RFC 2: Add Fiber::ExecutionContext::Isolated

spec/std/fiber/execution_context/global_queue_spec.cr

@@ -1,4 +1,5 @@
 require "./spec_helper"
+require "../../../support/thread"
 
 describe Fiber::ExecutionContext::GlobalQueue do
   it "#initialize" do
@@ -98,10 +99,9 @@ describe Fiber::ExecutionContext::GlobalQueue do
       increments = 15
       queue = Fiber::ExecutionContext::GlobalQueue.new(Thread::Mutex.new)
       ready = Thread::WaitGroup.new(n)
-      shutdown = Thread::WaitGroup.new(n)
 
-      n.times do |i|
-        Thread.new("ONE-#{i}") do |thread|
+      threads = Array(Thread).new(n) do |i|
+        new_thread("ONE-#{i}") do
           slept = 0
           ready.done
 
@@ -117,10 +117,6 @@ describe Fiber::ExecutionContext::GlobalQueue do
               break
             end
           end
-        rescue exception
-          Crystal::System.print_error "\nthread: #{thread.name}: exception: #{exception}"
-        ensure
-          shutdown.done
         end
       end
       ready.wait
@@ -130,7 +126,7 @@ describe Fiber::ExecutionContext::GlobalQueue do
         Thread.sleep(10.nanoseconds) if i % 10 == 9
       end
 
-      shutdown.wait
+      threads.each(&.join)
 
       # must have dequeued each fiber exactly X times
       fibers.each { |fc| fc.counter.should eq(increments) }
@@ -146,10 +142,9 @@ describe Fiber::ExecutionContext::GlobalQueue do
 
       queue = Fiber::ExecutionContext::GlobalQueue.new(Thread::Mutex.new)
       ready = Thread::WaitGroup.new(n)
-      shutdown = Thread::WaitGroup.new(n)
 
-      n.times do |i|
-        Thread.new("BULK-#{i}") do |thread|
+      threads = Array(Thread).new(n) do |i|
+        new_thread("BULK-#{i}") do
           slept = 0
 
           r = Fiber::ExecutionContext::Runnables(3).new(queue)
@@ -200,10 +195,6 @@ describe Fiber::ExecutionContext::GlobalQueue do
             slept += 1
             Thread.sleep(1.nanosecond) # don't burn CPU
           end
-        rescue exception
-          Crystal::System.print_error "\nthread #{thread.name} raised: #{exception}"
-        ensure
-          shutdown.done
         end
       end
       ready.wait
@@ -216,7 +207,7 @@ describe Fiber::ExecutionContext::GlobalQueue do
         Thread.sleep(10.nanoseconds) if i % 4 == 3
       end
 
-      shutdown.wait
+      threads.each(&.join)
 
       # must have dequeued each fiber exactly X times (no less, no more)
       fibers.each { |fc| fc.counter.should eq(increments) }

spec/std/fiber/execution_context/runnables_spec.cr

@@ -1,4 +1,5 @@
 require "./spec_helper"
+require "../../../support/thread"
 
 describe Fiber::ExecutionContext::Runnables do
   it "#initialize" do
@@ -190,14 +191,13 @@ describe Fiber::ExecutionContext::Runnables do
 
       global_queue = Fiber::ExecutionContext::GlobalQueue.new(Thread::Mutex.new)
       ready = Thread::WaitGroup.new(n)
-      shutdown = Thread::WaitGroup.new(n)
 
       all_runnables = Array(Fiber::ExecutionContext::Runnables(16)).new(n) do
         Fiber::ExecutionContext::Runnables(16).new(global_queue)
       end
 
-      n.times do |i|
-        Thread.new("RUN-#{i}") do |thread|
+      threads = Array(Thread).new(n) do |i|
+        new_thread("RUN-#{i}") do
           runnables = all_runnables[i]
           slept = 0
 
@@ -239,10 +239,6 @@ describe Fiber::ExecutionContext::Runnables do
             slept += 1
             Thread.sleep(1.nanosecond) # don't burn CPU
           end
-        rescue exception
-          Crystal::System.print_error "\nthread #{thread.name} raised: #{exception}"
-        ensure
-          shutdown.done
         end
       end
       ready.wait
@@ -255,7 +251,7 @@ describe Fiber::ExecutionContext::Runnables do
         Thread.sleep(10.nanoseconds) if i % 2 == 1
       end
 
-      shutdown.wait
+      threads.map(&.join)
 
       # must have dequeued each fiber exactly X times (no less, no more)
       fibers.each { |fc| fc.counter.should eq(increments) }

spec/std/file_spec.cr

@@ -1,4 +1,5 @@
 require "./spec_helper"
+require "../support/thread"
 
 private def it_raises_on_null_byte(operation, file = __FILE__, line = __LINE__, end_line = __END_LINE__, &block)
   it "errors on #{operation}", file, line, end_line do
@@ -109,7 +110,7 @@ describe "File" do
           #        thread or process also opened the file; we should pass
           #        O_NONBLOCK to the open(2) call itself, not afterwards
           file = nil
-          Thread.new { file = File.new(path, "w", blocking: nil) }
+          new_thread { file = File.new(path, "w", blocking: nil) }
 
           begin
             File.open(path, "r", blocking: false) do |file|

spec/std/thread/condition_variable_spec.cr

@@ -1,4 +1,5 @@
 require "../spec_helper"
+require "../../support/thread"
 
 # interpreter doesn't support threads yet (#14287)
 pending_interpreted describe: Thread::ConditionVariable do
@@ -7,7 +8,7 @@ pending_interpreted describe: Thread::ConditionVariable do
     cond = Thread::ConditionVariable.new
 
     mutex.synchronize do
-      Thread.new do
+      new_thread do
         mutex.synchronize { cond.signal }
       end
 
@@ -22,7 +23,7 @@ pending_interpreted describe: Thread::ConditionVariable do
     waiting = 0
 
     5.times do
-      Thread.new do
+      new_thread do
         mutex.synchronize do
           waiting += 1
           cv1.wait(mutex)
@@ -78,7 +79,7 @@ pending_interpreted describe: Thread::ConditionVariable do
     cond = Thread::ConditionVariable.new
 
     mutex.synchronize do
-      Thread.new do
+      new_thread do
         mutex.synchronize { cond.signal }
       end
 

spec/std/thread/mutex_spec.cr

@@ -1,4 +1,5 @@
 require "../spec_helper"
+require "../../support/thread"
 
 # interpreter doesn't support threads yet (#14287)
 pending_interpreted describe: Thread::Mutex do
@@ -7,7 +8,7 @@ pending_interpreted describe: Thread::Mutex do
     mutex = Thread::Mutex.new
 
     threads = Array.new(10) do
-      Thread.new do
+      new_thread do
         mutex.synchronize { a += 1 }
       end
     end
@@ -22,15 +23,15 @@ pending_interpreted describe: Thread::Mutex do
     mutex.try_lock.should be_false
     expect_raises(RuntimeError) { mutex.lock }
     mutex.unlock
-    Thread.new { mutex.synchronize { } }.join
+    new_thread { mutex.synchronize { } }.join
   end
 
   it "won't unlock from another thread" do
     mutex = Thread::Mutex.new
     mutex.lock
 
     expect_raises(RuntimeError) do
-      Thread.new { mutex.unlock }.join
+      new_thread { mutex.unlock }.join
     end
 
     mutex.unlock

spec/std/thread_spec.cr

@@ -1,24 +1,25 @@
 require "./spec_helper"
+require "../support/thread"
 
 # interpreter doesn't support threads yet (#14287)
 pending_interpreted describe: Thread do
   it "allows passing an argumentless fun to execute" do
     a = 0
-    thread = Thread.new { a = 1; 10 }
+    thread = new_thread { a = 1; 10 }
     thread.join
     a.should eq(1)
   end
 
   it "raises inside thread and gets it on join" do
-    thread = Thread.new { raise "OH NO" }
+    thread = new_thread { raise "OH NO" }
     expect_raises Exception, "OH NO" do
       thread.join
     end
   end
 
   it "returns current thread object" do
     current = nil
-    thread = Thread.new { current = Thread.current }
+    thread = new_thread { current = Thread.current }
     thread.join
     current.should be(thread)
     current.should_not be(Thread.current)
@@ -31,7 +32,7 @@ pending_interpreted describe: Thread do
   it "yields the processor" do
     done = false
 
-    thread = Thread.new do
+    thread = new_thread do
       3.times { Thread.yield }
       done = true
     end
@@ -51,7 +52,7 @@ pending_interpreted describe: Thread do
     {% end %}
 
     name = nil
-    thread = Thread.new(name: "some-name") do
+    thread = new_thread(name: "some-name") do
       name = Thread.current.name
     end
     thread.name.should eq("some-name")

spec/support/thread.cr

@@ -0,0 +1,10 @@
+{% begin %}
+  def new_thread(name = nil, &block) : Thread
+    {% if flag?(:execution_context) %}
+      ctx = Fiber::ExecutionContext::Isolated.new(name: name || "SPEC") { block.call }
+      ctx.@thread
+    {% else %}
+      Thread.new(name) { block.call }
+    {% end %}
+  end
+{% end %}

src/crystal/system/win32/file_descriptor.cr

@@ -519,7 +519,11 @@ private module ConsoleUtils
   @@read_requests = Deque(ReadRequest).new
   @@bytes_read = Deque(Int32).new
   @@mtx = ::Thread::Mutex.new
-  @@reader_thread = ::Thread.new { reader_loop }
+  {% if flag?(:execution_context) %}
+    @@reader_thread = ::Fiber::ExecutionContext::Isolated.new("READER-LOOP") { reader_loop }
+  {% else %}
+    @@reader_thread = ::Thread.new { reader_loop }
+  {% end %}
 
   private def self.reader_loop
     while true