Replace these with vectors allocated from the secure allocator.
This avoids mlock syscall churn on stack pages, as well as makes
it possible to get rid of these functions.
Please review this commit and the previous one carefully that
no `sizeof(vectortype)` remains in the memcpys and memcmps usage
(ick!), and `.data()` or `&vec[x]` is used as appropriate instead of
&vec.
Change CCrypter to use vectors with secure allocator instead of buffers
on in the object itself which will end up on the stack. This avoids
having to call LockedPageManager to lock stack memory pages to prevent the
memory from being swapped to disk. This is wasteful.
We normally prefer to connect to peers offering the relevant services.
If we're not connected to enough peers with relevant services, we
probably don't know about them and could use dnsseed's help.
The new benchmarks exercise script validation, CCoinsDBView caching,
mempool eviction, and wallet coin selection code.
All of the benchmarks added here are extremely simple and don't
necessarily mirror common real world conditions or interesting
performance edge cases. Details about how specific benchmarks can be
improved are noted in comments.
Github-Issue: #7883
Only allow skipping relevant services until there are four outbound
connections up.
This avoids quickly filling up with peers lacking the relevant
services when addrman has few or none of them.
There are only a few uses of `insecure_random` outside the tests.
This PR replaces uses of insecure_random (and its accompanying global
state) in the core code with an FastRandomContext that is automatically
seeded on creation.
This is meant to be used for inner loops. The FastRandomContext
can be in the outer scope, or the class itself, then rand32() is used
inside the loop. Useful e.g. for pushing addresses in CNode or the fee
rounding, or randomization for coin selection.
As a context is created per purpose, thus it gets rid of
cross-thread unprotected shared usage of a single set of globals, this
should also get rid of the potential race conditions.
- I'd say TxMempool::check is not called enough to warrant using a special
fast random context, this is switched to GetRand() (open for
discussion...)
- The use of `insecure_rand` in ConnectThroughProxy has been replaced by
an atomic integer counter. The only goal here is to have a different
credentials pair for each connection to go on a different Tor circuit,
it does not need to be random nor unpredictable.
- To avoid having a FastRandomContext on every CNode, the context is
passed into PushAddress as appropriate.
There remains an insecure_random for test usage in `test_random.h`.
This concretizes the numbers and adds a comment to make it clear that
these numbers are fixed by the protocol, and may avoid people forgetting
to claim numbers in the future (e.g. issue #8500).
Also gets rid of a weird unused `MSG_TYPE_MAX` in the middle of the
enumeration (thanks @paveljanik for noticing).
Pavel Janík