Forward error codes through pipeline

[gavv]

This task tracks support for reporting errors (status codes) from pipeline operations (construction, read and write).

Errors should be forwarded through the whole pipeline up to the user, and exposed via C API.

Depends on #303 and #614.

[gavv]

Status codes

• NoStatus
• StatusOK
• StatusPart
• StatusDrain
• StatusAbort
• StatusEnd
• StatusNoMem
• StatusNoRoute
• StatusErrDevice
• StatusErrFile
• StatusErrNetwork
• StatusErrThread
• StatusErrRand
• StatusBadSlot
• StatusBadInterface
• StatusBadProtocol
• StatusBadConfig
• StatusBadPacket
• StatusBadBuffer
• StatusBadArg
• StatusBadOperation

Port to statuses

init_status

Replace is_valid() with init_status(), and report initialization error codes.

• [x] roc_packet
• [x] roc_rtp
• [x] roc_rtcp
• [x] roc_fec
• [x] roc_audio
• [x] roc_pipeline
• [x] roc_ctl
• [x] roc_node
• [x] roc_sndio
• [x] roc_netio

readers & writers (#303, #614)

Update packet and frame readers and writers to return status, and report read/write error codes. Use StatusEnd instead of is_alive() to terminate sessions.

• [x] roc_packet
• [x] roc_rtp
• [x] roc_rtcp
• [x] roc_fec
• [x] roc_audio
• [x] roc_pipeline
• [x] roc_node
• [x] roc_sndio
• [x] roc_netio

refresh

Return and forward status from refresh().

• [x] add status to SenderSink::refresh()
• [x] add status to ReceiverSource::refresh()
• [x] forward status from RTCP to refresh()
• [x] in PipelineLoop, forward status from write() and refresh() via process_subframe_imp() via process_subframes_and_tasks() to SenderLoop::write() and ReceiverLoop::read()
• [x] in SenderLoop and ReceiverLoop, forward refresh status as read/write error

sessions

• [x] redirect session read/write errors to refresh() errors
• [x] trigger session removal by refresh() errors
• [x] don't use is_alive() in pipeline

routing

Return and handle StatusNoRoute.

• [x] ReceiverSession
• [x] ReceiverSessionRouter
• [x] ReceiverSessionGroup
• [x] ReceiverEndpoint
• [x] SenderEndpoint

parsers & composers (#737, #766)

Update IParser & IComposer implementations to return statuses instead of booleans.

• [ ] parsers
• [ ] composers

encoders & decoders (#739, #738, #767)

Update encoder and decoder implementations to return statuses instead of booleans.

• [ ] roc_audio (IFrameEncoder, IFrameDecoder)
• [ ] roc_fec (IBlockEncoder, IBlockDecoder)

fec reader & writer

Fix error reporting in fec::BlockReader and fec::BlockWriter.

• [x] return StatusAbort when session is broken
• [x] uses statuses instead of is_alive()
• [x] report all internal failures via status codes
• [ ] forward all errors from block encoder / decoder

control operations

Return statuses when creating slots, endpoints, etc. Forwards statuses through pipeline tasks.

• [ ] receiver
  • [ ] ReceiverSessionGroup
  • [ ] ReceiverSlot
  • [ ] ReceiverSource
  • [ ] ReceiverLoop
• [ ] sender
  • [ ] SenderSession
  • [ ] SenderSlot
  • [ ] SenderSink
  • [ ] SenderLoop

network operations

Migrate TCP classes to roc_status codes. SocketError enum should be hidden implementation detail.

• [ ] UDP
• [ ] TCP

device operations

Return status codes for operations.

• [x] io (return correct status)
• [x] open
• [x] pause
• [x] resume
• [x] restart
• [x] flush
• [x] close

API

• [ ] add error codes to C API
• [ ] update adapters
• [ ] forward errors to user