fix: resolve database deadlock:

[seelabs]

The rotateWithLock function holds a lock while it calls a callback function that's passed in by the caller. This is a problematic design that needs to be used very carefully. In this case, at least one caller passed in a callback that eventually relocks the mutex on the same thread, causing UB (a deadlock was observed). The caller was from SHAMapStoreImpl, and it called clearCaches. This clearCaches can potentially call fetchNodeObject, which tried to relock the mutex.

This patch resolves the issue by changing the mutex type to a recursive_mutex. Ideally, the code should be rewritten so it doesn't hold the mutex during the callback and the mutex should be changed back to a regular mutex.

Type of Change

• [x ] Bug fix (non-breaking change which fixes an issue)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 71.0%. Comparing base (24a275b) to head (e6e26d4). Report is 1 commits behind head on develop.

Additional details and impacted files

[](https://app.codecov.io/gh/XRPLF/rippled/pull/4989?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XRPLF) ```diff @@ Coverage Diff @@ ## develop #4989 +/- ## ======================================= Coverage 70.9% 71.0% ======================================= Files 796 796 Lines 66727 66727 Branches 10981 10973 -8 ======================================= + Hits 47333 47345 +12 + Misses 19394 19382 -12 ``` | [Files](https://app.codecov.io/gh/XRPLF/rippled/pull/4989?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XRPLF) | Coverage Δ | | |---|---|---| | [src/ripple/nodestore/impl/DatabaseRotatingImp.h](https://app.codecov.io/gh/XRPLF/rippled/pull/4989?src=pr&el=tree&filepath=src%2Fripple%2Fnodestore%2Fimpl%2FDatabaseRotatingImp.h&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XRPLF#diff-c3JjL3JpcHBsZS9ub2Rlc3RvcmUvaW1wbC9EYXRhYmFzZVJvdGF0aW5nSW1wLmg=) | `50.0% <ø> (ø)` | | ... and [3 files with indirect coverage changes](https://app.codecov.io/gh/XRPLF/rippled/pull/4989/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XRPLF) [](https://app.codecov.io/gh/XRPLF/rippled/pull/4989?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=XRPLF)