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caProvider: init issues

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avoid static init order issues
ref. count to allow multiple calls to CAClientFactory::start()
This commit is contained in:
Michael Davidsaver
2017-06-06 08:35:03 +02:00
parent 34eeb0717a
commit 6926d911ee
2 changed files with 37 additions and 80 deletions
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113
src/ca/caProvider.cpp
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@@ -9,9 +9,11 @@
/* for CA */
#include <cadef.h>
#include <epicsSignal.h>
#include <epicsThread.h>
#define epicsExportSharedSymbols
#include <pv/logger.h>
#include <pv/configuration.h>
#include <pv/caProvider.h>
#include <pv/caChannel.h>
@@ -23,13 +25,20 @@ using namespace epics::pvAccess::ca;
catch (std::exception &e) { LOG(logLevelError, "Unhandled exception caught from client code at %s:%d: %s", __FILE__, __LINE__, e.what()); } \
catch (...) { LOG(logLevelError, "Unhandled exception caught from client code at %s:%d.", __FILE__, __LINE__); }
std::string CAChannelProvider::PROVIDER_NAME = "ca";
CAChannelProvider::CAChannelProvider() : current_context(0), destroyed(false)
{
initialize();
}
CAChannelProvider::CAChannelProvider(const std::tr1::shared_ptr<Configuration>&)
: current_context(0)
, destroyed(false)
{
// Ignoring Configuration as CA only allows config via. environment,
// and we don't want to change this here.
initialize();
}
CAChannelProvider::~CAChannelProvider()
{
// call destroy() to destroy CA context
@@ -38,7 +47,7 @@ CAChannelProvider::~CAChannelProvider()
std::string CAChannelProvider::getProviderName()
{
return PROVIDER_NAME;
return "ca";
}
ChannelFind::shared_pointer CAChannelProvider::channelFind(
@@ -165,94 +174,42 @@ void CAChannelProvider::initialize()
}
static epicsThreadOnceId cafactory_once = EPICS_THREAD_ONCE_INIT;
static struct cafactory_gbl_t {
Mutex mutex;
int count;
cafactory_gbl_t() :count(0u) {}
} *cafactory_gbl;
// TODO global static variable (de/initialization order not guaranteed)
static Mutex mutex;
static CAChannelProvider::shared_pointer sharedProvider;
class CAChannelProviderFactoryImpl : public ChannelProviderFactory
static
void cafactory_init(void*)
{
public:
POINTER_DEFINITIONS(CAChannelProviderFactoryImpl);
virtual std::string getFactoryName()
{
return CAChannelProvider::PROVIDER_NAME;
}
virtual ChannelProvider::shared_pointer sharedInstance()
{
Lock guard(mutex);
if (!sharedProvider.get())
{
try {
// TODO use std::make_shared
std::tr1::shared_ptr<CAChannelProvider> tp(new CAChannelProvider());
sharedProvider = tp;
} catch (std::exception &e) {
LOG(logLevelError, "Unhandled exception caught at %s:%d: %s", __FILE__, __LINE__, e.what());
} catch (...) {
LOG(logLevelError, "Unhandled exception caught at %s:%d.", __FILE__, __LINE__);
}
}
return sharedProvider;
}
virtual ChannelProvider::shared_pointer newInstance(const std::tr1::shared_ptr<Configuration>& conf)
{
// Ignoring configuration as CA only allows config via. environment,
// and we don't want to change this here.
try {
// TODO use std::make_shared
std::tr1::shared_ptr<CAChannelProvider> tp(new CAChannelProvider());
ChannelProvider::shared_pointer ni = tp;
return ni;
} catch (std::exception &e) {
LOG(logLevelError, "Unhandled exception caught at %s:%d: %s", __FILE__, __LINE__, e.what());
return ChannelProvider::shared_pointer();
} catch (...) {
LOG(logLevelError, "Unhandled exception caught at %s:%d.", __FILE__, __LINE__);
return ChannelProvider::shared_pointer();
}
}
void destroySharedInstance()
{
if(!sharedProvider) return;
sharedProvider->destroy();
sharedProvider.reset();
}
};
static CAChannelProviderFactoryImpl::shared_pointer factory;
cafactory_gbl = new cafactory_gbl_t;
}
void CAClientFactory::start()
{
epicsSignalInstallSigAlarmIgnore();
epicsSignalInstallSigPipeIgnore();
Lock guard(mutex);
if (!factory.get())
factory.reset(new CAChannelProviderFactoryImpl());
epicsThreadOnce(&cafactory_once, &cafactory_init, 0);
registerChannelProviderFactory(factory);
Lock guard(cafactory_gbl->mutex);
if(cafactory_gbl->count++==0) {
if(!getChannelProviderRegistry()->add<CAChannelProvider>("ca", false))
LOG(logLevelError, "Unable to register \"ca\" provider\n");
}
}
void CAClientFactory::stop()
{
Lock guard(mutex);
epicsThreadOnce(&cafactory_once, &cafactory_init, 0);
if (factory.get())
{
unregisterChannelProviderFactory(factory);
factory->destroySharedInstance();
Lock guard(cafactory_gbl->mutex);
if(--cafactory_gbl->count==0) {
getChannelProviderRegistry()->remove("ca");
}
if(cafactory_gbl->count<0)
LOG(logLevelError, "too many calls to CAClientFactory::stop()");
}