.tv_sec = minDelay.getSecTruncToLong ();
tv.tv_usec = minDelay.getUSecTruncToLong ();
/*
* win32 requires this (others will
* run faster with this installed)
*/
if (!ioPending) {
/*
* recover from subtle differences between
* windows sockets and UNIX sockets implementation
* of select()
*/
if (tv.tv_sec!=0 || tv.tv_usec!=0) {
osiSleep (tv.tv_sec, tv.tv_usec);
}
status = 0;
}
else {
status = select (this->maxFD, &this->fdSets[fdrRead],
&this->fdSets[fdrWrite], &this->fdSets[fdrExcp], &tv);
}
staticTimerQueue.process();
if (status==0) {
this->processInProg = 0;
return;
}
else if (status<0) {
if (SOCKERRNO == SOCK_EINTR) {
this->processInProg = 0;
return;
}
else {
fprintf(stderr,
"fdManager: select failed because errno=%d=\"%s\"\n",
SOCKERRNO, SOCKERRSTR);
}
}
//
// Look for activity
//
iter=this->regList.first();
while (iter!=eol) {
tmp = iter;
tmp++;
if (FD_ISSET(iter->getFD(), &this->fdSets[iter->getType()])) {
FD_CLR(iter->getFD(), &this->fdSets[iter->getType()]);
this->regList.remove(*iter);
this->activeList.add(*iter);
iter->state = fdrActive;
}
iter=tmp;
}
//
// I am careful to prevent problems if they access the
// above list while in a "callBack()" routine
//
while ( (pReg = this->activeList.get()) ) {
pReg->state = fdrLimbo;
//
// Tag current reg so that we
// can detect if it was deleted
// during the call back
//
this->pCBReg = pReg;
pReg->callBack();
if (this->pCBReg != NULL) {
//
// check only after we see that it is non-null so
// that we dont trigger bounds-checker dangling pointer
// error
//
assert (this->pCBReg==pReg);
this->pCBReg = 0;
if (pReg->onceOnly) {
pReg->destroy();
}
else {
this->regList.add(*pReg);
pReg->state = fdrPending;
}
}
}
this->processInProg = 0;
}
//
// fdReg::destroy()
// (default destroy method)
//
epicsShareFunc void fdReg::destroy()
{
delete this;
}
//
// fdReg::~fdReg()
//
epicsShareFunc fdReg::~fdReg()
{
fileDescriptorManager.removeReg(*this);
}
//
// fdReg::show()
//
epicsShareFunc void fdReg::show(unsigned level) const
{
printf ("fdReg at %p\n", (void *) this);
if (level>1u) {
printf ("\tstate = %d, onceOnly = %d\n",
this->state, this->onceOnly);
}
this->fdRegId::show(level);
}
//
// fdRegId::show()
//
void fdRegId::show(unsigned level) const
{
printf ("fdRegId at %p\n", this);
if (level>1u) {
printf ("\tfd = %d, type = %d\n",
this->fd, this->type);
}
}
//
// fdRegId::resourceHash()
//
resTableIndex fdRegId::resourceHash (unsigned) const
{
resTableIndex hashid = (unsigned) this->fd;
//
// This assumes worst case hash table index width of 1 bit.
// We will iterate this loop 5 times on a 32 bit architecture.
//
// A good optimizer will unroll this loop?
// Experiments using the microsoft compiler show that this isnt
// slower than switching on the architecture size and urolling the
// loop explicitly (that solution has resulted in portability
// problems in the past).
//
for (unsigned i=(CHAR_BIT*sizeof(unsigned))/2u; i>0u; i >>= 1u) {
hashid ^= (hashid>>i);
}
//
// evenly distribute based on the type of interest also
//
hashid ^= this->type;
//
// the result here is always masked to the
// proper size after it is returned to the resource class
//
return hashid;
}
//
// fdManager::installReg()
//
epicsShareFunc void fdManager::installReg (fdReg &reg)
{
int status;
this->maxFD = fdManagerMaxInt(this->maxFD, reg.getFD()+1);
this->regList.add(reg);
reg.state = fdrPending;
status = this->fdTbl.add(reg);
if (status) {
fprintf (stderr,
"**** Warning - duplicate fdReg object\n");
fprintf (stderr,
"**** will not be seen by fdManager::lookUpFD()\n");
}
}
//
// fdManager::removeReg()
//
void fdManager::removeReg(fdReg &reg)
{
fdReg *pItemFound;
pItemFound = this->fdTbl.remove(reg);
if (pItemFound!=&reg) {
fprintf(stderr,
"fdManager::removeReg() bad fd registration object\n");
return;
}
//
// signal fdManager that the fdReg was deleted
// during the call back
//
if (this->pCBReg == &reg) {
this->pCBReg = 0;
}
switch (reg.state) {
case fdrActive:
this->activeList.remove(reg);
break;
case fdrPending:
this->regList.remove(reg);
break;
case fdrLimbo:
break;
default:
//
// here if memory corrupted
//
assert(0);
}
reg.state = fdrLimbo;
FD_CLR(reg.getFD(), &this->fdSets[reg.getType()]);
}
//
// lookUpFD()
//
epicsShareFunc fdReg *fdManager::lookUpFD(const SOCKET fd, const fdRegType type)
{
if (fd<0) {
return NULL;
}
fdRegId id (fd,type);
return this->fdTbl.lookup(id);
}