add bracket, reworked op and top-level perform

README.md

@@ -7,15 +7,17 @@ local function fibonacci(c, quit)
     local x, y = 0, 1
     local done = false
     repeat
-        op.choice(
-            c:put_op(x):wrap(function(value)
-                x, y = y, x+y
-            end),
-            quit:get_op():wrap(function(value)
-                print("quit")
-                done = true
-            end)
-        ):perform()
+        perform(
+            choice(
+                c:put_op(x):wrap(function(value)
+                    x, y = y, x+y
+                end),
+                quit:get_op():wrap(function(value)
+                    print("quit")
+                    done = true
+                end)
+            )
+        )
     until done
 end
 
@@ -35,7 +37,7 @@ end)
 fiber.main()
 ```
 
-Ported from the Snabb Project's [`fibers`](https://github.com/snabbco/snabb/tree/master/src/lib/fibers) and [`streams`](https://github.com/snabbco/snabb/tree/master/src/lib/stream) libraries, written by 
+Ported from the Snabb Project's [`fibers`](https://github.com/snabbco/snabb/tree/master/src/lib/fibers) and [`streams`](https://github.com/snabbco/snabb/tree/master/src/lib/stream) libraries, written by
 Andy Wingo as an implementation of Reppy et al's Concurrent ML(CML), and a fibers-based reimplementation of Lua's streams enabling smooth non-blocking access to files and sockets.
 
 Inspired by Andy's [blog post](https://wingolog.org/archives/2018/05/16/lightweight-concurrency-in-lua) introducing fibers on Lua
@@ -55,7 +57,7 @@ with the following points to bear in mind:
 ## Installation
 
 This is a pure Lua (with FFI) module with the following dependencies:
-  - lua-posix (for micro/nano timing and sleeping options, for forking and 
+  - lua-posix (for micro/nano timing and sleeping options, for forking and
   other syscall operations)
   - libffi and lua-cffi (if not using LuaJIT)
   - lua-bit32 (if not using LuaJIT)
@@ -76,7 +78,7 @@ These dependencies will be installed in a VScode devcontainer automatically. To
 
 ### Installation with LuaJIT on OpenWRT
 
-This is the simplest set up for running on OpenWRT.  
+This is the simplest set up for running on OpenWRT.
 
 `opkg update; opkg install luajit; opkg install luaposix`
 
@@ -111,15 +113,15 @@ This library implements a simple version of Concurrent ML(CML), and provides pri
 
 ## Progress
 
-All of the Snabb 'fibers' modules the following have so far been ported and 
-tested. All of Snabb's 'stream' module has also been ported, which can do 
-non-blocking reads and writes from file descriptors using familiar `line` 
-and `all` approaches. 
+All of the Snabb 'fibers' modules the following have so far been ported and
+tested. All of Snabb's 'stream' module has also been ported, which can do
+non-blocking reads and writes from file descriptors using familiar `line`
+and `all` approaches.
 
 We use the `cffi` module to port Wingo's `luajit` C ffi based
 buffers implementation in a way that will work across multiple architectures, as
 Lua versions of these buffers would be inefficient and lead to allocation and
-garbage collection without a substantial investment of time. 
+garbage collection without a substantial investment of time.
 
 ## Structured concurrency
 

examples/1-basic-usage/4-choices.lua

@@ -12,19 +12,22 @@ local fiber = require 'fibers.fiber'
 local channel = require 'fibers.channel'
 local op = require 'fibers.op'
 
+local perform, choice = op.perform, op.choice
+
 local function fibonacci(c, quit)
     local x, y = 0, 1
     local done = false
     repeat
-        op.choice(
+        local task = choice(
             c:put_op(x):wrap(function()
                 x, y = y, x+y
             end),
             quit:get_op():wrap(function()
                 print("quit")
                 done = true
             end)
-        ):perform()
+        )
+        perform(task)
     until done
 end
 
@@ -41,4 +44,4 @@ fiber.spawn(function()
     fiber.stop()
 end)
 
-fiber.main()
+fiber.main()

examples/1-basic-usage/5-choices-alt.lua

@@ -11,6 +11,8 @@ local channel = require 'fibers.channel'
 local sleep = require 'fibers.sleep'
 local op = require 'fibers.op'
 
+local perform, choice = op.perform, op.choice
+
 -- time.After() is a Go library function
 local function after(t)
     local chan = channel.new()
@@ -38,21 +40,22 @@ fiber.spawn(function()
     local boom = after(0.5)
     local done = false
     repeat
-        op.choice(
+        local task = choice(
             ticker:get_op():wrap(function()
                 print("tick.")
             end),
             boom:get_op():wrap(function()
                 print("BOOM!")
                 done = true
             end)
-        ):perform_alt(function()
+        ):or_else(function()
             print("    .")
             sleep.sleep(0.05)
         end)
+        perform(task)
     until done
 
     fiber.stop()
 end)
 
-fiber.main()
+fiber.main()

examples/1-basic-usage/6-choices-adv.lua

@@ -11,6 +11,8 @@ local cond = require 'fibers.cond'
 local op = require 'fibers.op'
 local sc = require 'fibers.utils.syscall'
 
+local perform, choice = op.perform, op.choice
+
 require("fibers.pollio").install_poll_io_handler()
 
 -- Set up the queues, channel and condition variable
@@ -60,8 +62,8 @@ fiber.spawn(function()
     socket.socket(sc.AF_UNIX, sc.SOCK_STREAM, 0):listen_unix(sockname)
     local sock = socket.connect_unix(sockname)
     while true do
-        -- Use op.choice to handle multiple potentially blocking actions
-        op.choice(
+        -- Use choice to handle multiple potentially blocking actions
+        local task = choice(
             data_q:get_op():wrap(function(value)
                 print("data received - writing to socket")
                 sock:write(value .. "\n")
@@ -79,8 +81,9 @@ fiber.spawn(function()
             sleep.sleep_op(0.5):wrap(function()
                 print("yawn - nothing happening")
             end)
-        ):perform()
+        )
+        perform(task)
     end
 end)
 
-fiber.main()
+fiber.main()

examples/1-basic-usage/context-examples.lua

@@ -5,6 +5,8 @@ local context = require 'fibers.context'
 local sleep = require 'fibers.sleep'
 local op = require 'fibers.op'
 
+local perform = op.perform
+
 -- Simulated work function
 local function do_work(task_name, duration)
     print(task_name .. " started")
@@ -20,8 +22,7 @@ local function sub_task_1(ctx)
         cancel("work_completed") -- Cancel the context (optional, as it will timeout)
     end)
 
-    local done_op = deadline_ctx:done_op()
-    op.choice(done_op):perform() -- Wait for the context to be done
+    perform(deadline_ctx:done_op()) -- Wait for the context to be done
     print("Sub-Task 1 status: " .. (deadline_ctx:err() or "completed"))
 end
 
@@ -33,8 +34,7 @@ local function sub_task_2(ctx)
         cancel("work_completed") -- Cancel the context when work is done
     end)
 
-    local done_op = cancel_ctx:done_op()
-    op.choice(done_op):perform() -- Wait for the context to be done
+    perform(cancel_ctx:done_op()) -- Wait for the context to be done
     print("Sub-Task 2 status: " .. (cancel_ctx:err() or "completed"))
 end
 

examples/2-lua-http/cq-http-fiber-test.lua

@@ -13,6 +13,8 @@ local sleep = require "fibers.sleep"
 local cqueues = require "cqueues"
 local exec = require "fibers.exec"
 
+local perform, choice = op.perform, op.choice
+
 print("installing poll handler")
 pollio.install_poll_io_handler()
 
@@ -32,14 +34,15 @@ local old_step; old_step = cqueues.interpose("step", function(self, timeout)
         local events = self:events()
         -- messy
         if events == 'r' then
-            pollio.fd_readable_op(self:pollfd()):perform()
+            perform(pollio.fd_readable_op(self:pollfd()))
         elseif events == 'w' then
-            pollio.fd_writable_op(self:pollfd()):perform()
+            perform(pollio.fd_writable_op(self:pollfd()))
         elseif events == 'rw' then
-            op.choice(
-                pollio.fd_readable_op(self:pollfd()),
-                pollio.fd_writable_op(self:pollfd())
-            ):perform()
+            perform(
+				choice(
+					pollio.fd_readable_op(self:pollfd()),
+					pollio.fd_writable_op(self:pollfd())
+            ))
         end
 		return old_step(self, 0.0)
 	end
@@ -135,4 +138,4 @@ fiber.spawn(function()
 end)
 
 print("starting fibers")
-fiber.main()
+fiber.main()

fibers/alarm.lua

@@ -7,6 +7,8 @@ local fiber = require 'fibers.fiber'
 local timer = require 'fibers.timer'
 local sc = require 'fibers.utils.syscall'
 
+local perform = op.perform
+
 local function days_in_year(y)
     return y % 4 == 0 and (y % 100 ~= 0 or y % 400 == 0) and 366 or 365
 end
@@ -240,7 +242,7 @@ end
 -- Wrapper for `absolute_op` that immediately performs the operation.
 -- @param t The absolute time (epoch) for the alarm.
 local function wait_absolute(t)
-    return wait_absolute_op(t):perform()
+    return perform(wait_absolute_op(t))
 end
 
 --- Creates an operation for a next (relative) alarm.
@@ -260,7 +262,7 @@ end
 -- @return An error if the time table is invalid.
 local function wait_next(t)
     local _, err = validate_next_table(t)
-    return err or assert(installed_alarm_handler):wait_next_op(t):perform()
+    return err or perform(assert(installed_alarm_handler):wait_next_op(t))
 end
 
 -- Public API
@@ -275,4 +277,4 @@ return {
     wait_next = wait_next,
     validate_next_table = validate_next_table,
     calculate_next = calculate_next
-}
+}

fibers/channel.lua

@@ -7,6 +7,8 @@
 local op = require 'fibers.op'
 local fifo = require 'fibers.utils.fifo'
 
+local perform = op.perform
+
 --- Channel class
 -- Represents a communication channel between fibers.
 -- @type Channel
@@ -115,7 +117,7 @@ end
 -- continue.  Otherwise, block until a receiver becomes available.
 -- @tparam any message The message to put into the Channel.
 function Channel:put(message)
-    self:put_op(message):perform()
+    return perform(self:put_op(message))
 end
 
 --- Get a message from the Channel.
@@ -125,7 +127,7 @@ end
 -- available.
 -- @treturn any The message retrieved from the Channel.
 function Channel:get()
-    return self:get_op():perform()
+    return perform(self:get_op())
 end
 
 --- @export

fibers/cond.lua

@@ -6,6 +6,8 @@
 
 local op = require 'fibers.op'
 
+local perform = op.perform
+
 local Cond = {}
 Cond.__index = Cond
 
@@ -24,7 +26,7 @@ end
 
 --- Put the fiber into a wait state on the condition variable.
 function Cond:wait()
-    return self:wait_op():perform()
+    return perform(self:wait_op())
 end
 
 --- Wake up all fibers that are waiting on this condition variable.

fibers/exec.lua

@@ -6,6 +6,8 @@ local op = require 'fibers.op'
 local buffer = require 'string.buffer'
 local sc = require 'fibers.utils.syscall'
 
+local perform, choice = op.perform, op.choice
+
 local io_mappings = {
     stdin = sc.STDIN_FILENO,
     stdout = sc.STDOUT_FILENO,
@@ -106,7 +108,7 @@ function Cmd:_output_collector(pipes)
             ops[#ops + 1] = self.ctx:done_op():wrap(close_pipes)
         end
 
-        op.choice(unpack(ops)):perform()
+        perform(choice(unpack(ops)))
     end
 
     return buf:tostring(), self:wait()
@@ -228,11 +230,11 @@ function Cmd:wait()
     if self.ctx then
         ops[#ops + 1] = self.ctx:done_op():wrap(function()
             self:kill()
-            pollio.fd_readable_op(self.process.pidfd):perform()
+            perform(pollio.fd_readable_op(self.process.pidfd))
         end)
     end
 
-    op.choice(unpack(ops)):perform()
+    perform(choice(unpack(ops)))
     local _, _, status = sc.waitpid(self.process.pid)
     self.process.state = status
     sc.close(self.process.pidfd)