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changed locking hierarchy

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This commit is contained in:
Jeff Hill
2001-03-21 01:07:27 +00:00
parent 0a9f914076
commit c0c2d30209
17 changed files with 1181 additions and 1328 deletions
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280
src/ca/searchTimer.cpp
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@@ -18,8 +18,9 @@
//
// searchTimer::searchTimer ()
//
searchTimer::searchTimer ( udpiiu &iiuIn, epicsTimerQueue &queueIn ) :
searchTimer::searchTimer ( udpiiu &iiuIn, epicsTimerQueue &queueIn, epicsMutex &mutexIn ) :
timer ( queueIn.createTimer ( *this ) ),
mutex ( mutexIn ),
iiu ( iiuIn ),
framesPerTry ( INITIALTRIESPERFRAME ),
framesPerTryCongestThresh ( UINT_MAX ),
@@ -133,6 +134,7 @@ void searchTimer::notifySearchResponse ( unsigned short retrySeqNoIn )
//
epicsTimerNotify::expireStatus searchTimer::expire ()
{
epicsAutoMutex locker ( this->mutex );
unsigned nFrameSent = 0u;
unsigned nChanSent = 0u;
@@ -142,165 +144,161 @@ epicsTimerNotify::expireStatus searchTimer::expire ()
if ( this->iiu.channelCount () == 0 ) {
return noRestart;
}
{
epicsAutoMutex locker ( this->mutex );
/*
* increment the retry sequence number
*/
this->retrySeqNo++; /* allowed to roll over */
/*
* dynamically adjust the number of UDP frames per
* try depending how many search requests are not
* replied to
*
* This determines how many search request can be
* sent together (at the same instant in time).
*
* The variable this->framesPerTry
* determines the number of UDP frames to be sent
* each time that expire() is called.
* If this value is too high we will waste some
* network bandwidth. If it is too low we will
* use very little of the incoming UDP message
* buffer associated with the server's port and
* will therefore take longer to connect. We
* initialize this->framesPerTry
* to a prime number so that it is less likely that the
* same channel is in the last UDP frame
* sent every time that this is called (and
* potentially discarded by a CA server with
* a small UDP input queue).
*/
/*
* increase frames per try only if we see better than
* a 93.75% success rate for one pass through the list
*/
if (this->searchResponsesWithinThisPass >
(this->searchTriesWithinThisPass-(this->searchTriesWithinThisPass/16u)) ) {
/*
* increment the retry sequence number
* increase UDP frames per try if we have a good score
*/
this->retrySeqNo++; /* allowed to roll over */
/*
* dynamically adjust the number of UDP frames per
* try depending how many search requests are not
* replied to
*
* This determines how many search request can be
* sent together (at the same instant in time).
*
* The variable this->framesPerTry
* determines the number of UDP frames to be sent
* each time that expire() is called.
* If this value is too high we will waste some
* network bandwidth. If it is too low we will
* use very little of the incoming UDP message
* buffer associated with the server's port and
* will therefore take longer to connect. We
* initialize this->framesPerTry
* to a prime number so that it is less likely that the
* same channel is in the last UDP frame
* sent every time that this is called (and
* potentially discarded by a CA server with
* a small UDP input queue).
*/
/*
* increase frames per try only if we see better than
* a 93.75% success rate for one pass through the list
*/
if (this->searchResponsesWithinThisPass >
(this->searchTriesWithinThisPass-(this->searchTriesWithinThisPass/16u)) ) {
if ( this->framesPerTry < MAXTRIESPERFRAME ) {
/*
* increase UDP frames per try if we have a good score
* a congestion avoidance threshold similar to TCP is now used
*/
if ( this->framesPerTry < MAXTRIESPERFRAME ) {
/*
* a congestion avoidance threshold similar to TCP is now used
*/
if ( this->framesPerTry < this->framesPerTryCongestThresh ) {
this->framesPerTry += this->framesPerTry;
}
else {
this->framesPerTry += (this->framesPerTry/8) + 1;
}
debugPrintf ( ("Increasing frame count to %u t=%u r=%u\n",
this->framesPerTry, this->searchTriesWithinThisPass, this->searchResponsesWithinThisPass) );
if ( this->framesPerTry < this->framesPerTryCongestThresh ) {
this->framesPerTry += this->framesPerTry;
}
else {
this->framesPerTry += (this->framesPerTry/8) + 1;
}
debugPrintf ( ("Increasing frame count to %u t=%u r=%u\n",
this->framesPerTry, this->searchTriesWithinThisPass, this->searchResponsesWithinThisPass) );
}
}
/*
* if we detect congestion because we have less than a 87.5% success
* rate then gradually reduce the frames per try
*/
else if ( this->searchResponsesWithinThisPass <
(this->searchTriesWithinThisPass-(this->searchTriesWithinThisPass/8u)) ) {
if (this->framesPerTry>1) {
this->framesPerTry--;
}
this->framesPerTryCongestThresh = this->framesPerTry/2 + 1;
debugPrintf ( ("Congestion detected - set frames per try to %u t=%u r=%u\n",
this->framesPerTry, this->searchTriesWithinThisPass,
this->searchResponsesWithinThisPass) );
}
while ( 1 ) {
/*
* if we detect congestion because we have less than a 87.5% success
* rate then gradually reduce the frames per try
* clear counter when we reach the end of the list
*
* if we are making some progress then
* dont increase the delay between search
* requests
*/
else if ( this->searchResponsesWithinThisPass <
(this->searchTriesWithinThisPass-(this->searchTriesWithinThisPass/8u)) ) {
if (this->framesPerTry>1) {
this->framesPerTry--;
}
this->framesPerTryCongestThresh = this->framesPerTry/2 + 1;
debugPrintf ( ("Congestion detected - set frames per try to %u t=%u r=%u\n",
this->framesPerTry, this->searchTriesWithinThisPass,
this->searchResponsesWithinThisPass) );
}
while ( 1 ) {
/*
* clear counter when we reach the end of the list
*
* if we are making some progress then
* dont increase the delay between search
* requests
*/
if ( this->searchTriesWithinThisPass >= this->iiu.channelCount () ) {
if ( this->searchResponsesWithinThisPass == 0u ) {
debugPrintf ( ("increasing search try interval\n") );
this->setRetryInterval ( this->minRetry + 1u );
}
this->minRetry = UINT_MAX;
/*
* increment the retry sequence number
* (this prevents the time of the next search
* try from being set to the current time if
* we are handling a response from an old
* search message)
*/
this->retrySeqNo++; /* allowed to roll over */
/*
* so that old search tries will not update the counters
*/
this->retrySeqAtPassBegin = this->retrySeqNo;
this->searchTriesWithinThisPass = 0;
this->searchResponsesWithinThisPass = 0;
debugPrintf ( ("saw end of list\n") );
if ( this->searchTriesWithinThisPass >= this->iiu.channelCount () ) {
if ( this->searchResponsesWithinThisPass == 0u ) {
debugPrintf ( ("increasing search try interval\n") );
this->setRetryInterval ( this->minRetry + 1u );
}
unsigned retryNoForThisChannel;
if ( ! this->iiu.searchMsg ( this->retrySeqNo, retryNoForThisChannel ) ) {
nFrameSent++;
if ( nFrameSent >= this->framesPerTry ) {
break;
}
this->iiu.flush ();
if ( ! this->iiu.searchMsg ( this->retrySeqNo, retryNoForThisChannel ) ) {
break;
}
}
if ( this->minRetry > retryNoForThisChannel ) {
this->minRetry = retryNoForThisChannel;
}
if ( this->searchTriesWithinThisPass < UINT_MAX ) {
this->searchTriesWithinThisPass++;
}
if ( nChanSent < UINT_MAX ) {
nChanSent++;
}
this->minRetry = UINT_MAX;
/*
* dont send any of the channels twice within one try
* increment the retry sequence number
* (this prevents the time of the next search
* try from being set to the current time if
* we are handling a response from an old
* search message)
*/
if ( nChanSent >= this->iiu.channelCount () ) {
/*
* add one to nFrameSent because there may be
* one more partial frame to be sent
*/
nFrameSent++;
/*
* cap this->framesPerTry to
* the number of frames required for all of
* the unresolved channels
*/
if ( this->framesPerTry > nFrameSent ) {
this->framesPerTry = nFrameSent;
}
this->retrySeqNo++; /* allowed to roll over */
/*
* so that old search tries will not update the counters
*/
this->retrySeqAtPassBegin = this->retrySeqNo;
this->searchTriesWithinThisPass = 0;
this->searchResponsesWithinThisPass = 0;
debugPrintf ( ("saw end of list\n") );
}
unsigned retryNoForThisChannel;
if ( ! this->iiu.searchMsg ( this->retrySeqNo, retryNoForThisChannel ) ) {
nFrameSent++;
if ( nFrameSent >= this->framesPerTry ) {
break;
}
this->iiu.datagramFlush ();
if ( ! this->iiu.searchMsg ( this->retrySeqNo, retryNoForThisChannel ) ) {
break;
}
}
if ( this->minRetry > retryNoForThisChannel ) {
this->minRetry = retryNoForThisChannel;
}
if ( this->searchTriesWithinThisPass < UINT_MAX ) {
this->searchTriesWithinThisPass++;
}
if ( nChanSent < UINT_MAX ) {
nChanSent++;
}
/*
* dont send any of the channels twice within one try
*/
if ( nChanSent >= this->iiu.channelCount () ) {
/*
* add one to nFrameSent because there may be
* one more partial frame to be sent
*/
nFrameSent++;
/*
* cap this->framesPerTry to
* the number of frames required for all of
* the unresolved channels
*/
if ( this->framesPerTry > nFrameSent ) {
this->framesPerTry = nFrameSent;
}
break;
}
}
// flush out the search request buffer
this->iiu.flush ();
this->iiu.datagramFlush ();
debugPrintf ( ("sent %u delay sec=%f\n", nFrameSent, this->period) );