[xemacs-hg @ 2003-02-13 09:57:04 by ben] profile updates profile.c: Major reworking. Keep track of new information -- total function timing (includes descendants), GC usage, total GC usage (includes descendants). New functions to be called appropriately from eval.c, alloc.c to keep track of this information. Keep track of when we're actually in a function vs. in its profile, for more accurate timing counts. Track profile overhead separately. Create new mechanism for specifying "internal sections" that are tracked just like regular Lisp functions and even appear in the backtrace if `backtrace-with-internal-sections' is non-nil (t by default for error-checking builds). Add some KKCC information for the straight (non-Elisp) hash table used by profile, which contains Lisp objects in its keys -- but not used yet. Remove old ad-hoc methods for tracking garbage collection, redisplay (which was incorrect anyway when Lisp was called within these sections). Don't record any tick info when blocking under MS Windows, since the timer there is in real time rather than in process time. Make `start-profiling', `stop-profiling' interactive. Be consistent wrt. recursive functions and functions currently on the stack when starting or stopping -- together these make implementing the `total' values extremely difficult. When we start profiling, we act as if we just entered all the functions currently on the stack. Likewise when exiting. Create vars in_profile for tracking time spent inside of profiling, and profiling_lock for setting exclusive access to the main hash table when reading from it or modifying it. (protects against getting screwed up by the signal handle going off at the same time. profile.h: New file. Create macros for declaring internal profiling sections. lisp.h: Move profile-related stuff to profile.h. alloc.c: Keep track of total consing, for profile. Tell profile when we are consing. Use new profile-section method for noting garbage-collection. alloc.c: Abort if we attempt to call the allocator reentrantly. backtrace.h, eval.c: Add info for use by profile in the backtrace frame and transfer PUSH_BACKTRACE/POP_BACKTRACE from eval.c, for use with profile. elhash.c: Author comment. eval.c, lisp.h: New Lisp var `backtrace-with-internal-sections'. Set to t when error-checking is on. eval.c: When unwinding, eval.c: Report to profile when we are about-to-call and just-called wrt. a function. alloc.c, eval.c: Allow for "fake" backtrace frames, for internal sections (used by profile and `backtrace-with-internal-sections'. event-Xt.c, event-gtk.c, event-msw.c, event-tty.c: Record when we are actually blocking on an event, for profile's sake. event-stream.c: Record internal profiling sections for getting, dispatching events. extents.c: Record internal profiling sections for map_extents. hash.c, hash.h: Add pregrow_hash_table_if_necessary(). (Used in profile code since the signal handler is the main grower but can't allow a realloc(). We make sure, at critical points, that the table is large enough.) lread.c: Create internal profiling sections for `load' (which may be triggered internally by autoload, etc.). redisplay.c: Remove old profile_redisplay_flag. Use new macros to declare internal profiling section for redisplay. text.c: Use new macros to declare internal profiling sections for char-byte conversion and internal-external conversion. SEMI-UNRELATED CHANGES: ----------------------- text.c: Update the long comments.

		DYNODUMP
		--------

Dynodump, not to be confused with DinoTurd (as seen in Jurassic Park),
is a shared object that provides one function:

	int dynodump(char *new_file);

dynodump(), called from a running program will write a new executable
in new_file a la unexec() in GNU Emacs.  The difference lies in the
relocations.

dynodump() will create an image with any relocations (which were
performed by the run-time dynamic linker) undone.  This allows the new
image to be run in a different environment.  There is, however, one
potentially major caveat.  If a symbol reference gets updated during
the running of the calling program, its updated value will be lost.
An example (with additional blank lines for legibility):

	$ cat lib.c
	char _foo[] = "hello";
	char _bar[] = "world";

	$ cc -G -o lib.so lib.c

	$ cat prog.c
	extern char _foo, _bar;
 
	int beenhere = 0;
	char * foo = &_foo;
	char * bar = &_bar;
 
	int
	main(void)
	{
	    (void) printf("%d: foo = %x\n", beenhere, foo);
	    (void) printf("%d: bar = %x, ", beenhere, bar);
 
	    if (!beenhere) {
	        beenhere = 1;
	        bar++;
	        dynodump("newfile");
	    }
	    (void) printf("%x\n", bar);
	}

	$ cc -o prog prog.c -R. lib.so dynodump.so

	$ ./prog
	0: foo = ef7503cc
	0: bar = ef7503d2, ef7503d3

	$ ./newfile
	1: foo = ef7503cc
	1: bar = ef7503d2, ef7503d2

Notice that in the run of newfile, bar points at "world" instead of
the perhaps expected "orld".

Dynodump supports sparc, intel, and power pc architectures.

Dynodump is buildable with GNU make and gcc.  If it works for you
with these tools, let me know.

unexec()
--------

Also supplied is an unexsol2.c which belongs in the XEmacs src
directory with the other unex*.c files.  The src/s/sol2.h should be
have the following added to it:

	#ifdef UNEXEC
	#undef UNEXEC
	#endif
	#define UNEXEC unexsol2.o

This unexec() will attempt to dlopen() the dynodump.so to find the
dynodump function.  The default is "../dynodump/dynodump.so" which
should be appropriate for the typical XEmacs build (unless you used
configure to set up separate build and source trees).  You may change
it by setting the DYNODUMP environment variable to the full path of
the dynodump shared object.

Other notes:

If you're using the 4.0 C compiler from Sun, you should arrange to
shut off the incremental linker.  This is done with the -xildoff
option to the compiler.  The common.mk and testsuite/Makefile files
have commentary and ready made lines for uncommenting for this
purpose.

If you're interested in playing with the UltraSPARC specific options
to the aforementioned compiler, then the same makefiles have some
commentary and flags settings to point you in that direction.

Questions:

dynodump() was developed by Rod.Evans@Eng.Sun.COM and
Georg.Nikodym@Canada.Sun.COM.  If you have questions, feel free to ask
them but be aware that Rod, "don't know jack about emacs."