Fix the usage of reserve_partial in the testcase. Also update the
maximum chunk size used by the testcase. The test always created only
one chunk as the maximum size tested by it (1 << 12 = 4KB) was less
than the default max chunk size (128 KB). So, use smaller chunk size,
512 bytes, to verify that partial_reserve can reserve multiple chunks.
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
We have to account for moved objects as well
as copied objects so they will be balanced with
the respective `del_live_object` calls called
by the destructor.
However, since chunked_vector requires the
value_type to be nothrow_move_constructible,
just count the additional live object, but
do not modify _countdown or, respectively, throw
an exception, as this should be considered only
for the default and copy constructors.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently, push_back or emplace_back reallocate the last chunk
before constructing the new element.
If the arg passed to push_back/emplace_back is a reference to an
existing element in the vector, reallocating the last chunk will
invalidate the arg reference before it is used.
This patch changes the order when reallocating
the last chunk in reserve_for_emplace_back:
First, a new chunk_ptr is allocated.
Then, the back_element is emplaced in the
newly allocated array.
And only then, existing elements in the current
last chunk are migrated to the new chunk.
Eventually, the new chunk replaces the existing chunk.
If no reservation is requried, the back element
is emplaced "in place" in the current last chunk.
Fixesscylladb/scylladb#18072
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
because it has a member variable whose type is a reference. and a
reference cannot be reassigned. this silences following warning from Clang:
```
/home/kefu/dev/scylladb/test/boost/chunked_vector_test.cc:152:27: error: explicitly defaulted move assignment operator is implicitly deleted [-Werror,-Wdefaulted-function-deleted]
exception_safe_class& operator=(exception_safe_class&&) = default;
^
/home/kefu/dev/scylladb/test/boost/chunked_vector_test.cc:132:31: note: move assignment operator of 'exception_safe_class' is implicitly deleted because field '_esc' is of reference type 'exception_safety_checker &'
exception_safety_checker& _esc;
^
```
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Range tombstones are kept in memory (cache/memtable) in
range_tombstone_list. It keeps them deoverlapped, so applying a range
tombstone which covers many range tombstones will erase existing range
tombstones from the list. This operation needs to be exception-safe,
so range_tombstone_list maintains an undo log. This undo log will
receive a record for each range tombstone which is removed. For
exception safety reasons, before pushing an undo log entry, we reserve
space in the log by calling std::vector::reserve(size() + 1). This is
O(N) where N is the number of undo log entries. Therefore, the whole
application is O(N^2).
This can cause reactor stalls and availability issues when replicas
apply such deletions.
This patch avoids the problem by reserving exponentially increasing
amount of space. Also, to avoid large allocations, switches the
container to chunked_vector.
Fixes#11211Closes#11215
Fixes the case of make_room() invoked with last_chunk_capacity_deficit
but _size not in the last reserved chunk.
Found during code review, no known user impact.
Fixes#10363.
Message-Id: <20220411222605.641614-1-tgrabiec@scylladb.com>
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
A variant of reserve() which allows gentle reserving of memory. This
variant will allocate just one chunk at a time. To drive it to
completion, one should call it repeatedly with the return value of the
previous call, until it returns 0.
This variant will be used in the next patch by the large bitset creation
code, to avoid stalls when allocating large bloom filters (which are
backed by large bitset).
1. Move tests to test (using singular seems to be a convention
in the rest of the code base)
2. Move boost tests to test/boost, other
(non-boost) unit tests to test/unit, tests which are
expected to be run manually to test/manual.
Update configure.py and test.py with new paths to tests.
