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_10_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/c2a84bee1228830e82b1d2e86dc836bc00ac812a Modified Files -------------- src/backend/storage/lmgr/spin.c | 97 ++++++++++++++++++++++++++++------------- src/test/regress/regress.c | 52 ++++++++++++++++++++++ 2 files changed, 119 insertions(+), 30 deletions(-)