[sr-dev] git:master: core: counters can be used before forking
Andrei Pelinescu-Onciul
andrei at iptel.org
Tue Aug 24 21:29:20 CEST 2010
Module: sip-router
Branch: master
Commit: a5583e0ccff1eda9c38041df9d15a8b21e3ebb0c
URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=a5583e0ccff1eda9c38041df9d15a8b21e3ebb0c
Author: Andrei Pelinescu-Onciul <andrei at iptel.org>
Committer: Andrei Pelinescu-Onciul <andrei at iptel.org>
Date: Tue Aug 24 21:14:50 2010 +0200
core: counters can be used before forking
Counters can now be incremented (not only registered) before
counters_prefork_init(). This enables using them also from
mod_init() or the fixup functions (not recommended but needed for
"indirect" calls).
Fixes crashes when modules call a counter using function from
mod_init() or a fixup.
E.g.: xlog(s) does a dns lookup from mod_init. If the lookup fails
the dns code will try to increment the new dns.failed_dns_request
counter.
Reported-by: Michal Matyska michal.matyska iptel org
---
counters.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++-------
counters.h | 5 +++-
pt.c | 1 +
3 files changed, 65 insertions(+), 10 deletions(-)
diff --git a/counters.c b/counters.c
index dd8ddf7..56bcd2f 100644
--- a/counters.c
+++ b/counters.c
@@ -23,6 +23,7 @@
* History:
* --------
* 2010-08-06 initial version (andrei)
+ * 2010-08-24 counters can be used (inc,add) before prefork_init (andrei)
*/
#include "counters.h"
@@ -47,6 +48,11 @@
/* leave space for one flag */
#define MAX_COUNTER_ID 32767
+/* size (number of entries) of the temporary array used for keeping stats
+ pre-prefork init. Note: if more counters are registered then this size,
+ the array will be dynamically increased (doubled each time). The value
+ here is meant only to optimize startup/memory fragmentation. */
+#define PREINIT_CNTS_VALS_SIZE 128
struct counter_record {
str group;
@@ -85,7 +91,7 @@ static int grp_no; /* number of groups */
counter_array_t* _cnts_vals;
int _cnts_row_len; /* number of elements per row */
static int cnts_no; /* number of registered counters */
-static int cnts_max_rows; /* set to process number */
+static int cnts_max_rows; /* set to 0 if not yet fully init */
@@ -101,6 +107,8 @@ int init_counters()
goto error;
str_hash_init(&grp_hash_table);
cnts_no = 1; /* start at 1 (0 used only for invalid counters) */
+ cnts_max_rows = 0; /* 0 initially, !=0 after full init
+ (counters_prefork_init()) */
grp_no = 0;
cnt_id2record_size = CNT_ID2RECORD_SIZE;
cnt_id2record = pkg_malloc(sizeof(*cnt_id2record) * cnt_id2record_size);
@@ -127,7 +135,12 @@ void destroy_counters()
struct str_hash_entry* e;
struct str_hash_entry* bak;
if (_cnts_vals) {
- shm_free(_cnts_vals);
+ if (cnts_max_rows)
+ /* fully init => it is in shm */
+ shm_free(_cnts_vals);
+ else
+ /* partially init (before prefork) => pkg */
+ pkg_free(_cnts_vals);
_cnts_vals = 0;
}
if (cnts_hash_table.table) {
@@ -160,6 +173,7 @@ void destroy_counters()
grp_sorted_max_size = 0;
cnts_no = 0;
_cnts_row_len = 0;
+ cnts_max_rows = 0;
grp_no = 0;
}
@@ -171,7 +185,9 @@ void destroy_counters()
*/
int counters_prefork_init(int max_process_no)
{
+ counter_array_t* old;
int size, row_size;
+ counter_handle_t h;
/* round cnts_no so that cnts_no * sizeof(counter) it's a CACHELINE_PAD
multiple */
/* round-up row_size to a CACHELINE_PAD multiple if needed */
@@ -183,11 +199,20 @@ int counters_prefork_init(int max_process_no)
/* get updated cnts_no (row length) */
_cnts_row_len = row_size / sizeof(*_cnts_vals);
size = max_process_no * row_size;
+ /* replace the temporary pre-fork pkg array (with only 1 row) with
+ the final shm version (with max_process_no rows) */
+ old = _cnts_vals;
_cnts_vals = shm_malloc(max_process_no * row_size);
if (_cnts_vals == 0)
return -1;
memset(_cnts_vals, 0, max_process_no * row_size);
cnts_max_rows = max_process_no;
+ /* copy prefork values into the newly shm array */
+ if (old) {
+ for (h.id = 0; h.id < cnts_no; h.id++)
+ counter_pprocess_val(process_no, h) = old[h.id].v;
+ pkg_free(old);
+ }
return 0;
}
@@ -286,7 +311,9 @@ static struct counter_record* cnt_hash_add(
struct counter_record* cnt_rec;
struct grp_record* grp_rec;
struct counter_record** p;
+ counter_array_t* v;
int doc_len;
+ int n;
e = 0;
if (cnts_no >= MAX_COUNTER_ID)
@@ -323,7 +350,31 @@ static struct counter_record* cnt_hash_add(
cnt_rec->doc.s[0] = 0;
e->key = cnt_rec->name;
e->flags = 0;
- /* add it a pointer to it in the records array */
+ /* check to see if it fits in the prefork tmp. vals array.
+ This array contains only one "row", is allocated in pkg and
+ is used only until counters_prefork_init() (after that the
+ array is replaced with a shm version with all the needed rows).
+ */
+ if (cnt_rec->h.id >= _cnts_row_len || _cnts_vals == 0) {
+ /* array to small or not yet allocated => reallocate/allocate it
+ (min size PREINIT_CNTS_VALS_SIZE, max MAX_COUNTER_ID)
+ */
+ n = (cnt_rec->h.id < PREINIT_CNTS_VALS_SIZE) ?
+ PREINIT_CNTS_VALS_SIZE :
+ ((2 * (cnt_rec->h.id + (cnt_rec->h.id == 0)) < MAX_COUNTER_ID)?
+ (2 * (cnt_rec->h.id + (cnt_rec->h.id == 0))) :
+ MAX_COUNTER_ID + 1);
+ v = pkg_realloc(_cnts_vals, n * sizeof(*_cnts_vals));
+ if (v == 0)
+ /* realloc/malloc error */
+ goto error;
+ _cnts_vals = v;
+ /* zero newly allocated memory */
+ memset(&_cnts_vals[_cnts_row_len], 0,
+ (n - _cnts_row_len) * sizeof(*_cnts_vals));
+ _cnts_row_len = n; /* record new length */
+ }
+ /* add a pointer to it in the records array */
if (cnt_id2record_size <= cnt_rec->h.id) {
/* must increase the array */
p = pkg_realloc(cnt_id2record,
@@ -438,7 +489,7 @@ int counter_register( counter_handle_t* handle, const char* group,
str n;
struct counter_record* cnt_rec;
- if (unlikely(_cnts_vals)) {
+ if (unlikely(cnts_max_rows)) {
/* too late */
BUG("late attempt to register counter: %s.%s\n", group, name);
goto error;
@@ -554,7 +605,7 @@ counter_val_t counter_get_raw_val(counter_handle_t handle)
BUG("counters not fully initialized yet\n");
return 0;
}
- if (unlikely(handle.id >= cnts_no || handle.id < 0)) {
+ if (unlikely(handle.id >= cnts_no || (short)handle.id < 0)) {
BUG("invalid counter id %d (max %d)\n", handle.id, cnts_no - 1);
return 0;
}
@@ -597,7 +648,7 @@ void counter_reset(counter_handle_t handle)
{
int r;
- if (unlikely(_cnts_vals == 0)) {
+ if (unlikely(_cnts_vals == 0 || cnt_id2record == 0)) {
/* not init yet */
BUG("counters not fully initialized yet\n");
return;
@@ -622,7 +673,7 @@ void counter_reset(counter_handle_t handle)
*/
char* counter_get_name(counter_handle_t handle)
{
- if (unlikely(_cnts_vals == 0)) {
+ if (unlikely(_cnts_vals == 0 || cnt_id2record == 0)) {
/* not init yet */
BUG("counters not fully initialized yet\n");
goto error;
@@ -645,7 +696,7 @@ error:
*/
char* counter_get_group(counter_handle_t handle)
{
- if (unlikely(_cnts_vals == 0)) {
+ if (unlikely(_cnts_vals == 0 || cnt_id2record == 0)) {
/* not init yet */
BUG("counters not fully initialized yet\n");
goto error;
@@ -668,7 +719,7 @@ error:
*/
char* counter_get_doc(counter_handle_t handle)
{
- if (unlikely(_cnts_vals == 0)) {
+ if (unlikely(_cnts_vals == 0 || cnt_id2record == 0)) {
/* not init yet */
BUG("counters not fully initialized yet\n");
goto error;
diff --git a/counters.h b/counters.h
index ca09ab4..6081ae0 100644
--- a/counters.h
+++ b/counters.h
@@ -109,7 +109,10 @@ char* counter_get_name(counter_handle_t handle);
char* counter_get_group(counter_handle_t handle);
char* counter_get_doc(counter_handle_t handle);
-/** gets the per process value of counter h for process p_no. */
+/** gets the per process value of counter h for process p_no.
+ * Note that if used before counter_prefork_init() process_no is 0
+ * and _cnts_vals will point into a temporary one "row" array.
+ */
#define counter_pprocess_val(p_no, h) \
_cnts_vals[(p_no) * _cnts_row_len + (h).id].v
diff --git a/pt.c b/pt.c
index 994f998..68842e6 100644
--- a/pt.c
+++ b/pt.c
@@ -47,6 +47,7 @@
#if defined PKG_MALLOC || defined SHM_MEM
#include "cfg_core.h"
#endif
+#include "daemonize.h"
#include <stdio.h>
#include <time.h> /* time(), used to initialize random numbers */
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