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fixed deadlock discovered during connect / disconnect test

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This commit is contained in:
Jeff Hill
2000-10-20 23:34:39 +00:00
parent 8e49220af5
commit 0c1583ff7b
9 changed files with 94 additions and 77 deletions
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96
src/ca/comQueSend.cpp
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@@ -99,42 +99,38 @@ inline unsigned bufferReservoir::nBytes ()
return ( this->reservedBufs.count () * comBuf::maxBytes () );
}
// o lock the comQueSend
// o reserve sufficent space for entire message
// reserve sufficent space for entire message
// (this allows the recv thread to add a message
// to the que while some other thread is flushing
// and therefore prevents deadlocks, and it also
// allows proper status to be returned)
// o unlock comQueSend if status is not ECA_NORMAL
inline int comQueSend::lockAndReserveSpace ( unsigned msgSize, bufferReservoir &reservoir )
inline int comQueSend::lockAndReserveSpace ( unsigned msgSize,
bufferReservoir &reservoir, bool enablePreemptionDuringFlush )
{
unsigned bytesReserved = reservoir.nBytes ();
unsigned unoccupied;
this->mutex.lock ();
comBuf *pComBuf = this->bufs.last ();
if ( pComBuf ) {
unoccupied = pComBuf->unoccupiedBytes ();
}
else {
unoccupied = 0u;
}
while ( true ) {
comBuf *pComBuf = this->bufs.last ();
if ( pComBuf ) {
bytesReserved += pComBuf->unoccupiedBytes ();
}
if ( bytesReserved >= msgSize || this->bufs.count () < 4 ) {
break;
}
if ( ! this->flushToWirePermit () ) {
if ( this->bufs.count () >= 32u ) {
this->mutex.unlock ();
return ECA_TOLARGE;
}
break;
}
// flush if conditions indicate. second part of this guarantees
// that we will not flush out a buffer with almost nothing
// in it (this has a large impact on performance)
if ( this->bufs.count () <= 1u || unoccupied >= msgSize ) {
bytesReserved = unoccupied;
}
else {
this->mutex.unlock ();
if ( ! this->flushToWire () ) {
return ECA_DISCONNCHID;
}
if ( this->bufs.count () >= 32u ) {
return ECA_TOLARGE;
}
this->flushToWire ( enablePreemptionDuringFlush );
this->mutex.lock ();
}
@@ -320,7 +316,7 @@ unsigned comQueSend::occupiedBytes () const
return nBytes;
}
bool comQueSend::flushToWire ()
bool comQueSend::flushToWire ( bool enablePreemptionDuringFlush )
{
bool success = false;
@@ -345,7 +341,7 @@ bool comQueSend::flushToWire ()
success = true;
break;
}
success = pBuf->flushToWire ( *this );
success = pBuf->flushToWire ( *this, enablePreemptionDuringFlush );
pBuf->destroy ();
if ( ! success ) {
this->mutex.lock ();
@@ -396,7 +392,7 @@ int comQueSend::writeRequest ( unsigned serverId, unsigned type, unsigned nElem,
assert ( serverId <= 0xffffffff );
int status = this->lockAndReserveSpace ( postcnt + 16u, reservoir );
int status = this->lockAndReserveSpace ( postcnt + 16u, reservoir, true );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_WRITE ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( postcnt ) ); // postsize
@@ -446,7 +442,7 @@ int comQueSend::writeNotifyRequest ( unsigned ioId, unsigned serverId, unsigned
assert ( serverId <= 0xffffffff );
int status = this->lockAndReserveSpace ( postcnt + 16u, reservoir );
int status = this->lockAndReserveSpace ( postcnt + 16u, reservoir, true );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_WRITE_NOTIFY ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( postcnt ) ); // postsize
@@ -475,7 +471,7 @@ int comQueSend::readCopyRequest ( unsigned ioId, unsigned serverId, unsigned typ
assert ( serverId <= 0xffffffff );
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, true );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_READ ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -502,7 +498,7 @@ int comQueSend::readNotifyRequest ( unsigned ioId, unsigned serverId, unsigned t
assert ( serverId <= 0xffffffff );
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, true );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_READ_NOTIFY ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -524,7 +520,7 @@ int comQueSend::createChannelRequest ( unsigned id, const char *pName, unsigned
assert ( id <= 0xffffffff );
assert ( postCnt <= 0xffff );
int status = this->lockAndReserveSpace ( postCnt + 16u, reservoir );
int status = this->lockAndReserveSpace ( postCnt + 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_CLAIM_CIU ) ); // cmd
@@ -544,6 +540,7 @@ int comQueSend::createChannelRequest ( unsigned id, const char *pName, unsigned
if ( postCnt > nameLength ) {
comQueSend_copyIn ( this->bufs, reservoir, nillBytes, postCnt - nameLength );
}
this->mutex.unlock ();
}
@@ -557,7 +554,7 @@ int comQueSend::clearChannelRequest ( unsigned clientId, unsigned serverId )
assert ( serverId <= 0xffffffff );
assert ( clientId <= 0xffffffff );
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, true );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_CLEAR_CHANNEL ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -571,7 +568,8 @@ int comQueSend::clearChannelRequest ( unsigned clientId, unsigned serverId )
return status;
}
int comQueSend::subscriptionRequest ( unsigned ioId, unsigned serverId, unsigned type, unsigned nElem, unsigned mask )
int comQueSend::subscriptionRequest ( unsigned ioId, unsigned serverId,
unsigned type, unsigned nElem, unsigned mask, bool enablePreemptionDuringFlush )
{
bufferReservoir reservoir;
@@ -584,7 +582,7 @@ int comQueSend::subscriptionRequest ( unsigned ioId, unsigned serverId, unsigned
assert ( serverId <= 0xffffffff );
assert ( ioId <= 0xffffffff );
int status = this->lockAndReserveSpace ( 32u, reservoir );
int status = this->lockAndReserveSpace ( 32u, reservoir, enablePreemptionDuringFlush );
if ( status == ECA_NORMAL ) {
// header
@@ -617,14 +615,14 @@ int comQueSend::subscriptionCancelRequest ( unsigned ioId, unsigned serverId, un
assert ( serverId <= 0xffffffff );
assert ( ioId <= 0xffffffff );
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, true );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_EVENT_CANCEL ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( type ) ); // dataType
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( nElem ) ); // count
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint32_t> ( serverId ) ); // cid
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint32_t> ( ioId ) ); // available
comQueSend_copyIn ( this->bufs, reservoir, static_cast < ca_uint16_t > ( CA_PROTO_EVENT_CANCEL ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast < ca_uint16_t > ( 0u ) ); // postsize
comQueSend_copyIn ( this->bufs, reservoir, static_cast < ca_uint16_t > ( type ) ); // dataType
comQueSend_copyIn ( this->bufs, reservoir, static_cast < ca_uint16_t > ( nElem ) ); // count
comQueSend_copyIn ( this->bufs, reservoir, static_cast < ca_uint32_t > ( serverId ) ); // cid
comQueSend_copyIn ( this->bufs, reservoir, static_cast < ca_uint32_t > ( ioId ) ); // available
this->mutex.unlock ();
}
@@ -635,7 +633,7 @@ int comQueSend::disableFlowControlRequest ()
{
bufferReservoir reservoir;
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_EVENTS_ON ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -652,7 +650,7 @@ int comQueSend::enableFlowControlRequest ()
{
bufferReservoir reservoir;
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_EVENTS_OFF ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -669,7 +667,7 @@ int comQueSend::noopRequest ()
{
bufferReservoir reservoir;
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_NOOP ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -686,7 +684,7 @@ int comQueSend::echoRequest ()
{
bufferReservoir reservoir;
int status = this->lockAndReserveSpace ( 16u, reservoir );
int status = this->lockAndReserveSpace ( 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_ECHO ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( 0u ) ); // postsize
@@ -706,7 +704,7 @@ int comQueSend::hostNameSetRequest ( const char *pName )
unsigned postSize = CA_MESSAGE_ALIGN ( size );
assert ( postSize < 0xffff );
int status = this->lockAndReserveSpace ( postSize + 16u, reservoir );
int status = this->lockAndReserveSpace ( postSize + 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_HOST_NAME ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( postSize ) ); // postsize
@@ -717,6 +715,7 @@ int comQueSend::hostNameSetRequest ( const char *pName )
comQueSend_copyIn ( this->bufs, reservoir, pName, size );
comQueSend_copyIn ( this->bufs, reservoir, nillBytes, postSize - size );
this->mutex.unlock ();
}
return status;
@@ -729,7 +728,7 @@ int comQueSend::userNameSetRequest ( const char *pName )
unsigned postSize = CA_MESSAGE_ALIGN ( size );
assert ( postSize < 0xffff );
int status = this->lockAndReserveSpace ( postSize + 16u, reservoir );
int status = this->lockAndReserveSpace ( postSize + 16u, reservoir, false );
if ( status == ECA_NORMAL ) {
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( CA_PROTO_CLIENT_NAME ) ); // cmd
comQueSend_copyIn ( this->bufs, reservoir, static_cast <ca_uint16_t> ( postSize ) ); // postsize
@@ -740,6 +739,7 @@ int comQueSend::userNameSetRequest ( const char *pName )
comQueSend_copyIn ( this->bufs, reservoir, pName, size );
comQueSend_copyIn ( this->bufs, reservoir, nillBytes, postSize - size );
this->mutex.unlock ();
}
return status;