epics/pvAccess
0
0
Fork 0
Code Issues Pull Requests Projects Wiki Activity

Collect ca_client_context operations

Browse Source 
Each instance of the caContext class represents a separate CA context,
so each CAChannelProvider creates one and keeps a shared_ptr to it,
making that available to its channels and channel operations. These
also take their own shared_ptr to it as well so the context cannot be
destroyed while it might be needed.

A related caContext Attach object is intended to be short-lived, and
to be allocated on the stack. When created it saves the current CA
context for the thread, replacing it from the caContext given to its
constructor. CA operations will now use the attached context. When the
Attach destructor runs it detaches the thread from the current context
(checking still has the expected value) and re-attaches the thread to
any context that was saved by the constructor.
This commit is contained in:
Andrew Johnson
2020-10-08 00:13:24 -05:00
committed by mdavidsaver
parent 25dde0f4ba
commit f9c40e96cf
8 changed files with 175 additions and 91 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
src/ca/caChannel.cpp
View File

@@ -111,7 +111,8 @@ CAChannel::CAChannel(std::string const & channelName,
channelID(0),
channelCreated(false),
channelConnected(false),
connectNotification(new Notification())
connectNotification(new Notification()),
ca_context(channelProvider->caContext())
{
}
@@ -120,17 +121,17 @@ void CAChannel::activate(short priority)
ChannelRequester::shared_pointer req(channelRequester.lock());
if (!req) return;
connectNotification->setClient(shared_from_this());
attachContext();
Attach to(ca_context);
int result = ca_create_channel(channelName.c_str(),
ca_connection_handler,
this,
priority, // TODO mapping
&channelID);
ca_connection_handler, this,
priority, // TODO mapping
&channelID);
if (result == ECA_NORMAL) {
channelCreated = true;
CAChannelProviderPtr provider(channelProvider.lock());
if(provider) provider->addChannel(shared_from_this());
EXCEPTION_GUARD(req->channelCreated(Status::Ok, shared_from_this()));
channelCreated = true;
CAChannelProviderPtr provider(channelProvider.lock());
if (provider)
provider->addChannel(shared_from_this());
EXCEPTION_GUARD(req->channelCreated(Status::Ok, shared_from_this()));
}
else {
Status errorStatus(Status::STATUSTYPE_ERROR, string(ca_message(result)));
@@ -162,7 +163,7 @@ void CAChannel::disconnectChannel()
}
monitorlist.resize(0);
/* Clear CA Channel */
attachContext();
Attach to(ca_context);
int result = ca_clear_channel(channelID);
if (result == ECA_NORMAL) return;
string mess("CAChannel::disconnectChannel() ");
@@ -361,18 +362,6 @@ void CAChannelGetField::callRequester(CAChannelPtr const & caChannel)
/* ---------------------------------------------------------- */
void CAChannel::attachContext()
{
CAChannelProviderPtr provider(channelProvider.lock());
if (provider) {
provider->attachContext();
return;
}
string mess("CAChannel::attachContext provider does not exist ");
mess += getChannelName();
throw std::runtime_error(mess);
}
CAChannelGetPtr CAChannelGet::create(
CAChannel::shared_pointer const & channel,
ChannelGetRequester::shared_pointer const & channelGetRequester,
@@ -389,7 +378,8 @@ CAChannelGet::CAChannelGet(CAChannel::shared_pointer const & channel,
channelGetRequester(channelGetRequester),
pvRequest(pvRequest),
getStatus(Status::Ok),
getNotification(new Notification())
getNotification(new Notification()),
ca_context(channel->caContext())
{}
CAChannelGet::~CAChannelGet()
@@ -445,8 +435,8 @@ void CAChannelGet::get()
{
ChannelGetRequester::shared_pointer getRequester(channelGetRequester.lock());
if (!getRequester) return;
channel->attachContext();
bitSet->clear();
Attach to(ca_context);
int result = ca_array_get_callback(dbdToPv->getRequestType(),
0,
channel->getChannelID(), ca_get_handler, this);
@@ -492,7 +482,8 @@ CAChannelPut::CAChannelPut(CAChannel::shared_pointer const & channel,
isPut(false),
getStatus(Status::Ok),
putStatus(Status::Ok),
putNotification(new Notification())
putNotification(new Notification()),
ca_context(channel->caContext())
{}
CAChannelPut::~CAChannelPut()
@@ -603,8 +594,8 @@ void CAChannelPut::get()
isPut = false;
}
channel->attachContext();
bitSet->clear();
Attach to(ca_context);
int result = ca_array_get_callback(dbdToPv->getRequestType(),
0,
channel->getChannelID(), ca_put_get_handler, this);
@@ -737,7 +728,8 @@ CAChannelMonitor::CAChannelMonitor(
isStarted(false),
pevid(NULL),
eventMask(DBE_VALUE | DBE_ALARM),
eventNotification(new Notification())
eventNotification(new Notification()),
ca_context(channel->caContext())
{}
CAChannelMonitor::~CAChannelMonitor()
@@ -833,7 +825,7 @@ Status CAChannelMonitor::start()
isStarted = true;
monitorQueue->start();
}
channel->attachContext();
Attach to(ca_context);
int result = ca_create_subscription(dbdToPv->getRequestType(),
0,
channel->getChannelID(), eventMask,
@@ -859,6 +851,7 @@ Status CAChannelMonitor::stop()
isStarted = false;
}
monitorQueue->stop();
// Attach to(ca_context); -- Not required!
int result = ca_clear_subscription(pevid);
if (result==ECA_NORMAL)
return Status::Ok;