Now that rqueue_ is an STL-compatible container,
priority_scheduler::awakened() can use std::find_if() to search for a context
with a lower priority.
Now that rqueue_ is an intrusive_list, priority_scheduler::property_change()
need not search it: it can simply test with context::ready_is_linked(). Now
that it's a doubly-linked list, we can use context::ready_unlink() to unlink.
Now that method parameters have been renamed from 'f' to 'ctx', change all
references in comments accordingly.
There was a bug when the ready queue wasn't empty, but there was no
lower-priority fiber already in the queue. In that case the fiber wouldn't be
inserted. We want the loop just to advance the iterator, but to perform the
insert regardless of where the iterator ends up. (With this logic, empty() is
no longer a special case.)
Restore the ~Verbose() message.
Add a note to the condition_variable::wait_for(..., pred) overload.
fiber_specific_ptr::reset() has no default argument.
Remove mention of launch policy deferred, since no API accepts a launch
policy argument.
Copy construction or copy assignment of a shared_future leaves other.valid()
unchanged. It won't be 'true' unless it was 'true' before.
Mention that [shared_]future::get_exception_ptr() does not invalidate.
Note that 'blocks' and 'suspends' are used interchangeably.
Add some cross-references; add link to std::allocator_arg_t. Clarify the
cross-reference to the paragraph describing BOOST_FIBERS_NO_ATOMICS.
Reformat some overly-long source lines.
When the running thread's main fiber calls this_fiber::properties<>() without
yet having passed through sched_algorithm_with_properties::awakened(), which
is what actually instantiates the fiber_properties subclass, you could end up
without a properties instance. Fortunately there's an easy workaround: call
yield().
Remove that workaround from examples/priority.cpp.
The complex logic to make a single pass through the ready queue to find the
old location and also the new insertion point was unfortunately error-prone.
Recast it as two separate passes: a simple search loop to find and unlink the
fiber_context*, then a call to awakened() to reinsert it in the correct place.
sched_algorithm_with_properties<> must intercept awakened() calls before
forwarding control to the subclass override. That pretty much requires two
different virtual methods: one for sched_algorithm subclasses WITHOUT
properties, the other for sched_algorithm_with_properties subclasses.
Originally we used a different name (awakened_props()), but that was
bothersome. It makes more sense to use a different awakened() overload
instead, one that passes in the relevant properties object.
Fix examples/priority.cpp accordingly.
Also delegate instantiation of a new properties object to new_properties()
virtual method. Overriding this method allows you to customize allocation,
instead of sched_algorithm_with_properties<> unconditionally putting the new
properties object on the heap. Validate the new_properties() return value.
