src/test/modules/injection_points/injection_stats_fixed.c

   1 /*--------------------------------------------------------------------------
   2  *
   3  * injection_stats_fixed.c
   4  *              Code for fixed-numbered statistics of injection points.
   5  *
   6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * IDENTIFICATION
  10  *              src/test/modules/injection_points/injection_stats_fixed.c
  11  *
  12  * -------------------------------------------------------------------------
  13  */
  14
  15 #include "postgres.h"
  16
  17 #include "fmgr.h"
  18
  19 #include "common/hashfn.h"
  20 #include "funcapi.h"
  21 #include "injection_stats.h"
  22 #include "pgstat.h"
  23 #include "utils/builtins.h"
  24 #include "utils/pgstat_internal.h"
  25
  26 /* Structures for statistics of injection points, fixed-size */
  27 typedef struct PgStat_StatInjFixedEntry
  28 {
  29         PgStat_Counter numattach;       /* number of points attached */
  30         PgStat_Counter numdetach;       /* number of points detached */
  31         PgStat_Counter numrun;          /* number of points run */
  32         PgStat_Counter numcached;       /* number of points cached */
  33         PgStat_Counter numloaded;       /* number of points loaded */
  34         TimestampTz stat_reset_timestamp;
  35 } PgStat_StatInjFixedEntry;
  36
  37 typedef struct PgStatShared_InjectionPointFixed
  38 {
  39         LWLock          lock;                   /* protects all the counters */
  40         uint32          changecount;
  41         PgStat_StatInjFixedEntry stats;
  42         PgStat_StatInjFixedEntry reset_offset;
  43 } PgStatShared_InjectionPointFixed;
  44
  45 /* Callbacks for fixed-numbered stats */
  46 static void injection_stats_fixed_init_shmem_cb(void *stats);
  47 static void injection_stats_fixed_reset_all_cb(TimestampTz ts);
  48 static void injection_stats_fixed_snapshot_cb(void);
  49
  50 static const PgStat_KindInfo injection_stats_fixed = {
  51         .name = "injection_points_fixed",
  52         .fixed_amount = true,
  53         .write_to_file = true,
  54
  55         .shared_size = sizeof(PgStat_StatInjFixedEntry),
  56         .shared_data_off = offsetof(PgStatShared_InjectionPointFixed, stats),
  57         .shared_data_len = sizeof(((PgStatShared_InjectionPointFixed *) 0)->stats),
  58
  59         .init_shmem_cb = injection_stats_fixed_init_shmem_cb,
  60         .reset_all_cb = injection_stats_fixed_reset_all_cb,
  61         .snapshot_cb = injection_stats_fixed_snapshot_cb,
  62 };
  63
  64 /*
  65  * Kind ID reserved for statistics of injection points.
  66  */
  67 #define PGSTAT_KIND_INJECTION_FIXED     130
  68
  69 /* Track if fixed-numbered stats are loaded */
  70 static bool inj_fixed_loaded = false;
  71
  72 static void
  73 injection_stats_fixed_init_shmem_cb(void *stats)
  74 {
  75         PgStatShared_InjectionPointFixed *stats_shmem =
  76                 (PgStatShared_InjectionPointFixed *) stats;
  77
  78         LWLockInitialize(&stats_shmem->lock, LWTRANCHE_PGSTATS_DATA);
  79 }
  80
  81 static void
  82 injection_stats_fixed_reset_all_cb(TimestampTz ts)
  83 {
  84         PgStatShared_InjectionPointFixed *stats_shmem =
  85                 pgstat_get_custom_shmem_data(PGSTAT_KIND_INJECTION_FIXED);
  86
  87         LWLockAcquire(&stats_shmem->lock, LW_EXCLUSIVE);
  88         pgstat_copy_changecounted_stats(&stats_shmem->reset_offset,
  89                                                                         &stats_shmem->stats,
  90                                                                         sizeof(stats_shmem->stats),
  91                                                                         &stats_shmem->changecount);
  92         stats_shmem->stats.stat_reset_timestamp = ts;
  93         LWLockRelease(&stats_shmem->lock);
  94 }
  95
  96 static void
  97 injection_stats_fixed_snapshot_cb(void)
  98 {
  99         PgStatShared_InjectionPointFixed *stats_shmem =
 100                 pgstat_get_custom_shmem_data(PGSTAT_KIND_INJECTION_FIXED);
 101         PgStat_StatInjFixedEntry *stat_snap =
 102                 pgstat_get_custom_snapshot_data(PGSTAT_KIND_INJECTION_FIXED);
 103         PgStat_StatInjFixedEntry *reset_offset = &stats_shmem->reset_offset;
 104         PgStat_StatInjFixedEntry reset;
 105
 106         pgstat_copy_changecounted_stats(stat_snap,
 107                                                                         &stats_shmem->stats,
 108                                                                         sizeof(stats_shmem->stats),
 109                                                                         &stats_shmem->changecount);
 110
 111         LWLockAcquire(&stats_shmem->lock, LW_SHARED);
 112         memcpy(&reset, reset_offset, sizeof(stats_shmem->stats));
 113         LWLockRelease(&stats_shmem->lock);
 114
 115         /* compensate by reset offsets */
 116 #define FIXED_COMP(fld) stat_snap->fld -= reset.fld;
 117         FIXED_COMP(numattach);
 118         FIXED_COMP(numdetach);
 119         FIXED_COMP(numrun);
 120         FIXED_COMP(numcached);
 121         FIXED_COMP(numloaded);
 122 #undef FIXED_COMP
 123 }
 124
 125 /*
 126  * Workhorse to do the registration work, called in _PG_init().
 127  */
 128 void
 129 pgstat_register_inj_fixed(void)
 130 {
 131         pgstat_register_kind(PGSTAT_KIND_INJECTION_FIXED, &injection_stats_fixed);
 132
 133         /* mark stats as loaded */
 134         inj_fixed_loaded = true;
 135 }
 136
 137 /*
 138  * Report fixed number of statistics for an injection point.
 139  */
 140 void
 141 pgstat_report_inj_fixed(uint32 numattach,
 142                                                 uint32 numdetach,
 143                                                 uint32 numrun,
 144                                                 uint32 numcached,
 145                                                 uint32 numloaded)
 146 {
 147         PgStatShared_InjectionPointFixed *stats_shmem;
 148
 149         /* leave if disabled */
 150         if (!inj_fixed_loaded || !inj_stats_enabled)
 151                 return;
 152
 153         stats_shmem = pgstat_get_custom_shmem_data(PGSTAT_KIND_INJECTION_FIXED);
 154
 155         pgstat_begin_changecount_write(&stats_shmem->changecount);
 156         stats_shmem->stats.numattach += numattach;
 157         stats_shmem->stats.numdetach += numdetach;
 158         stats_shmem->stats.numrun += numrun;
 159         stats_shmem->stats.numcached += numcached;
 160         stats_shmem->stats.numloaded += numloaded;
 161         pgstat_end_changecount_write(&stats_shmem->changecount);
 162 }
 163
 164 /*
 165  * SQL function returning fixed-numbered statistics for injection points.
 166  */
 167 PG_FUNCTION_INFO_V1(injection_points_stats_fixed);
 168 Datum
 169 injection_points_stats_fixed(PG_FUNCTION_ARGS)
 170 {
 171         TupleDesc       tupdesc;
 172         Datum           values[5] = {0};
 173         bool            nulls[5] = {0};
 174         PgStat_StatInjFixedEntry *stats;
 175
 176         if (!inj_fixed_loaded || !inj_stats_enabled)
 177                 PG_RETURN_NULL();
 178
 179         pgstat_snapshot_fixed(PGSTAT_KIND_INJECTION_FIXED);
 180         stats = pgstat_get_custom_snapshot_data(PGSTAT_KIND_INJECTION_FIXED);
 181
 182         /* Initialise attributes information in the tuple descriptor */
 183         tupdesc = CreateTemplateTupleDesc(5);
 184         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "numattach",
 185                                            INT8OID, -1, 0);
 186         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "numdetach",
 187                                            INT8OID, -1, 0);
 188         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "numrun",
 189                                            INT8OID, -1, 0);
 190         TupleDescInitEntry(tupdesc, (AttrNumber) 4, "numcached",
 191                                            INT8OID, -1, 0);
 192         TupleDescInitEntry(tupdesc, (AttrNumber) 5, "numloaded",
 193                                            INT8OID, -1, 0);
 194         BlessTupleDesc(tupdesc);
 195
 196         values[0] = Int64GetDatum(stats->numattach);
 197         values[1] = Int64GetDatum(stats->numdetach);
 198         values[2] = Int64GetDatum(stats->numrun);
 199         values[3] = Int64GetDatum(stats->numcached);
 200         values[4] = Int64GetDatum(stats->numloaded);
 201         nulls[0] = false;
 202         nulls[1] = false;
 203         nulls[2] = false;
 204         nulls[3] = false;
 205         nulls[4] = false;
 206
 207         /* Returns the record as Datum */
 208         PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls)));
 209 }