[libcxx-commits] [libcxx] [libc++] Refactor some code in monotonic_buffer_resource (PR #117271)
Peng Xie via libcxx-commits
libcxx-commits at lists.llvm.org
Sun Dec 1 18:19:35 PST 2024
https://github.com/love1angel updated https://github.com/llvm/llvm-project/pull/117271
>From b2b1b6d7bf45891f221fa8e630b2ed02213910c3 Mon Sep 17 00:00:00 2001
From: Peng Xie <helianthus547 at gmail.com>
Date: Fri, 22 Nov 2024 09:21:07 +0800
Subject: [PATCH] [libc++] Refactor some code in monotonic_buffer_resource
1. remove unused __default_buffer_alignment
2. two __try_allocate_from_chunk are identical, move to implementation
file. previous sybmol can be remove from ABI without ABI breaking.
This patch refactor some code in monotonic_buffer_resource.
---
.../monotonic_buffer_resource.h | 5 +--
libcxx/lib/abi/CHANGELOG.TXT | 11 ++++++
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...bcxxabi.v1.stable.exceptions.nonew.abilist | 2 -
...xxabi.v1.stable.noexceptions.nonew.abilist | 2 -
libcxx/src/memory_resource.cpp | 37 +++++++++----------
12 files changed, 30 insertions(+), 41 deletions(-)
diff --git a/libcxx/include/__memory_resource/monotonic_buffer_resource.h b/libcxx/include/__memory_resource/monotonic_buffer_resource.h
index c5a2b556707f6a..942d490ce3aead 100644
--- a/libcxx/include/__memory_resource/monotonic_buffer_resource.h
+++ b/libcxx/include/__memory_resource/monotonic_buffer_resource.h
@@ -27,8 +27,7 @@ namespace pmr {
// [mem.res.monotonic.buffer]
class _LIBCPP_AVAILABILITY_PMR _LIBCPP_EXPORTED_FROM_ABI monotonic_buffer_resource : public memory_resource {
- static const size_t __default_buffer_capacity = 1024;
- static const size_t __default_buffer_alignment = 16;
+ static constexpr size_t __default_buffer_capacity = 1024;
struct __chunk_footer {
__chunk_footer* __next_;
@@ -38,7 +37,6 @@ class _LIBCPP_AVAILABILITY_PMR _LIBCPP_EXPORTED_FROM_ABI monotonic_buffer_resour
_LIBCPP_HIDE_FROM_ABI size_t __allocation_size() {
return (reinterpret_cast<char*>(this) - __start_) + sizeof(*this);
}
- void* __try_allocate_from_chunk(size_t, size_t);
};
struct __initial_descriptor {
@@ -48,7 +46,6 @@ class _LIBCPP_AVAILABILITY_PMR _LIBCPP_EXPORTED_FROM_ABI monotonic_buffer_resour
char* __end_;
size_t __size_;
};
- void* __try_allocate_from_chunk(size_t, size_t);
};
public:
diff --git a/libcxx/lib/abi/CHANGELOG.TXT b/libcxx/lib/abi/CHANGELOG.TXT
index f630a5a4046dff..2b490d00e393e1 100644
--- a/libcxx/lib/abi/CHANGELOG.TXT
+++ b/libcxx/lib/abi/CHANGELOG.TXT
@@ -16,6 +16,17 @@ New entries should be added directly below the "Version" header.
Version 20.0
------------
+* [libc++][PMR] Remove duplicate implementation of __try_allocate_from_chunk
+
+ This patch removes member functions __try_allocate_from_chunk from __chunk_footer and __initial_descriptor.
+ The two implementations were almost identical and can be easily moved to be implementation details of the built library.
+ Since they were only used from within the built library, the removal of these symbols should not be an ABI break.
+
+ All platforms
+ -------------
+ Symbol removed: _ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm
+ Symbol removed: _ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm
+
* [libc++] Remove the pointer safety functions from the dylib
The pointer safety functions were never implemented by anyone in a non-trivial
diff --git a/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
index 63a9872ee5558a..7f6d1f32e28be8 100644
--- a/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/arm64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1594,8 +1594,6 @@
{'is_defined': True, 'name': '__ZNSt3__13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/i686-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/i686-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist
index 4bb93b8f3105e1..50f87bc05ec91c 100644
--- a/libcxx/lib/abi/i686-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/i686-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1230,8 +1230,6 @@
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr25monotonic_buffer_resource11do_allocateEjj', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt6__ndk13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEjj', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt6__ndk13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEjj', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr28unsynchronized_pool_resource11do_allocateEjj', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEjj', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
index 0fbe2aa69fb75c..7ab386411a957b 100644
--- a/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/powerpc-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -580,8 +580,6 @@
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr20null_memory_resourceEv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
index bba9e49f23f3af..dd1833f139b2b7 100644
--- a/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/powerpc64-ibm-aix.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -580,8 +580,6 @@
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr20null_memory_resourceEv', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
-{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
{'import_export': 'EXP', 'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'storage_mapping_class': 'DS', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
index c0045384d6625b..473f2c4be6b671 100644
--- a/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-apple-darwin.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1594,8 +1594,6 @@
{'is_defined': True, 'name': '__ZNSt3__13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '__ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '__ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist
index 80fdddda7cabbb..975d7ef20676b3 100644
--- a/libcxx/lib/abi/x86_64-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-linux-android21.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1230,8 +1230,6 @@
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr25monotonic_buffer_resource11do_allocateEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt6__ndk13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt6__ndk13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr28unsynchronized_pool_resource11do_allocateEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt6__ndk13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist
index 3225e5edbcdc34..d52678ebabfb15 100644
--- a/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-freebsd.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1245,8 +1245,6 @@
{'is_defined': True, 'name': '_ZNSt3__13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
index ec8217067f352a..66a634585e9193 100644
--- a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.exceptions.nonew.abilist
@@ -1243,8 +1243,6 @@
{'is_defined': True, 'name': '_ZNSt3__13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
index 6e82c97963a13f..1c247963684cb4 100644
--- a/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
+++ b/libcxx/lib/abi/x86_64-unknown-linux-gnu.libcxxabi.v1.stable.noexceptions.nonew.abilist
@@ -1214,8 +1214,6 @@
{'is_defined': True, 'name': '_ZNSt3__13pmr20null_memory_resourceEv', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr20set_default_resourceEPNS0_15memory_resourceE', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource11do_allocateEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource14__chunk_footer25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
-{'is_defined': True, 'name': '_ZNSt3__13pmr25monotonic_buffer_resource20__initial_descriptor25__try_allocate_from_chunkEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource11do_allocateEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__do_allocateEPNS0_15memory_resourceEmm', 'type': 'FUNC'}
{'is_defined': True, 'name': '_ZNSt3__13pmr28unsynchronized_pool_resource12__adhoc_pool13__release_ptrEPNS0_15memory_resourceE', 'type': 'FUNC'}
diff --git a/libcxx/src/memory_resource.cpp b/libcxx/src/memory_resource.cpp
index 0cd575e995c0ff..e182e5aa66ef9f 100644
--- a/libcxx/src/memory_resource.cpp
+++ b/libcxx/src/memory_resource.cpp
@@ -413,6 +413,8 @@ bool synchronized_pool_resource::do_is_equal(const memory_resource& other) const
// 23.12.6, mem.res.monotonic.buffer
+constexpr size_t __default_growth_factor = 2;
+
static void* align_down(size_t align, size_t size, void*& ptr, size_t& space) {
if (size > space)
return nullptr;
@@ -429,23 +431,20 @@ static void* align_down(size_t align, size_t size, void*& ptr, size_t& space) {
return ptr;
}
-void* monotonic_buffer_resource::__initial_descriptor::__try_allocate_from_chunk(size_t bytes, size_t align) {
- if (!__cur_)
- return nullptr;
- void* new_ptr = static_cast<void*>(__cur_);
- size_t new_capacity = (__cur_ - __start_);
- void* aligned_ptr = align_down(align, bytes, new_ptr, new_capacity);
- if (aligned_ptr != nullptr)
- __cur_ = static_cast<char*>(new_ptr);
- return aligned_ptr;
-}
-
-void* monotonic_buffer_resource::__chunk_footer::__try_allocate_from_chunk(size_t bytes, size_t align) {
- void* new_ptr = static_cast<void*>(__cur_);
- size_t new_capacity = (__cur_ - __start_);
+template <bool is_initial, typename Chunk>
+void* __try_allocate_from_chunk(Chunk& self, size_t bytes, size_t align) {
+ if constexpr (is_initial) {
+ // only for __initial_descriptor.
+ // if __initial_descriptor.__cur_ equals nullptr, means no available buffer given when ctor.
+ // here we just return nullptr, let the caller do the next handling.
+ if (!self.__cur_)
+ return nullptr;
+ }
+ void* new_ptr = static_cast<void*>(self.__cur_);
+ size_t new_capacity = (self.__cur_ - self.__start_);
void* aligned_ptr = align_down(align, bytes, new_ptr, new_capacity);
if (aligned_ptr != nullptr)
- __cur_ = static_cast<char*>(new_ptr);
+ self.__cur_ = static_cast<char*>(new_ptr);
return aligned_ptr;
}
@@ -462,10 +461,10 @@ void* monotonic_buffer_resource::do_allocate(size_t bytes, size_t align) {
return roundup(newsize, footer_align) + footer_size;
};
- if (void* result = __initial_.__try_allocate_from_chunk(bytes, align))
+ if (void* result = __try_allocate_from_chunk<true, __initial_descriptor>(__initial_, bytes, align))
return result;
if (__chunks_ != nullptr) {
- if (void* result = __chunks_->__try_allocate_from_chunk(bytes, align))
+ if (void* result = __try_allocate_from_chunk<false, __chunk_footer>(*__chunks_, bytes, align))
return result;
}
@@ -478,7 +477,7 @@ void* monotonic_buffer_resource::do_allocate(size_t bytes, size_t align) {
size_t previous_capacity = previous_allocation_size();
if (aligned_capacity <= previous_capacity) {
- size_t newsize = 2 * (previous_capacity - footer_size);
+ size_t newsize = __default_growth_factor * (previous_capacity - footer_size);
aligned_capacity = roundup(newsize, footer_align) + footer_size;
}
@@ -491,7 +490,7 @@ void* monotonic_buffer_resource::do_allocate(size_t bytes, size_t align) {
footer->__align_ = align;
__chunks_ = footer;
- return __chunks_->__try_allocate_from_chunk(bytes, align);
+ return __try_allocate_from_chunk<false, __chunk_footer>(*__chunks_, bytes, align);
}
} // namespace pmr
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