Move functions related to errors output on stderr from log.c to a newly
created errors.c file. It targets print_message and
ha_alert/warning/notice/diag functions and related startup_logs feature.
A memory allocation failure happening in chash_init_server_tree while
trying to allocate a server's lb_nodes item used in consistent hashing
would have resulted in a crash. This function is only called during
configuration parsing.
It was raised in GitHub issue #1233.
It could be backported to all stable branches.
A memory allocation failure happening in mworker_env_to_proc_list when
trying to allocate a mworker_proc would have resulted in a crash. This
function is only called during init.
It was raised in GitHub issue #1233.
It could be backported to all stable branches.
A memory allocation failure happening during peers_register_table would
have resulted in a crash. This function is only called during init.
It was raised in GitHub issue #1233.
It could be backported to all stable branches.
Two calloc calls were not checked in the srv_parse_source function.
Considering that this function could be called at runtime through a
dynamic server creation via the CLI, this could lead to an unfortunate
crash.
It was raised in GitHub issue #1233.
It could be backported to all stable branches even though the runtime
crash could only happen on branches where dynamic server creation is
possible.
b_slow_realign() function may be used to realign a buffer with a given
amount of output data, eventually 0. In such case, the head is set to
0. This function is not designed to be used with input only buffers, like
those used in the muxes. It is the purpose of b_slow_realign_ofs()
function. It does almost the same, realign a buffer. But it do so by setting
the buffer head to a specific offset.
h1 parsing functions (h1_parse_msg_*) returns the number of bytes parsed or
0 if nothing is parsed because an error occurred or some data are
missing. But they never return negative values. Thus, instead of a signed
integer, these function now return a size_t value.
The H1 and FCGI muxes are updated accordingly. Note that h1_parse_msg_data()
has been slightly adapted because the parsing of chunked messages still need
to handle negative values when a parsing error is reported by
h1_parse_chunk_size() or h1_skip_chunk_crlf().
The output of "show map/acl" now contains the 'entry_cnt' value that
represents the count of all the entries for each map/acl, not just the
active ones, which means that it also includes entries currently being
added.
The following functions used in CA/CRL file hot update were not defined
in OpenSSL 1.0.2 so they need to be defined in openssl-compat :
- X509_CRL_get_signature_nid
- X509_CRL_get0_lastUpdate
- X509_CRL_get0_nextUpdate
- X509_REVOKED_get0_serialNumber
- X509_REVOKED_get0_revocationDate
This patch adds the "set ssl crl-file" and "commit ssl crl-file"
commands, following the same logic as the certificate and CA file update
equivalents.
When trying to update a Certificate Revocation List (CRL) file via a
"set" command, we start by looking for the entry in the CA file tree and
then building a new cafile_entry out of the payload, without adding it
to the tree yet. It will only be added when a "commit" command is
called.
During a "commit" command, we insert the newly built cafile_entry in the
CA file tree while keeping the previous entry. We then iterate over all
the instances that used the CRL file and rebuild a new one and its
dedicated SSL context for every one of them.
When all the contexts are properly created, the old instances get
replaced by the new ones and the old CRL file is removed from the tree.
The CA files and CRL files are stored in the same cafile_tree so this
patch adds a new field the the cafile_entry structure that specifies the
type of the entry. Since a ca-file can also have some CRL sections, the
type will be based on the option used to load the file and not on its
content (ca-file vs crl-file options).
This patch adds the "set ssl ca-file" and "commit ssl ca-file" commands,
following the same logic as the certificate update equivalents.
When trying to update a ca-file entry via a "set" command, we start by
looking for the entry in the cafile_tree and then building a new
cafile_entry out of the given payload. This new object is not added to
the cafile_tree until "commit" is called.
During a "commit" command, we insert the newly built cafile_entry in the
cafile_tree, while keeping the previous entry as well. We then iterate
over all the instances linked in the old cafile_entry and rebuild a new
ckch instance for every one of them. The newly inserted cafile_entry is
used for all those new instances and their respective SSL contexts.
When all the contexts are properly created, the old instances get
replaced by the new ones and the old cafile_entry is removed from the
tree.
This fixes a subpart of GitHub issue #1057.
Adds a way to insert a new uncommitted cafile_entry in the tree. This
entry will be the one fetched by any lookup in the tree unless the
oldest cafile_entry is explicitely looked for. This way, until a "commit
ssl ca-file" command is completed, there could be two cafile_entries
with the same path in the tree, the original one and the newly updated
one.
The updated CA content coming from the CLI during a ca-file update will
directly be in memory and not on disk so the way CAs are loaded in a
cafile_entry for now (via X509_STORE_load_locations calls) cannot be
used.
This patch adds a way to fill a cafile_entry directly from memory and to
load the contained certificate and CRL sections into an SSL store.
CRL sections are managed as well as certificates in order to mimic the
way CA files are processed when specified in an option. Indeed, when
parsing a CA file given through a ca-file or ca-verify-file option, we
iterate over the different sections in ssl_set_cert_crl_file and load
them regardless of their type. This ensures that a file that was
properly parsed when given as an option will also be accepted by the
CLI.
In order for the link between the cafile_entry and the default ckch
instance to be built, we need to give a pointer to the instance during
the ssl_sock_prepare_ctx call.
Each ca-file entry of the tree will now hold a list of the ckch
instances that use it so that we can iterate over them when updating the
ca-file via a cli command. Since the link between the SSL contexts and
the CA file tree entries is only built during the ssl_sock_prepare_ctx
function, which are called after all the ckch instances are created, we
need to add a little post processing after each ssl_sock_prepare_ctx
that builds the link between the corresponding ckch instance and CA file
tree entries.
In order to manage the ca-file and ca-verify-file options, any ckch
instance can be linked to multiple CA file tree entries and any CA file
entry can link multiple ckch instances. This is done thanks to a
dedicated list of ckch_inst references stored in the CA file tree
entries over which we can iterate (during an update for instance). We
avoid having one of those instances go stale by keeping a list of
references to those references in the instances.
When deleting a ckch_inst, we can then remove all the ckch_inst_link
instances that reference it, and when deleting a cafile_entry, we
iterate over the list of ckch_inst reference and clear the corresponding
entry in their own list of ckch_inst_link references.
This patch moves all the ssl_store related code to ssl_ckch.c since it
will mostly be used there once the CA file update CLI commands are all
implemented. It also makes the cafile_entry structure visible as well as
the cafile_tree.
This function was not used anymore after the atomic updates were
implemented in 2.3, and it must not be used given that it does not
yield and can easily make the process hang for tens of seconds on
large acls/maps. Let's remove it before someone uses it as an
example to implement something else!
It's still very difficult to find all commands starting with a given
keyword like "set", "show" etc. Let's sort the lines by usage message,
this is much more convenient.
The build fails on versions older than 1.0.1d which is the first one
introducing CRYPTO_memcmp(), so let's have a define for this instead
of enabling it whenever USE_OPENSSL is set. One could also wonder why
we're relying on openssl for such a trivial thing, and a simple local
implementation could also allow to restore lexicographic ordering.
Some of the Lua doc and a few places still used "Haproxy" or "HAproxy".
There was even one "HA proxy". A few of them were in an example of VTest
output, indicating that VTest ought to be fixed as well. No big deal but
better address all the remaining ones so that these inconsistencies stop
spreading around.
listener-t comes with openssl just due to the SSL_CTX type that is
declred as a typedef in openssl hence cannot be abstracted at this
level. However connection-t.h doen't need all that just to know that
bind_conf is a struct. Let's declare it with other external types
instead..
These ones are used by virtually every config parser. Not only they
provide no benefit in being inlined, but they imply a very deep
dependency starting at proxy.h, which results for example in task.c
including openssl.
Let's move these two functions to cfgparse.c.
These caddr_* functions were once placed into tools.h in the hope they
would be useful but nobody knows they exist. They could deserve being
moved to their own file with other pointer manipulation functions maybe,
but for now they're the only reason left for stick_table.h to include
tools.h, so let's move them directly there since it's its only user.
This allows to remove tools.h from stick_table.h and slightly reduce
the overall build time.
This function has no business being inlined in stick_table.h since it's
only used at boot time by the config parser. In addition it causes an
undesired dependency on tools.h because it uses parse_time_err(). Let's
move it to stick_table.c.
No idea why this was put inlined into connection.h, it's used only once
for haproxy -vv, and requires tools.h, causing an undesired dependency
from connection.h. Let's move it to connection.c instead where it ought
to have been.
Only mworker uses proc_self, and it was declared in global.h, forcing
users of global.h to include mworker and its dependencies.
Moving it to mworker reduces the preprocessed size of version.c from
170 to 125kB by shrinking the number of local includes from 30 to 16
and the number of system includes from 147 to 132.
The presence of this field causes a long dependency chain because almost
everyone includes global-t.h, and vars include sample_data which include
some system includes as well as HTTP parts.
There is absolutely no reason for having the process-wide variables in
the global struct, let's just move them into vars.c and vars.h. This
reduces from ~190k to ~170k the preprocessed output of version.c.
This will allow some fields to be produced with a higher accuracy when
the requester indicates being able to parse floats. Rates and times are
among the elements which can make sense.
Currently the stats filling function knows nothing about the caller's
needs, so let's pass the STAT_* flags so that it can adapt to the
requester's constraints.
For stats reporting it can be convenient to report floats at low rates
instead of discrete integers. We do have quite some precision since we
currently divide counters by number of milliseconds, so we can usually
add 3 digits after the decimal point.
We already had ultoa_r() and friends but nothing to emit inline floats.
This is now done with ftoa_r() and F2A/F2H. Note that the latter both use
the itoa_str[] as temporary storage and that the HTML format currently is
the exact same as the ASCII one. The trailing zeroes are always timmed so
these outputs are usable in user-visible output.
When using "%f" to print a float, it automatically gets 6 digits after
the decimal point and there's no way to automatically adjust to the
required ones by dropping trailing zeroes. This function does exactly
this and automatically drops the decimal point if all digits after it
were zeroes. This will make numbers more friendly in stats and makes
outputs shorter (e.g. JSON where everything is just a "number").
The function is designed to be easy to use with snprint() and chunks:
snprintf:
flt_trim(buf, 0, snprintf(buf, sizeof(buf), "%f", x));
chunk_printf:
out->data = flt_trim(out->area, 0, chunk_printf(out, "%f", x));
chunk_appendf:
size_t prev_data = out->data;
out->data = flt_trim(out->area, prev_data, chunk_appendf(out, "%f", x));
Add a new proxy capability for proxy with load-balancing capabilities.
This help to differentiate listen/frontend/backend with special proxies
such as peer proxies.
Support experimental actions. It is mandatory to use
'expose-experimental-directives' before to be able to use them.
If such action is present in the config file, the tainted status of the
process is updated. Another tainted status is set when an experimental
action is executed.
Define a new keyword flag KWF_MATCH_PREFIX. This is used to replace the
match_pfx field of action struct.
This has the benefit to have more explicit action declaration, and now
it is possible to quickly implement experimental actions.
Add a new flag to mark a keyword as experimental. An experimental
keyword cannot be used if the global 'expose-experimental-directives' is
not present first.
Only keywords parsed through a standard cfg_keywords lists in
global/proxies section will be automatically detected if declared
experimental. To support a keyword outside of these lists,
check_kw_experimental must be called manually during its parsing.
If an experimental keyword is present in the config, the tainted flag is
updated.
For the moment, no keyword is marked as experimental.
This field will be used to add various mechanism to config parsing.
Currently no flag value is implemented. The following commit will
implement experimental keywords.
Add a global flag named 'tainted'. Its purpose is to report various
status about experimental features used for the current process
lifetime.
By default it is initialized to 0. It can be set/retrieve by a couple of
new functions mark_tainted()/get_tainted(). Once a flag is set, it
cannot be resetted.
Currently, no tainted status is implemented, it will be the subject of
the following commits.
The new function split_version() converts a parsable haproxy version to
an array of integers. The function compare_current_version() compares an
arbitrary version to the current one. These two functions were written
by Thierry Fournier in 2013, and are still usable as-is. They will be
used to write config language predicates.
Till now it was only presented in the version output but could not be
consulted outside of haproxy.c, let's export it as a variable, and set
it to an empty string if not defined.
Let's add a few fields to the global struct to store information about
the current file being processed, the current line number and the current
section. This will be used to retrieve them using special variables.
When the abortonclose option is enabled, to be sure to be immediately
notified when a shutdown is received from the client, the frontend
conn-stream must be sure the mux will wait for read events. To do so, the
CO_RFL_KEEP_RECV flag is set when mux->rcv_buf() is called. This new flag
instructs the mux to wait for read events, regardless its internal state.
This patch is required to fix abortonclose option for H1 client connections.
When channel_may_recv() is called for an HTX stream, the HTX version,
channel_htx_may_recv() is called. This patch is mandatory to fix a bug
related to the abortonclose option.
This adds the necessary flags to permit run-time enabling/disabling of
memory profiling. For now this is disabled.
A few words were added to the management doc about it and recalling that
this is limited to certain OSes.
get_sym_curr_addr() will return the address of the first occurrence of
the given symbol while get_sym_next_addr() will return the address of
the next occurrence of the symbol. These ones return NULL on non-linux,
non-ELF, non-USE_DL.
Implement a safe mechanism to close front idling connection which
prevents the soft-stop to complete. Every h1/h2 front connection is
added in a new per-thread list instance. On shutdown, a new task is
waking up which calls wake mux operation on every connection still
present in the new list.
A new stopping_list attach point has been added in the connection
structure. As this member is only used for frontend connections, it
shared the same union as the session_list reserved for backend
connections.
Move the session_list attach point in an anonymous union. This member is
only used for backend connections. This commit is in preparation for the
support of stopping frontend idling connections which will add another
member to the union.
This change means that a special care must be taken to be sure that only
backend connections manipulate the session_list. A few BUG_ON has been
added as special guard to prevent from misuse.
The purpose of this debugging option was to prevent certain pools from
masking other ones when they were shared. For example, task, http_txn,
h2s, h1s, h1c, session, fcgi_strm, and connection are all 192 bytes and
would normally be mergedi, but not with this option. The problem is that
certain pools are declared multiple times with various parameters, which
are often very close, and due to the way the option works, they're not
shared either. Good examples of this are captures and stick tables. Some
configurations have large numbers of stick-tables of pretty similar types
and it's very common to end up with the following when the option is
enabled:
$ socat - /tmp/sock1 <<< "show pools" | grep stick
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753800=56
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753880=57
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753900=58
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753980=59
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753a00=60
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753a80=61
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753b00=62
- Pool sticktables (224 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x753780=55
In addition to not being convenient, it can have important effects on the
memory usage because these pools will not share their entries, so one stick
table cannot allocate from another one's pool.
This patch solves this by going back to the initial goal which was not to
have different pools in the same list. Instead of masking the MAP_F_SHARED
flag, it simply adds a test on the pool's name, and disables pool sharing
if the names differ. This way pools are not shared unless they're of the
same name and size, which doesn't hinder debugging. The same test above
now returns this:
$ socat - /tmp/sock1 <<< "show pools" | grep stick
- Pool sticktables (160 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 7 users, @0x3fadb30 [SHARED]
- Pool sticktables (224 bytes) : 0 allocated (0 bytes), 0 used, needed_avg 0, 0 failures, 1 users, @0x3facaa0 [SHARED]
This is much better. This should probably be backported, in order to limit
the side effects of DEBUG_DONT_SHARE_POOLS being enabled in production.
DragonflyBSD already has an attribute __read_mostly which serves the
same purpose as the one in compiler.h.
No need to be backported as it was added in the current 2.4-dev.
Instead of being able to purge only values older than a specific value,
let's support arbitrary ranges and make pat_ref_purge_older() just be
one special case of this one.
Thanks to the commit "BUG/MINOR: applet: Notify the other side if data were
consumed by an applet", it is no longer necessary to notify the producer when an
applet skips output data. Now, it is the default applet handler responsibility
to take care of that.
Move cpu_map structure outside of the global struct to a global
variable defined in cpuset.c compilation unit. This allows to reorganize
the includes without having to define _GNU_SOURCE everywhere for the
support of the cpu_set_t.
This fixes the compilation with musl libc, most notably used for the
alpine based docker image.
This fixes the github issue #1235.
No need to backport as this feature is new in the current
2.4-dev.
The HTX functions used to add new HTX blocks in a message have been moved to
the header file to inline them in calling functions. These functions are
small enough.
A normalized URI is the internal term used to specify an URI is stored using
the absolute format (scheme + authority + path). For now, it is only used
for H2 clients. It is the default and recommended format for H2 request.
However, it is unusual for H1 servers to receive such URI. So in this case,
we only send the path of the absolute URI. It is performed for H1 servers,
but not for FCGI applications. This patch fixes the difference.
Note that it is not a real bug, because FCGI applications should support
abosolute URI.
Note also a normalized URI is only detected for H2 clients when a request is
received. There is no such test on the H1 side. It means an absolute URI
received from an H1 client will be sent without modification to an H1 server
or a FCGI application.
To make it possible, a dedicated function has been added to get the H1
URI. This function is called by the H1 and the FCGI multiplexer when a
request is sent to a server.
This patch should fix the issue #1232. It must be backported as far as 2.2.
In proxy.c, when process is stopping we try to flush tables content
using 'stktable_trash_oldest'. A check on a counter "table->syncing" was
made to verify if there is no pending resync in progress.
But using multiple threads this counter can be increased by an other thread
only after some delay, so the content of some tables can be trashed earlier and
won't be pushed to the new process (after reload, some tables appear reset and
others don't).
This patch re-names the counter "table->syncing" to "table->refcnt" and
the counter is increased during configuration parsing (registering a table to
a peer section) to protect tables during runtime and until resync of a new
process has succeeded or failed.
The inc/dec operations are now made using atomic operations
because multiple peer sections could refer to the same table in futur.
This fix addresses github #1216.
This patch should be backported on all branches multi-thread support (v >= 1.8)
The compiler cannot guess that tv_sec or tv_usec might have unused
parts, so the multiply by 1000 and the divide by 1000 are both
performed using 64-bit constants to stick to the common type. This is
not needed since we only keep the final 32 bits, let's help the compiler
here by casting these fields to uint. The tv_update_date() code is much
cleaner (48 bytes smaller in the CAS loop) as it avoids some register
spilling at a location where that's really unwanted.
The compilation is currently broken on platform without USE_CPU_AFFINITY
set. An error has been reported by the cygwin build of the CI.
This does not need to be backported.
In file included from include/haproxy/global-t.h:27,
from include/haproxy/global.h:26,
from include/haproxy/fd.h:33,
from src/ev_poll.c:22:
include/haproxy/cpuset-t.h:32:3: error: #error "No cpuset support implemented on this platform"
32 | # error "No cpuset support implemented on this platform"
| ^~~~~
include/haproxy/cpuset-t.h:37:2: error: unknown type name ‘CPUSET_REPR’
37 | CPUSET_REPR cpuset;
| ^~~~~~~~~~~
make: *** [Makefile:944: src/ev_poll.o] Error 1
make: *** Waiting for unfinished jobs....
In file included from include/haproxy/global-t.h:27,
from include/haproxy/global.h:26,
from include/haproxy/fd.h:33,
from include/haproxy/connection.h:30,
from include/haproxy/ssl_sock.h:27,
from src/ssl_sample.c:30:
include/haproxy/cpuset-t.h:32:3: error: #error "No cpuset support implemented on this platform"
32 | # error "No cpuset support implemented on this platform"
| ^~~~~
include/haproxy/cpuset-t.h:37:2: error: unknown type name ‘CPUSET_REPR’
37 | CPUSET_REPR cpuset;
| ^~~~~~~~~~~
make: *** [Makefile:944: src/ssl_sample.o] Error 1
Render numa detection optional with a global configuration statement
'no numa-cpu-mapping'. This can be used if the applied affinity of the
algorithm is not optimal. Also complete the documentation with this new
keyword.
On process startup, the CPU topology of the machine is inspected. If a
multi-socket CPU machine is detected, automatically define the process
affinity on the first node with active cpus. This is done to prevent an
impact on the overall performance of the process in case the topology of
the machine is unknown to the user.
This step is not executed in the following condition :
- a non-null nbthread statement is present
- a restrictive 'cpu-map' statement is present
- the process affinity is already restricted, for example via a taskset
call
For the record, benchmarks were executed on a machine with 2 CPUs
Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz. In both clear and ssl
scenario, the performance were sub-optimal without the automatic
rebinding on a single node.
Allow to specify multiple cpu ids/ranges in parse_cpu_set separated by a
comma. This is optional and must be activated by a parameter.
The comma support is disabled for the parsing of the 'cpu-map' config
statement. However, it will be useful to parse files in sysfs when
inspecting the cpus topology for NUMA automatic process binding.
Create a function thread_cpu_mask_forced. Its purpose is to report if a
restrictive cpu mask is active for the current proces, for example due
to a taskset invocation. It is only implemented for the linux platform
currently.
Use the platform independent type hap_cpuset for the cpu-map statement
parsing. This allow to address CPU index greater than LONGBITS.
Update the documentation to reflect the removal of this limit except for
platforms without cpu_set_t type or equivalent.
Replace the unsigned long parameter by a hap_cpuset. This allows to
address CPU with index greater than LONGBITS.
This function is used to parse the 'cpu-map' statement. However at the
moment, the result is casted back to a long to store it in the global
structure. The next step is to replace ulong in in cpu_map in the
global structure with hap_cpuset.
This module can be used to manipulate a cpu sets in a platform agnostic
way. Use the type cpu_set_t/cpuset_t if available on the platform, or
fallback to unsigned long, which limits de facto the maximum cpu index
to LONGBITS.
Now that SLZ is merged, let's update the makefile and compression
files to use it. As a result, SLZ_INC and SLZ_LIB are neither defined
nor used anymore.
USE_SLZ is enabled by default ("USE_SLZ=default") and can be disabled
by passing "USE_SLZ=" or by enabling USE_ZLIB=1.
The doc was updated to reflect the changes.
This normalizer removes "/./" segments from the path component.
Usually the dot refers to the current directory which renders those segments redundant.
See GitHub Issue #714.
The current "ADD" vs "ADDQ" is confusing because when thinking in terms
of appending at the end of a list, "ADD" naturally comes to mind, but
here it does the opposite, it inserts. Several times already it's been
incorrectly used where ADDQ was expected, the latest of which was a
fortunate accident explained in 6fa922562 ("CLEANUP: stream: explain
why we queue the stream at the head of the server list").
Let's use more explicit (but slightly longer) names now:
LIST_ADD -> LIST_INSERT
LIST_ADDQ -> LIST_APPEND
LIST_ADDED -> LIST_INLIST
LIST_DEL -> LIST_DELETE
The same is true for MT_LISTs, including their "TRY" variant.
LIST_DEL_INIT keeps its short name to encourage to use it instead of the
lazier LIST_DELETE which is often less safe.
The change is large (~674 non-comment entries) but is mechanical enough
to remain safe. No permutation was performed, so any out-of-tree code
can easily map older names to new ones.
The list doc was updated.
Amaury noticed that I managed to break the build of DEBUG_FAIL_ALLOC
for the second time with 207c09509 ("MINOR: pools: move the fault
injector to __pool_alloc()"). The joy of endlessly reworking patch
sets... No backport is needed, that was in the just merged cleanup
series.
By having a pair of dummy pool_get_from_cache() and pool_put_to_cache()
we can remove some ugly ifdefs, so let's do this. We've already done it
for the shared cache.
This function has become too big (251 bytes) and is now hurting
performance a lot, with up to 4% request rate being lost over the last
pool changes. Let's move it to pool.c as a regular function. Other
attempts were made to cut it in half but it's still inefficient. Doing
this results in saving ~90kB of object code, and even 112kB since the
pool changes, with code that is even slightly faster!
Conversely, pool_get_from_cache(), which remains half of this size, is
still faster inlined, likely in part due to the immediate use of the
returned pointer afterwards.
Since pool_get_from_cache() and pool_put_to_cache() were now only wrappers
to the local cache versions which do all the job, let's merge them together
so that there is no more local-cache specific function.
Now when pool_get_from_local_cache() fails, it automatically falls back
to pool_get_from_shared_cache(), which used to always be done in
pool_get_from_cache(). Thus now the API is simpler as we always allocate
and free from/to the local caches.
Till now it used to call it only if there were not too many objects into
the local cache otherwise would send the latest one directly into the
shared cache. Now it always sends to the local cache and it's up to the
local cache to free its oldest objects. From a cache freshness perspective
it's better this way since we always evict cold objects instead of hot
ones. From an API perspective it's better because it will help make the
shared cache invisible to the public API.
These two functions are now responsible for allocating directly from
the cache and releasing to the cache.
Now the pool_alloc() function simply does this:
if cache enabled
return pool_alloc_from_cache() if no NULL
return pool_alloc_nocache() otherwise
and the pool_free() function does this:
if cache enabled
pool_put_to_cache()
else
pool_free_nocache()
For now this only introduces these two functions without changing anything
else, but the goal is to soon allow to make them implementation-specific.
Continuing the unification of local and shared pools, now the usage of
pools is governed by CONFIG_HAP_POOLS without which allocations and
releases are performed directly from the OS using pool_alloc_nocache()
and pool_free_nocache().
There are two levels of freeing to the OS:
- code that wants to keep the pool's usage counters updated uses
pool_free_area() and handles the counters itself. That's what
pool_put_to_shared_cache() does in the no-global-pools case.
- code that does not want to update the counters because they were
already updated only calls pool_free_area().
Let's extract these calls to establish the symmetry with pool_get_from_os()
and pool_alloc_nocache(), resulting in pool_put_to_os() (which only updates
the allocated counter) and pool_free_nocache() (which also updates the used
counter). This will later allow to simplify the generic code.
Calling pool_free_area() inside a lock in pool_put_to_shared_cache() is
a very bad idea. Fortunately this only happens on the lowest end platforms
which almost never use threads or in very small counts.
This change consists in zeroing the pointer once already released to the
cache in the first test so that the second stage knows if it needs to
pass it to the OS or not. This has slightly reduced the length of the
A part of the code cannot be factored out because it still uses non-atomic
inc/dec for pool->used and pool->allocated as these are located under the
pool's lock. While it can make sense in terms of bus cycles, it does not
make sense in terms of code normalization. Further, some operations were
still performed under a lock that could be totally removed via the use of
atomic ops.
There is still one occurrence in pool_put_to_shared_cache() in the locked
code where pool_free_area() is called under the lock, which must absolutely
be fixed.
