Thread: pgsql: Fix deadlock danger when atomic ops are done under spinlock.
Fix deadlock danger when atomic ops are done under spinlock. This was a danger only for --disable-spinlocks in combination with atomic operations unsupported by the current platform. While atomics.c was careful to signal that a separate semaphore ought to be used when spinlock emulation is active, spin.c didn't actually implement that mechanism. That's my (Andres') fault, it seems to have gotten lost during the development of the atomic operations support. Fix that issue and add test for nesting atomic operations inside a spinlock. Author: Andres Freund Discussion: https://postgr.es/m/20200605023302.g6v3ydozy5txifji@alap3.anarazel.de Backpatch: 9.5- Branch ------ REL_11_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/825d89dda5add2eecdc26fa36365720b22c72b71 Modified Files -------------- src/backend/storage/lmgr/spin.c | 97 ++++++++++++++++++++++++++++------------- src/test/regress/regress.c | 52 ++++++++++++++++++++++ 2 files changed, 119 insertions(+), 30 deletions(-)