This changes the PoolAllocator to default the alignment to the given type. This makes the code simpler, and most importantly
fixes a bug on ARM 32bit that caused OOM: The class CTxOut has a member CAmount which is an int64_t and on ARM 32bit int64_t
are 8 byte aligned which is larger than the pointer alignment of 4 bytes. So for CCoinsMap to be able to use the pool, we
need to use the alignment of the member instead of just alignof(void*).
Affects both secure_allocator and zero_after_free_allocator.
Giving the C++ Standard Committee control of the public interface of your type means they will break it. C++23 adds a new `allocate_at_least` member to `std::allocator`. Very bad things happen when, say, `std::vector` uses `allocate_at_least` from `secure_allocator`'s base to allocate memory which it then tries to free with `secure_allocator::deallocate`.
Drive-by: Aggressively remove facilities unnecessary since C++11 from both allocators to keep things simple.
Any identifier starting with two _, or one _ followed by a capital letter is reserved for the compiler and thus must not be used. See: https://stackoverflow.com/a/228797/7130273
-BEGIN VERIFY SCRIPT-
s() { git grep -l "$1" src | xargs sed -i "s/$1/$2/g"; }
s '__pushKV' 'pushKVEnd'
s '_EraseTx' 'EraseTxNoLock'
s '_Other' 'Other'
-END VERIFY SCRIPT-
A memory resource similar to std::pmr::unsynchronized_pool_resource, but
optimized for node-based containers.
Co-Authored-By: Pieter Wuille <pieter@wuille.net>
`SecureString` is a `std::string` specialization with
a secure allocator. However, it's treated like a C-
string (no explicit length and null-terminated). This
can cause unexpected behavior. For instance, if a user
enters a passphrase with an embedded null character
(which is possible through Qt and the JSON-RPC), it will
ignore any characters after the null, giving the user
a false sense of security.
Instead of assigning `SecureString` via `std::string::c_str()`,
assign it via a `std::string_view` of the original. This
explicitly captures the size and doesn't make any extraneous
copies in memory.
986255026 Use the noexcept specifier (C++11) instead of deprecated throw() (practicalswift)
Pull request description:
Use the `noexcept` specifier (C++11) instead of deprecated `throw()`.
Tree-SHA512: cf9b6b18f61f2f59bbeceb2e43b5cd07a60f5e569c8def05c410cb72326d597c80cb731059969ef89fa5fddaae1242225886e6109fcb535c4ad62d56ebcdf1ea
Add a pool for locked memory chunks, replacing LockedPageManager.
This is something I've been wanting to do for a long time. The current
approach of locking objects where they happen to be on the stack or heap
in-place causes a lot of mlock/munlock system call overhead, slowing
down any handling of keys.
Also locked memory is a limited resource on many operating systems (and
using a lot of it bogs down the system), so the previous approach of
locking every page that may contain any key information (but also other
information) is wasteful.
