On Wed, 28 Dec 2005, Tom Lane wrote: > > Because the code uses _NoHoldoff, there won't be any check of > InterruptPending in that segment of code.
I guess the danger I claimed may not really happen because of the "ImmediateInterruptOK" variable. Since it is almost always false (except reading inputs and some very limited local usage), so even we don't HOLD_INTERRUPTS() in UnpinBuffer(), we are still protected by this variable in die() when a SIGTERM sneaks in. -- But this is dangerous AFAICS, since we must gaurantee that nowhere during holding BufHdrLock will invoke CHECK_FOR_INTERRUPTS(), which is *not* protected by "ImmediateInterruptOK". In other words, if we agree that the above behavior is safe, then we can use _NoHoldoff in almost the whole buffer manager code on condition that we are sure that no CHECK_FOR_INTERRUPTS() invoked while holding spinlock. So for example, in UnlockBuffers(), remove the HOLD_INTERRUPTS() pair; in write_buffer(), change LockBufHdr() to LockBufferHdr_NoHoldoff(). Regards, Qingqing ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org