Remove not used after all kAllowRemoveReentrance parameter from IterateOverFullSlots.

We decided to not allow reentrance in absl::erase_if and absl::container_internal::c_for_each_fast.

PiperOrigin-RevId: 645273965
Change-Id: I75dfc73b93ba10f0e051bf0833723af887e1bb36

2 files changed, 13 insertions, 56 deletions

diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index a722f522..724df193 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -1862,7 +1862,7 @@ inline void* SlotAddress(void* slot_array, size_t slot, size_t slot_size) {
 // Iterates over all full slots and calls `cb(const ctrl_t*, SlotType*)`.
 // If kAllowRemoveReentrance is false, no erasure from this table allowed during
 // Callback call. This mode is slightly faster.
-template <bool kAllowRemoveReentrance, class SlotType, class Callback>
+template <class SlotType, class Callback>
 ABSL_ATTRIBUTE_ALWAYS_INLINE inline void IterateOverFullSlots(
     const CommonFields& c, SlotType* slot, Callback cb) {
   const size_t cap = c.capacity();
@@ -1885,28 +1885,20 @@ ABSL_ATTRIBUTE_ALWAYS_INLINE inline void IterateOverFullSlots(
     --ctrl;
     --slot;
     for (uint32_t i : mask) {
-      if (!kAllowRemoveReentrance || ABSL_PREDICT_TRUE(IsFull(ctrl[i]))) {
-        cb(ctrl + i, slot + i);
-      }
+      cb(ctrl + i, slot + i);
     }
     return;
   }
   size_t remaining = c.size();
   while (remaining != 0) {
     for (uint32_t i : GroupFullEmptyOrDeleted(ctrl).MaskFull()) {
-      if (!kAllowRemoveReentrance || ABSL_PREDICT_TRUE(IsFull(ctrl[i]))) {
-        cb(ctrl + i, slot + i);
-      }
+      cb(ctrl + i, slot + i);
       --remaining;
     }
     ctrl += Group::kWidth;
-    if (kAllowRemoveReentrance && *(ctrl - 1) == ctrl_t::kSentinel) {
-      break;
-    } else {
-      assert((remaining == 0 || *(ctrl - 1) != ctrl_t::kSentinel) &&
-             "element was erased from hash table unexpectedly");
-    }
     slot += Group::kWidth;
+    assert((remaining == 0 || *(ctrl - 1) != ctrl_t::kSentinel) &&
+            "element was erased from hash table unexpectedly");
   }
 }
 
@@ -2750,7 +2742,7 @@ class raw_hash_set {
     size_t offset = cap;
     const size_t shift =
         is_single_group(cap) ? (PerTableSalt(control()) | 1) : 0;
-    IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    IterateOverFullSlots(
         that.common(), that.slot_array(),
         [&](const ctrl_t* that_ctrl,
             slot_type* that_slot) ABSL_ATTRIBUTE_ALWAYS_INLINE {
@@ -3537,7 +3529,7 @@ class raw_hash_set {
   inline void destroy_slots() {
     assert(!is_soo());
     if (PolicyTraits::template destroy_is_trivial<Alloc>()) return;
-    IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    IterateOverFullSlots(
         common(), slot_array(),
         [&](const ctrl_t*, slot_type* slot)
             ABSL_ATTRIBUTE_ALWAYS_INLINE { this->destroy(slot); });
@@ -3882,7 +3874,7 @@ class raw_hash_set {
     }
     // We only do validation for small tables so that it's constant time.
     if (capacity() > 16) return;
-    IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    IterateOverFullSlots(
         common(), slot_array(), assert_consistent);
 #endif
   }
@@ -4064,7 +4056,7 @@ struct HashtableFreeFunctionsAccess {
       return 1;
     }
     size_t num_deleted = 0;
-    IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    IterateOverFullSlots(
         c->common(), c->slot_array(), [&](const ctrl_t* ctrl, auto* slot) {
           if (pred(Set::PolicyTraits::element(slot))) {
             c->destroy(slot);
@@ -4086,7 +4078,7 @@ struct HashtableFreeFunctionsAccess {
       return;
     }
     using ElementTypeWithConstness = decltype(*c->begin());
-    IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    IterateOverFullSlots(
         c->common(), c->slot_array(), [&cb](const ctrl_t*, auto* slot) {
           ElementTypeWithConstness& element = Set::PolicyTraits::element(slot);
           cb(element);
diff --git a/absl/container/internal/raw_hash_set_test.cc b/absl/container/internal/raw_hash_set_test.cc
index 673d78a6..ba603d2b 100644
--- a/absl/container/internal/raw_hash_set_test.cc
+++ b/absl/container/internal/raw_hash_set_test.cc
@@ -3334,12 +3334,12 @@ TEST(Table, IterateOverFullSlotsEmpty) {
   auto fail_if_any = [](const ctrl_t*, auto* i) {
     FAIL() << "expected no slots " << **i;
   };
-  container_internal::IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+  container_internal::IterateOverFullSlots(
       RawHashSetTestOnlyAccess::GetCommon(t),
       RawHashSetTestOnlyAccess::GetSlots(t), fail_if_any);
   for (size_t i = 0; i < 256; ++i) {
     t.reserve(i);
-    container_internal::IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    container_internal::IterateOverFullSlots(
         RawHashSetTestOnlyAccess::GetCommon(t),
         RawHashSetTestOnlyAccess::GetSlots(t), fail_if_any);
   }
@@ -3354,7 +3354,7 @@ TEST(Table, IterateOverFullSlotsFull) {
     expected_slots.push_back(idx);
 
     std::vector<int64_t> slots;
-    container_internal::IterateOverFullSlots</*kAllowRemoveReentrance=*/false>(
+    container_internal::IterateOverFullSlots(
         RawHashSetTestOnlyAccess::GetCommon(t),
         RawHashSetTestOnlyAccess::GetSlots(t),
         [&t, &slots](const ctrl_t* ctrl, auto* i) {
@@ -3368,41 +3368,6 @@ TEST(Table, IterateOverFullSlotsFull) {
   }
 }
 
-TEST(Table, IterateOverFullSlotsAllowReentrance) {
-  std::vector<int64_t> expected_values;
-  for (int64_t idx = 0; idx < 128; ++idx) {
-    NonSooIntTable t;
-    for (int val = 0; val <= idx; ++val) {
-      t.insert(val);
-    }
-
-    // We are inserting only even values.
-    // Only one element across 2*k and 2*k+1 should be visited.
-    if (idx % 2 == 0) {
-      expected_values.push_back(idx);
-    }
-
-    std::vector<int64_t> actual_values;
-    container_internal::IterateOverFullSlots</*kAllowRemoveReentrance=*/true>(
-        RawHashSetTestOnlyAccess::GetCommon(t),
-        RawHashSetTestOnlyAccess::GetSlots(t),
-        [&t, &actual_values](const ctrl_t* ctrl, auto* i) {
-          int64_t value = **i;
-          // Erase the other element from 2*k and 2*k+1 pair.
-          t.erase(value ^ 1);
-          ptrdiff_t ctrl_offset =
-              ctrl - RawHashSetTestOnlyAccess::GetCommon(t).control();
-          ptrdiff_t slot_offset = i - RawHashSetTestOnlyAccess::GetSlots(t);
-          ASSERT_EQ(ctrl_offset, slot_offset);
-          // Add an even value from the pair.
-          // Only one element for each 2*k and 2*k+1 pair should be inserted.
-          actual_values.push_back(value - value % 2);
-        });
-    EXPECT_THAT(actual_values,
-                testing::UnorderedElementsAreArray(expected_values));
-  }
-}
-
 template <typename T>
 class SooTable : public testing::Test {};
 using FreezableSooTableTypes =