On Mon, Feb 27, 2017 at 5:13 AM, Noah Misch <n...@leadboat.com> wrote: > Dear 7b4ac19 authors, > > Field ps_snapshot_data usually receives four-byte alignment within > ParallelIndexScanDescData, but it contains the eight-byte whenTaken field. > The select_parallel test dies with SIGBUS on "Oracle Solaris 10 1/13 > s10s_u11wos_24a SPARC", building with gcc 4.9.2. Some credible fixes: > > 1. Move the SerializedSnapshotData declaration from snapmgr.c to snapmgr.h and > declare the ps_snapshot_data field to be of type SerializedSnapshotData. > Probably also add a field "TransactionId xids[FLEXIBLE_ARRAY_MEMBER]" to > SerializedSnapshotData, to assert the variable-length nature. > > 2. Change "char ps_snapshot_data[FLEXIBLE_ARRAY_MEMBER]" to "int64 ...". I > have attached this in SerializedSnapshot-int64-v1.patch. > > 3. Change no declarations, and make snapmgr.c memcpy() the > SerializedSnapshotData through a local buffer. I have attached this as > SerializedSnapshot-memcpy-v1.patch. > > I like (2) well enough, but I don't see that technique used elsewhere in the > tree. (1) is more typical of PostgreSQL, though I personally like it when > structs can stay private to a file. (3) is also well-attested, particularly > in xlog replay code. I am leaning toward (2). Other opinions?
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In my imagination, we were already doing #3, so I'd probably favor that approach. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
