you will get threads that are implemented with the portable POSIX
threads. These threads can run concurrently (unlike the previous
"coop" thread implementation), but need to cooperate for things like
-the GC. See the manual for details. [XXX - write this.]
+the GC.
The default is "pthreads", unless your platform doesn't have pthreads,
in which case "null" threads are used.
+See the manual for details, nodes "Initialization", "Multi-Threading",
+"Blocking", and others.
+
** There is the new notion of 'discouraged' features.
This is a milder form of deprecation.
* Changes to Scheme functions and syntax
+** Guardians have changed back to their original semantics
+
+Guardians now behave like described in the paper by Dybvig et al. In
+particular, they no longer make guarantees about the order in which
+they return objects, and they can no longer be greedy.
+
+They no longer drop cyclic data structures.
+
+The C function scm_make_guardian has been changed incompatibly and no
+longer takes the 'greedy_p' argument.
+
+** New function hashx-remove!
+
+This function completes the set of 'hashx' functions.
+
+** The concept of dynamic roots has been factored into continuation
+ barriers and dynamic states.
+
+Each thread has a current dynamic state that carries the values of the
+fluids. You can create and copy dynamic states and use them as the
+second argument for 'eval'. See "Fluids and Dynamic States" in the
+manual.
+
+To restrict the influence that captured continuations can have on the
+control flow, you can errect continuation barriers. See "Continuation
+Barriers" in the manual.
+
+The function call-with-dynamic-root now essentially temporarily
+installs a new dynamic state and errects a continuation barrier.
+
** The default load path no longer includes "." at the end.
Automatically loading modules from the current directory should not
procedures like 'generalized-vector-ref'. Generalized vectors include
strings, bitvectors, ordinary vectors, and uniform numeric vectors.
-Arrays use generalized vectors their storage, so that you still have
-arrays of characters, bits, etc. However, uniform-array-read! and
-uniform-array-write can no longer read/write strings and bitvectors.
+Arrays use generalized vectors as their storage, so that you still
+have arrays of characters, bits, etc. However, uniform-array-read!
+and uniform-array-write can no longer read/write strings and
+bitvectors.
** There is now support for copy-on-write substrings, mutation-sharing
substrings and read-only strings.
guile> #: foo
#:foo
+** The printing of symbols that might look like keywords can be
+ controlled.
+
+The new printer option 'quote-keywordish-symbols' controls how symbols
+are printed that have a colon as their first or last character. The
+default now is to only quote a symbol with #{...}# when the read
+option 'keywords' is not '#f'. Thus:
+
+ guile> (define foo (string->symbol ":foo"))
+ guile> (read-set! keywords #f)
+ guile> foo
+ :foo
+ guile> (read-set! keywords 'prefix)
+ guile> foo
+ #{:foo}#
+ guile> (print-set! quote-keywordish-symbols #f)
+ guile> foo
+ :foo
+
** 'while' now provides 'break' and 'continue'
break and continue were previously bound in a while loop, but not
These are convenient ways to run calculations in parallel in new
threads. See "Parallel forms" in the manual for details.
-** Fair mutexes and condition variables
-
-Fair mutexes and condition variables have been added. The fairness
-means that scheduling is arranged to give as equal time shares as
-possible and that threads are awakened in a first-in-first-out
-manner. This is not guaranteed with standard mutexes and condition
-variables.
-
-In addition, fair mutexes are recursive. Locking a fair mutex that
-you have already locked will succeed. Every call to lock-mutex must
-be matched with a call to unlock-mutex. Only the last call to
-unlock-mutex will actually unlock the mutex.
-
-A fair condition variable must be used together with a fair mutex,
-just as a standard condition variable must be used together with a
-standard mutex.
-
-*** New functions: make-fair-mutex, make-fair-condition-variable'
-
-Make a new fair mutex and a new fair condition variable respectively.
-
** New function 'try-mutex'.
This function will attempt to lock a mutex but will return immediately
C code can use the new functions scm_sigaction_for_thread and
scm_system_async_mark_for_thread to pass the new thread argument.
+When a thread blocks on a mutex, a condition variable or is waiting
+for IO to be possible, it will still execute system asyncs. This can
+be used to interrupt such a thread by making it execute a 'throw', for
+example.
+
** The function 'system-async' is deprecated.
You can now pass any zero-argument procedure to 'system-async-mark'.
* Changes to the C interface
+** The functions scm_hash_fn_remove_x and scm_hashx_remove_x no longer
+ take a 'delete' function argument.
+
+This argument makes no sense since the delete function is used to
+remove a pair from an alist, and this must not be configurable.
+
+This is an incompatible change.
+
+** The GH interface is now subject to the deprecation mechanism
+
+The GH interface has been deprecated for quite some time but now it is
+actually removed from Guile when it is configured with
+--disable-deprecated.
+
+See the manual "Transitioning away from GH" for more information.
+
** A new family of functions for converting between C values and
Scheme values has been added.
** The old uniform vector and bitvector implementations have been
unceremoniously removed.
-This implementation exposed the detailes of the tagging system of
+This implementation exposed the details of the tagging system of
Guile. Use the new C API explained in the manual in node "Uniform
Numeric Vectors" and "Bit Vectors", respectively.
Thus the call to scm_frame_unwind_handler above could be replaced with
simply scm_frame_free (mem).
-** New way to block and unblock asyncs
+** New functions scm_c_call_with_blocked_asyncs and
+ scm_c_call_with_unblocked_asyncs
+
+Like scm_call_with_blocked_asyncs etc. but for C functions.
+
+** New functions scm_frame_block_asyncs and scm_frame_unblock_asyncs
In addition to scm_c_call_with_blocked_asyncs you can now also use
scm_frame_block_asyncs in a 'frame' (see above). Likewise for
scm_c_call_with_unblocked_asyncs and scm_frame_unblock_asyncs.
+** The macros SCM_DEFER_INTS, SCM_ALLOW_INTS, SCM_REDEFER_INTS,
+ SCM_REALLOW_INTS have been deprecated.
+
+They do no longer fulfill their original role of blocking signal
+delivery. Depending on what you want to achieve, replace a pair of
+SCM_DEFER_INTS and SCM_ALLOW_INTS with a frame that locks a mutex,
+blocks asyncs, or both. See node "Critical Sections" in the manual.
+
+** The value 'scm_mask_ints' is no longer writable.
+
+Previously, you could set scm_mask_ints directly. This is no longer
+possible. Use scm_c_call_with_blocked_asyncs and
+scm_c_call_with_unblocked_asyncs instead.
+
** New way to temporarily set the current input, output or error ports
C code can now use scm_frame_current_<foo>_port in a 'frame' (see
This is an incompatible change.
-** The value 'scm_mask_ints' is no longer writable.
-
-Previously, you could set scm_mask_ints directly. This is no longer
-possible. Use scm_c_call_with_blocked_asyncs and
-scm_c_call_with_unblocked_asyncs instead.
-
-** New functions scm_c_call_with_blocked_asyncs and
- scm_c_call_with_unblocked_asyncs
-
-Like scm_call_with_blocked_asyncs etc. but for C functions.
-
** New snarfer macro SCM_DEFINE_PUBLIC.
This is like SCM_DEFINE, but also calls scm_c_export for the defined
Use scm_std_select, scm_std_sleep, scm_std_usleep instead.
-** SCM_DEFER_INTS and SCM_ALLOW_INTS have been deprecated.
-
-Use, for example, scm_frame_critical_section to mark critical
-sections.
+** The GC can no longer be blocked.
-SCM_REDEFER_INTS and SCM_REALLOW_INTS are deprecated as well, of
-course.
+The global flags scm_gc_heap_lock and scm_block_gc have been removed.
+The GC can now run (partially) concurrently with other code and thus
+blocking it is not well defined.
** Many definitions have been removed that were previously deprecated.
HCoop / bpt / guile.git / blobdiff