trace2/tr2_ctr.c

   1 #include "git-compat-util.h"
   2 #include "thread-utils.h"
   3 #include "trace2/tr2_tgt.h"
   4 #include "trace2/tr2_tls.h"
   5 #include "trace2/tr2_ctr.h"
   6
   7 /*
   8  * A global counter block to aggregrate values from the partial sums
   9  * from each thread.
  10  */
  11 static struct tr2_counter_block final_counter_block; /* access under tr2tls_mutex */
  12
  13 /*
  14  * Define metadata for each global counter.
  15  *
  16  * This array must match the "enum trace2_counter_id" and the values
  17  * in "struct tr2_counter_block.counter[*]".
  18  */
  19 static struct tr2_counter_metadata tr2_counter_metadata[TRACE2_NUMBER_OF_COUNTERS] = {
  20         [TRACE2_COUNTER_ID_TEST1] = {
  21                 .category = "test",
  22                 .name = "test1",
  23                 .want_per_thread_events = 0,
  24         },
  25         [TRACE2_COUNTER_ID_TEST2] = {
  26                 .category = "test",
  27                 .name = "test2",
  28                 .want_per_thread_events = 1,
  29         },
  30         [TRACE2_COUNTER_ID_PACKED_REFS_JUMPS] = {
  31                 .category = "packed-refs",
  32                 .name = "jumps_made",
  33                 .want_per_thread_events = 0,
  34         },
  35         [TRACE2_COUNTER_ID_FSYNC_WRITEOUT_ONLY] = {
  36                 .category = "fsync",
  37                 .name = "writeout-only",
  38                 .want_per_thread_events = 0,
  39         },
  40         [TRACE2_COUNTER_ID_FSYNC_HARDWARE_FLUSH] = {
  41                 .category = "fsync",
  42                 .name = "hardware-flush",
  43                 .want_per_thread_events = 0,
  44         },
  45
  46         /* Add additional metadata before here. */
  47 };
  48
  49 void tr2_counter_increment(enum trace2_counter_id cid, uint64_t value)
  50 {
  51         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
  52         struct tr2_counter *c = &ctx->counter_block.counter[cid];
  53
  54         c->value += value;
  55
  56         ctx->used_any_counter = 1;
  57         if (tr2_counter_metadata[cid].want_per_thread_events)
  58                 ctx->used_any_per_thread_counter = 1;
  59 }
  60
  61 void tr2_update_final_counters(void)
  62 {
  63         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
  64         enum trace2_counter_id cid;
  65
  66         if (!ctx->used_any_counter)
  67                 return;
  68
  69         /*
  70          * Access `final_counter_block` requires holding `tr2tls_mutex`.
  71          * We assume that our caller is holding the lock.
  72          */
  73
  74         for (cid = 0; cid < TRACE2_NUMBER_OF_COUNTERS; cid++) {
  75                 struct tr2_counter *c_final = &final_counter_block.counter[cid];
  76                 const struct tr2_counter *c = &ctx->counter_block.counter[cid];
  77
  78                 c_final->value += c->value;
  79         }
  80 }
  81
  82 void tr2_emit_per_thread_counters(tr2_tgt_evt_counter_t *fn_apply)
  83 {
  84         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
  85         enum trace2_counter_id cid;
  86
  87         if (!ctx->used_any_per_thread_counter)
  88                 return;
  89
  90         /*
  91          * For each counter, if the counter wants per-thread events
  92          * and this thread used it (the value is non-zero), emit it.
  93          */
  94         for (cid = 0; cid < TRACE2_NUMBER_OF_COUNTERS; cid++)
  95                 if (tr2_counter_metadata[cid].want_per_thread_events &&
  96                     ctx->counter_block.counter[cid].value)
  97                         fn_apply(&tr2_counter_metadata[cid],
  98                                  &ctx->counter_block.counter[cid],
  99                                  0);
 100 }
 101
 102 void tr2_emit_final_counters(tr2_tgt_evt_counter_t *fn_apply)
 103 {
 104         enum trace2_counter_id cid;
 105
 106         /*
 107          * Access `final_counter_block` requires holding `tr2tls_mutex`.
 108          * We assume that our caller is holding the lock.
 109          */
 110
 111         for (cid = 0; cid < TRACE2_NUMBER_OF_COUNTERS; cid++)
 112                 if (final_counter_block.counter[cid].value)
 113                         fn_apply(&tr2_counter_metadata[cid],
 114                                  &final_counter_block.counter[cid],
 115                                  1);
 116 }