Re: (ITS#7775) LMDB terminates Postfix daemon process without logfile record

[wietse@porcupine.org]

Wietse Venema:
> Hallvard Breien Furuseth:
> > wietse@porcupine.org writes:
> > >Hallvard Breien Furuseth:
> > >> I suppose we could s/assert(foo)/mdb_assert(mc, foo)/ when that
> > >> compiles so it can report env, txn, dbi.  Howard, should I do that?
> > > 
> > > That was my idea. Allow me to code up an example, it is simpler
> > > than arguing in the abstract.
> > 
> > By all means, but I expect we understand each other.  I just needed to
> > know how muchimpact this needs to have on the lmdb's code.  The answer
> > is it must walk all over it.  And now that I think of it, it'll likely
> > introduce merge conflicts in every outstanding branch of any size.
> > So my preference is not to do this just yet.
> 
> I am settling for less, and come with a few-line change, so that
> LMDB might still end up in this month's stable Postfix release.
> 
> Hang on for a few more minutes.

Below is my "least painful" patch for both parties. What do you think?

	Wietse

*** ./work/mdb-mdb/libraries/liblmdb/mdb.c-	Tue Nov 12 11:10:33 2013
--- ./work/mdb-mdb/libraries/liblmdb/mdb.c	Thu Jan  2 16:30:47 2014
***************
*** 65,71 ****
  #include <fcntl.h>
  #endif
  
- #include <assert.h>
  #include <errno.h>
  #include <limits.h>
  #include <stddef.h>
--- 65,70 ----
***************
*** 146,151 ****
--- 145,155 ----
  # error "Two's complement, reasonably sized integer types, please"
  #endif
  
+ /* assert(3) clone. Move this to the project-correct location. */
+ static void mdb_assert(const char *, const char *, int, const char *);
+ #define assert(e) ((e) ? (void) 0 : mdb_assert(__func__, __FILE__, \
+ 			    __LINE__, #e))
+ 
  /** @defgroup internal	MDB Internals
   *	@{
   */
***************
*** 3288,3293 ****
--- 3292,3311 ----
  	return MDB_SUCCESS;
  }
  
+ void
+ (*mdb_assert_cb)(const char *,...);
+ 
+ static void
+ mdb_assert(const char *func, const char *file, int line, const char *text)
+ {
+ 	if (mdb_assert_cb != 0)
+ 		mdb_assert_cb("Assertion failed: file %s, line %d, function %s: %s",
+ 			file, line, func, text);
+ 	fprintf(stderr, "Assertion failed: file %s, line %d, function %s: %s\n",
+ 		file, line, func, text);
+ 	abort();
+ }
+ 
  static int
  mdb_env_map(MDB_env *env, void *addr, int newsize)
  {
*** ./work/mdb-mdb/libraries/liblmdb/lmdb.h-	Tue Nov 12 11:10:33 2013
--- ./work/mdb-mdb/libraries/liblmdb/lmdb.h	Thu Jan  2 16:01:37 2014
***************
*** 1429,1434 ****
--- 1429,1441 ----
  	 * @return 0 on success, non-zero on failure.
  	 */
  int	mdb_reader_check(MDB_env *env, int *dead);
+ 
+ 	/** @brief Notify application of assertion failure.
+ 	* This should become obsolete as lmdb's error handling matures.
+ 	* @param[in] fmt The assertion message, not including newline.
+ 	*/
+ extern void (*mdb_assert_cb)(const char *fmt, ...);
+ 
  /**	@} */
  
  #ifdef __cplusplus