A number of internal flags started to be exposed to external programs
at the location of their definition since commit 77acaf5af ("MINOR:
flags: add a new file to host flag dumping macros"). This allowed the
"flags" utility to decode many more of them and always correctly. The
condition to expose them was to rely on the preliminary definition of
EOF that indicates that stdio is already included. But this was a
wrong approach. It only guarantees that snprintf() can safely be used
but still causes large functions to be built. But stdio is often
included before some of these includes, so these heavy inline functions
actually have to be compiled in many cases. The result is that the
build time significantly increased, especially with fast compilers
like gcc -O0 which took +50% or TCC which took +100%!
This patch addresses the problem by instead relying on an explicit
macro HA_EXPOSE_FLAGS that the calling program must explicitly define
before including these files. flags.c does this and that's all. The
previous build time is now restored with a speed up of 20 to 50%
depending on the build options.
The new functions fconn_show_flags() and fstrm_show_flags() decode the flags
state into a string, and are used by dev/flags:
$ /dev/flags/flags fconn 0x3100
fconn->flags = FCGI_CF_GET_VALUES | FCGI_CF_KEEP_CONN | FCGI_CF_MPXS_CONNS
./dev/flags/flags fstrm 0x3300
fstrm->flags = FCGI_SF_WANT_SHUTW | FCGI_SF_WANT_SHUTR | FCGI_SF_OUTGOING_DATA | FCGI_SF_BEGIN_SENT
The new functions h1c_show_flags() and h1s_show_flags() decode the flags
state into a string, and are used by dev/flags:
$ /dev/flags/flags h1c 0x2200
h1c->flags = H1C_F_ST_READY | H1C_F_ST_ATTACHED
./dev/flags/flags h1s 0x190
h1s->flags = H1S_F_BODYLESS_RESP | H1S_F_NOT_FIRST | H1S_F_WANT_KAL
The new functions h2c_show_flags() and h2s_show_flags() decode the flags
state into a string, and are used by dev/flags:
$ ./dev/flags/flags h2c 0x0600
h2c->flags = H2_CF_DEM_IN_PROGRESS | H2_CF_DEM_SHORT_READ
$ ./dev/flags/flags h2s 0x7003
h2s->flags = H2_SF_HEADERS_RCVD | H2_SF_OUTGOING_DATA | H2_SF_HEADERS_SENT \
| H2_SF_ES_SENT | H2_SF_ES_RCVD
The new function is fd_show_flags() and it reports known FD flags:
$ ./dev/flags/flags fd 0x000121
fd->flags = FD_POLL_IN | FD_EV_READY_W | FD_EV_ACTIVE_R
There's no more point keeping functions that are just wrappers around
other ones, let's directly call them from the main entry point. It helps
visually control the mapping between output formats and their definition
and doesn't require to invent long names. For a bit more readability, the
tmpbuf and its size adopted slightly shorter names.
The new function is strm_et_show_flags(). Only the error type is
handled at the moment, as a bit more complex logic is needed to
mix the values and enums present in some fields.
The two new functions are se_show_flags() and sc_show_flags().
Maybe something could be done for SC_ST_* values but as it's a
small enum, a simple switch/case should work fine.
The two new functions are chn_show_analysers() and chn_show_flags().
They work on an existing buffer so one was declared in flags.c for this
purpose. File flags.c does not have to know about channel flags anymore.
This was added in 2.6 by commit c78a9698e ("MINOR: connection: add a new
flag CO_FL_FDLESS on fd-less connections") but forgotten in flags.c.
This must be backported to 2.6.
The proposed decoding options were not updated after the changes in 2.6,
let's fix that by taking the names from the existing declaration. This
should be backported to 2.6.
TASK_SHARED_WQ was set upon task creation and never changed afterwards.
Thus if a task was created to run anywhere (e.g. a check or a Lua task),
all its timers would always pass through the shared timers queue with a
lock. Now we know that tid<0 indicates a shared task, so we can use that
to decide whether or not to use the shared queue. The task might be
migrated using task_set_affinity() but it's always dequeued first so
the check will still be valid.
Not only this removes a flag that's difficult to keep synchronized with
the thread ID, but it should significantly lower the load on systems with
many checks. A quick test with 5000 servers and fast checks that were
saturating the CPU shows that the check rate increased by 20% (hence the
CPU usage dropped by 17%). It's worth noting that run_task_lists() almost
no longer appears in perf top now.
This flag was the only remaining one that was inverted as a blocking
condition, requiring special handling to preset it on sedesc allocation.
Let's flip it in its definition and accessors.
There's no more reason for keepin the code and definitions in conn_stream,
let's move all that to stconn. The alphabetical ordering of include files
was adjusted.
This flag indicates the that stream endpoint is willing to consume output
data from the stream. Its new name makes this more explicit. The function
names will be updated accordingly, which will remove the disturbing "get"
everywhere.
The following flags are not at all related to the endpoint but to the
connector itself:
- SE_FL_RXBLK_ROOM
- SE_FL_RXBLK_BUFF
- SE_FL_RXBLK_CHAN
As such they have no business staying in the endpoint descriptor and
they must move to the stream connector. They've also been renamed
accordingly to better match what they correspond to (the same name
as the function that sets them).
The rare occurrences of cs_rx_blocked() were replaced by an explicit
test on the list of flags. The reason is that cs_rx_blocked() used to
preserve some tests that are not needed at certain places since already
known. For the same reason SE_FL_RXBLK_ANY wasn't converted. As such it
will later be possible to carefully review these few locations and
eliminate the unneeded flags from the tests. No particular function
was made to test them since they're explicit enough.
It now looks like ci_putchk() and friends could very well place the flag
themselves on the connector when they detect a buffer full condition, as
this would significantly simplify the high-level API. But all usages must
first be reviewed before this simplification can be done. For now it
remains done by applet_put*() instead.
It's more explicit this way. The cs_rx_endp_ready() function could be
removed so that the flag is directly tested. In the future it should
be inverted and the few places where it's set (or preserved via
SE_FL_APP_MASK) could be dropped.
This flag is exclusively used when a front applet needs to wait for the
other side to connect (or fail to). Let's give it a more explicit name
and remove the ambiguous function that was used only once.
This also ensures we will not risk to set it back on a new endpoint
after cs_reset_endp() via SE_FL_APP_MASK, because the flag being
specific to the endpoint only and not to the connector, we don't
want to preserve it when replacing the endpoint.
This flag is no more needed, it was only set on shut read to be tested
by cs_rx_blocked() which is now properly tested for shutr as well. The
cs_rx_blk_shut() calls were removed. Interestingly it allowed to remove
a special case in the L7 retry code.
This also ensures we will not risk to set it back on a new endpoint
after cs_reset_endp() via SE_FL_APP_MASK.
Just like for the conn_stream, now that these addresses are dynamically
allocated, there is no single case where the pointer is set without the
corresponding flag, and the flag is used as a permission to dereference
the pointer. Let's just replace the test of the flag with a test of the
pointer and remove all flag assignment. This makes the code clearer
(especially in "if" conditions) and saves the need for future code to
think about properly setting the flag after setting the pointer.
These flags indicate that the ->src or ->dst field in the conn_stream
is not null, which is something the caller already sees (and even tests
from the two sets of functions that set them). They maintain some burden
because an agent trying to set a source or destination has to manually
set the flags in addition to setting the pointer, so they provide no
value anymore, let's drop them.
This flag is no longer needed now that it must always match the presence
of a destination address on the backend conn_stream. Worse, before previous
patch, if it were to be accidently removed while the address is present, it
could result in a leak of that address since alloc_dst_address() would first
be called to flush it.
Its usage has a long history where addresses were stored in an area shared
with the connection, but as this is no longer the case, there's no reason
for putting this burden onto application-level code that should not focus
on setting obscure flags.
The only place where that made a small difference is in the dequeuing code
in case of queue redistribution, because previously the code would first
clear the flag, and only later when trying to deal with the queue, would
release the address. It's not even certain whether there would exist a
code path going to connect_server() without calling pendconn_dequeue()
first (e.g. retries on queue timeout maybe?).
Now the pendconn_dequeue() code will rely on SF_ASSIGNED to decide to
clear and release the address, since that flag is always set while in
a server's queue, and its clearance implies that we don't want to keep
the address. At least it remains consistent and there's no more risk of
leaking it.
Remaining flags and associated functions are move in the conn-stream
scope. These flags are added on the endpoint and not the conn-stream
itself. This way it will be possible to get them from the mux or the
applet. The functions to get or set these flags are renamed accordingly with
the "cs_" prefix and updated to manipualte a conn-stream instead of a
stream-interface.
Only the server side is concerned by the stream-interface error type. It is
useless to have an err_type field on the client side. So, it is now move to
the stream. SI_ET_* are renames STRM_ET_* and moved in stream-t.h header
file.
Flag to get the source ip/port with getsockname is now handled at the stream
level. Thus SI_FL_SRC_ADDR stream-int flag is replaced by SF_SRC_ADDR stream
flag.
Flag to consider a stream as indepenent is now handled at the conn-stream
level. Thus SI_FL_INDEP_STR stream-int flag is replaced by CS_FL_INDEP_STR
conn-stream flags.
Flag to not wake the stream up on I/O is now handled at the conn-stream
level. Thus SI_FL_DONT_WAKE stream-int flag is replaced by CS_FL_DONT_WAKE
conn-stream flags.
Flags to disable lingering and half-close are now handled at the conn-stream
level. Thus SI_FL_NOLINGER and SI_FL_NOHALF stream-int flags are replaced by
CS_FL_NOLINGER and CS_FL_NOHALF conn-stream flags.
Instead of setting a stream-interface flag to then set the corresponding
conn-stream endpoint flag, we now only rely the conn-stream endoint. Thus
SI_FL_KILL_CON is replaced by CS_EP_KILL_CONN.
In addition si_must_kill_conn() is replaced by cs_must_kill_conn().
Instead of relying on the conn-stream error, via CS_FL_ERR flags, we now
directly use the error at the endpoint level with the flag CS_EP_ERROR. It
should be safe to do so. But we must be careful because it is still possible
that an error is processed too early. Anyway, a conn-stream has always a
valid endpoint, maybe detached from any endpoint, but valid.
SI_FL_ERR is removed and replaced by CS_FL_ERROR. It is a transient patch
because the idea is to rely on the endpoint to handle errors at this
level. But if for any reason it is not possible, the stream-interface flags
will still be replaced.
The expiration date in the stream-interface was only used on the server side
to set the connect, queue or turn-around timeout. It was checked on the
frontend stream-interface, but never used concretely. So it was removed and
replaced by a connect expiration date in the stream itself. Thus, SI_FL_EXP
flag in stream-interfaces is replaced by a stream flag, SF_CONN_EXP.
The source and destination addresses at the applicative layer are moved from
the stream-interface to the conn-stream. This simplifies a bit the code and
it is a logicial step to remove the stream-interface.
The L7 retries only concerns the stream when a server connection is
established. Thus instead of storing the L7 buffer into the
stream-interface, it may be moved to the stream. And because it is only
available for HTTP streams, it may be moved in the HTTP transaction.
Associated flags are also moved into the HTTP transaction.
Willy Tarreau
Christopher Faulet