note that the old code inserted added headers at the beginning of the
list, reasoning unknown. this seems counter-intuitive as the headers
would end up in the request in the reverse order they were added,
but this was irrelevant, as the headers were originally first put
into the hashmap hashofheaders before sending it to the client.
since the hashmap didn't preserve ordering, the headers would appear
in random order anyway.
also fixes a bug where the ErrorFile directive would create a
new hashmap on every added item, effectively allowing only
the use of the last specified errornumber, and producing memory
leaks on each config reload.
- we need to free the config after it has been succesfully loaded,
not unconditionally before reloading.
- we also need to free them before exiting from the main program
to have clean valgrind output.
previously, default values were stored once into a static struct,
then on each reload item by item copied manually into a "new"
config struct.
this has proven to be errorprone, as additions in one of the 2
locations were not propagated to the second one, apart from
being simply a lot of gratuitous code.
we now simply load the default values directly into the config
struct to be used on each reload.
closes#283
the existing codebase used an elaborate and complex approach for
its parallelism:
5 different config file options, namely
- MaxClients
- MinSpareServers
- MaxSpareServers
- StartServers
- MaxRequestsPerChild
were used to steer how (and how many) parallel processes tinyproxy
would spin up at start, how many processes at each point needed to
be idle, etc.
it seems all preforked processes would listen on the server port
and compete with each other about who would get assigned the new
incoming connections.
since some data needs to be shared across those processes, a half-
baked "shared memory" implementation was provided for this purpose.
that implementation used to use files in the filesystem, and since
it had a big FIXME comment, the author was well aware of how hackish
that approach was.
this entire complexity is now removed. the main thread enters
a loop which polls on the listening fds, then spins up a new
thread per connection, until the maximum number of connections
(MaxClients) is hit. this is the only of the 5 config options
left after this cleanup. since threads share the same address space,
the code necessary for shared memory access has been removed.
this means that the other 4 mentioned config option will now
produce a parse error, when encountered.
currently each thread uses a hardcoded default of 256KB per thread
for the thread stack size, which is quite lavish and should be
sufficient for even the worst C libraries, but people may want
to tweak this value to the bare minimum, thus we may provide a new
config option for this purpose in the future.
i suspect that on heavily optimized C libraries such a musl, a
stack size of 8-16 KB per thread could be sufficient.
since the existing list implementation in vector.c did not provide
a way to remove a single item from an existing list, i added my
own list implementation from my libulz library which offers this
functionality, rather than trying to add an ad-hoc, and perhaps
buggy implementation to the vector_t list code. the sblist
code is contained in an 80 line C file and as simple as it can get,
while offering good performance and is proven bugfree due to years
of use in other projects.
using the "BasicAuth" keyword in tinyproxy.conf.
base64 code was written by myself and taken from my own library "libulz".
for this purpose it is relicensed under the usual terms of the tinyproxy
license.
This allows for later reloading the config at SIGHUP (e.g.).
First the old config data is freed, then the defaults that
are given as a parameter are copied over in a rather clumsy
manual fashion (maybe something more clever can be done here)
and finally, the actual config file is loaded.
Michael
