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Diffstat (limited to 'runtime/statsobj.h')
| -rw-r--r-- | runtime/statsobj.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/runtime/statsobj.h b/runtime/statsobj.h new file mode 100644 index 00000000..14b33215 --- /dev/null +++ b/runtime/statsobj.h @@ -0,0 +1,158 @@ +/* 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 */ |