[cleanup] Remove low level counters (#30611)

* [cleanup] Remove low level counters

* clean up code

* Automated change: Fix sanity tests

* fix

Co-authored-by: ctiller <ctiller@users.noreply.github.com>

include/grpc/impl/codegen/atm_gcc_atomic.h

@@ -33,20 +33,6 @@ typedef intptr_t gpr_atm;
 #define GPR_ATM_MAX INTPTR_MAX
 #define GPR_ATM_MIN INTPTR_MIN
 
-#ifdef GPR_LOW_LEVEL_COUNTERS
-extern gpr_atm gpr_counter_atm_cas;
-extern gpr_atm gpr_counter_atm_add;
-#define GPR_ATM_INC_COUNTER(counter) \
-  __atomic_fetch_add(&counter, 1, __ATOMIC_RELAXED)
-#define GPR_ATM_INC_CAS_THEN(blah) \
-  (GPR_ATM_INC_COUNTER(gpr_counter_atm_cas), blah)
-#define GPR_ATM_INC_ADD_THEN(blah) \
-  (GPR_ATM_INC_COUNTER(gpr_counter_atm_add), blah)
-#else
-#define GPR_ATM_INC_CAS_THEN(blah) blah
-#define GPR_ATM_INC_ADD_THEN(blah) blah
-#endif
-
 #define gpr_atm_full_barrier() (__atomic_thread_fence(__ATOMIC_SEQ_CST))
 
 #define gpr_atm_acq_load(p) (__atomic_load_n((p), __ATOMIC_ACQUIRE))
@@ -57,34 +43,39 @@ extern gpr_atm gpr_counter_atm_add;
   (__atomic_store_n((p), (intptr_t)(value), __ATOMIC_RELAXED))
 
 #define gpr_atm_no_barrier_fetch_add(p, delta) \
-  GPR_ATM_INC_ADD_THEN(                        \
-      __atomic_fetch_add((p), (intptr_t)(delta), __ATOMIC_RELAXED))
+  __atomic_fetch_add((p), (intptr_t)(delta), __ATOMIC_RELAXED)
 #define gpr_atm_full_fetch_add(p, delta) \
-  GPR_ATM_INC_ADD_THEN(                  \
-      __atomic_fetch_add((p), (intptr_t)(delta), __ATOMIC_ACQ_REL))
+  __atomic_fetch_add((p), (intptr_t)(delta), __ATOMIC_ACQ_REL)
 
 static __inline int gpr_atm_no_barrier_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
-  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
-      p, &o, n, 0, __ATOMIC_RELAXED, __ATOMIC_RELAXED));
+  // Need to be c89 compatible, so we can't use false for the fourth argument.
+  // NOLINTNEXTLINE(modernize-use-bool-literals)
+  return __atomic_compare_exchange_n(p, &o, n, 0, __ATOMIC_RELAXED,
+                                     __ATOMIC_RELAXED);
 }
 
 static __inline int gpr_atm_acq_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
-  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
-      p, &o, n, 0, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED));
+  // Need to be c89 compatible, so we can't use false for the fourth argument.
+  // NOLINTNEXTLINE(modernize-use-bool-literals)
+  return __atomic_compare_exchange_n(p, &o, n, 0, __ATOMIC_ACQUIRE,
+                                     __ATOMIC_RELAXED);
 }
 
 static __inline int gpr_atm_rel_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
-  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
-      p, &o, n, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED));
+  // Need to be c89 compatible, so we can't use false for the fourth argument.
+  // NOLINTNEXTLINE(modernize-use-bool-literals)
+  return __atomic_compare_exchange_n(p, &o, n, 0, __ATOMIC_RELEASE,
+                                     __ATOMIC_RELAXED);
 }
 
 static __inline int gpr_atm_full_cas(gpr_atm* p, gpr_atm o, gpr_atm n) {
-  return GPR_ATM_INC_CAS_THEN(__atomic_compare_exchange_n(
-      p, &o, n, 0, __ATOMIC_ACQ_REL, __ATOMIC_RELAXED));
+  // Need to be c89 compatible, so we can't use false for the fourth argument.
+  // NOLINTNEXTLINE(modernize-use-bool-literals)
+  return __atomic_compare_exchange_n(p, &o, n, 0, __ATOMIC_ACQ_REL,
+                                     __ATOMIC_RELAXED);
 }
 
-#define gpr_atm_full_xchg(p, n) \
-  GPR_ATM_INC_CAS_THEN(__atomic_exchange_n((p), (n), __ATOMIC_ACQ_REL))
+#define gpr_atm_full_xchg(p, n) __atomic_exchange_n((p), (n), __ATOMIC_ACQ_REL)
 
 #ifdef __cplusplus
 }

include/grpc/impl/codegen/atm_gcc_sync.h

@@ -28,8 +28,6 @@
 typedef intptr_t gpr_atm;
 #define GPR_ATM_MAX INTPTR_MAX
 #define GPR_ATM_MIN INTPTR_MIN
-#define GPR_ATM_INC_CAS_THEN(blah) blah
-#define GPR_ATM_INC_ADD_THEN(blah) blah
 
 #define GPR_ATM_COMPILE_BARRIER_() __asm__ __volatile__("" : : : "memory")
 

include/grpc/impl/codegen/atm_windows.h

@@ -29,8 +29,6 @@
 typedef intptr_t gpr_atm;
 #define GPR_ATM_MAX INTPTR_MAX
 #define GPR_ATM_MIN INTPTR_MIN
-#define GPR_ATM_INC_CAS_THEN(blah) blah
-#define GPR_ATM_INC_ADD_THEN(blah) blah
 
 #define gpr_atm_full_barrier MemoryBarrier
 

src/core/lib/gpr/sync_abseil.cc

@@ -33,12 +33,6 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 
-#ifdef GPR_LOW_LEVEL_COUNTERS
-gpr_atm gpr_mu_locks = 0;
-gpr_atm gpr_counter_atm_cas = 0;
-gpr_atm gpr_counter_atm_add = 0;
-#endif
-
 void gpr_mu_init(gpr_mu* mu) {
   static_assert(sizeof(gpr_mu) == sizeof(absl::Mutex),
                 "gpr_mu and Mutex must be the same size");

src/core/lib/gpr/sync_posix.cc

@@ -29,12 +29,6 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 
-#ifdef GPR_LOW_LEVEL_COUNTERS
-gpr_atm gpr_mu_locks = 0;
-gpr_atm gpr_counter_atm_cas = 0;
-gpr_atm gpr_counter_atm_add = 0;
-#endif
-
 void gpr_mu_init(gpr_mu* mu) {
 #ifdef GRPC_ASAN_ENABLED
   GPR_ASSERT(pthread_mutex_init(&mu->mutex, nullptr) == 0);
@@ -55,9 +49,6 @@ void gpr_mu_destroy(gpr_mu* mu) {
 }
 
 void gpr_mu_lock(gpr_mu* mu) {
-#ifdef GPR_LOW_LEVEL_COUNTERS
-  GPR_ATM_INC_COUNTER(gpr_mu_locks);
-#endif
 #ifdef GRPC_ASAN_ENABLED
   GPR_ASSERT(pthread_mutex_lock(&mu->mutex) == 0);
 #else

src/core/lib/gpr/time_posix.cc

@@ -140,13 +140,7 @@ static gpr_timespec now_impl(gpr_clock_type clock) {
 
 gpr_timespec (*gpr_now_impl)(gpr_clock_type clock_type) = now_impl;
 
-#ifdef GPR_LOW_LEVEL_COUNTERS
-gpr_atm gpr_now_call_count;
-#endif
 gpr_timespec gpr_now(gpr_clock_type clock_type) {
-#ifdef GPR_LOW_LEVEL_COUNTERS
-  __atomic_fetch_add(&gpr_now_call_count, 1, __ATOMIC_RELAXED);
-#endif
   // validate clock type
   GPR_ASSERT(clock_type == GPR_CLOCK_MONOTONIC ||
              clock_type == GPR_CLOCK_REALTIME ||

test/cpp/microbenchmarks/helpers.cc

@@ -76,22 +76,4 @@ void TrackCounters::AddToLabel(std::ostream& out, benchmark::State& state) {
         << grpc_stats_histo_percentile(
                &stats, static_cast<grpc_stats_histograms>(i), 99.0);
   }
-#ifdef GPR_LOW_LEVEL_COUNTERS
-  out << " locks/iter:"
-      << ((double)(gpr_atm_no_barrier_load(&gpr_mu_locks) -
-                   mu_locks_at_start_) /
-          (double)state.iterations())
-      << " atm_cas/iter:"
-      << ((double)(gpr_atm_no_barrier_load(&gpr_counter_atm_cas) -
-                   atm_cas_at_start_) /
-          (double)state.iterations())
-      << " atm_add/iter:"
-      << ((double)(gpr_atm_no_barrier_load(&gpr_counter_atm_add) -
-                   atm_add_at_start_) /
-          (double)state.iterations())
-      << " nows/iter:"
-      << ((double)(gpr_atm_no_barrier_load(&gpr_now_call_count) -
-                   now_calls_at_start_) /
-          (double)state.iterations());
-#endif
 }

test/cpp/microbenchmarks/helpers.h

@@ -41,13 +41,6 @@ class LibraryInitializer {
   grpc::internal::GrpcLibrary init_lib_;
 };
 
-#ifdef GPR_LOW_LEVEL_COUNTERS
-extern gpr_atm gpr_mu_locks;
-extern gpr_atm gpr_counter_atm_cas;
-extern gpr_atm gpr_counter_atm_add;
-extern gpr_atm gpr_now_call_count;
-#endif
-
 class TrackCounters {
  public:
   TrackCounters() { grpc_stats_collect(&stats_begin_); }
@@ -59,15 +52,6 @@ class TrackCounters {
  private:
   grpc_stats_data stats_begin_;
   std::vector<std::string> labels_;
-#ifdef GPR_LOW_LEVEL_COUNTERS
-  const size_t mu_locks_at_start_ = gpr_atm_no_barrier_load(&gpr_mu_locks);
-  const size_t atm_cas_at_start_ =
-      gpr_atm_no_barrier_load(&gpr_counter_atm_cas);
-  const size_t atm_add_at_start_ =
-      gpr_atm_no_barrier_load(&gpr_counter_atm_add);
-  const size_t now_calls_at_start_ =
-      gpr_atm_no_barrier_load(&gpr_now_call_count);
-#endif
 };
 
 #endif