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add osmo_use_count API 

Provide a common implementation of use counting that supports naming each user
as well as counting more than just one use per user, depending on the rules the
caller implies.

In osmo-msc, we were originally using a simple int counter to see whether a
connection is still in use or should be discarded. For clarity, we later added
names to each user in the form of a bitmask of flags, to figure out exactly
which users are still active: for logging and to debug double get / double put
bugs. This however is still not adequate, since there may be more than one CM
Service Request pending. Also, it is a specialized implementation that is not
re-usable.

With this generalized implementation, we can:

- fix the problem of inadequate counting of multiple concurrent CM Service
  Requests (more than one use count per user category),
- directly use arbitrary names for uses like __func__ or "foo" (no need to
  define enums and value_string[]s),
- re-use the same code for e.g. vlr_subscr and get fairly detailed VLR
  susbscriber usage logging for free.

Change-Id: Ife31e6798b4e728a23913179e346552a7dd338c0
This commit is contained in:
Neels Hofmeyr 2019-02-11 20:32:25 +01:00 committed by Neels Hofmeyr
parent 0c7826e9bd
commit 0e8df1c7e4
9 changed files with 1031 additions and 0 deletions
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1
include/Makefile.am
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@ -53,6 +53,7 @@ nobase_include_HEADERS = \
osmocom/core/utils.h \
osmocom/core/write_queue.h \
osmocom/core/sockaddr_str.h \
osmocom/core/use_count.h \
osmocom/crypt/auth.h \
osmocom/crypt/gprs_cipher.h \
osmocom/ctrl/control_cmd.h \

228
include/osmocom/core/use_count.h Normal file
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@ -0,0 +1,228 @@
/*! \file use_count.h
* Generic object usage counter API (get, put and deallocate on zero count).
*/
/*
* (C) 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
*
* All Rights Reserved
*
* Author: Neels Hofmeyr <neels@hofmeyr.de>
*
* SPDX-License-Identifier: GPL-2.0+
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#pragma once
#include <stdint.h>
#include <stdlib.h>
#include <osmocom/core/linuxlist.h>
/*! \defgroup use_count Use Counter
* @{
* \file use_count.h
*/
struct osmo_use_count_entry;
/*! Invoked when a use count changes.
*
* The implementation is free to trigger actions on arbitrary use count changes, typically to free the
* use_count->talloc_object when the total use count reaches zero.
*
* The implementation may modify use_count_entry->count, for example for handling of get()/put() bugs, to clamp specific use
* tokens to specific counts, or to prevent the caller from put()ting into negative counts. When returning an error,
* there is no implicit undo -- if errors need to be corrected, this function is responsible for that.
*
* Be aware: use token strings are not copied, and use count entries usually remain listed also when they reach a zero
* count. This is trivially perfectly ok when using string literals as use tokens. It is also possible to use
* dynamically allocated string tokens, but should a use token string become invalid memory when reaching zero count, it
* is the responsibility of this function to set the use_count_entry->use = NULL; this is required to avoid subsequent
* osmo_use_count_get_put() invocations from calling strcmp() on invalid memory. (Setting use = NULL cannot be done
* implicitly after this callback invocation, because callback implementations are allowed to completely deallocate the
* talloc_object and the use_count list entries, and setting use = NULL after that would be a use-after-free.)
*
* \param[in] use_count_entry Use count entry that is being modified.
* \param[in] old_use_count Use count the item had before the change in use count.
* \param[in] file Source file string, passed in as __FILE__ from macro osmo_use_count_get_put().
* \param[in] line Source file line, passed in as __LINE__ from macro osmo_use_count_get_put().
* \return 0 on success, negative if any undesired use count is reached; this rc will be returned by
* osmo_use_count_get_put().
*/
typedef int (* osmo_use_count_cb_t )(struct osmo_use_count_entry *use_count_entry, int32_t old_use_count,
const char *file, int line);
/*! Use counter state for one used object, managing N distinct named counters.
*
* Manage any number of uses of an object, with name tokens given to each use.
*
* A typical use tracking done by a single instance of this struct may look like:
* "VLR subscr MSISDN-23 + SMS-receiver: now used by 6 (attached,2*SMS-receiver,SMS-pending,SMS,Paging)"
* (This is a DREF log statement from an osmo-msc run delivering an SMS.)
*
* Use tokens are given as const char* strings. Typically string literals like "foo", __func__, or also NULL. Tokens may
* be dynamically allocated or static char[] buffers as long as they are guaranteed to remain unchanged while referenced
* by an osmo_use_count_entry. (Breakage occurs if one token magically changes to equal another listed token.)
*
* Instead of using string literals in the code directly, callers should use a #define, so that typos are caught at
* compile time rather than introducing obscure failures that are hard to spot for humans -- don't use foo_get("bar")
* and foo_put("bar"), but '#define FOO_USE_BAR "bar"' for foo_get(FOO_USE_BAR) and foo_put(FOO_USE_BAR).
*
* Counts are int32_t values, a separate count per use token string. Counts can be negative, though in the typical use
* case are only positive or 0. Enforcing a range is entirely up to the osmo_use_count_cb_t() implementation.
*
* The talloc_object must be a pointer eligible to be a talloc context, i.e. either obtained from a function like
* talloc_zero() or NULL. talloc_object is typically a pointer to the object that this struct is a member of. Use count
* entries may be allocated as talloc children of this (see also "Avoiding dynamic allocation" below).
*
* The use_cb() implementation allows to trigger actions when reaching specific use counts, e.g. deallocate when
* reaching a total sum across all use tokens of zero.
*
* On initialization, this struct can be left fully zero initialized (the llist_head use_counts is implicitly
* initialized upon the first osmo_use_count_get_put()). Usually, set only a talloc_object and a use_cb, though neither
* is strictly required.
*
* Avoiding dynamic allocation: dynamic allocation can be avoided completely by providing sufficient static use count
* entries with osmo_use_count_make_static_entries(). Otherwise, each new use token will dynamically allocate a new
* osmo_use_count_entry; note that once allocated, these entries stay around even if they reached an entry count of
* zero, and will be re-used for subsequent use count tokens. So even if not using osmo_use_count_make_static_entries(),
* each osmo_use_count will keep dynamic allocations at a minimum. See also the documentation for osmo_use_count_cb_t.
*
* List traversal considerations: your typical use count list would max at about six entries in practice. Traversing six
* llist->next pointers is less effort than doing a common strlen().
*
* Obtaining the total use count: osmo_use_count_total() traverses all use token entries and forms a sum. It is trivial
* to keep a separate total count that completely avoids the need for calling this function, which is entirely up to the
* individual osmo_use_count_cb_t() implementation. The optimization gained is usually not worth it, though.
*
* Use token comparison considerations: strcmp() to compare use tokens is a fairly good tradeoff:
* - when the strings differ, strcmp() usually exits on the first or second character.
* - when the strings are identical, they are usually the exact same char* address (from compile-time string constant),
* meaning that strcmp() is completely skipped.
* (quote: "if (e->use == use || (use && e->use && !strcmp(e->use, use)))")
* - if we specified compile-time string constant use as requirement, we wouldn't need strcmp() at all, but this
* minuscule overhead has the benefit of complete correctness for any kinds of use token strings.
*
* Example:
*
* struct foo {
* struct osmo_use_count use_count;
* };
*
* // Convenience macros for struct foo instances. These are strict about use count errors.
* #define foo_get(FOO, USE) OSMO_ASSERT( osmo_use_count_get_put(&(FOO)->use_count, USE, 1) == 0 );
* #define foo_put(FOO, USE) OSMO_ASSERT( osmo_use_count_get_put(&(FOO)->use_count, USE, -1) == 0 );
*
* int foo_use_cb(struct osmo_use_count_entry *use_count_entry, int32_t old_use_count, const char *file, int line)
* {
* struct foo *foo = use_count_entry->use_count->talloc_object;
* if (osmo_use_count_total(&use_count_entry->use_count) == 0)
* talloc_free(foo);
* }
*
* // The function name is a convenient use token:
* void rx_stop_baz_request(struct foo *foo)
* {
* foo_get(foo, __func__);
*
* foo_put(foo, "baz");
* printf("Stopped Bazing (%p)\n", foo);
*
* foo_put(foo, __func__);
* }
*
* void use_count_example()
* {
* struct foo *foo = talloc_zero(ctx, struct foo);
* *foo = (struct foo){
* .use_count = {
* .talloc_object = foo,
* .use_cb = foo_use_cb,
* },
* };
*
* foo_get(foo, "bar"); // one osmo_use_count_entry was allocated
* foo_get(foo, "baz"); // a second osmo_use_count_entry was allocated
* foo_get(foo, "baz"); // still two entries
*
* printf("use: %s\n", osmo_use_count_name_buf(namebuf, sizeof(namebuf), &foo->use_count));
* // "use: 3 (bar,2*baz)"
*
* foo_put(foo, "bar"); // still two entries, one entry is idle ("bar"=0)
* foo_put(foo, "baz");
* rx_stop_baz_request(foo);
* // Final "baz" was put(), foo_use_cb() deallocated object foo, as well as all use count entries.
* };
*/
struct osmo_use_count {
/*! Context to talloc-allocate use count entries from (if at all necessary); back-pointer to the owning object
* for osmo_use_count_cb_t implementations. */
void *talloc_object;
/*! If not NULL, this is invoked for each use count change. */
osmo_use_count_cb_t use_cb;
/*! List of use tokens. No need to touch this, the llist is initialized implicitly. */
struct llist_head use_counts;
};
/*! One named counter in the list managed by osmo_use_count.
* Gets created as necessary by osmo_use_count_get_put(). The total current use count of an object is the sum of all
* individual osmo_use_count_entry->count.
*
* object <--backpointer-+
* t| .osmo_use_count |
* a| .talloc_object ------------+
* l| .use_counts llist: use count
* l|-> - osmo_use_count_entry: "foo" 1
* o|-> - osmo_use_count_entry: "bar" 3
* c|-> - osmo_use_count_entry: "baz" 0 (currently unused entry)
*/
struct osmo_use_count_entry {
/*! Entry in osmo_use_count->use_counts. */
struct llist_head entry;
/*! Parent use count and backpointer to the talloc_object. */
struct osmo_use_count *use_count;
/*! Use token string that was passed to osmo_use_count_get_put(). */
const char *use;
/*! Current use count amount for only this use token string.
* If zero, this entry is currently unused and kept around to avoid frequent de-/allocation. */
int32_t count;
};
/*! Change the use count for a given use token.
* \param USE_LIST A struct osmo_use_count*, e.g. &my_obj->use_count.
* \param USE A use token: arbitrary string (const char*). This must remain valid memory, e.g. string constants.
* \param CHANGE Signed integer value to add to the use count: positive means get(), negative means put().
* \return Negative on range violations or USE_LIST == NULL, the use_cb()'s return value, or 0 on success.
*/
#define osmo_use_count_get_put(USE_LIST, USE, CHANGE) \
_osmo_use_count_get_put(USE_LIST, USE, CHANGE, __FILE__, __LINE__)
int _osmo_use_count_get_put(struct osmo_use_count *uc, const char *use, int32_t change,
const char *file, int line);
const char *osmo_use_count_name_buf(char *buf, size_t buf_len, const struct osmo_use_count *uc);
int32_t osmo_use_count_total(const struct osmo_use_count *uc);
int32_t osmo_use_count_by(const struct osmo_use_count *uc, const char *use);
struct osmo_use_count_entry *osmo_use_count_find(const struct osmo_use_count *uc, const char *use);
void osmo_use_count_free(struct osmo_use_count_entry *use_count_entry);
void osmo_use_count_make_static_entries(struct osmo_use_count *uc, struct osmo_use_count_entry *buf,
size_t buf_n_entries);
/*! @} */

1
src/Makefile.am
View File

@ -26,6 +26,7 @@ libosmocore_la_SOURCES = timer.c timer_gettimeofday.c timer_clockgettime.c \
isdnhdlc.c \
tdef.c \
sockaddr_str.c \
use_count.c \
$(NULL)
if HAVE_SSSE3

279
src/use_count.c Normal file
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@ -0,0 +1,279 @@
/*! \file use_count.c
* Generic object usage counter Implementation (get, put and deallocate on zero count).
*/
/*
* (C) 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
*
* All Rights Reserved
*
* Author: Neels Hofmeyr <neels@hofmeyr.de>
*
* SPDX-License-Identifier: GPL-2.0+
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <errno.h>
#include <inttypes.h>
#include <string.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/use_count.h>
/*! \addtogroup use_count
*
* Generic object usage counter (get, put and deallocate on zero count).
*
* For an example and a detailed description, see struct osmo_use_count.
*
* @{
* \file use_count.c
*/
/*! Add two int32_t but make sure to min- and max-clamp at INT32_MIN and INT32_MAX, respectively. */
static inline bool count_safe(int32_t *val_p, int32_t add)
{
int32_t val = *val_p;
/* A simpler implementation would just let the integer overflow and compare with previous value afterwards, but
* that causes runtime errors in the address sanitizer. So let's just do this without tricks. */
if (add < 0 && val < 0 && val - INT32_MIN < -add) {
*val_p = INT32_MIN;
return false;
}
if (add > 0 && val > 0 && INT32_MAX - val < add) {
*val_p = INT32_MAX;
return false;
}
*val_p = val + add;
return true;
}
/*! Return the sum of all use counts, min- and max-clamped at INT32_MIN and INT32_MAX.
* \param[in] uc Use counts to sum up.
* \return Accumulated counts, or 0 if uc is NULL.
*/
int32_t osmo_use_count_total(const struct osmo_use_count *uc)
{
struct osmo_use_count_entry *e;
int32_t total = 0;
if (!uc || !uc->use_counts.next)
return 0;
llist_for_each_entry(e, &uc->use_counts, entry) {
count_safe(&total, e->count);
}
return total;
}
/*! Return use count by a single use token.
* \param[in] uc Use counts to look up in.
* \param[in] use Use token.
* \return Use count, or 0 if uc is NULL or use token is not present.
*/
int32_t osmo_use_count_by(const struct osmo_use_count *uc, const char *use)
{
const struct osmo_use_count_entry *e;
if (!uc)
return 0;
e = osmo_use_count_find(uc, use);
if (!e)
return 0;
return e->count;
}
/*! Write a comprehensive listing of use counts to a string buffer.
* Reads like "12 (3*barring,fighting,8*kungfoo)".
* \param[inout] buf Destination buffer.
* \param[in] buf_len sizeof(buf).
* \param[in] uc Use counts to print.
* \return buf, always nul-terminated (except when buf_len < 1).
*/
const char *osmo_use_count_name_buf(char *buf, size_t buf_len, const struct osmo_use_count *uc)
{
int32_t count = osmo_use_count_total(uc);
struct osmo_strbuf sb = { .buf = buf, .len = buf_len };
struct osmo_use_count_entry *e;
bool first;
OSMO_STRBUF_PRINTF(sb, "%" PRId32 " (", count);
first = true;
llist_for_each_entry(e, &uc->use_counts, entry) {
if (!e->count)
continue;
if (!first)
OSMO_STRBUF_PRINTF(sb, ",");
first = false;
if (e->count != 1)
OSMO_STRBUF_PRINTF(sb, "%" PRId32 "*", e->count);
OSMO_STRBUF_PRINTF(sb, "%s", e->use ? : "NULL");
}
if (first)
OSMO_STRBUF_PRINTF(sb, "-");
OSMO_STRBUF_PRINTF(sb, ")");
return buf;
}
/* Return a use token's use count entry -- probably you want osmo_use_count_by() instead.
* \param[in] uc Use counts to look up in.
* \param[in] use Use token.
* \return matching entry, or NULL if not present.
*/
struct osmo_use_count_entry *osmo_use_count_find(const struct osmo_use_count *uc, const char *use)
{
struct osmo_use_count_entry *e;
if (!uc->use_counts.next)
return NULL;
llist_for_each_entry(e, &uc->use_counts, entry) {
if (e->use == use || (use && e->use && !strcmp(e->use, use)))
return e;
}
return NULL;
}
/*! Find a use count entry that currently has zero count, and re-use that for this new use token. */
static struct osmo_use_count_entry *osmo_use_count_repurpose_zero_entry(struct osmo_use_count *uc, const char *use)
{
struct osmo_use_count_entry *e;
if (!uc->use_counts.next)
return NULL;
llist_for_each_entry(e, &uc->use_counts, entry) {
if (!e->count) {
e->use = use;
return e;
}
}
return NULL;
}
/*! Allocate a new use count entry, happens implicitly in osmo_use_count_get_put(). */
static struct osmo_use_count_entry *osmo_use_count_create(struct osmo_use_count *uc, const char *use)
{
struct osmo_use_count_entry *e = talloc_zero(uc->talloc_object, struct osmo_use_count_entry);
if (!e)
return NULL;
*e = (struct osmo_use_count_entry){
.use_count = uc,
.use = use,
};
if (!uc->use_counts.next)
INIT_LLIST_HEAD(&uc->use_counts);
llist_add_tail(&e->entry, &uc->use_counts);
return e;
}
/*! Deallocate a use count entry.
* Normally, this is not necessary -- it is ok and even desirable to leave use count entries around even when they reach
* a count of zero, until the use_count->talloc_object deallocates and removes all of them in one flush. This avoids
* repeated allocation and deallocation for use tokens, because use count entries that have reached zero count are
* repurposed for any other use tokens. A cleanup makes sense only if a very large number of differing use tokens surged
* at the same time, and the owning object will not be deallocated soon; if so, this should be done by the
* osmo_use_count_cb_t implementation.
*
* osmo_use_count_free() must *not* be called on use count entries that were added by
* osmo_use_count_make_static_entries(). This is the responsibility of the osmo_use_count_cb_t() implementation.
*
* \param[in] use_count_entry Use count entry to unlist and free.
*/
void osmo_use_count_free(struct osmo_use_count_entry *use_count_entry)
{
if (!use_count_entry)
return;
llist_del(&use_count_entry->entry);
talloc_free(use_count_entry);
}
/*! Implementation for osmo_use_count_get_put(), which can also be directly invoked to pass source file information. For
* arguments besides file and line, see osmo_use_count_get_put().
* \param[in] file Source file path, as in __FILE__.
* \param[in] line Source file line, as in __LINE__.
*/
int _osmo_use_count_get_put(struct osmo_use_count *uc, const char *use, int32_t change,
const char *file, int line)
{
struct osmo_use_count_entry *e;
int32_t old_use_count;
if (!change)
return 0;
e = osmo_use_count_find(uc, use);
if (!e)
e = osmo_use_count_repurpose_zero_entry(uc, use);
if (!e)
e = osmo_use_count_create(uc, use);
if (!e)
return -ENOMEM;
if (!e->count) {
/* move to end */
llist_del(&e->entry);
llist_add_tail(&e->entry, &uc->use_counts);
}
old_use_count = e->count;
if (!count_safe(&e->count, change)) {
e->count = old_use_count;
return -ERANGE;
}
if (uc->use_cb)
return uc->use_cb(e, old_use_count, file, line);
return 0;
}
/*! Add N static use token entries to avoid dynamic allocation of use count tokens.
* When not using this function, use count entries are talloc allocated from uc->talloc_object as talloc context. This
* means that there are small dynamic allocations for each use count token. osmo_use_count_get_put() normally leaves
* zero-count entries around and re-purposes them later, so the number of small allocations is at most the number of
* concurrent differently-named uses of the same object. If that is not enough, this function allows completely avoiding
* dynamic use count allocations, by adding N static entries with a zero count and a NULL use token. They will be used
* by osmo_use_count_get_put(), and, if the caller avoids using osmo_use_count_free(), the osmo_use_count implementation
* never deallocates them. The idea is that the entries are members of the uc->talloc_object, or that they will by other
* means be implicitly deallocated by the talloc_object. It is fine to call
* osmo_use_count_make_static_entries(buf_n_entries=N) and later have more than N concurrent uses, i.e. it is no problem
* to mix static and dynamic entries. To completely avoid dynamic use count entries, N has to >= the maximum number of
* concurrent differently-named uses that will occur in the lifetime of the talloc_object.
*
* struct my_object {
* struct osmo_use_count use_count;
* struct osmo_use_count_entry use_count_buf[3]; // planning for 3 concurrent users
* };
*
* void example() {
* struct my_object *o = talloc_zero(ctx, struct my_object);
* osmo_use_count_make_static_entries(&o->use_count, o->use_count_buf, ARRAY_SIZE(o->use_count_buf));
* }
*/
void osmo_use_count_make_static_entries(struct osmo_use_count *uc, struct osmo_use_count_entry *buf,
size_t buf_n_entries)
{
size_t idx;
if (!uc->use_counts.next)
INIT_LLIST_HEAD(&uc->use_counts);
for (idx = 0; idx < buf_n_entries; idx++) {
struct osmo_use_count_entry *e = &buf[idx];
*e = (struct osmo_use_count_entry){
.use_count = uc,
};
llist_add_tail(&e->entry, &uc->use_counts);
}
}
/*! @} */

5
tests/Makefile.am
View File

@ -31,6 +31,7 @@ check_PROGRAMS = timer/timer_test sms/sms_test ussd/ussd_test \
tdef/tdef_vty_test_config_subnode \
tdef/tdef_vty_test_dynamic \
sockaddr_str/sockaddr_str_test \
use_count/use_count_test \
$(NULL)
if ENABLE_MSGFILE
@ -240,6 +241,9 @@ tdef_tdef_vty_test_dynamic_LDADD = $(LDADD) $(top_builddir)/src/vty/libosmovty.l
sockaddr_str_sockaddr_str_test_SOURCES = sockaddr_str/sockaddr_str_test.c
sockaddr_str_sockaddr_str_test_LDADD = $(LDADD)
use_count_use_count_test_SOURCES = use_count/use_count_test.c
use_count_use_count_test_LDADD = $(LDADD)
# The `:;' works around a Bash 3.2 bug when the output is not writeable.
$(srcdir)/package.m4: $(top_srcdir)/configure.ac
:;{ \
@ -309,6 +313,7 @@ EXTRA_DIST = testsuite.at $(srcdir)/package.m4 $(TESTSUITE) \
tdef/tdef_vty_test_config_subnode.vty \
tdef/tdef_vty_test_dynamic.vty \
sockaddr_str/sockaddr_str_test.ok \
use_count/use_count_test.ok use_count/use_count_test.err \
$(NULL)
DISTCLEANFILES = atconfig atlocal conv/gsm0503_test_vectors.c

7
tests/testsuite.at
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@ -337,3 +337,10 @@ AT_KEYWORDS([sockaddr_str])
cat $abs_srcdir/sockaddr_str/sockaddr_str_test.ok > expout
AT_CHECK([$abs_top_builddir/tests/sockaddr_str/sockaddr_str_test], [0], [expout], [ignore])
AT_CLEANUP
AT_SETUP([use_count])
AT_KEYWORDS([use_count])
cat $abs_srcdir/use_count/use_count_test.ok > expout
cat $abs_srcdir/use_count/use_count_test.err > experr
AT_CHECK([$abs_top_builddir/tests/use_count/use_count_test], [0], [expout], [experr])
AT_CLEANUP

339
tests/use_count/use_count_test.c Normal file
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@ -0,0 +1,339 @@
/* Test implementation for osmo_use_count API. */
/*
* (C) 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
*
* All Rights Reserved
*
* Author: Neels Hofmeyr <neels@hofmeyr.de>
*
* SPDX-License-Identifier: GPL-2.0+
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/application.h>
#include <osmocom/core/fsm.h>
#include <osmocom/core/use_count.h>
static void *ctx = NULL;
#define log(fmt, args...) fprintf(stderr, fmt, ##args)
enum {
DFOO,
};
#define FOO_USE_BARRING "barring"
#define FOO_USE_FIGHTING "fighting"
#define FOO_USE_KUNG "kungfoo"
#define FOO_USE_RELEASING "releasing"
LLIST_HEAD(all_foo);
struct foo {
struct llist_head entry;
struct osmo_fsm_inst *fi;
struct osmo_use_count use_count;
struct osmo_use_count_entry use_count_buf[10];
};
enum foo_fsm_events {
FOO_EV_UNUSED,
};
static char name_buf[1024];
#define use_count_name(UL) osmo_use_count_name_buf(name_buf, sizeof(name_buf), UL)
int foo_use_cb(struct osmo_use_count_entry *use_count_entry, int32_t old_use_count,
const char *file, int line)
{
struct osmo_use_count *use_count = use_count_entry->use_count;
struct foo *foo = use_count->talloc_object;
const char *use = use_count_entry->use;
int32_t new_use_count = use_count_entry->count;
if (use && (!strcmp(use, FOO_USE_BARRING) || !strcmp(use, FOO_USE_RELEASING))
&& new_use_count > 1) {
LOGPFSMLSRC(foo->fi, LOGL_ERROR, file, line,
"Attempt to get more than one %s\n", use);
/* Fix the use count */
use_count_entry->count = 1;
return -ERANGE;
}
LOGPFSMLSRC(foo->fi, LOGL_NOTICE, file, line, "%s %+d %s: now used by %s\n",
foo->fi->id, new_use_count - old_use_count, use ? : "NULL", use_count_name(use_count));
if (new_use_count < 0) {
LOGPFSMLSRC(foo->fi, LOGL_ERROR, file, line, "Negative use count on %s: %s\n",
use ? : "NULL", use_count_name(use_count));
/* Let it pass for the sake of this test */
}
if (osmo_use_count_total(use_count) == 0)
osmo_fsm_inst_dispatch(foo->fi, FOO_EV_UNUSED, NULL);
return 0;
}
#define foo_get_put(FOO, USE, CHANGE) do { \
int rc = osmo_use_count_get_put(&(FOO)->use_count, USE, CHANGE); \
if (rc) \
log("osmo_use_count_get_put(%s, %s, %d) returned error: %d %s\n", \
(FOO)->fi->id, USE ? : "NULL", CHANGE, rc, strerror(-rc)); \
} while(0)
#define foo_get(FOO, USE) foo_get_put(FOO, USE, 1)
#define foo_put(FOO, USE) foo_get_put(FOO, USE, -1)
enum foo_fsm_states {
FOO_ST_IN_USE,
FOO_ST_IN_RELEASE,
};
void foo_fsm_in_use(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
OSMO_ASSERT(event == FOO_EV_UNUSED);
osmo_fsm_inst_state_chg(fi, FOO_ST_IN_RELEASE, 0, 0);
}
void foo_fsm_in_release_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct foo *foo = fi->priv;
foo_get(foo, FOO_USE_RELEASING);
}
void foo_fsm_in_release(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
OSMO_ASSERT(event == FOO_EV_UNUSED);
osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REGULAR, NULL);
}
#define S(x) (1 << (x))
static const struct osmo_fsm_state foo_fsm_states[] = {
[FOO_ST_IN_USE] = {
.name = "IN_USE",
.in_event_mask = 0
| S(FOO_EV_UNUSED)
,
.out_state_mask = 0
| S(FOO_ST_IN_RELEASE)
,
.action = foo_fsm_in_use,
},
[FOO_ST_IN_RELEASE] = {
.name = "IN_RELEASE",
.in_event_mask = 0
| S(FOO_EV_UNUSED)
,
.out_state_mask = 0
,
.onenter = foo_fsm_in_release_onenter,
.action = foo_fsm_in_release,
},
};
static const struct value_string foo_fsm_event_names[] = {
OSMO_VALUE_STRING(FOO_EV_UNUSED),
{}
};
void foo_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
{
struct foo *foo = fi->priv;
llist_del(&foo->entry);
}
static struct osmo_fsm foo_fsm = {
.name = "foo",
.states = foo_fsm_states,
.event_names = foo_fsm_event_names,
.num_states = ARRAY_SIZE(foo_fsm_states),
.log_subsys = DFOO,
.cleanup = foo_cleanup,
};
static struct foo *foo_alloc(const char *name, size_t static_entries)
{
struct foo *foo;
struct osmo_fsm_inst *fi = osmo_fsm_inst_alloc(&foo_fsm, ctx, NULL, LOGL_DEBUG, name);
OSMO_ASSERT(fi);
OSMO_ASSERT(static_entries <= ARRAY_SIZE(foo->use_count_buf));
foo = talloc_zero(fi, struct foo);
*foo = (struct foo){
.fi = fi,
.use_count = {
.talloc_object = foo,
.use_cb = foo_use_cb,
},
};
fi->priv = foo;
osmo_use_count_make_static_entries(&foo->use_count, foo->use_count_buf, static_entries);
llist_add_tail(&foo->entry, &all_foo);
return foo;
}
void print_foos()
{
int count = 0;
struct foo *foo;
fprintf(stderr, "\nall use counts:\n");
llist_for_each_entry(foo, &all_foo, entry) {
fprintf(stderr, "%s: %s\n", foo->fi->id, use_count_name(&foo->use_count));
count++;
}
fprintf(stderr, "%d foos\n\n", count);
}
static void test_use_count_fsm()
{
struct foo *a, *b, *c;
log("\n%s()\n", __func__);
a = foo_alloc("a", 0);
b = foo_alloc("b", 2);
c = foo_alloc("c", 10);
print_foos();
log("A few gets and puts, logging source file information\n");
log_set_print_filename2(osmo_stderr_target, LOG_FILENAME_BASENAME);
foo_get(a, FOO_USE_BARRING);
foo_get(b, FOO_USE_BARRING);
foo_get(b, FOO_USE_FIGHTING);
print_foos();
log("Attempt to get more than one on limited 'barring' user:\n");
foo_get(b, FOO_USE_BARRING);
print_foos();
log("Put away one user of b\n");
foo_put(b, FOO_USE_BARRING);
print_foos();
log("(no longer log source file information)\n");
log_set_print_filename2(osmo_stderr_target, LOG_FILENAME_NONE);
log("Test null use token\n");
foo_get(a, NULL);
print_foos();
foo_put(a, NULL);
print_foos();
log("Put away last user of a, goes to RELEASING state and waits for a hypothetic async release process\n");
foo_put(a, FOO_USE_BARRING);
print_foos();
log("Async releasing of a is done, will dealloc\n");
foo_put(a, FOO_USE_RELEASING);
print_foos();
log("Use b multiple times\n");
foo_get(b, FOO_USE_KUNG);
foo_get(b, FOO_USE_KUNG);
foo_put(b, FOO_USE_KUNG);
foo_get(b, FOO_USE_KUNG);
foo_get(b, FOO_USE_KUNG);
print_foos();
log("Test range: set kung-fu to INT32_MAX-1, then get three more; total count gets max-clamped to INT32_MAX\n");
foo_get_put(b, FOO_USE_KUNG, INT32_MAX-1 - osmo_use_count_by(&b->use_count, FOO_USE_KUNG));
print_foos();
foo_get(b, FOO_USE_KUNG);
foo_get(b, FOO_USE_KUNG);
foo_get(b, FOO_USE_KUNG);
foo_get_put(b, FOO_USE_FIGHTING, 2);
foo_get_put(b, FOO_USE_KUNG, -3);
foo_put(b, FOO_USE_KUNG);
foo_put(b, FOO_USE_KUNG);
foo_get(b, FOO_USE_FIGHTING);
foo_get(b, FOO_USE_FIGHTING);
foo_get(b, FOO_USE_FIGHTING);
print_foos();
log("Release all uses of b\n");
foo_get_put(b, FOO_USE_KUNG, - osmo_use_count_by(&b->use_count, FOO_USE_KUNG));
foo_get_put(b, FOO_USE_FIGHTING, - osmo_use_count_by(&b->use_count, FOO_USE_FIGHTING));
log("Signal async release as done\n");
foo_put(b, FOO_USE_RELEASING);
print_foos();
log("Release something not gotten before: a get/put bug goes into negative count\n");
foo_put(c, FOO_USE_KUNG);
print_foos();
log("More negative\n");
foo_put(c, FOO_USE_KUNG);
foo_put(c, FOO_USE_KUNG);
print_foos();
log("Also release c\n");
foo_get_put(c, FOO_USE_KUNG, 4);
foo_put(c, FOO_USE_KUNG);
log("Signal async release as done\n");
foo_put(c, FOO_USE_RELEASING);
print_foos();
}
static const struct log_info_cat default_categories[] = {
[DFOO] = {
.name = "DFOO",
.description = "FOO",
.enabled = 1, .loglevel = LOGL_DEBUG,
},
};
static const struct log_info log_info = {
.cat = default_categories,
.num_cat = ARRAY_SIZE(default_categories),
};
int main(int argc, char **argv)
{
ctx = talloc_named_const(NULL, 0, "use_count_test.c");
osmo_fsm_log_addr(false);
osmo_init_logging2(ctx, &log_info);
log_set_print_filename2(osmo_stderr_target, LOG_FILENAME_BASENAME);
log_set_print_filename2(osmo_stderr_target, LOG_FILENAME_NONE);
log_set_print_filename_pos(osmo_stderr_target, LOG_FILENAME_POS_LINE_END);
log_set_print_category(osmo_stderr_target, 1);
log_set_print_category_hex(osmo_stderr_target, 0);
log_set_print_level(osmo_stderr_target, 1);
log_set_use_color(osmo_stderr_target, 0);
osmo_fsm_register(&foo_fsm);
test_use_count_fsm();
return EXIT_SUCCESS;
}

171
tests/use_count/use_count_test.err Normal file
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@ -0,0 +1,171 @@
test_use_count_fsm()
DFOO DEBUG foo(a){IN_USE}: Allocated
DFOO DEBUG foo(b){IN_USE}: Allocated
DFOO DEBUG foo(c){IN_USE}: Allocated
all use counts:
a: 0 (-)
b: 0 (-)
c: 0 (-)
3 foos
A few gets and puts, logging source file information
DFOO NOTICE foo(a){IN_USE}: a +1 barring: now used by 1 (barring) (use_count_test.c:223)
DFOO NOTICE foo(b){IN_USE}: b +1 barring: now used by 1 (barring) (use_count_test.c:225)
DFOO NOTICE foo(b){IN_USE}: b +1 fighting: now used by 2 (barring,fighting) (use_count_test.c:226)
all use counts:
a: 1 (barring)
b: 2 (barring,fighting)
c: 0 (-)
3 foos
Attempt to get more than one on limited 'barring' user:
DFOO ERROR foo(b){IN_USE}: Attempt to get more than one barring (use_count_test.c:231)
osmo_use_count_get_put(b, barring, 1) returned error: -34 Numerical result out of range
all use counts:
a: 1 (barring)
b: 2 (barring,fighting)
c: 0 (-)
3 foos
Put away one user of b
DFOO NOTICE foo(b){IN_USE}: b -1 barring: now used by 1 (fighting) (use_count_test.c:235)
all use counts:
a: 1 (barring)
b: 1 (fighting)
c: 0 (-)
3 foos
(no longer log source file information)
Test null use token
DFOO NOTICE foo(a){IN_USE}: a +1 NULL: now used by 2 (barring,NULL)
all use counts:
a: 2 (barring,NULL)
b: 1 (fighting)
c: 0 (-)
3 foos
DFOO NOTICE foo(a){IN_USE}: a -1 NULL: now used by 1 (barring)
all use counts:
a: 1 (barring)
b: 1 (fighting)
c: 0 (-)
3 foos
Put away last user of a, goes to RELEASING state and waits for a hypothetic async release process
DFOO NOTICE foo(a){IN_USE}: a -1 barring: now used by 0 (-)
DFOO DEBUG foo(a){IN_USE}: Received Event FOO_EV_UNUSED
DFOO DEBUG foo(a){IN_USE}: state_chg to IN_RELEASE
DFOO NOTICE foo(a){IN_RELEASE}: a +1 releasing: now used by 1 (releasing)
all use counts:
a: 1 (releasing)
b: 1 (fighting)
c: 0 (-)
3 foos
Async releasing of a is done, will dealloc
DFOO NOTICE foo(a){IN_RELEASE}: a -1 releasing: now used by 0 (-)
DFOO DEBUG foo(a){IN_RELEASE}: Received Event FOO_EV_UNUSED
DFOO DEBUG foo(a){IN_RELEASE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DFOO DEBUG foo(a){IN_RELEASE}: Freeing instance
DFOO DEBUG foo(a){IN_RELEASE}: Deallocated
all use counts:
b: 1 (fighting)
c: 0 (-)
2 foos
Use b multiple times
DFOO NOTICE foo(b){IN_USE}: b +1 kungfoo: now used by 2 (fighting,kungfoo)
DFOO NOTICE foo(b){IN_USE}: b +1 kungfoo: now used by 3 (fighting,2*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b -1 kungfoo: now used by 2 (fighting,kungfoo)
DFOO NOTICE foo(b){IN_USE}: b +1 kungfoo: now used by 3 (fighting,2*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b +1 kungfoo: now used by 4 (fighting,3*kungfoo)
all use counts:
b: 4 (fighting,3*kungfoo)
c: 0 (-)
2 foos
Test range: set kung-fu to INT32_MAX-1, then get three more; total count gets max-clamped to INT32_MAX
DFOO NOTICE foo(b){IN_USE}: b +2147483643 kungfoo: now used by 2147483647 (fighting,2147483646*kungfoo)
all use counts:
b: 2147483647 (fighting,2147483646*kungfoo)
c: 0 (-)
2 foos
DFOO NOTICE foo(b){IN_USE}: b +1 kungfoo: now used by 2147483647 (fighting,2147483647*kungfoo)
osmo_use_count_get_put(b, kungfoo, 1) returned error: -34 Numerical result out of range
osmo_use_count_get_put(b, kungfoo, 1) returned error: -34 Numerical result out of range
DFOO NOTICE foo(b){IN_USE}: b +2 fighting: now used by 2147483647 (3*fighting,2147483647*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b -3 kungfoo: now used by 2147483647 (3*fighting,2147483644*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b -1 kungfoo: now used by 2147483646 (3*fighting,2147483643*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b -1 kungfoo: now used by 2147483645 (3*fighting,2147483642*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b +1 fighting: now used by 2147483646 (4*fighting,2147483642*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b +1 fighting: now used by 2147483647 (5*fighting,2147483642*kungfoo)
DFOO NOTICE foo(b){IN_USE}: b +1 fighting: now used by 2147483647 (6*fighting,2147483642*kungfoo)
all use counts:
b: 2147483647 (6*fighting,2147483642*kungfoo)
c: 0 (-)
2 foos
Release all uses of b
DFOO NOTICE foo(b){IN_USE}: b -2147483642 kungfoo: now used by 6 (6*fighting)
DFOO NOTICE foo(b){IN_USE}: b -6 fighting: now used by 0 (-)
DFOO DEBUG foo(b){IN_USE}: Received Event FOO_EV_UNUSED
DFOO DEBUG foo(b){IN_USE}: state_chg to IN_RELEASE
DFOO NOTICE foo(b){IN_RELEASE}: b +1 releasing: now used by 1 (releasing)
Signal async release as done
DFOO NOTICE foo(b){IN_RELEASE}: b -1 releasing: now used by 0 (-)
DFOO DEBUG foo(b){IN_RELEASE}: Received Event FOO_EV_UNUSED
DFOO DEBUG foo(b){IN_RELEASE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DFOO DEBUG foo(b){IN_RELEASE}: Freeing instance
DFOO DEBUG foo(b){IN_RELEASE}: Deallocated
all use counts:
c: 0 (-)
1 foos
Release something not gotten before: a get/put bug goes into negative count
DFOO NOTICE foo(c){IN_USE}: c -1 kungfoo: now used by -1 (-1*kungfoo)
DFOO ERROR foo(c){IN_USE}: Negative use count on kungfoo: -1 (-1*kungfoo)
all use counts:
c: -1 (-1*kungfoo)
1 foos
More negative
DFOO NOTICE foo(c){IN_USE}: c -1 kungfoo: now used by -2 (-2*kungfoo)
DFOO ERROR foo(c){IN_USE}: Negative use count on kungfoo: -2 (-2*kungfoo)
DFOO NOTICE foo(c){IN_USE}: c -1 kungfoo: now used by -3 (-3*kungfoo)
DFOO ERROR foo(c){IN_USE}: Negative use count on kungfoo: -3 (-3*kungfoo)
all use counts:
c: -3 (-3*kungfoo)
1 foos
Also release c
DFOO NOTICE foo(c){IN_USE}: c +4 kungfoo: now used by 1 (kungfoo)
DFOO NOTICE foo(c){IN_USE}: c -1 kungfoo: now used by 0 (-)
DFOO DEBUG foo(c){IN_USE}: Received Event FOO_EV_UNUSED
DFOO DEBUG foo(c){IN_USE}: state_chg to IN_RELEASE
DFOO NOTICE foo(c){IN_RELEASE}: c +1 releasing: now used by 1 (releasing)
Signal async release as done
DFOO NOTICE foo(c){IN_RELEASE}: c -1 releasing: now used by 0 (-)
DFOO DEBUG foo(c){IN_RELEASE}: Received Event FOO_EV_UNUSED
DFOO DEBUG foo(c){IN_RELEASE}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
DFOO DEBUG foo(c){IN_RELEASE}: Freeing instance
DFOO DEBUG foo(c){IN_RELEASE}: Deallocated
all use counts:
0 foos

0
tests/use_count/use_count_test.ok Normal file
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