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ruby--ruby/spec/ruby/shared/fiber/resume.rb
Koichi Sasada bf3b2a4374 relax Fiber#transfer's restriction
Using Fiber#transfer with Fiber#resume for a same Fiber is
limited (once Fiber#transfer is called for a fiber, the fiber
can not be resumed more). This restriction was introduced to
protect the resume/yield chain, but we realized that it is too much
to protect the chain. Instead of the current restriction, we
introduce some other protections.

(1) can not transfer to the resuming fiber.
(2) can not transfer to the yielding fiber.
(3) can not resume transferred fiber.
(4) can not yield from not-resumed fiber.

[Bug #17221]

Also at the end of a transferred fiber, it had continued on root fiber.
However, if the root fiber resumed a fiber (and that fiber can resumed
another fiber), this behavior also breaks the resume/yield chain.
So at the end of a transferred fiber, switch to the edge of resume
chain from root fiber.
For example, root fiber resumed f1 and f1 resumed f2, transferred to
f3 and f3 terminated, then continue from the fiber f2 (it was continued
from root fiber without this patch).
2020-10-12 22:58:41 +09:00

58 lines
1.6 KiB
Ruby

describe :fiber_resume, shared: true do
it "can be invoked from the root Fiber" do
fiber = Fiber.new { :fiber }
fiber.send(@method).should == :fiber
end
it "raises a FiberError if invoked from a different Thread" do
fiber = Fiber.new { 42 }
Thread.new do
-> {
fiber.send(@method)
}.should raise_error(FiberError)
end.join
# Check the Fiber can still be used
fiber.send(@method).should == 42
end
it "passes control to the beginning of the block on first invocation" do
invoked = false
fiber = Fiber.new { invoked = true }
fiber.send(@method)
invoked.should be_true
end
it "returns the last value encountered on first invocation" do
fiber = Fiber.new { 1+1; true }
fiber.send(@method).should be_true
end
it "runs until the end of the block" do
obj = mock('obj')
obj.should_receive(:do).once
fiber = Fiber.new { 1 + 2; a = "glark"; obj.do }
fiber.send(@method)
end
it "accepts any number of arguments" do
fiber = Fiber.new { |a| }
-> { fiber.send(@method, *(1..10).to_a) }.should_not raise_error
end
it "raises a FiberError if the Fiber is dead" do
fiber = Fiber.new { true }
fiber.send(@method)
-> { fiber.send(@method) }.should raise_error(FiberError)
end
it "raises a LocalJumpError if the block includes a return statement" do
fiber = Fiber.new { return; }
-> { fiber.send(@method) }.should raise_error(LocalJumpError)
end
it "raises a LocalJumpError if the block includes a break statement" do
fiber = Fiber.new { break; }
-> { fiber.send(@method) }.should raise_error(LocalJumpError)
end
end