1 /**
2 * Contains the garbage collector configuration.
3 *
4 * Copyright: Copyright Digital Mars 2016
5 * License: $(WEB www.boost.org/LICENSE_1_0.txt, Boost License 1.0).
6 */
7
8 module gc.config;
9
10 import core.stdc.stdlib;
11 import core.stdc.stdio;
12 import core.stdc.ctype;
13 import core.stdc.string;
14 import core.vararg;
15
16 nothrow @nogc:
17 extern extern(C) string[] rt_args();
18
19 extern extern(C) __gshared bool rt_envvars_enabled;
20 extern extern(C) __gshared bool rt_cmdline_enabled;
21 extern extern(C) __gshared string[] rt_options;
22
23 __gshared Config config;
24
25 struct Config
26 {
27 bool disable; // start disabled
28 ubyte profile; // enable profiling with summary when terminating program
29 string gc = "conservative"; // select gc implementation conservative|manual
30
31 size_t initReserve; // initial reserve (MB)
32 size_t minPoolSize = 1; // initial and minimum pool size (MB)
33 size_t maxPoolSize = 64; // maximum pool size (MB)
34 size_t incPoolSize = 3; // pool size increment (MB)
35 float heapSizeFactor = 2.0; // heap size to used memory ratio
36
37 @nogc nothrow:
38
initializeConfig39 bool initialize()
40 {
41 import core.internal.traits : externDFunc;
42
43 alias rt_configCallBack = string delegate(string) @nogc nothrow;
44 alias fn_configOption = string function(string opt, scope rt_configCallBack dg, bool reverse) @nogc nothrow;
45
46 alias rt_configOption = externDFunc!("rt.config.rt_configOption", fn_configOption);
47
48 string parse(string opt) @nogc nothrow
49 {
50 if (!parseOptions(opt))
51 return "err";
52 return null; // continue processing
53 }
54 string s = rt_configOption("gcopt", &parse, true);
55 return s is null;
56 }
57
helpConfig58 void help()
59 {
60 version (unittest) if (inUnittest) return;
61
62 string s = "GC options are specified as white space separated assignments:
63 disable:0|1 - start disabled (%d)
64 profile:0|1|2 - enable profiling with summary when terminating program (%d)
65 gc:conservative|manual - select gc implementation (default = conservative)
66
67 initReserve:N - initial memory to reserve in MB (%lld)
68 minPoolSize:N - initial and minimum pool size in MB (%lld)
69 maxPoolSize:N - maximum pool size in MB (%lld)
70 incPoolSize:N - pool size increment MB (%lld)
71 heapSizeFactor:N - targeted heap size to used memory ratio (%g)
72 ";
73 printf(s.ptr, disable, profile, cast(long)initReserve, cast(long)minPoolSize,
74 cast(long)maxPoolSize, cast(long)incPoolSize, heapSizeFactor);
75 }
76
parseOptionsConfig77 bool parseOptions(string opt)
78 {
79 opt = skip!isspace(opt);
80 while (opt.length)
81 {
82 auto tail = find!(c => c == ':' || c == '=' || c == ' ')(opt);
83 auto name = opt[0 .. $ - tail.length];
84 if (name == "help")
85 {
86 help();
87 opt = skip!isspace(tail);
88 continue;
89 }
90 if (tail.length <= 1 || tail[0] == ' ')
91 return optError("Missing argument for", name);
92 tail = tail[1 .. $];
93
94 switch (name)
95 {
96 foreach (field; __traits(allMembers, Config))
97 {
98 static if (!is(typeof(__traits(getMember, this, field)) == function))
99 {
100 case field:
101 if (!parse(name, tail, __traits(getMember, this, field)))
102 return false;
103 break;
104 }
105 }
106 break;
107
108 default:
109 return optError("Unknown", name);
110 }
111 opt = skip!isspace(tail);
112 }
113 return true;
114 }
115 }
116
117 private:
118
optError(in char[]msg,in char[]name)119 bool optError(in char[] msg, in char[] name)
120 {
121 version (unittest) if (inUnittest) return false;
122
123 fprintf(stderr, "%.*s GC option '%.*s'.\n",
124 cast(int)msg.length, msg.ptr,
125 cast(int)name.length, name.ptr);
126 return false;
127 }
128
inout(char)129 inout(char)[] skip(alias pred)(inout(char)[] str)
130 {
131 return find!(c => !pred(c))(str);
132 }
133
inout(char)134 inout(char)[] find(alias pred)(inout(char)[] str)
135 {
136 foreach (i; 0 .. str.length)
137 if (pred(str[i])) return str[i .. $];
138 return null;
139 }
140
141 bool parse(T:size_t)(const(char)[] optname, ref inout(char)[] str, ref T res)
142 in { assert(str.length); }
143 body
144 {
145 size_t i, v;
146 for (; i < str.length && isdigit(str[i]); ++i)
147 v = 10 * v + str[i] - '0';
148
149 if (!i)
150 return parseError("a number", optname, str);
151 if (v > res.max)
152 return parseError("a number " ~ T.max.stringof ~ " or below", optname, str[0 .. i]);
153 str = str[i .. $];
154 res = cast(T) v;
155 return true;
156 }
157
parse(const (char)[]optname,ref inout (char)[]str,ref bool res)158 bool parse(const(char)[] optname, ref inout(char)[] str, ref bool res)
159 in { assert(str.length); }
160 body
161 {
162 if (str[0] == '1' || str[0] == 'y' || str[0] == 'Y')
163 res = true;
164 else if (str[0] == '0' || str[0] == 'n' || str[0] == 'N')
165 res = false;
166 else
167 return parseError("'0/n/N' or '1/y/Y'", optname, str);
168 str = str[1 .. $];
169 return true;
170 }
171
parse(const (char)[]optname,ref inout (char)[]str,ref float res)172 bool parse(const(char)[] optname, ref inout(char)[] str, ref float res)
173 in { assert(str.length); }
174 body
175 {
176 // % uint f %n \0
177 char[1 + 10 + 1 + 2 + 1] fmt=void;
178 // specify max-width
179 immutable n = snprintf(fmt.ptr, fmt.length, "%%%uf%%n", cast(uint)str.length);
180 assert(n > 4 && n < fmt.length);
181
182 int nscanned;
version(CRuntime_DigitalMars)183 version (CRuntime_DigitalMars)
184 {
185 /* Older sscanf's in snn.lib can write to its first argument, causing a crash
186 * if the string is in readonly memory. Recent updates to DMD
187 * https://github.com/dlang/dmd/pull/6546
188 * put string literals in readonly memory.
189 * Although sscanf has been fixed,
190 * http://ftp.digitalmars.com/snn.lib
191 * this workaround is here so it still works with the older snn.lib.
192 */
193 // Create mutable copy of str
194 const length = str.length;
195 char* mptr = cast(char*)malloc(length + 1);
196 assert(mptr);
197 memcpy(mptr, str.ptr, length);
198 mptr[length] = 0;
199 const result = sscanf(mptr, fmt.ptr, &res, &nscanned);
200 free(mptr);
201 if (result < 1)
202 return parseError("a float", optname, str);
203 }
204 else
205 {
206 if (sscanf(str.ptr, fmt.ptr, &res, &nscanned) < 1)
207 return parseError("a float", optname, str);
208 }
209 str = str[nscanned .. $];
210 return true;
211 }
212
parse(const (char)[]optname,ref inout (char)[]str,ref inout (char)[]res)213 bool parse(const(char)[] optname, ref inout(char)[] str, ref inout(char)[] res)
214 in { assert(str.length); }
215 body
216 {
217 auto tail = str.find!(c => c == ':' || c == '=' || c == ' ');
218 res = str[0 .. $ - tail.length];
219 if (!res.length)
220 return parseError("an identifier", optname, str);
221 str = tail;
222 return true;
223 }
224
parseError(in char[]exp,in char[]opt,in char[]got)225 bool parseError(in char[] exp, in char[] opt, in char[] got)
226 {
227 version (unittest) if (inUnittest) return false;
228
229 fprintf(stderr, "Expecting %.*s as argument for GC option '%.*s', got '%.*s' instead.\n",
230 cast(int)exp.length, exp.ptr,
231 cast(int)opt.length, opt.ptr,
232 cast(int)got.length, got.ptr);
233 return false;
234 }
235
min(size_t a,size_t b)236 size_t min(size_t a, size_t b) { return a <= b ? a : b; }
237
version(unittest)238 version (unittest) __gshared bool inUnittest;
239
240 unittest
241 {
242 inUnittest = true;
243 scope (exit) inUnittest = false;
244
245 Config conf;
246 assert(!conf.parseOptions("disable"));
247 assert(!conf.parseOptions("disable:"));
248 assert(!conf.parseOptions("disable:5"));
249 assert(conf.parseOptions("disable:y") && conf.disable);
250 assert(conf.parseOptions("disable:n") && !conf.disable);
251 assert(conf.parseOptions("disable:Y") && conf.disable);
252 assert(conf.parseOptions("disable:N") && !conf.disable);
253 assert(conf.parseOptions("disable:1") && conf.disable);
254 assert(conf.parseOptions("disable:0") && !conf.disable);
255
256 assert(conf.parseOptions("disable=y") && conf.disable);
257 assert(conf.parseOptions("disable=n") && !conf.disable);
258
259 assert(conf.parseOptions("profile=0") && conf.profile == 0);
260 assert(conf.parseOptions("profile=1") && conf.profile == 1);
261 assert(conf.parseOptions("profile=2") && conf.profile == 2);
262 assert(!conf.parseOptions("profile=256"));
263
264 assert(conf.parseOptions("disable:1 minPoolSize:16"));
265 assert(conf.disable);
266 assert(conf.minPoolSize == 16);
267
268 assert(conf.parseOptions("heapSizeFactor:3.1"));
269 assert(conf.heapSizeFactor == 3.1f);
270 assert(conf.parseOptions("heapSizeFactor:3.1234567890 disable:0"));
271 assert(conf.heapSizeFactor > 3.123f);
272 assert(!conf.disable);
273 assert(!conf.parseOptions("heapSizeFactor:3.0.2.5"));
274 assert(conf.parseOptions("heapSizeFactor:2"));
275 assert(conf.heapSizeFactor == 2.0f);
276
277 assert(!conf.parseOptions("initReserve:foo"));
278 assert(!conf.parseOptions("initReserve:y"));
279 assert(!conf.parseOptions("initReserve:20.5"));
280
281 assert(conf.parseOptions("help"));
282 assert(conf.parseOptions("help profile:1"));
283 assert(conf.parseOptions("help profile:1 help"));
284
285 assert(conf.parseOptions("gc:manual") && conf.gc == "manual");
286 assert(conf.parseOptions("gc:my-gc~modified") && conf.gc == "my-gc~modified");
287 assert(conf.parseOptions("gc:conservative help profile:1") && conf.gc == "conservative" && conf.profile == 1);
288
289 // the config parse doesn't know all available GC names, so should accept unknown ones
290 assert(conf.parseOptions("gc:whatever"));
291 }
292