Change the GC so that it can mark and sweep objects in-place, instead
of always copying. This change is helpful for reducing peak memory
use while performing a collection on a large, old heap.
Some non-copying support was already in place for locked objects,
but the new implementation is faster and more general. As an
alternative to locking, the storage manager now provides "immobile"
allocation (currently only for bytevectors, vectors, and boxes),
which allocates an object that won't move but that can be GCed if
it's not referenced. A locked object is an object that has been
immobiled and that is on a global list --- mostly the old,
non-scalable implementation of locked objects brought back, since
immobile objects cover the cases that need to scale.
original commit: aecb7b736cb1d52764c292fa6364a674958dfde3
Replace repetitive C code in "gc.c" and "vfasl.c" with an
implementation using a little "Parenthe-C" language, which is a
somewhat declarative description of object tracing. From that
descrition, we generate different kinds of tracing functions, such as
the copy function or the sweep function.
The little language is still bascially C, just with parentheses and
parameterization that is much better than trying to use the C
preprocessor. (The "mkgc.ss" file includes the compiler from
Parenthe-C to C.)
Besides replacing existing code, we also generate a new traversal to
implement `compute-object-sizes`. Finally, the GC can now perform a
fused `collect` and `compute-object-sizes` in a single traversal.
Also improve the way that locked objects are detected during GC. This
can make a significant difference (on the order of 10-20% for a full
collection) when locked objects are long-lived.
original commit: de1f5c41d729ac75822a1f1e633ec6d042c883dc
For a collect rendezvous, call the collect-notify handler in
the main thread if it is active. A collect-notify handler can
then make sure the main thread is active and try again, if
that's useful to an application.
original commit: 0bc286e81827f029dd02a3627a192edd053b3b91
loadability without actually loading; also, support for unregistering
guarded objects.
- improved error reporting for library compilation-instance errors:
now including the name of the object file from which the "wrong"
compilation instance was loaded, if it was loaded from (or compiled
to) an object file and the original importing library, if it was
previously loaded from an object file due to a library import.
syntax.ss, 7.ss, interpret.ss,
8.ms, root-experr*
- removed situation and for-input? arguments from $make-load-binary,
since the only consumer always passes 'load and #f.
7.ss,
scheme.c
- $separate-eval now prints the stderr and stdout of the subprocess
to help in diagnosing separate-eval and separate-compile issues.
mat.ss
- added unregister-guardian, which can be used to unregister
the unressurected objects registered with any guardian. guardian?
can be used to distinguish guardian procedures from other objects.
cp0.ss, cmacros.ss, cpnanopass.ss, ftype.ss, primdata.ss,
prims.ss,
gcwrapper.c, prim.c, externs.h,
4.ms, primvars.ms
release_notes.stex
smgmt.stex, threads.stex
- added verify-loadability. given a situation (visit, revisit,
or load) and zero or more pathnames (each of which may be optionally
paired with a library search path), verity-loadability checks
whether the set of object files named by those pathnames and any
additional object files required by library requirements in the
given situation can be loaded together. it raises an exception
in each case where actually attempting to load the files would
raise an exception and additionally in cases where loading files
would result in the compilation or loading of source files in
place of the object files. if the check is successful,
verity-loadability returns an unspecified value. in either case,
although portions of the object files are read, none of the
information read from the object files is retained, and none of
the object code is read, so there are no side effects other than
the file operations and possibly the raising of an exception.
library and program info records are now moved to the top of each
object file produced by one of the file compilation routines,
just after recompile info, with a marker to allow verity-loadability
to stop reading once it reads all such records. this change is
not entirely backward compatible; the repositioning of the records
can be detected by a call to list-library made from a loaded file
before the definition of one or more libraries. it is fully
backward compatible for typical library files that contain a
single library definition and nothing else. adding this feature
required changes to the object-file format and corresponding
changes in the compiler and library manager. it also required
moving cross-library optimization information from library/ct-info
records (which verity-loadability must read) to the invoke-code
for each library (which verity-loadability does not read) to
avoid reading and permanently associating record-type descriptors
in the code with their uids.
compile.ss, syntax.ss, expand-lang.ss, primdata.ss, 7.ss,
7.ms, misc.ms, root-experr*, patch*,
system.stex, release_notes.stex
- fixed a bug that bit only with the compiler compiled at
optimize-level 2: add-library/rt-records was building a library/ct-info
wrapper rather than a library/rt-info wrapper.
compile.ss
- fixed a bug in visit-library that could result in an indefinite
recursion: it was not checking to make sure the call to $visit
actually added compile-time info to the libdesc record. it's not
clear, however, whether the libdesc record can be missing
compile-time information on entry to visit-library, so the code
that calls $visit (and now checks for compile-time information
having been added) might not be reachable. ditto for
revisit-library.
syntax.ss
syntax.ss, primdata.ss,
7.ms, root-experr*, patch*,
system.stex, release_notes.stex
- added some argument-error checks for library-directories and
library-extensions, and fixed up the error messages a bit.
syntax.ss,
7.ms, root-experr*
- compile-whole-program now inserts the program record into the
object file for the benefit of verify-loadability.
syntax.ss,
7.ms, root-experr*
- changed 'loading' import-notify messages to the more precise
'visiting' or 'revisiting' in a couple of places.
syntax.ss,
7.ms, 8.ms
original commit: b911ed47190727b0e1d6a88c0e473d1757accdcd
