We mark the intro circuit with a new flag saying that the pow is
in the cpuworker queue. When the cpuworker comes back, it either
has a solution, in which case we proceed with sending the intro1
cell, or it has no solution, in which case we unmark the intro
circuit and let the whole process restart on the next iteration of
connection_ap_handshake_attach_circuit().
prepares the way for client-side pow cpuworkers
also happens to resolve bug https://bugs.torproject.org/tpo/core/tor/40617
(which went into 0.4.7.4-alpha) because now we survive initing the
cpuworker subsystem when we're not a relay.
We discovered two cases where edge connections can stall during testing:
1. Due to final data sitting in the edge inbuf when it was resumed
2. Due to flag synchronization between the token bucket and XON/XOFF
The first issue has always existed in C-Tor, but we were able to tickle it
in scp testing. If the last data from the protocol is able to fit in the
inbuf, but not large enough to send, if an XOFF or connection block comes in
at exactly that point, when the edge connection resumes, there will be no
data to read from the socket, but the inbuf can just sit there, never
draining.
We noticed the second issue along the way to finding the first. It seems
wrong, but it didn't seem to affect anything in practice.
These are extremely rare in normal operation, but with conflux, XON/XOFF
activity is more common, so we hit these.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Streams can get blocked on a circuit in two ways:
1. When the circuit package window is full
2. When the channel's cell queue is too high
Conflux needs to decouple stream blocking from both of these conditions,
because streams can continue on another circuit, even if the primary circuit
is blocked for either of these cases.
However, both conflux and congestion control need to know if the channel's
cell queue hit the highwatermark and is still draining, because this condition
is used by those components, independent of stream state.
Therefore, this commit renames the 'streams_blocked_on_chan' variable to
signify that it refers to the cell queue state, and also refactors the actual
stream blocking bits out, so they can be handled separately if conflux is
present.
We cap our number of CPU worker threads to at least 2 even if we have a
single core. But also, before we used to always add one extra thread
regardless of the number of core.
This meant that we were off when re-using the get_num_cpus() function
when calculating our onionskin work overhead because we were always off
by one.
This commit makes it that we always use the number of thread our actual
thread pool was configured with.
Fixes#40719
Signed-off-by: David Goulet <dgoulet@torproject.org>
Cap this to 2 threads always because we need a low and high priority
thread even with a single core.
Fixes#40713
Signed-off-by: David Goulet <dgoulet@torproject.org>
Until now, there was this magic number (64) used as the maximum number
of tasks a CPU worker can take at once.
This commit makes it a consensus parameter so our future selves can
think of a better value depending on network conditions.
Part of #40704
Signed-off-by: David Goulet <dgoulet@torproject.org>
This also incidently removes a use of uninitialized stack data from the
connection_or_set_ext_or_identifier() function.
Fixes#40648
Signed-off-by: David Goulet <dgoulet@torproject.org>
This also incidently removes a use of uninitialized stack data from the
connection_or_set_ext_or_identifier() function.
Fixes#40648
Signed-off-by: David Goulet <dgoulet@torproject.org>
Using tor_free is wrong; event_free must be called for objects obtained from
event_new. Additionally, this slightly simplifies the code.
Also, add a static_assert to prevent further instances.
We only need to rate limit reading on edges for flow control, as per the rate
that comes in the XON from the other side. When we rate limit reading from the
edge source to this rate, we will only deliver that fast to the other side,
thus satisfying its rate request.
Signed-off-by: David Goulet <dgoulet@torproject.org>
The connection type for the listener part was missing from the "is
connection a listener" function.
This lead to our periodic event that retries our listeners to keep
trying to bind() again on an already opened MetricsPort.
Closes#40370
Signed-off-by: David Goulet <dgoulet@torproject.org>
Mike Perry
Roger Dingledine
David Goulet
Gabriela Moldovan
Alex Xu (Hello71)
qontinuum
Nick Mathewson
George Kadianakis