Added ability to integrate with foreign event loops

This commit is contained in:
hogliux
2019-10-08 18:59:56 +01:00
committed by Stanislav Angelovič
parent e30ce194ab
commit 0440dcb15b
3 changed files with 60 additions and 6 deletions

View File

@ -46,6 +46,13 @@ namespace sdbus {
class IConnection
{
public:
struct PollData
{
int fd;
short int events;
uint64_t timeout_usec;
};
virtual ~IConnection() = default;
/*!
@ -103,6 +110,41 @@ namespace sdbus {
* @throws sdbus::Error in case of failure
*/
virtual void addObjectManager(const std::string& objectPath) = 0;
/*!
* @brief Returns parameters you can pass to poll
*
* To integrate sdbus with your app's own custom event handling system
* (without the requirement of an extra thread), you can use this
* method to query which file descriptors, poll events and timeouts you
* should add to your app's poll call in your main event loop. If these
* file descriptors signal, then you should call processPendingRequest
* to process the event. This means that all of sdbus's callbacks will
* arrive on your app's main event thread (opposed to on a thread created
* by sdbus-c++). If you are unsure what this all means then use
* enterProcessingLoop() or enterProcessingLoopAsync() instead.
*
* To integrate sdbus-c++ into a gtk app, pass the file descriptor returned
* by this method to g_main_context_add_poll.
*
* @throws sdbus::Error in case of failure
*/
virtual PollData getProcessLoopPollData() = 0;
/*!
* @brief Process a pending request
*
* Processes a single dbus event. All of sdbus-c++'s callbacks will be called
* from within this method. This method should ONLY be used in conjuction
* with getProcessLoopPollData(). enterProcessingLoop() and
* enterProcessingLoopAsync() will call this method for you, so there is no
* need to call it when using these. If you are unsure what this all means then
* don't use this method.
*
* @returns true if an event was processed
* @throws sdbus::Error in case of failure
*/
virtual bool processPendingRequest() = 0;
};
/*!

View File

@ -108,6 +108,20 @@ void Connection::leaveProcessingLoop()
joinWithProcessingLoop();
}
sdbus::IConnection::PollData Connection::getProcessLoopPollData()
{
sdbus::IConnection::PollData pollData;
ISdBus::PollData sdbusPollData;
auto r = iface_->sd_bus_get_poll_data(bus_.get(), &sdbusPollData);
SDBUS_THROW_ERROR_IF(r < 0, "Failed to get bus poll data", -r);
pollData.fd = sdbusPollData.fd;
pollData.events = sdbusPollData.events;
pollData.timeout_usec = sdbusPollData.timeout_usec;
return pollData;
}
const ISdBus& Connection::getSdBusInterface() const
{
return *iface_.get();
@ -345,15 +359,12 @@ bool Connection::waitForNextRequest()
assert(bus != nullptr);
assert(loopExitFd_ != 0);
ISdBus::PollData sdbusPollData;
auto r = iface_->sd_bus_get_poll_data(bus, &sdbusPollData);
SDBUS_THROW_ERROR_IF(r < 0, "Failed to get bus poll data", -r);
auto sdbusPollData = getProcessLoopPollData();
struct pollfd fds[] = {{sdbusPollData.fd, sdbusPollData.events, 0}, {loopExitFd_, POLLIN, 0}};
auto fdsCount = sizeof(fds)/sizeof(fds[0]);
auto timeout = sdbusPollData.timeout_usec == (uint64_t) -1 ? (uint64_t)-1 : (sdbusPollData.timeout_usec+999)/1000;
r = poll(fds, fdsCount, timeout);
auto r = poll(fds, fdsCount, timeout);
if (r < 0 && errno == EINTR)
return true; // Try again

View File

@ -57,6 +57,8 @@ namespace sdbus { namespace internal {
void enterProcessingLoop() override;
void enterProcessingLoopAsync() override;
void leaveProcessingLoop() override;
bool processPendingRequest() override;
sdbus::IConnection::PollData getProcessLoopPollData() override;
void addObjectManager(const std::string& objectPath) override;
SlotPtr addObjectManager(const std::string& objectPath, void* /*dummy*/) override;
@ -99,7 +101,6 @@ namespace sdbus { namespace internal {
void finishHandshake(sd_bus* bus);
static int createProcessingLoopExitDescriptor();
static void closeProcessingLoopExitDescriptor(int fd);
bool processPendingRequest();
bool waitForNextRequest();
static std::string composeSignalMatchFilter( const std::string& objectPath
, const std::string& interfaceName