e2bab2aa16 multiprocess: add multiprocess travis configuration (Russell Yanofsky)
603fd6a2e7 depends: add MULTIPROCESS depends option (Russell Yanofsky)
5d1377b52b build: multiprocess autotools changes (Russell Yanofsky)
Pull request description:
This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).
---
This PR consists of build changes only. It adds an `--enable-multiprocess` autoconf option (off by default and marked experimental), that builds new `bitcoin-node` and `bitcoin-gui` binaries. These currently function the same as existing `bitcoind` and `bitcoin-qt` binaries, but are extended in #10102 with IPC features to execute node, wallet, and gui functions in separate processes.
In addition to adding the `--enable-multiprocess` config flag, it also adds a depends package and autoconf rules to build with the [libmultiprocess](https://github.com/chaincodelabs/libmultiprocess) library, and it adds new travis configuration to exercise the build code and run functional tests with the new binaries.
The changes in this PR were originally part of #10102 but were moved into #16367 to be able to develop and review the multiprocess build changes independently of the code changes. #16367 was briefly merged and then reverted in #18588. Only change since #16367 has been dropping the `native_boost.mk` depends package which was pointed out to be no longer necessary in https://github.com/bitcoin/bitcoin/pull/16367#issuecomment-596484337 and https://github.com/bitcoin/bitcoin/pull/18588#pullrequestreview-391765649
ACKs for top commit:
practicalswift:
ACK e2bab2aa16
Sjors:
tACK e2bab2aa16 on macOS 10.15.4
hebasto:
ACK e2bab2aa16, tested on Linux Mint 19.3 (x86_64):
Tree-SHA512: b5a76eab5abf63d9d8b6d628cbdff4cc1888eef15cafa0a5d56369e2f9d02595fed623f4b74b2cf2830c42c05a774f0943e700f9c768a82d9d348cad199e135c
97b21b302a