We need a little refactoring for this to work, since the
initialization code for the periodic events assumes that libevent is
already initialized, which it can't be until it's configured.
This change, combined with the previous ones, lets other subsystems
declare their own periodic events, without mainloop.c having to know
about them. Implements ticket 30293.
This is necessary to get the number of includes in main.c back under
control. (In the future, we could just use the subsystem manager for
this kind of stuff.)
Add a tracker for bootstrap progress, tracking events related to
origin circuit and ORCONN states. This uses the ocirc_event and
orconn_event publish-subscribe subsystems.
Part of ticket 27167.
Add a publish-subscribe subsystem to publish messages about changes to
origin circuits.
Functions in circuitbuild.c and circuitlist.c publish messages to this
subsystem.
Move circuit event constants out of control.h so that subscribers
don't have to include all of control.h to take actions based on
messages they receive.
Part of ticket 27167.
Add a publish-subscribe subsystem to publish messages about changes to
OR connections.
connection_or_change_state() in connection_or.c and
control_event_or_conn_event() in control.c publish messages to this
subsystem via helper functions.
Move state constants from connection_or.h to orconn_state.h so that
subscribers don't have to include all of connection_or.h to take
actions based on changes in OR connection state. Move event constants
from control.h for similar reasons.
Part of ticket 27167.
This patch adds a new Process subsystem for running external programs in
the background of Tor. The design is focused around a new type named
`process_t` which have an API that allows the developer to easily write
code that interacts with the given child process. These interactions
includes:
- Easy API for writing output to the child process's standard input
handle.
- Receive callbacks whenever the child has output on either its standard
output or standard error handles.
- Receive callback when the child process terminates.
We also support two different "protocols" for handling output from the
child process. The default protocol is the "line" protocol where the
process output callbacks will be invoked only when there is complete
lines (either "\r\n" or "\n" terminated). We also support the "raw"
protocol where the read callbacks will get whatever the operating system
delivered to us in a single read operation.
This patch does not include any operating system backends, but the Unix
and Windows backends will be included in separate commits.
See: https://bugs.torproject.org/28179
Our tests showed that this function is responsible for a huge number
of our malloc/free() calls. It's a prime candidate for being
memoized.
Closes ticket 27225.
