Add low-overhead profiler. Part 3: command line interface.

1 files changed, 216 insertions, 0 deletions

diff --git a/src/jit/p.lua b/src/jit/p.lua
new file mode 100644
index 00000000..a93172da
--- /dev/null
+++ b/src/jit/p.lua
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+----------------------------------------------------------------------------
+-- LuaJIT profiler.
+--
+-- Copyright (C) 2005-2013 Mike Pall. All rights reserved.
+-- Released under the MIT license. See Copyright Notice in luajit.h
+----------------------------------------------------------------------------
+--
+-- This module is a simple command line interface to the built-in
+-- low-overhead profiler of LuaJIT.
+--
+-- The lower-level API of the profiler is accessible via the "jit.profile"
+-- module or the luaJIT_profile_* C API.
+--
+-- Example usage:
+--
+--   luajit -jp myapp.lua
+--   luajit -jp=s myapp.lua
+--   luajit -jp=-s myapp.lua
+--   luajit -jp=vl myapp.lua
+--   luajit -jp=G,profile.txt myapp.lua
+--
+-- The following dump features are available:
+--
+--   f  Stack dump: function name, Otherwise module:line. Default mode
+--   F  Stack dump: ditto, but always prepend module.
+--   l  Stack dump: module:line.
+--   <number> stack dump depth (callee < caller). Default: 1.
+--   -<number> Inverse stack dump depth (caller > callee).
+--   s  Split stack dump after first stack level. Implies abs(depth) >= 2.
+--   p  Show full path for module names.
+--   v  Show VM states. Can be combined with stack dumps, e.g. vf or fv.
+--   z  Show zones. Can be combined with stack dumps, e.g. zf or fz.
+--   r  Show raw sample counts. Default: show percentages.
+--   G  Produce output suitable for graphical tools (e.g. flame graphs).
+--   n<number> Show top N samples. Default: 10.
+--   i<number> Sampling interval in milliseconds. Default: 10.
+--
+----------------------------------------------------------------------------
+
+-- Cache some library functions and objects.
+local jit = require("jit")
+assert(jit.version_num == 20100, "LuaJIT core/library version mismatch")
+local profile = require("jit.profile")
+local vmdef = require("jit.vmdef")
+local pairs, tonumber, floor, min = pairs, tonumber, math.floor, math.min
+local sort, format = table.sort, string.format
+local stdout = io.stdout
+local zone -- Load jit.zone module on demand.
+
+-- Output file handle.
+local out
+
+------------------------------------------------------------------------------
+
+local prof_ud
+local prof_states, prof_split, prof_maxn, prof_raw, prof_fmt, prof_depth
+local prof_count1, prof_count2, prof_samples
+
+local map_vmmode = {
+  N = "Compiled",
+  I = "Interpreted",
+  C = "C code",
+  G = "Garbage Collector",
+  J = "JIT Compiler",
+}
+
+-- Profiler callback.
+local function prof_cb(th, samples, vmmode)
+  prof_samples = prof_samples + samples
+  local key_stack, key_stack2, key_state
+  -- Collect keys for sample.
+  if prof_states then
+    if prof_states == "v" then
+      key_state = map_vmmode[vmmode] or vmmode
+    else
+      key_state = zone:get() or "(none)"
+    end
+  end
+  if prof_fmt then
+    key_stack = profile.dumpstack(th, prof_fmt, prof_depth)
+    key_stack = key_stack:gsub("%[builtin#(%d+)%]", function(x)
+      return vmdef.ffnames[tonumber(x)]
+    end)
+    if prof_split == 2 then
+      local k1, k2 = key_stack:match("(.-) [<>] (.*)")
+      if k2 then key_stack, key_stack2 = k1, k2 end
+    end
+  end
+  -- Order keys.
+  local k1, k2
+  if prof_split == 1 then
+    if key_state then
+      k1 = key_state
+      if key_stack then k2 = key_stack end
+    end
+  elseif key_stack then
+    k1 = key_stack
+    if key_stack2 then k2 = key_stack2 elseif key_state then k2 = key_state end
+  end
+  -- Coalesce samples in one or two levels.
+  if k1 then
+    local t1 = prof_count1
+    t1[k1] = (t1[k1] or 0) + samples
+    if k2 then
+      local t2 = prof_count2
+      local t3 = t2[k1]
+      if not t3 then t3 = {}; t2[k1] = t3 end
+      t3[k2] = (t3[k2] or 0) + samples
+    end
+  end
+end
+
+------------------------------------------------------------------------------
+
+-- Show top N list.
+local function prof_top(count1, count2, samples, indent)
+  local t, n = {}, 0
+  for k, v in pairs(count1) do
+    n = n + 1
+    t[n] = k
+  end
+  if not t[1] then return end
+  sort(t, function(a, b) return count1[a] > count1[b] end)
+  local raw = prof_raw
+  for i=1,min(n, prof_maxn) do
+    local k = t[i]
+    local v = count1[k]
+    if not raw then
+      out:write(format("%s%2d%%  %s\n", indent, floor(v*100/samples + 0.5), k))
+    elseif raw == "r" then
+      out:write(format("%s%5d  %s\n", indent, v, k))
+    else
+      out:write(format("%s %d\n", k, v))
+    end
+    if count2 then
+      local r = count2[k]
+      if r then
+        prof_top(r, nil, v, prof_depth < 0 and "  -> " or "  <- ")
+      end
+    end
+  end
+end
+
+------------------------------------------------------------------------------
+
+-- Finish profiling and dump result.
+local function prof_finish()
+  if prof_ud then
+    profile.stop()
+    local samples = prof_samples
+    if samples == 0 then return end
+    prof_top(prof_count1, prof_count2, samples, "")
+    prof_count1 = nil
+    prof_count2 = nil
+    prof_ud = nil
+  end
+end
+
+-- Start profiling.
+local function prof_start(mode)
+  local interval = ""
+  mode = mode:gsub("i%d*", function(s) interval = s; return "" end)
+  prof_maxn = 10
+  mode = mode:gsub("n(%d+)", function(s) prof_maxn = tonumber(s); return "" end)
+  prof_depth = 1
+  mode = mode:gsub("%-?%d+", function(s) prof_depth = tonumber(s); return "" end)
+  local m = {}
+  for c in mode:gmatch(".") do m[c] = c end
+  prof_states = m.z or m.v
+  if prof_states == "z" then zone = require("jit.zone") end
+  local scope = m.l or m.f or m.F or (prof_states and "" or "f")
+  local flags = (m.p or "")
+  prof_raw = m.r
+  if m.s then
+    prof_split = 2
+    if prof_depth == -1 or m["-"] then prof_depth = -2
+    elseif prof_depth == 1 then prof_depth = 2 end
+  else
+    prof_split = (scope == "" or mode:find("[zv].*[lfF]")) and 1 or 0
+  end
+  if m.G and scope ~= "" then
+    prof_fmt = flags..scope.."Z;"
+    prof_depth = -100
+    prof_raw = true
+    prof_maxn = 2147483647
+  elseif scope == "" then
+    prof_fmt = false
+  else
+    prof_fmt = flags..scope..(prof_depth >= 0 and "Z < " or "Z > ")
+  end
+  prof_count1 = {}
+  prof_count2 = {}
+  prof_samples = 0
+  profile.start(scope:lower()..interval, prof_cb)
+  prof_ud = newproxy(true)
+  getmetatable(prof_ud).__gc = prof_finish
+end
+
+------------------------------------------------------------------------------
+
+local function start(mode, outfile)
+  if not outfile then outfile = os.getenv("LUAJIT_PROFILEFILE") end
+  if outfile then
+    out = outfile == "-" and stdout or assert(io.open(outfile, "w"))
+  else
+    out = stdout
+  end
+  prof_start(mode or "f")
+end
+
+-- Public module functions.
+return {
+  start = start, -- For -j command line option.
+  stop = prof_finish
+}
+