summaryrefslogtreecommitdiffstats
path: root/runtime/statsobj.h
blob: 14b33215f1277f73431986856dd136d34cdde43c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/* The statsobj object.
 *
 * Copyright 2010-2012 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of the rsyslog runtime library.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *       http://www.apache.org/licenses/LICENSE-2.0
 *       -or-
 *       see COPYING.ASL20 in the source distribution
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef INCLUDED_STATSOBJ_H
#define INCLUDED_STATSOBJ_H

#include "atomic.h"

/* The following data item is somewhat dirty, in that it does not follow
 * our usual object calling conventions. However, much like with "Debug", we
 * do this to gain speed. If we finally come to a platform that does not
 * provide resolution of names for dynamically loaded modules, we need to find
 * a work-around, but until then, we use the direct access.
 * If set to 0, statistics are not gathered, otherwise they are.
 */
extern int GatherStats;

/* our basic counter type -- need 32 bit on 32 bit platform. 
 * IMPORTANT: this type *MUST* be supported by atomic instructions!
 */
typedef uint64 intctr_t;

/* counter types */
typedef enum statsCtrType_e {
	ctrType_IntCtr,
	ctrType_Int
} statsCtrType_t;

/* stats line format types */
typedef enum statsFmtType_e {
	statsFmt_Legacy,
	statsFmt_JSON,
	statsFmt_CEE
} statsFmtType_t;


/* helper entity, the counter */
typedef struct ctr_s {
	uchar *name;
	statsCtrType_t ctrType;
	union {
		intctr_t *pIntCtr;
		int *pInt;
	} val;
	struct ctr_s *next, *prev;
} ctr_t;

/* the statsobj object */
struct statsobj_s {
	BEGINobjInstance;		/* Data to implement generic object - MUST be the first data element! */
	uchar *name;
	pthread_mutex_t mutCtr;		/* to guard counter linked-list ops */
	ctr_t *ctrRoot;			/* doubly-linked list of statsobj counters */
	ctr_t *ctrLast;
	/* used to link ourselves together */
	statsobj_t *prev;
	statsobj_t *next;
};


/* interfaces */
BEGINinterface(statsobj) /* name must also be changed in ENDinterface macro! */
	INTERFACEObjDebugPrint(statsobj);
	rsRetVal (*Construct)(statsobj_t **ppThis);
	rsRetVal (*ConstructFinalize)(statsobj_t *pThis);
	rsRetVal (*Destruct)(statsobj_t **ppThis);
	rsRetVal (*SetName)(statsobj_t *pThis, uchar *name);
	rsRetVal (*GetStatsLine)(statsobj_t *pThis, cstr_t **ppcstr);
	rsRetVal (*GetAllStatsLines)(rsRetVal(*cb)(void*, cstr_t*), void *usrptr, statsFmtType_t fmt);
	rsRetVal (*AddCounter)(statsobj_t *pThis, uchar *ctrName, statsCtrType_t ctrType, void *pCtr);
	rsRetVal (*EnableStats)(void);
ENDinterface(statsobj)
#define statsobjCURR_IF_VERSION 10 /* increment whenever you change the interface structure! */
/* Changes
 * v2-v9 rserved for future use in "older" version branches
 * v10, 2012-04-01: GetAllStatsLines got fmt parameter
 */


/* prototypes */
PROTOTYPEObj(statsobj);


/* macros to handle stats counters
 * These are to be used by "counter providers". Note that we MUST
 * specify the mutex name, even though at first it looks like it
 * could be automatically be generated via e.g. "mut##ctr". 
 * Unfortunately, this does not work if counter is e.g. "pThis->ctr".
 * So we decided, for clarity, to always insist on specifying the mutex
 * name (after all, it's just a few more keystrokes...).
 * --------------------------------------------------------------------
 *                               NOTE WELL
 * --------------------------------------------------------------------
 * There are actually two types of stats counters: "regular" counters,
 * which are only used for stats purposes and "dual" counters, which 
 * are primarily used for other purposes but can be included in stats
 * as well. ALL regular counters MUST be initialized with
 * STATSCOUNTER_INIT and only be modified by STATSCOUNTER_* functions.
 * They MUST NOT be used for any other purpose (if this seems to make
 * sense, consider changing it to a dual counter).
 * Dual counters are somewhat dangerous in that a single variable is
 * used for two purposes: the actual application need and stats
 * counting. However, this is supported for performance reasons, as it
 * provides insight into the inner engine workings without need for
 * additional counters (and their maintenance code). Dual counters
 * MUST NOT be modified by STATSCOUNTER_* functions. Most importantly,
 * it is expected that the actua application code provides proper
 * (enough) synchronized access to these counters. Most importantly,
 * this means they have NO stats-system mutex associated to them.
 *
 * The interface function AddCounter() is a read-only function. It 
 * only provides the stats subsystem with a reference to a counter.
 * It is irrelevant if the counter is a regular or dual one. For that
 * reason, AddCounter() must not modify the counter contents, as in
 * the case of a dual counter application code may be broken.
 */
#define STATSCOUNTER_DEF(ctr, mut) \
	intctr_t ctr; \
	DEF_ATOMIC_HELPER_MUT64(mut);

#define STATSCOUNTER_INIT(ctr, mut) \
	INIT_ATOMIC_HELPER_MUT64(mut); \
	ctr = 0;

#define STATSCOUNTER_INC(ctr, mut) \
	if(GatherStats) \
		ATOMIC_INC_uint64(&ctr, &mut);

#define STATSCOUNTER_DEC(ctr, mut) \
	if(GatherStats) \
		ATOMIC_DEC_uint64(&ctr, mut);

/* the next macro works only if the variable is already guarded
 * by mutex (or the users risks a wrong result). It is assumed 
 * that there are not concurrent operations that modify the counter.
 */
#define STATSCOUNTER_SETMAX_NOMUT(ctr, newmax) \
	if(GatherStats && ((newmax) > (ctr))) \
		ctr = newmax;

#endif /* #ifndef INCLUDED_STATSOBJ_H */