GitHub pull request #2612 of commit 70270b2c3613ded3e36f5d59be83278a6b88ba6a, no merge conflicts.sha1origin/pr/2612/mergeghprbActualCommit70270b2c3613ded3e36f5d59be83278a6b88ba6aghprbActualCommitAuthorghprbActualCommitAuthorEmailghprbAuthorRepoGitUrlhttps://github.com/iovisor/bcc.gitghprbTriggerAuthorghprbTriggerAuthorEmailghprbTriggerAuthorLoginyonghong-songghprbTriggerAuthorLoginMention@yonghong-songghprbPullId2612ghprbTargetBranchmasterghprbSourceBranchyhs_devGIT_BRANCHyhs_devghprbPullAuthorEmailghprbPullAuthorLoginyonghong-songghprbPullAuthorLoginMention@yonghong-songghprbPullDescriptionGitHub pull request #2612 of commit 70270b2c3613ded3e36f5d59be83278a6b88ba6a, no merge conflicts.ghprbPullTitleAdd map-in-map supportghprbPullLinkhttps://github.com/iovisor/bcc/pull/2612ghprbPullLongDescriptionAdd BPF_MAP_TYPE_HASH_OF_MAPS and BPF_MAP_TYPE_HASH_OF_MAPS\r\nsupports in bcc. Two new constructs below are introduced\r\nto bpf program:\r\n```\r\n BPF_HASH_OF_MAPS(map_name, \"inner_map_name\", max_entries)\r\n BPF_ARRAY_OF_MAPS(map_name, \"inner_map_name\", max_entries)\r\n```\r\nIn the above, \"inner_map_name\" is for metadata purpose and there\r\nmust be a map defined in bpf program with map name \"inner_map_name\".\r\n\r\nBoth python and C++ APIs are added.\r\n\r\nFor python, a new Table API get_fd() is introduced to get\r\nthe fd of a map so that the fd can be used by a map-in-map\r\ndo update. The get_fd() is already exposed as API function\r\nin C++. For C++, without get_fd(), we will need to\r\ntemplatize basic functions like update_value etc, which\r\nI feed too heavy weight. Because of C++ using get_fd()\r\nmechanism, so I exposed similar API on python side\r\nfor parity reason.\r\n\r\nFor map-in-map, the inner map lookup/update/delete won't have\r\nexplicit map names. Considering map-in-map is not\r\nused very frequently, I feel looking primitive\r\nbpf_map_{lookup,update,delete}_elem() probably okay,\r\nso I did not create any new bcc specific\r\nconstructs for this purpose.\r\n\r\nAdded both C++ and python test cases to show how to\r\nuse the above two new map type in bcc.\r\n\r\nSigned-off-by: Yonghong Song <yhs@fb.com>ghprbCommentBody[buildbot, test this please]ghprbGhRepositoryiovisor/bccghprbCredentialsId6d3daf13-69b8-48b1-9c8f-ec5353264113false<a title="Add map-in-map support" href="https://github.com/iovisor/bcc/pull/2612">PR #2612</a>: Add map-in-map support#14811284547460664bcc-pr #148148false1481212SUCCESS1574750235920https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/148/git148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=fc25/148/148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=fc26/148/148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=fc27/148/148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=fc28/148/148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=ubuntu1604/148/148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=ubuntu1710/148/148https://buildbot.iovisor.org/jenkins/user/dalehamel/my-views/view/all/job/bcc-pr/label=ubuntu1804/148/