This new flag "SI_FL_ISBACK" is set only on the back SI and is cleared
on the front SI. That way it's possible only by looking at the SI to
know what side it is.
We'll soon remove direct references to the channels from the stream
interface since everything belongs to the same session, so let's
first not dereference si->ib / si->ob anymore and use macros instead.
The channels were pointers to outside structs and this is not needed
anymore since the buffers have moved, but this complicates operations.
Move them back into the session so that both channels and stream interfaces
are always allocated for a session. Some places (some early sample fetch
functions) used to validate that a channel was NULL prior to dereferencing
it. Now instead we check if chn->buf is NULL and we force it to remain NULL
until the channel is initialized.
In some cases we don't want to known if a fetch or converter
fails. We just want a valid string. After this patch, we
have two sets of fetches and two sets of converters. There are:
txn.f, txn.sf, txn.c, txn.sc. The version prefixed by 's' always
returns strings for any type, and returns an empty string in the
error case or when the data are not available. This is particularly
useful when manipulating headers or cookies.
To add data in channel, it is necessary to process in two times.
First time, get the channel object, and after send data:
local req = txn:req_channel()
req:send("data\n")
Now, the function is converted as a variable containing the req
and res aobject. We can process as following:
txn.req:send("data\n")
This patch implements a wrapper to give access to the converters
in the Lua code. The converters are used with the transaction.
The automatically created function are prefixed by "conv_".
HAProxy proposes many sample fetches. It is possible that the
automatic registration of the sample fetches causes a collision
with an existing Lua function. This patch sets a namespace for
the sample fetches.
Actually an object is just a userdata value with a metatable.
This mode causes some problems like I can't add lua own data.
This new model uses an array as object base, and affect the
userdata at the index 0.
The core entry is just a collection of function, it doesn't depends on
special variable. This patch just converts an object contained in a
metatable in object contained in a normal table.
A few function names in Lua had underscores which did not appear in their
C counterpart. Since almost all of them already had similar names, better
uniformize the naming convention.
For now we don't perform any operation on IP addresses, so at least
we'd like to be able to pass them as strings so that we can log them
or whatever in Lua. Without this patch txn.src(txn) returns "nil" and
now it returns the correct IP address.
Lua 5.3 provides an opaque space associated with each
coroutine stack. This patch uses this lot of memory to
store the "struct hlua *" associated pointer.
This patch makes the retrieval of the "struct hlua *"
associated struct faster because it replace a lookup in
a tree by an immediate access to the data.
This reverts commit cd9084f77683106ace2fb863080e7d10e71c39fc.
This commit introduced a regression making it impossible to leave
process_session() during a forced yield because the analyser was always
set on the response even if not needed. The result was a busy loop
making haproxy spin at 100% without even polling anymore in case a
forced yield was performed.
The problem it tried to address (intercept response data from a request
analyser before forwarding) is not a trivial issue to address since
wakeups based on reads will not necessarily happen unless there's write
activity.
Anyway, if functions are attached specifically to a request or to a
response, it's for a reason. So for now let's be clear about the fact
that it's unreliable to try to process data from the opposite channel
until a better solution is found.
This patch fix the Lua library check. Only the version
5.3 or later is allowed.
This bug is added by the patch "MEDIUM: lua: use the
Lua-5.3 version of the library" with commit id
f90838b71a3c7f84e1d8b4ff85760a35d60c6910
Specs says that the receive() function with an argument "*l"
must return a line without the final "\n" ( or without "\r\n").
This patch removes these two final bytes.
When we try to write data in a session from another session, the "req"
buffer is not allowed. This patch try to allocate the buffer. The session
wait if the buffer is not yet avalaible.
When a socket is initilized in the body context, a segfaut is generated
because the memory pools are not initilized. This atch check if these
memory pool are initialized.
The function buffer_contig_space() returns the contiguous space avalaible
to add data (at the end of the input side) while the function
hlua_channel_send_yield() needs to insert data starting at p. Here we
introduce a new function bi_space_for_replace() which returns the amount
of space that can be inserted at the head of the input side with one of
the buffer_replace* functions.
This patch proposes a function that returns the space avalaible after buf->p.
The request action can't handle the reponse trafic because its
automatically forwarded. The forard with CHN_INFINITE_FORWARD
is set because any anamizers are registered on the response
channel.
This patch automatically register the request analyzer on the
reponse channel when its yield. This prevent the automatic
tranfer of the response bytes.
The hook function called each nth Lua instructions just
do a yield. Sometimes this yield is not allowed, because
some functions are not compatible.
The Lua-5.3 permits to known if the yield is avalaible with
the function lua_isyieldable().
If the processing is interrupted in non yieldable state,
we try to execute a yield asap. The yield will be may
available at the end of the non-yieldable currently
executed function. So, we require interrupt at the end
of the current function.
But, Lua cannot yield when its returning from a function,
so, we can fix the interrupt hook to 1 instruction,
expecting that the function is finnished.
During this time, the execution timeout is always checked.
The Lua-5.3 version of the library adds a required function to fix
a bug with the forced-yield system.
This patch permits to build with the Lua-5.3 library. Main changes
are:
- "unsigned" type disappear to be replaced by signed type,
- prototype of the yield function callback changes.
First we allow to use the reserved size to write the data that
will be sent. The reserved size remain guaranty because the
writed data will be sent quickly and the reserved room we be
again avalaible.
This permits to guaranty that the function send always have
avalaible space to send data (except if it cannot connect to
the server).
The function buffer_replace2 works only on contiguous buffer.
This patch also detects if the required size is contiguous.
If it not the case we realign the buffer.
If we are writing in the request buffer, we are not waked up
when the data are forwarded because it is useles. The request
analyzers are waked up only when data is incoming. So, if the
request buffer is full, we set the WAKE_ON_WRITE flag.
Before this patch, each yield in a Lua action set a flags to be
waked up when some activity were detected on the response channel.
This behavior causes loop in the analyzer process.
This patch set the wake up on response buffer activity only if we
really want to be waked up on this activity.
This patch reset the flags except th run flag before resuming
the Lua execution. If this initialisation is not done, some
flags can remain at the end of the Lua execution and give bad
informations.
Check if the buffer is avalaible because HAProxy doesn't allocate
the request buffer if its not required. Sometimes, the Lua need to
write some data to the server before that the client send his data.
This patch check the expiration of the execution timeout for each
yield source, and test also the execution timeout before resuming
the execution of the Lua code.
This patch permits to interrupt the Lua execution each n# of
instructions. It is useful for controling the execution time
of an Lua code, and permits at the HAProxy schedule to process
some others tasks waiting execution.
This flag indicate that the current yield is returned by the Lua
execution task control. If this flag is set, the current task may
quit but will be set in the run queue to be re-executed immediatly.
This patch modify the "hlua_yieldk()" function, it adds an argument
that contain a field containing yield options.
This is used to ensure that the task doesn't become a zombie
when the Lua returns a yield. The yield wrapper ensure that an
timer used for waking up the task will be set.
The timer is reseted to TICK_ETERNITY if the Lua execution is
done.
This first patch permits to cofigure the Lua execution exipiration.
This expiration is configured but it is not yet avalaible, it will
be add in a future patch.
In the future, the lua execution must return scheduling informations.
We want more than one flag, so I convert an integer used with an
enum into an interer used as bitfield.
In some cases the Lua "send" function fails. This is caused by the
return of "buffer_replace2()" is not tested. I checked avalaible space
in the buffer and I supposed than "buffer_replace2()" took all the
data. In some cases, "buffer_replace2()" cannot take the incoming
data, it returns the amount of data copied.
This patch check the amount of data really copied by "buffer_replace2()"
and advance the buffer with taking this value in account.
When a Lua script calls an internal haproxy sample fetch, it may segfault in
some conditions :
- when a fetch has no argument,
- when there is no room left to store the special type ARGT_STOP in the argument
list (this one shouldn't happen currently as there isn't any sample fetch with
enough arguments to fill the allocated buffer).
Example of Lua code which reproduces a segfault :
core.register_fetches("segfault", function(txn, ...)
return txn.req_ver(txn)
end)
haproxy Lua support begins with Lua 5.2. In order to ease the diagnostic on
compilation error, a preprocessor error is added when an incompatible version
is used.
The compatibility is determined by the presence of LUA_VERSION_NUM and its
magic value (502 for Lua 5.2.x).
Actually, the Lua context is always initilized in each
session, even if the session doesn't use Lua. This
behavior cause 5% performances loss.
This patch initilize the Lua only if it is use by the
session. The initialization is now on demand.
The code was a bit of a pain to follow because of this, especially
when some of it heavily relies on longjmp... This refreshing makes
it slightly easier to read.
This patch provides a yield function. This function permits to
give back the hand at the HAProxy scheduler. It is used when the
lua processing consumes a lot of time.
