Tom Lane wrote: > Alvaro Herrera <[EMAIL PROTECTED]> writes: > > Oh, another thing that I think may be happening is that the stack is > > restored in longjmp, so it is trying to report an error elsewhere but > > it crashes because something got overwritten or something; i.e. a > > bug in the error recovery code. > > Hm, something trying to elog before the setjmp's been executed? > Although I thought it was coded so that elog.c would just proc_exit > if there was noplace to longjmp to. A mistake here might explain > the lack of any message in the postmaster log: if elog.c thinks it > should longjmp then it doesn't print the message first.
Well, there seems to be plenty of code which is happy to elog(ERROR) before the longjmp target block has been set; for example InitFileAccess(), which is called on BaseInit(), which comes before sigsetjmp() both on postgres.c and autovacuum.c. (This particular case is elog(FATAL) not ERROR however). mdinit() also does some memory allocation which could certainly fail. I'm wondering if it wouldn't be more robust to define a longjmp target block before calling BaseInit(), and have it exit cleanly in case of failure (which is what you say elog.c should be doing if there is no target block). In errstart(), it is checked if PG_exception_stack is NULL. Now, this symbol is defined in elog.c and initialized to NULL, but I wonder if a child process inherits the value that postmaster set, or it comes back to NULL. The backend would not inherit any of the values the postmaster set if the latter were the case, so I'm assuming that PG_exception_stack stays as the postmaster left it. I wonder what happens if the child process finds that this is an invalid point to jump to? -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
