diff options
Diffstat (limited to 'applause.lua')
| -rw-r--r-- | applause.lua | 83 |
1 files changed, 70 insertions, 13 deletions
diff --git a/applause.lua b/applause.lua index 4f278b1..5fe77e4 100644 --- a/applause.lua +++ b/applause.lua @@ -1,6 +1,9 @@ local sndfile = require "sndfile" -local ffi = require "ffi" local bit = require "bit" +local ffi = require "ffi" +-- According to LuaJIT docs, it makes sense to cache +-- the FFI namespace +local C = ffi.C -- Make table.new() available (a LuaJIT extension) require "table.new" @@ -35,9 +38,9 @@ function benchmark(fnc) local t1 = ffi.new("struct timespec[1]") local t2 = ffi.new("struct timespec[1]") - ffi.C.clock_gettime("CLOCK_PROCESS_CPUTIME_ID", t1) + C.clock_gettime("CLOCK_PROCESS_CPUTIME_ID", t1) fnc() - ffi.C.clock_gettime("CLOCK_PROCESS_CPUTIME_ID", t2) + C.clock_gettime("CLOCK_PROCESS_CPUTIME_ID", t2) local t1_ms = t1[0].tv_sec*1000 + t1[0].tv_nsec/1000000 local t2_ms = t2[0].tv_sec*1000 + t2[0].tv_nsec/1000000 @@ -45,6 +48,20 @@ function benchmark(fnc) print("Elapsed CPU time: "..(t2_ms - t1_ms).."ms") end +-- +-- Define the Lua FFI part of Applause's C core. +-- These functions and types are defined in applause.c +-- +ffi.cdef[[ +enum applause_audio_state { + APPLAUSE_AUDIO_OK = 0, + APPLAUSE_AUDIO_INTERRUPTED, + APPLAUSE_AUDIO_XRUN +}; + +enum applause_audio_state applause_push_sample(double sample_double); +]] + -- Sample rate -- This is overwritten by the C core samplerate = 44100 @@ -62,10 +79,8 @@ function msec(x) return sec((x or 1)/1000) end -- A clock signal is necessary to "trigger" the recalculation -- of a stream's current sample. -- The clock signal is a boolean oscillating between true and --- false. The global function is for advancing the clock more --- or less efficiently from the play() method implemented in C. +-- false. local clock_signal = false -function clockCycle() clock_signal = not clock_signal end -- FIXME: Inconsistent naming. Use all-lower case for functions -- and methods? @@ -371,9 +386,49 @@ function Stream:len() return math.huge -- infinity end --- implemented in applause.c function Stream:play() - error("C function not registered!") + self:reset() + + local tick = self:tick() + + -- Make sure JIT compilation is turned on for the generator function + -- and all subfunctions. + -- This should not be necessary theoretically. + jit.on(true, true) + jit.on(tick, true) + + -- Perform garbage collection cycle and turn it off + -- temporarily. This improves the realtime properties + -- of the sample generation loop below. + collectgarbage("collect") + collectgarbage("stop") + + local state + repeat + -- Advance clock + clock_signal = not clock_signal + + local sample = tick() + if not sample then break end + + -- FIXME: What if the sample is not a number, + -- perhaps we should check that here + state = C.applause_push_sample(sample) + + -- React to buffer underruns. + -- This is done here instead of in the realtime thread + -- even though it is already overloaded, so as not to + -- affect other applications in the Jack graph. + if state == C.APPLAUSE_AUDIO_XRUN then + io.stderr:write("WARNING: Buffer underrun detected\n") + end + until state == C.APPLAUSE_AUDIO_INTERRUPTED + + collectgarbage("restart") + + if state == C.APPLAUSE_AUDIO_INTERRUPTED then + error("SIGINT received", 2) + end end -- implemented in applause.c @@ -394,11 +449,13 @@ function Stream:save(filename, format) local tick = self:tick() while true do - clockCycle() + clock_signal = not clock_signal local sample = tick() if not sample then break end + -- FIXME: What if the sample is not a number, + -- perhaps we should check that here hnd:write(sample) end @@ -416,7 +473,7 @@ function Stream:totable() local vector = table.new(self:len(), 0) while true do - clockCycle() + clock_signal = not clock_signal local value = tick() if not value then break end @@ -1554,15 +1611,15 @@ function Client:ctor(pid) end function Client:play() - ffi.C.kill(self.pid, 10); -- SIGUSR1 + C.kill(self.pid, 10); -- SIGUSR1 end function Client:stop() - ffi.C.kill(self.pid, 12); -- SIGUSR2 + C.kill(self.pid, 12); -- SIGUSR2 end function Client:kill() - ffi.C.kill(self.pid, 15); -- SIGTERM + C.kill(self.pid, 15); -- SIGTERM end Client.__gc = Client.kill |