unord: Extract key to avoid preemptive mallocs in insert/emplace
unordered_set::emplace and unordered_map::emplace construct a node, then
try to insert it. If insertion fails, the node gets deleted.
To avoid this unnecessary malloc traffic, check to see if the argument
to emplace has the appropriate key_type. If so, we can use that key
directly and delay the malloc until we're sure we're inserting something
new.
Test updates by Eric Fiselier, who rewrote the old allocation tests to
include the new cases.
There are two orthogonal future directions:
1. Apply the same optimization to set and map.
2. Extend the optimization to when the argument is not key_type, but can
be converted to it without side effects. Ideally, we could do this
whenever key_type is trivially destructible and the argument is
trivially convertible to key_type, but in practise the relevant type
traits "blow up sometimes". At least, we should catch a few simple
cases (such as when both are primitive types).
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@263746 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__hash_table b/include/__hash_table
index e8cebe0..16a0f5e 100644
--- a/include/__hash_table
+++ b/include/__hash_table
@@ -100,6 +100,23 @@
return size_t(1) << (std::numeric_limits<size_t>::digits - __clz(__n-1));
}
+#ifndef _LIBCPP_CXX03_LANG
+struct __extract_key_fail_tag {};
+struct __extract_key_self_tag {};
+struct __extract_key_first_tag {};
+
+template <class _ValTy, class _Key,
+ class _RawValTy = typename __unconstref<_ValTy>::type>
+struct __can_extract_key
+ : conditional<is_same<_RawValTy, _Key>::value, __extract_key_self_tag,
+ __extract_key_fail_tag>::type {};
+
+template <class _Pair, class _Key, class _First, class _Second>
+struct __can_extract_key<_Pair, _Key, pair<_First, _Second>>
+ : conditional<is_same<typename remove_const<_First>::type, _Key>::value,
+ __extract_key_first_tag, __extract_key_fail_tag>::type {};
+#endif
+
template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;
template <class _NodePtr> class _LIBCPP_TYPE_VIS_ONLY __hash_iterator;
@@ -903,6 +920,7 @@
typedef typename _NodeTypes::__node_value_type __node_value_type;
typedef typename _NodeTypes::__container_value_type __container_value_type;
+ typedef typename _NodeTypes::key_type key_type;
typedef value_type& reference;
typedef const value_type& const_reference;
typedef typename __alloc_traits::pointer pointer;
@@ -1041,13 +1059,49 @@
#ifndef _LIBCPP_CXX03_LANG
template <class _Key, class ..._Args>
+ _LIBCPP_INLINE_VISIBILITY
pair<iterator, bool> __emplace_unique_key_args(_Key const& __k, _Args&&... __args);
template <class... _Args>
- pair<iterator, bool> __emplace_unique(_Args&&... __args);
+ _LIBCPP_INLINE_VISIBILITY
+ pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
+
+ template <class _Pp>
+ _LIBCPP_INLINE_VISIBILITY
+ pair<iterator, bool> __emplace_unique(_Pp&& __x) {
+ return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
+ __can_extract_key<_Pp, key_type>());
+ }
template <class... _Args>
+ _LIBCPP_INLINE_VISIBILITY
+ pair<iterator, bool> __emplace_unique(_Args&&... __args) {
+ return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
+ }
+
+ template <class _Pp>
+ _LIBCPP_INLINE_VISIBILITY
+ pair<iterator, bool>
+ __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
+ return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
+ }
+ template <class _Pp>
+ _LIBCPP_INLINE_VISIBILITY
+ pair<iterator, bool>
+ __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
+ return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
+ }
+ template <class _Pp>
+ _LIBCPP_INLINE_VISIBILITY
+ pair<iterator, bool>
+ __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
+ return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
+ }
+
+ template <class... _Args>
+ _LIBCPP_INLINE_VISIBILITY
iterator __emplace_multi(_Args&&... __args);
template <class... _Args>
+ _LIBCPP_INLINE_VISIBILITY
iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
@@ -1989,7 +2043,7 @@
template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class... _Args>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique(_Args&&... __args)
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_impl(_Args&&... __args)
{
__node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
pair<iterator, bool> __r = __node_insert_unique(__h.get());
diff --git a/test/libcxx/containers/unord/unord.set/insert_dup_alloc.pass.cpp b/test/libcxx/containers/unord/unord.set/insert_dup_alloc.pass.cpp
deleted file mode 100644
index 76ceafe..0000000
--- a/test/libcxx/containers/unord/unord.set/insert_dup_alloc.pass.cpp
+++ /dev/null
@@ -1,48 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// Check that we don't allocate when trying to insert a duplicate value into a
-// unordered_set. See PR12999 http://llvm.org/bugs/show_bug.cgi?id=12999
-
-#include <cassert>
-#include <unordered_set>
-#include "count_new.hpp"
-#include "MoveOnly.h"
-
-int main()
-{
- {
- std::unordered_set<int> s;
- assert(globalMemCounter.checkNewCalledEq(0));
-
- for(int i=0; i < 100; ++i)
- s.insert(3);
-
- assert(s.size() == 1);
- assert(s.count(3) == 1);
- assert(globalMemCounter.checkNewCalledEq(2));
- }
- assert(globalMemCounter.checkOutstandingNewEq(0));
- globalMemCounter.reset();
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
- {
- std::unordered_set<MoveOnly> s;
- assert(globalMemCounter.checkNewCalledEq(0));
-
- for(int i=0; i<100; i++)
- s.insert(MoveOnly(3));
-
- assert(s.size() == 1);
- assert(s.count(MoveOnly(3)) == 1);
- assert(globalMemCounter.checkNewCalledEq(2));
- }
- assert(globalMemCounter.checkOutstandingNewEq(0));
- globalMemCounter.reset();
-#endif
-}
diff --git a/test/std/containers/unord/unord.map/unord.map.modifiers/insert_allocator_requirements.pass.cpp b/test/std/containers/unord/unord.map/unord.map.modifiers/insert_allocator_requirements.pass.cpp
deleted file mode 100644
index e889ce3..0000000
--- a/test/std/containers/unord/unord.map/unord.map.modifiers/insert_allocator_requirements.pass.cpp
+++ /dev/null
@@ -1,143 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// <unordered_map>
-
-// class unordered_map
-
-// insert(...);
-
-// UNSUPPORTED: c++98, c++03
-
-
-#include <unordered_map>
-#include <iostream>
-#include <cassert>
-
-#include "test_macros.h"
-#include "count_new.hpp"
-#include "container_test_types.h"
-
-#if TEST_STD_VER >= 11
-template <class Arg>
-void PrintInfo(int line, Arg&& arg)
-#else
-template <class Arg>
-void PrintInfo(int line, Arg arg)
-#endif
-{
- std::cout << "In " << __FILE__ << ":" << line << ":\n " << arg << "\n" << std::endl;
-}
-#define PRINT(...) PrintInfo(__LINE__, __VA_ARGS__)
-
-template <class Container>
-void testContainerInsert()
-{
- typedef typename Container::value_type ValueTp;
- typedef Container C;
- typedef std::pair<typename C::iterator, bool> R;
- ConstructController* cc = getConstructController();
- cc->reset();
- {
- PRINT("Testing C::insert(const value_type&)");
- Container c;
- const ValueTp v(42, 1);
- cc->expect<const ValueTp&>();
- assert(c.insert(v).second);
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- const ValueTp v2(42, 1);
- assert(c.insert(v2).second == false);
- }
- }
- {
- PRINT("Testing C::insert(value_type&)");
- Container c;
- ValueTp v(42, 1);
- cc->expect<const ValueTp&>();
- assert(c.insert(v).second);
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- ValueTp v2(42, 1);
- assert(c.insert(v2).second == false);
- }
- }
- {
- PRINT("Testing C::insert(value_type&&)");
- Container c;
- ValueTp v(42, 1);
- cc->expect<ValueTp&&>();
- assert(c.insert(std::move(v)).second);
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- ValueTp v2(42, 1);
- assert(c.insert(std::move(v2)).second == false);
- }
- }
- {
- PRINT("Testing C::insert(std::initializer_list<ValueTp>)");
- Container c;
- std::initializer_list<ValueTp> il = { ValueTp(1, 1), ValueTp(2, 1) };
- cc->expect<ValueTp const&>(2);
- c.insert(il);
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- c.insert(il);
- }
- }
- {
- PRINT("Testing C::insert(Iter, Iter) for *Iter = value_type const&");
- Container c;
- const ValueTp ValueList[] = { ValueTp(1, 1), ValueTp(2, 1), ValueTp(3, 1) };
- cc->expect<ValueTp const&>(3);
- c.insert(std::begin(ValueList), std::end(ValueList));
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- c.insert(std::begin(ValueList), std::end(ValueList));
- }
- }
- {
- PRINT("Testing C::insert(Iter, Iter) for *Iter = value_type&&");
- Container c;
- ValueTp ValueList[] = { ValueTp(1, 1), ValueTp(2, 1) , ValueTp(3, 1) };
- cc->expect<ValueTp&&>(3);
- c.insert(std::move_iterator<ValueTp*>(std::begin(ValueList)),
- std::move_iterator<ValueTp*>(std::end(ValueList)));
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- ValueTp ValueList2[] = { ValueTp(1, 1), ValueTp(2, 1) , ValueTp(3, 1) };
- c.insert(std::move_iterator<ValueTp*>(std::begin(ValueList2)),
- std::move_iterator<ValueTp*>(std::end(ValueList2)));
- }
- }
- {
- PRINT("Testing C::insert(Iter, Iter) for *Iter = value_type&");
- Container c;
- ValueTp ValueList[] = { ValueTp(1, 1), ValueTp(2, 1) , ValueTp(3, 1) };
- cc->expect<ValueTp const&>(3);
- c.insert(std::begin(ValueList), std::end(ValueList));
- assert(!cc->unchecked());
- {
- DisableAllocationGuard g;
- c.insert(std::begin(ValueList), std::end(ValueList));
- }
- }
-}
-
-
-int main()
-{
- testContainerInsert<TCT::unordered_map<> >();
-}
diff --git a/test/std/containers/unord/unord.map/unord.map.modifiers/insert_and_emplace_allocator_requirements.pass.cpp b/test/std/containers/unord/unord.map/unord.map.modifiers/insert_and_emplace_allocator_requirements.pass.cpp
new file mode 100644
index 0000000..a7df3e7
--- /dev/null
+++ b/test/std/containers/unord/unord.map/unord.map.modifiers/insert_and_emplace_allocator_requirements.pass.cpp
@@ -0,0 +1,249 @@
+//===----------------------------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <unordered_map>
+
+// class unordered_map
+
+// insert(...);
+
+// UNSUPPORTED: c++98, c++03
+
+
+#include <unordered_map>
+#include <iostream>
+#include <cassert>
+
+#include "test_macros.h"
+#include "count_new.hpp"
+#include "container_test_types.h"
+
+#if TEST_STD_VER >= 11
+template <class Arg>
+void PrintInfo(int line, Arg&& arg)
+#else
+template <class Arg>
+void PrintInfo(int line, Arg arg)
+#endif
+{
+ std::cout << "In " << __FILE__ << ":" << line << ":\n " << arg << "\n" << std::endl;
+}
+#define PRINT(...) PrintInfo(__LINE__, __VA_ARGS__)
+
+template <class Container>
+void testContainerInsert()
+{
+ typedef typename Container::value_type ValueTp;
+ typedef Container C;
+ typedef std::pair<typename C::iterator, bool> R;
+ ConstructController* cc = getConstructController();
+ cc->reset();
+ {
+ PRINT("Testing C::insert(const value_type&)");
+ Container c;
+ const ValueTp v(42, 1);
+ cc->expect<const ValueTp&>();
+ assert(c.insert(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42, 1);
+ assert(c.insert(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::insert(value_type&)");
+ Container c;
+ ValueTp v(42, 1);
+ cc->expect<const ValueTp&>();
+ assert(c.insert(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp v2(42, 1);
+ assert(c.insert(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::insert(value_type&&)");
+ Container c;
+ ValueTp v(42, 1);
+ cc->expect<ValueTp&&>();
+ assert(c.insert(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp v2(42, 1);
+ assert(c.insert(std::move(v2)).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::insert(const value_type&&)");
+ Container c;
+ const ValueTp v(42, 1);
+ cc->expect<const ValueTp&>();
+ assert(c.insert(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42, 1);
+ assert(c.insert(std::move(v2)).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::insert(std::initializer_list<ValueTp>)");
+ Container c;
+ std::initializer_list<ValueTp> il = { ValueTp(1, 1), ValueTp(2, 1) };
+ cc->expect<ValueTp const&>(2);
+ c.insert(il);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ c.insert(il);
+ }
+ }
+ {
+ PRINT("Testing C::insert(Iter, Iter) for *Iter = value_type const&");
+ Container c;
+ const ValueTp ValueList[] = { ValueTp(1, 1), ValueTp(2, 1), ValueTp(3, 1) };
+ cc->expect<ValueTp const&>(3);
+ c.insert(std::begin(ValueList), std::end(ValueList));
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ c.insert(std::begin(ValueList), std::end(ValueList));
+ }
+ }
+ {
+ PRINT("Testing C::insert(Iter, Iter) for *Iter = value_type&&");
+ Container c;
+ ValueTp ValueList[] = { ValueTp(1, 1), ValueTp(2, 1) , ValueTp(3, 1) };
+ cc->expect<ValueTp&&>(3);
+ c.insert(std::move_iterator<ValueTp*>(std::begin(ValueList)),
+ std::move_iterator<ValueTp*>(std::end(ValueList)));
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp ValueList2[] = { ValueTp(1, 1), ValueTp(2, 1) , ValueTp(3, 1) };
+ c.insert(std::move_iterator<ValueTp*>(std::begin(ValueList2)),
+ std::move_iterator<ValueTp*>(std::end(ValueList2)));
+ }
+ }
+ {
+ PRINT("Testing C::insert(Iter, Iter) for *Iter = value_type&");
+ Container c;
+ ValueTp ValueList[] = { ValueTp(1, 1), ValueTp(2, 1) , ValueTp(3, 1) };
+ cc->expect<ValueTp const&>(3);
+ c.insert(std::begin(ValueList), std::end(ValueList));
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ c.insert(std::begin(ValueList), std::end(ValueList));
+ }
+ }
+}
+
+
+template <class Container>
+void testContainerEmplace()
+{
+ typedef typename Container::value_type ValueTp;
+ typedef typename Container::key_type Key;
+ typedef typename Container::mapped_type Mapped;
+ typedef typename std::pair<Key, Mapped> NonConstKeyPair;
+ typedef Container C;
+ typedef std::pair<typename C::iterator, bool> R;
+ ConstructController* cc = getConstructController();
+ cc->reset();
+ {
+ PRINT("Testing C::emplace(const value_type&)");
+ Container c;
+ const ValueTp v(42, 1);
+ cc->expect<const ValueTp&>();
+ assert(c.emplace(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42, 1);
+ assert(c.emplace(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(value_type&)");
+ Container c;
+ ValueTp v(42, 1);
+ cc->expect<ValueTp&>();
+ assert(c.emplace(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp v2(42, 1);
+ assert(c.emplace(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(value_type&&)");
+ Container c;
+ ValueTp v(42, 1);
+ cc->expect<ValueTp&&>();
+ assert(c.emplace(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp v2(42, 1);
+ assert(c.emplace(std::move(v2)).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(const value_type&&)");
+ Container c;
+ const ValueTp v(42, 1);
+ cc->expect<const ValueTp&&>();
+ assert(c.emplace(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42, 1);
+ assert(c.emplace(std::move(v2)).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(pair<Key, Mapped> const&)");
+ Container c;
+ const NonConstKeyPair v(42, 1);
+ cc->expect<const NonConstKeyPair&>();
+ assert(c.emplace(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const NonConstKeyPair v2(42, 1);
+ assert(c.emplace(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(pair<Key, Mapped> &&)");
+ Container c;
+ NonConstKeyPair v(42, 1);
+ cc->expect<NonConstKeyPair&&>();
+ assert(c.emplace(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ NonConstKeyPair v2(42, 1);
+ assert(c.emplace(std::move(v2)).second == false);
+ }
+ }
+}
+
+
+int main()
+{
+ testContainerInsert<TCT::unordered_map<> >();
+ testContainerEmplace<TCT::unordered_map<> >();
+}
diff --git a/test/std/containers/unord/unord.set/insert_allocator_requirements.pass.cpp b/test/std/containers/unord/unord.set/insert_and_emplace_allocator_requirements.pass.cpp
similarity index 66%
rename from test/std/containers/unord/unord.set/insert_allocator_requirements.pass.cpp
rename to test/std/containers/unord/unord.set/insert_and_emplace_allocator_requirements.pass.cpp
index f5a30c2..14e0892 100644
--- a/test/std/containers/unord/unord.set/insert_allocator_requirements.pass.cpp
+++ b/test/std/containers/unord/unord.set/insert_and_emplace_allocator_requirements.pass.cpp
@@ -12,6 +12,7 @@
// class unordered_set
// insert(...)
+// emplace(...)
// UNSUPPORTED: c++98, c++03
@@ -83,6 +84,19 @@
}
}
{
+ PRINT("Testing C::insert(const value_type&&)");
+ Container c;
+ const ValueTp v(42);
+ cc->expect<const ValueTp&>();
+ assert(c.insert(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42);
+ assert(c.insert(std::move(v2)).second == false);
+ }
+ }
+ {
PRINT("Testing C::insert(std::initializer_list<ValueTp>)");
Container c;
std::initializer_list<ValueTp> il = { ValueTp(1), ValueTp(2) };
@@ -136,7 +150,71 @@
}
+template <class Container>
+void testContainerEmplace()
+{
+ typedef typename Container::value_type ValueTp;
+ typedef Container C;
+ typedef std::pair<typename C::iterator, bool> R;
+ ConstructController* cc = getConstructController();
+ cc->reset();
+ {
+ PRINT("Testing C::emplace(const value_type&)");
+ Container c;
+ const ValueTp v(42);
+ cc->expect<const ValueTp&>();
+ assert(c.emplace(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42);
+ assert(c.emplace(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(value_type&)");
+ Container c;
+ ValueTp v(42);
+ cc->expect<ValueTp&>();
+ assert(c.emplace(v).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp v2(42);
+ assert(c.emplace(v2).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(value_type&&)");
+ Container c;
+ ValueTp v(42);
+ cc->expect<ValueTp&&>();
+ assert(c.emplace(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ ValueTp v2(42);
+ assert(c.emplace(std::move(v2)).second == false);
+ }
+ }
+ {
+ PRINT("Testing C::emplace(const value_type&&)");
+ Container c;
+ const ValueTp v(42);
+ cc->expect<const ValueTp&&>();
+ assert(c.emplace(std::move(v)).second);
+ assert(!cc->unchecked());
+ {
+ DisableAllocationGuard g;
+ const ValueTp v2(42);
+ assert(c.emplace(std::move(v2)).second == false);
+ }
+ }
+}
+
+
int main()
{
testContainerInsert<TCT::unordered_set<> >();
+ testContainerEmplace<TCT::unordered_set<> >();
}
