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30 <div class="sectionbody">
31 <div class="listingblock">
32 <div class="content"><div class="highlight"><pre><span class="k">signature</span><span class="w"> </span><span class="n">MLTON_PROFILE</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
33 <span class="w"> </span><span class="k">sig</span><span class="w"></span>
34 <span class="w"> </span><span class="k">structure</span><span class="w"> </span><span class="n">Data</span><span class="p">:</span><span class="w"></span>
35 <span class="w"> </span><span class="k">sig</span><span class="w"></span>
36 <span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"></span>
38 <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">equals</span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="n">*</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">bool</span><span class="w"></span>
39 <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">free</span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">unit</span><span class="w"></span>
40 <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">malloc</span><span class="p">:</span><span class="w"> </span><span class="n">unit</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">t</span><span class="w"></span>
41 <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">write</span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="n">*</span><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">unit</span><span class="w"></span>
42 <span class="w"> </span><span class="k">end</span><span class="w"></span>
44 <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">isOn</span><span class="p">:</span><span class="w"> </span><span class="n">bool</span><span class="w"></span>
45 <span class="w"> </span><span class="k">val</span><span class="w"> </span><span class="n">withData</span><span class="p">:</span><span class="w"> </span><span class="n">Data</span><span class="p">.</span><span class="n">t</span><span class="w"> </span><span class="n">*</span><span class="w"> </span><span class="p">(</span><span class="n">unit</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">'a</span><span class="p">)</span><span class="w"> </span><span class="p">-></span><span class="w"> </span><span class="n">'a</span><span class="w"></span>
46 <span class="w"> </span><span class="k">end</span><span class="w"></span>
47 </pre></div></div></div>
48 <div class="paragraph"><p><span class="monospaced">MLton.Profile</span> provides <a href="Profiling">Profiling</a> control from within the
49 program, allowing you to profile individual portions of your
50 program. With <span class="monospaced">MLton.Profile</span>, you can create many units of profiling
51 data (essentially, mappings from functions to counts) during a run of
52 a program, switch between them while the program is running, and
53 output multiple <span class="monospaced">mlmon.out</span> files.</p></div>
54 <div class="ulist"><ul>
57 <span class="monospaced">isOn</span>
59 <div class="paragraph"><p>a compile-time constant that is false only when compiling <span class="monospaced">-profile no</span>.</p></div>
63 <span class="monospaced">type Data.t</span>
65 <div class="paragraph"><p>the type of a unit of profiling data. In order to most efficiently
66 execute non-profiled programs, when compiling <span class="monospaced">-profile no</span> (the
67 default), <span class="monospaced">Data.t</span> is equivalent to <span class="monospaced">unit ref</span>.</p></div>
71 <span class="monospaced">Data.equals (x, y)</span>
73 <div class="paragraph"><p>returns true if the <span class="monospaced">x</span> and <span class="monospaced">y</span> are the same unit of profiling data.</p></div>
77 <span class="monospaced">Data.free x</span>
79 <div class="paragraph"><p>frees the memory associated with the unit of profiling data <span class="monospaced">x</span>. It
80 is an error to free the current unit of profiling data or to free a
81 previously freed unit of profiling data. When compiling
82 <span class="monospaced">-profile no</span>, <span class="monospaced">Data.free x</span> is a no-op.</p></div>
86 <span class="monospaced">Data.malloc ()</span>
88 <div class="paragraph"><p>returns a new unit of profiling data. Each unit of profiling data is
89 allocated from the process address space (but is <em>not</em> in the MLton
90 heap) and consumes memory proportional to the number of source
91 functions. When compiling <span class="monospaced">-profile no</span>, <span class="monospaced">Data.malloc ()</span> is
92 equivalent to allocating a new <span class="monospaced">unit ref</span>.</p></div>
96 <span class="monospaced">write (x, f)</span>
98 <div class="paragraph"><p>writes the accumulated ticks in the unit of profiling data <span class="monospaced">x</span> to file
99 <span class="monospaced">f</span>. It is an error to write a previously freed unit of profiling
100 data. When compiling <span class="monospaced">-profile no</span>, <span class="monospaced">write (x, f)</span> is a no-op. A
101 profiled program will always write the current unit of profiling data
102 at program exit to a file named <span class="monospaced">mlmon.out</span>.</p></div>
106 <span class="monospaced">withData (d, f)</span>
108 <div class="paragraph"><p>runs <span class="monospaced">f</span> with <span class="monospaced">d</span> as the unit of profiling data, and returns the
109 result of <span class="monospaced">f</span> after restoring the current unit of profiling data.
110 When compiling <span class="monospaced">-profile no</span>, <span class="monospaced">withData (d, f)</span> is equivalent to
111 <span class="monospaced">f ()</span>.</p></div>
117 <h2 id="_example">Example</h2>
118 <div class="sectionbody">
119 <div class="paragraph"><p>Here is an example, taken from the <span class="monospaced">examples/profiling</span> directory,
120 showing how to profile the executions of the <span class="monospaced">fib</span> and <span class="monospaced">tak</span> functions
121 separately. Suppose that <span class="monospaced">fib-tak.sml</span> contains the following.</p></div>
122 <div class="listingblock">
123 <div class="content"><div class="highlight"><pre><span class="k">structure</span><span class="w"> </span><span class="n">Profile</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">MLton</span><span class="p">.</span><span class="n">Profile</span><span class="w"></span>
125 <span class="k">val</span><span class="w"> </span><span class="n">fibData</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Profile</span><span class="p">.</span><span class="n">Data</span><span class="p">.</span><span class="n">malloc</span><span class="w"> </span><span class="p">()</span><span class="w"></span>
126 <span class="k">val</span><span class="w"> </span><span class="n">takData</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Profile</span><span class="p">.</span><span class="n">Data</span><span class="p">.</span><span class="n">malloc</span><span class="w"> </span><span class="p">()</span><span class="w"></span>
128 <span class="k">fun</span><span class="w"> </span><span class="n">wrap</span><span class="w"> </span><span class="p">(</span><span class="n">f</span><span class="p">,</span><span class="w"> </span><span class="n">d</span><span class="p">)</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
129 <span class="w"> </span><span class="n">Profile</span><span class="p">.</span><span class="n">withData</span><span class="w"> </span><span class="p">(</span><span class="n">d</span><span class="p">,</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="p">()</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="n">f</span><span class="w"> </span><span class="n">x</span><span class="p">)</span><span class="w"></span>
131 <span class="k">val</span><span class="w"> </span><span class="k">rec</span><span class="w"> </span><span class="n">fib</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
132 <span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="mi">0</span><span class="w"></span>
133 <span class="w"> </span><span class="p">|</span><span class="w"> </span><span class="mi">1</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="mi">1</span><span class="w"></span>
134 <span class="w"> </span><span class="p">|</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="n">fib</span><span class="w"> </span><span class="p">(</span><span class="n">n</span><span class="w"> </span><span class="n">-</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="n">+</span><span class="w"> </span><span class="n">fib</span><span class="w"> </span><span class="p">(</span><span class="n">n</span><span class="w"> </span><span class="n">-</span><span class="w"> </span><span class="mi">2</span><span class="p">)</span><span class="w"></span>
135 <span class="k">val</span><span class="w"> </span><span class="n">fib</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">wrap</span><span class="w"> </span><span class="p">(</span><span class="n">fib</span><span class="p">,</span><span class="w"> </span><span class="n">fibData</span><span class="p">)</span><span class="w"></span>
137 <span class="k">fun</span><span class="w"> </span><span class="n">tak</span><span class="w"> </span><span class="p">(</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">,</span><span class="n">z</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
138 <span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">not</span><span class="w"> </span><span class="p">(</span><span class="n">y</span><span class="w"> </span><span class="n"><</span><span class="w"> </span><span class="n">x</span><span class="p">)</span><span class="w"></span>
139 <span class="w"> </span><span class="k">then</span><span class="w"> </span><span class="n">z</span><span class="w"></span>
140 <span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="n">tak</span><span class="w"> </span><span class="p">(</span><span class="n">tak</span><span class="w"> </span><span class="p">(</span><span class="n">x</span><span class="w"> </span><span class="n">-</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="n">y</span><span class="p">,</span><span class="w"> </span><span class="n">z</span><span class="p">),</span><span class="w"></span>
141 <span class="w"> </span><span class="n">tak</span><span class="w"> </span><span class="p">(</span><span class="n">y</span><span class="w"> </span><span class="n">-</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="n">z</span><span class="p">,</span><span class="w"> </span><span class="n">x</span><span class="p">),</span><span class="w"></span>
142 <span class="w"> </span><span class="n">tak</span><span class="w"> </span><span class="p">(</span><span class="n">z</span><span class="w"> </span><span class="n">-</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="n">x</span><span class="p">,</span><span class="w"> </span><span class="n">y</span><span class="p">))</span><span class="w"></span>
143 <span class="k">val</span><span class="w"> </span><span class="n">tak</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">wrap</span><span class="w"> </span><span class="p">(</span><span class="n">tak</span><span class="p">,</span><span class="w"> </span><span class="n">takData</span><span class="p">)</span><span class="w"></span>
145 <span class="k">val</span><span class="w"> </span><span class="k">rec</span><span class="w"> </span><span class="n">f</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
146 <span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="p">()</span><span class="w"></span>
147 <span class="w"> </span><span class="p">|</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="p">(</span><span class="n">fib</span><span class="w"> </span><span class="mi">38</span><span class="p">;</span><span class="w"> </span><span class="n">f</span><span class="w"> </span><span class="p">(</span><span class="n">n-</span><span class="mi">1</span><span class="p">))</span><span class="w"></span>
148 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">f</span><span class="w"> </span><span class="mi">2</span><span class="w"></span>
150 <span class="k">val</span><span class="w"> </span><span class="k">rec</span><span class="w"> </span><span class="n">g</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
151 <span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="p">()</span><span class="w"></span>
152 <span class="w"> </span><span class="p">|</span><span class="w"> </span><span class="n">n</span><span class="w"> </span><span class="p">=></span><span class="w"> </span><span class="p">(</span><span class="n">tak</span><span class="w"> </span><span class="p">(</span><span class="mi">18</span><span class="p">,</span><span class="mi">12</span><span class="p">,</span><span class="mi">6</span><span class="p">);</span><span class="w"> </span><span class="n">g</span><span class="w"> </span><span class="p">(</span><span class="n">n-</span><span class="mi">1</span><span class="p">))</span><span class="w"></span>
153 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">g</span><span class="w"> </span><span class="mi">500</span><span class="w"></span>
155 <span class="k">fun</span><span class="w"> </span><span class="n">done</span><span class="w"> </span><span class="p">(</span><span class="n">data</span><span class="p">,</span><span class="w"> </span><span class="n">file</span><span class="p">)</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
156 <span class="w"> </span><span class="p">(</span><span class="n">Profile</span><span class="p">.</span><span class="n">Data</span><span class="p">.</span><span class="n">write</span><span class="w"> </span><span class="p">(</span><span class="n">data</span><span class="p">,</span><span class="w"> </span><span class="n">file</span><span class="p">)</span><span class="w"></span>
157 <span class="w"> </span><span class="p">;</span><span class="w"> </span><span class="n">Profile</span><span class="p">.</span><span class="n">Data</span><span class="p">.</span><span class="n">free</span><span class="w"> </span><span class="n">data</span><span class="p">)</span><span class="w"></span>
159 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">done</span><span class="w"> </span><span class="p">(</span><span class="n">fibData</span><span class="p">,</span><span class="w"> </span><span class="s">"mlmon.fib.out"</span><span class="p">)</span><span class="w"></span>
160 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">done</span><span class="w"> </span><span class="p">(</span><span class="n">takData</span><span class="p">,</span><span class="w"> </span><span class="s">"mlmon.tak.out"</span><span class="p">)</span><span class="w"></span>
161 </pre></div></div></div>
162 <div class="paragraph"><p>Compile and run the program.</p></div>
163 <div class="listingblock">
164 <div class="content monospaced">
165 <pre>% mlton -profile time fib-tak.sml
168 <div class="paragraph"><p>Separately display the profiling data for <span class="monospaced">fib</span></p></div>
169 <div class="listingblock">
170 <div class="content monospaced">
171 <pre>% mlprof fib-tak mlmon.fib.out
172 5.77 seconds of CPU time (0.00 seconds GC)
176 <unknown> 3.1%</pre>
178 <div class="paragraph"><p>and for <span class="monospaced">tak</span></p></div>
179 <div class="listingblock">
180 <div class="content monospaced">
181 <pre>% mlprof fib-tak mlmon.tak.out
182 0.68 seconds of CPU time (0.00 seconds GC)
187 <div class="paragraph"><p>Combine the data for <span class="monospaced">fib</span> and <span class="monospaced">tak</span> by calling <span class="monospaced">mlprof</span>
188 with multiple <span class="monospaced">mlmon.out</span> files.</p></div>
189 <div class="listingblock">
190 <div class="content monospaced">
191 <pre>% mlprof fib-tak mlmon.fib.out mlmon.tak.out mlmon.out
192 6.45 seconds of CPU time (0.00 seconds GC)
197 <unknown> 2.8%</pre>
202 <div id="footnotes"><hr></div>
204 <div id="footer-text">
206 <div id="footer-badges">