Extract platform-specifics of Fiber, Thread and EventLoop

src/crystal/event/event_loop_libevent.cr

@@ -0,0 +1,65 @@
+require "./event_libevent"
+
+module Crystal::EventLoop
+  @@eb = Crystal::Event::Base.new
+  @@dns_base : Crystal::Event::DnsBase?
+
+  # Reinitializes the event loop after a fork.
+  def self.after_fork
+    @@eb.reinit
+  end
+
+  # Runs the event loop.
+  def self.resume
+    loop_fiber.resume
+  end
+
+  private def self.loop_fiber
+    @@loop_fiber ||= Fiber.new { @@eb.run_loop }
+  end
+
+  # Create a new resume event for a fiber.
+  def self.create_resume_event(fiber)
+    @@eb.new_event(-1, LibEvent2::EventFlags::None, fiber) do |s, flags, data|
+      data.as(Fiber).resume
+    end
+  end
+
+  # Creates a write event for a file descriptor.
+  def self.create_fd_write_event(io : IO::Evented, edge_triggered : Bool = false)
+    flags = LibEvent2::EventFlags::Write
+    flags |= LibEvent2::EventFlags::Persist | LibEvent2::EventFlags::ET if edge_triggered
+
+    @@eb.new_event(io.fd, flags, io) do |s, flags, data|
+      io_ref = data.as(typeof(io))
+      if flags.includes?(LibEvent2::EventFlags::Write)
+        io_ref.resume_write
+      elsif flags.includes?(LibEvent2::EventFlags::Timeout)
+        io_ref.resume_write(timed_out: true)
+      end
+    end
+  end
+
+  # Creates a read event for a file descriptor.
+  def self.create_fd_read_event(io : IO::Evented, edge_triggered : Bool = false)
+    flags = LibEvent2::EventFlags::Read
+    flags |= LibEvent2::EventFlags::Persist | LibEvent2::EventFlags::ET if edge_triggered
+
+    @@eb.new_event(io.fd, flags, io) do |s, flags, data|
+      io_ref = data.as(typeof(io))
+      if flags.includes?(LibEvent2::EventFlags::Read)
+        io_ref.resume_read
+      elsif flags.includes?(LibEvent2::EventFlags::Timeout)
+        io_ref.resume_read(timed_out: true)
+      end
+    end
+  end
+
+  private def self.dns_base
+    @@dns_base ||= @@eb.new_dns_base
+  end
+
+  def self.create_dns_request(nodename, servname, hints, data, &callback : LibEvent2::DnsGetAddrinfoCallback)
+    dns_base.getaddrinfo(nodename, servname, hints, data, &callback)
+  end
+end

src/crystal/event_loop.cr

@@ -1,60 +1,30 @@
-require "./event"
-
 module Crystal::EventLoop
-  @@eb = Crystal::Event::Base.new
-  @@dns_base : Crystal::Event::DnsBase?
-
-  def self.after_fork
-    @@eb.reinit
-  end
-
-  def self.resume
-    loop_fiber.resume
-  end
-
-  private def self.loop_fiber
-    @@loop_fiber ||= Fiber.new { @@eb.run_loop }
-  end
+  # Runs the event loop.
+  # def self.resume : Nil
 
-  def self.create_resume_event(fiber)
-    @@eb.new_event(-1, LibEvent2::EventFlags::None, fiber) do |s, flags, data|
-      data.as(Fiber).resume
-    end
-  end
+  # Reinitializes the event loop after a fork.
+  # def self.after_fork : Nil
 
-  def self.create_fd_write_event(io : IO::Evented, edge_triggered : Bool = false)
-    flags = LibEvent2::EventFlags::Write
-    flags |= LibEvent2::EventFlags::Persist | LibEvent2::EventFlags::ET if edge_triggered
+  # Create a new resume event for a fiber.
+  # def self.create_resume_event(fiber : Fiber) : Crystal::Event
 
-    @@eb.new_event(io.fd, flags, io) do |s, flags, data|
-      io_ref = data.as(typeof(io))
-      if flags.includes?(LibEvent2::EventFlags::Write)
-        io_ref.resume_write
-      elsif flags.includes?(LibEvent2::EventFlags::Timeout)
-        io_ref.resume_write(timed_out: true)
-      end
-    end
-  end
+  # Creates a write event for a file descriptor.
+  # def self.create_fd_write_event(io : IO::Evented, edge_triggered : Bool = false)
 
-  def self.create_fd_read_event(io : IO::Evented, edge_triggered : Bool = false)
-    flags = LibEvent2::EventFlags::Read
-    flags |= LibEvent2::EventFlags::Persist | LibEvent2::EventFlags::ET if edge_triggered
-
-    @@eb.new_event(io.fd, flags, io) do |s, flags, data|
-      io_ref = data.as(typeof(io))
-      if flags.includes?(LibEvent2::EventFlags::Read)
-        io_ref.resume_read
-      elsif flags.includes?(LibEvent2::EventFlags::Timeout)
-        io_ref.resume_read(timed_out: true)
-      end
-    end
-  end
+  # Creates a read event for a file descriptor.
+  # def self.create_fd_read_event(io : IO::Evented, edge_triggered : Bool = false)
+end
 
-  private def self.dns_base
-    @@dns_base ||= @@eb.new_dns_base
-  end
+struct Crystal::Event
+  # Frees the event.
+  # def free : Nil
 
-  def self.create_dns_request(nodename, servname, hints, data, &callback : LibEvent2::DnsGetAddrinfoCallback)
-    dns_base.getaddrinfo(nodename, servname, hints, data, &callback)
-  end
+  # Adds a new timeout to this event.
+  # def add(time_span : Time::Span?) : Nil
 end
+
+{% if flag?(:unix) %}
+  require "./event/event_loop_libevent"
+{% else %}
+  {% raise "event_loop not supported" %}
+{% end %}

src/crystal/system/fiber.cr

@@ -0,0 +1,16 @@
+module Crystal::System::Fiber
+  # Allocates memory for a stack.
+  # def self.allocate_stack(stack_size : Int) : Void*
+
+  # Frees memory of a stack.
+  # def self.free_stack(stack : Void*, stack_size : Int) : Nil
+
+  # Determines location of the top of the main process fiber's stack.
+  # def self.main_fiber_stack(stack_bottom : Void*) : Void*
+end
+
+{% if flag?(:unix) %}
+  require "./unix/fiber"
+{% else %}
+  {% raise "fiber not supported" %}
+{% end %}

src/crystal/system/unix/fiber.cr

@@ -0,0 +1,24 @@
+require "c/sys/mman"
+
+module Crystal::System::Fiber
+  def self.allocate_stack(stack_size) : Void*
+    flags = LibC::MAP_PRIVATE | LibC::MAP_ANON
+    {% if flag?(:openbsd) && !flag?(:"openbsd6.2") %}
+      flags |= LibC::MAP_STACK
+    {% end %}
+
+    pointer = LibC.mmap(nil, stack_size, LibC::PROT_READ | LibC::PROT_WRITE, flags, -1, 0)
+    raise Errno.new("Cannot allocate new fiber stack") if pointer == LibC::MAP_FAILED
+
+    {% if flag?(:linux) %}
+      LibC.madvise(pointer, stack_size, LibC::MADV_NOHUGEPAGE)
+    {% end %}
+
+    LibC.mprotect(pointer, 4096, LibC::PROT_NONE)
+    pointer
+  end
+
+  def self.free_stack(stack : Void*, stack_size) : Nil
+    LibC.munmap(stack, stack_size)
+  end
+end

src/crystal/system/unix/getrandom.cr

@@ -80,7 +80,7 @@ module Crystal::System::Random
     loop do
       read_bytes = LibC.syscall(LibC::SYS_getrandom, buf, LibC::SizeT.new(buf.size), 0)
       if read_bytes < 0 && (Errno.value == Errno::EINTR || Errno.value == Errno::EAGAIN)
-        Fiber.yield
+        ::Fiber.yield
       else
         return read_bytes
       end

src/fiber.cr

@@ -1,4 +1,3 @@
-require "c/sys/mman"
 require "thread/linked_list"
 require "./fiber/context"
 require "./fiber/stack_pool"

src/fiber/stack_pool.cr

@@ -1,3 +1,5 @@
+require "crystal/system/fiber"
+
 class Fiber
   # :nodoc:
   class StackPool
@@ -12,7 +14,7 @@ class Fiber
     def collect(count = lazy_size // 2)
       count.times do
         if stack = @deque.shift?
-          LibC.munmap(stack, STACK_SIZE)
+          Crystal::System::Fiber.free_stack(stack, STACK_SIZE)
         else
           return
         end
@@ -21,7 +23,7 @@ class Fiber
 
     # Removes a stack from the bottom of the pool, or allocates a new one.
     def checkout
-      stack = @deque.pop? || allocate
+      stack = @deque.pop? || Crystal::System::Fiber.allocate_stack(STACK_SIZE)
       {stack, stack + STACK_SIZE}
     end
 
@@ -35,22 +37,5 @@ class Fiber
     def lazy_size
       @deque.size
     end
-
-    private def allocate
-      flags = LibC::MAP_PRIVATE | LibC::MAP_ANON
-      {% if flag?(:openbsd) && !flag?(:"openbsd6.2") %}
-        flags |= LibC::MAP_STACK
-      {% end %}
-
-      pointer = LibC.mmap(nil, STACK_SIZE, LibC::PROT_READ | LibC::PROT_WRITE, flags, -1, 0)
-      raise Errno.new("Cannot allocate new fiber stack") if pointer == LibC::MAP_FAILED
-
-      {% if flag?(:linux) %}
-        LibC.madvise(pointer, STACK_SIZE, LibC::MADV_NOHUGEPAGE)
-      {% end %}
-
-      LibC.mprotect(pointer, 4096, LibC::PROT_NONE)
-      pointer
-    end
   end
 end