phkmalloc/2

"zero' and 'junk' options to help find and diagnose malloc abuse.
EXTRA_SANITY defaults "junk" to on.
Don't dump the internal state, unless EXTRA_SANITY.
General code cleanup.
Error messages cleaned up a bit, more checking earlier.
EXTRA_SANITY is default at this time (just in case).
Performance (without EXTRA_SANITY) is better, beats gnumalloc in
both time & space most of the time:

	# In-memory test.
	./malloc 50000000 2000 8192
	159.2u 1.5s 2:41.85 99.3% 5+7742k 0+0io 0pf+0w
	./gnumalloc 50000000 2000 8192
	272.6u 0.4s 4:35.01 99.3% 5+8533k 0+0io 0pf+0w

	# Swap-space test.
	./malloc 500000 14000 8192
	6.5u 4.1s 4:08.87 4.3% 5+49209k 0+0io 9772pf+0w
	./gnumalloc 500000 14000 8192
	16.2u 14.5s 15:36.14 3.2% 5+54100k 0+0io 47651pf+0w

	# Small items test.
	./malloc 20000000 20000 2048
	67.0u 0.3s 1:07.83 99.2% 5+18199k 0+0io 4pf+0w
	./gnumalloc 20000000 20000 2048
	66.2u 0.3s 1:07.03 99.3% 5+18107k 0+0io 0pf+0w

SANITY is not an option anymore. (!!)

1 files changed, 17 insertions, 20 deletions

diff --git a/lib/libc/stdlib/malloc.3 b/lib/libc/stdlib/malloc.3
index b191415..94a3fd6 100644
--- a/lib/libc/stdlib/malloc.3
+++ b/lib/libc/stdlib/malloc.3
@@ -111,25 +111,6 @@ is zero and
 is not a null pointer, the object it points to is freed.
 .Pp
 
-.Pp
-The default is to compile with the ``SANITY'' option,
-which trades a couple of percent of performance for rather rigorous 
-sanity checking of the arguments passed to
-.Xr free 
-and
-.Xr realloc .
-.Pp
-If compiled without the ``SANITY'' option and the argument does not 
-match a pointer earlier returned by the
-.Xr calloc ,
-.Xr malloc ,
-or
-.Xr realloc
-function, or if the space has been deallocated by a call to
-.Fn free
-or
-.Xr realloc ,
-general havoc will be imminent.
 .Sh ENVIRONMENT
 This malloc will check the environment for a variable called
 .Em MALLOC_OPTIONS
@@ -139,15 +120,31 @@ Flags are single letters, uppercase means on, lowercase means off.
 .It A
 ``abort'' malloc will coredump the process, rather that tollerate failure.
 This is a very handy debugging aid, since the core file will represent the
-time of failure, rather than when the NULL pointer was accessed.
+time of failure,
+rather than when the NULL pointer was accessed.
+
 .It D
 ``dump'' malloc will dump statistics in a file called ``malloc.out'' at exit.
+
+.It J
+``junk'' fill some junk into the area allocated.
+Currently junk is bytes of 0xd0, this is pronounced ``Duh'' :-)
+
 .It R
 ``realloc'' always reallocate when
 .Fn realloc
 is called, even if the initial allocation was big enough.
 This can substantially aid in compacting memory.
+
+.It Z
+``zero'' fill some junk into the area allocated (see ``J''),
+except for the exact length the user asked for, which is zerod.
+
 .El
+.Pp
+The ``J'' and ``Z'' is mostly for testing and debugging,
+if a program changes behaviour if either of these options are used,
+it is buggy.
 .Sh RETURN VALUES
 The
 .Fn malloc