mwrap-perl changes merged

mwrap-perl changes merged

[Eric Wong]

pushed to https://80x24.org/mwrap.git

commit b5ab9be6686aa778a4cfd7622c598736b9c42321
parent 4356beb8237a92b3 (picohttpparser: fix __SSE_4_2__ CPP check, 2023-01-07)
parent 2c25edb01139365f (undefine Mwrap::SourceLocation.allocate, 2023-01-07)
Date:   Sun Jan 8 05:03:26 2023 +0000

    Merge changes from the Perl side

    This contains many changes from https://80x24.org/mwrap-perl.git

    * Built-in RCU-friendly version of dlmalloc, no more fragile dlsym(3m)
      resolution of malloc-family functions in the constructor

    * Allocations are now backed by O_TMPFILE on $TMPDIR on modern Linux.
      Since mwrap increases memory usage greatly and I needed to use it
      on a system where I needed more VM space but lacked the ability
      to add swap.

    * Configurable C backtrace level via MWRAP=bt:$DEPTH where $DEPTH
      is a non-negative integer.  Be careful about increasing it, even
      a depth of 3-4 can be orders-of-magnitude more expensive in
      time and space.  This can be changed dynamically at runtime via
      local HTTP (see below).

    * Embedded per-process local-socket-only HTTP server obsoletes
      MwrapRack when combined with mwrap-rproxy from the Perl dist
      (set `MWRAP=socket_dir:/dir/of/sockets')
      See https://80x24.org/mwrap-perl/20221210015518.272576-4-e@80x24.org/
      for more info.

      It now supports downloading CSV (suitable for importing into sqlite 3.32.0+)

    * License switched to GPL-3+ to be compatible with GNU binutils
      since we may take code from addr2line in the future.

    * libxxhash supported if XXH3_64bits is available.