Set timestamping socket options in individual socket implementations instead of ntcs::Compat in order to detect failure #115
Conversation
…instead of ntcs::Compat in order to detect failure
|
|
||
| error = streamSocket->setOption(option); | ||
| if (error) { | ||
| BSLS_LOG_DEBUG("Failed to set socket option: " |
There was a problem hiding this comment.
Shouldn't we use NTCI_LOG_DEBUG everywhere instead of BSLS_LOG_DEBUG?
And maybe warning would suit better for this case?
There was a problem hiding this comment.
Done, but I'm keeping the DEBUG severity level. WARN is too loud for a requested-but-unavailable feature, not required for operation.
| static bool supportsTimestamps(); | ||
| /// process supports asynchronous socket notifications via some mechanism | ||
| /// such as the Linux error queue. | ||
| static bool supportsNotifications(); |
There was a problem hiding this comment.
That sounds sort of strange when it is at nts level. Concept of notifications was introduced on Reactor level, which is NTC.
There was a problem hiding this comment.
I have removed ntscfg::Platform::supportsTimestamps in favor of a new function, ntsu::SocketOptionUtil::supportsTimestamps(socket). We need low-level support for platform capabilities, because even if the high-level interface is in NTC the low-level mechanics are requested from NTS.
groups/nts/ntsu/ntsu_timestamputil.h
Outdated
|
|
||
| // Timestamp reporting. | ||
| e_SOF_TIMESTAMPING_SOFTWARE = (1 << 4), | ||
| e_SOF_TIMESTAMPING_SYS_HARDWARE = (1 << 5), |
There was a problem hiding this comment.
SOF_TIMESTAMPING_SYS_HARDWARE flag is deprecated afaik, and I suggest not to use it
|
|
||
| { ntsu::TimestampUtil::e_SOF_TIMESTAMPING_TX_HARDWARE, 0, 0, 0 }, | ||
| { ntsu::TimestampUtil::e_SOF_TIMESTAMPING_TX_SOFTWARE, 0, 0, 0 }, | ||
| { ntsu::TimestampUtil::e_SOF_TIMESTAMPING_TX_SCHED, 3, 17, 0 }, |
There was a problem hiding this comment.
I thought you wanted to make a cut at TX timestamping usage being supported only starting from 4.18. Then it's not clear why you want to have kernel 3.17 mentioned here.
There was a problem hiding this comment.
I'm not sure we need this facility; currently its preprocessed out. The idea was to detect the run-time kernel version and clear out the bits for unsupported flags. My testing shows that this isn't needed. I'm a bit paranoid about what we may find in the future, though, so I'd like to leave this system in even though it is preprocessed out of the code. In the meantime, I've stated the minimum necessary kernel version for all timestamping features is 4.18 (RHEL 8).
If we find this system is necessary in the future, we'll go an exactly specify when each of the these flags were introduced. If we don't find this system necessary after some time has passed let's just remove it.
|
|
||
| e_SOF_TIMESTAMPING_TX_GENERATION = | ||
| e_SOF_TIMESTAMPING_TX_HARDWARE | |
There was a problem hiding this comment.
We've never exercised tx harware timestamps. And I am inclined to think that it will lead to logical errors regarding how tx timestamp notifications are processed. I think that if HW TX timestamps are supported, then the way we request them we will receive both SF and HW TX timestamps in diferent messages. Probably they all will have the same type (like TimestampUtil::e_SCM_TSTAMP_SND). And the we are cursed in ntcr::StreamSocket
There was a problem hiding this comment.
I'm trying to find some machine where I can test hardware TX timestamping. I'd like to leave this as-is until we verify that our correlation implementation needs enhancement to accomodate hardware TX timestamps.
…im support for all timestamping options begins with Linux 4.18
| ntsa::Error privateZeroCopyEngage( | ||
| const bsl::shared_ptr<DatagramSocket>& self, | ||
| bsl::size_t threshold); | ||
|
|
||
| // Process the completion of one or more zero-copy tranmsissions described |
There was a problem hiding this comment.
tranmsissions -> transmissions
groups/ntc/ntcr/ntcr_streamsocket.h
Outdated
| ntsa::Error privateZeroCopyEngage( | ||
| const bsl::shared_ptr<StreamSocket>& self, | ||
| bsl::size_t threshold); | ||
|
|
||
| // Process the completion of one or more zero-copy tranmsissions described |
There was a problem hiding this comment.
tranmsissions -> transmissions
The current implementation sets timestamping options in
ntcs::Compat::configureimmediately after the socket file descriptor is created. On some Linux platforms that do not support our requested timestamping configuration, setting this socket option fails with an error other than "not supported". The current implementation failsntcs::Compat::configurein this case which causesntcr::StreamSocketto fail to open.This PR moves the location where we set the timestamping options from
ntcs::Compat::configuretontcr::StreamSocket::privateOpenandntcr::DatagramSocket::privateOpen. In this location we now detect that setting the timestamping option failed, specifically, and we proceed with timestamping disabled.