being edited in DrRacket (via places)
Added an API to let tools have access to that
information (and compute more stuff)
Used that to make an online version of Check Syntax
which led to a separately callable Check Syntax API.
Although a future thread used an atomic compare-and-swap to
set "is a list" or "not a list" flag on pairs via the
JIT-implemented `list?', the hashing function in the runtime
thread did not; as a result, it might be possible to lose
a hash code due to cache inconsistency (although I'm not
sure it's actually possible, and I couldn't trigger a problem
with a test). Most of the changes are related to using
an atomic compare-and-swap when setting a hash code, as
well as clean-ups to related code. Processor-count tests
avoid using atomic compare-and-swap on uniprocessors, which
might not support the relevant machine instructions.
As significantly, the compare-and-swap operation for the
JIT-implemented `list?' did not actually set flags on
a pair that has a hash code. This could lead to `list?'
tests that were not constant time (but only if the relevant
pair's `eq?' hash code had been used previously).
* a single function to set up all environment parameters.
* improve `getarg's treatment of default thunk
* Add an error display handler that doesn't show the context and instead
add a ,bt command to show it.
Since sets are implemented using the elements as the domain of a hash table,
the following must be true:
* element contracts for (seteq ...) must be flat
* element contracts for (seteqv ...) must be flat
* element contracts for (set ...) must be chaperones, and the resulting
contract is a chaperone contract
Also, change higher-order set/c contracts to be chaperone contracts
due to the new restrictions.
Not too much, but already tests large parts of sensitive code. Caught a
bug where ,top would use (enter! #f) but enter grabbed the wrong
namespace since it was instantiated in the wrong namespace.
