OILS / cpp / obj_layout_test.cc View on Github | oilshell.org

212 lines, 106 significant
1#include "_gen/core/runtime.asdl.h" // Cell, etc
2#include "_gen/frontend/syntax.asdl.h"
3#include "vendor/greatest.h"
4
5TEST sizeof_syntax() {
6 // 40 bytes (after merging with line_span January 2023)
7 // - Get rid of 'string val'
8 // - Replace 'int line_id' with SourceLine
9 // - Maybe recompute length on demand
10 log("sizeof(Token) = %d", sizeof(syntax_asdl::Token));
11 log("alignof(Token) = %d", alignof(syntax_asdl::Token));
12 log("alignof(Token*) = %d", alignof(syntax_asdl::Token *));
13 log("");
14
15 // 2024-03 - both of these are 64 bytes
16 log("sizeof(BracedVarSub) = %d", sizeof(syntax_asdl::BracedVarSub));
17 log("sizeof(command::Simple) = %d", sizeof(syntax_asdl::command::Simple));
18 log("");
19
20 // Only 8 bytes
21 log("sizeof(CompoundWord) = %d", sizeof(syntax_asdl::CompoundWord));
22
23 // Reordered to be 16 bytes
24 log("sizeof(runtime_asdl::Cell) = %d", sizeof(runtime_asdl::Cell));
25
26 // 24 bytes: std::vector
27 log("sizeof(List<int>) = %d", sizeof(List<int>));
28 log("sizeof(List<BigStr*>) = %d", sizeof(List<BigStr *>));
29
30 log("sizeof(Slab<int>) = %d", sizeof(Slab<int>));
31 log("sizeof(Slab<BigStr*>) = %d", sizeof(Slab<BigStr *>));
32 // Right after object header
33 log("kSlabHeaderSize = %d", kSlabHeaderSize);
34
35 // Unlike Python, this is -1, not 255!
36 int mod = -1 % 256;
37 log("mod = %d", mod);
38
39 log("alignof(bool) = %d", alignof(bool));
40 log("alignof(int) = %d", alignof(int));
41 log("alignof(float) = %d", alignof(float));
42
43 log("sizeof(BigStr) = %d", sizeof(BigStr));
44 log("alignof(BigStr) = %d", alignof(BigStr));
45
46 log("sizeof(BigStr*) = %d", sizeof(BigStr *));
47 log("alignof(BigStr*) = %d", alignof(BigStr *));
48
49 log("alignof(max_align_t) = %d", alignof(max_align_t));
50
51 PASS();
52}
53
54// Doesn't really test anything
55TEST sizeof_core_types() {
56 log("");
57 // 4 bytes, for lower case / upper case etc.
58 log("sizeof(wchar_t) = %d", sizeof(wchar_t));
59
60 // 8 byte header
61 log("sizeof(ObjHeader) = %d", sizeof(ObjHeader));
62 // 8 + 128 possible entries
63 // log("sizeof(LayoutFixed) = %d", sizeof(LayoutFixed));
64
65 // 24 = 4 + (4 + 4 + 4) + 8
66 // Feels like a small string optimization here would be nice.
67 log("sizeof(BigStr) = %d", sizeof(BigStr));
68 // 16 = 4 + pad4 + 8
69 log("sizeof(List) = %d", sizeof(List<int>));
70 // 32 = 4 + pad4 + 8 + 8 + 8
71 log("sizeof(Dict) = %d", sizeof(Dict<int, int>));
72
73#ifndef MARK_SWEEP
74 int min_obj_size = sizeof(LayoutForwarded);
75 int short_str_size = aligned(kStrHeaderSize + 1);
76
77 log("kStrHeaderSize = %d", kStrHeaderSize);
78 log("aligned(kStrHeaderSize + 1) = %d", short_str_size);
79 log("sizeof(LayoutForwarded) = %d", min_obj_size);
80
81 ASSERT(min_obj_size <= short_str_size);
82#endif
83
84#if 0
85 char* p = static_cast<char*>(gHeap.Allocate(17));
86 char* q = static_cast<char*>(gHeap.Allocate(9));
87 log("p = %p", p);
88 log("q = %p", q);
89#endif
90
91 // BigStr = 16 and List = 24.
92 // Rejected ideas about slicing:
93 //
94 // - Use data[len] == '\0' as OWNING and data[len] != '\0' as a slice?
95 // It doesn't work because s[1:] would always have that problem
96 //
97 // - s->data == (void*)(s + 1)
98 // Owning string has the data RIGHT AFTER?
99 // Maybe works? but probably a bad idea because of GLOBAL BigStr instances.
100
101 log("");
102 log("sizeof(BigStr) = %zu", sizeof(BigStr));
103 log("sizeof(List<int>) = %zu", sizeof(List<int>));
104 log("sizeof(Dict<int, BigStr*>) = %zu", sizeof(Dict<int, BigStr *>));
105 log("sizeof(Tuple2<int, int>) = %zu", sizeof(Tuple2<int, int>));
106 log("sizeof(Tuple2<BigStr*, BigStr*>) = %zu",
107 sizeof(Tuple2<BigStr *, BigStr *>));
108 log("sizeof(Tuple3<int, int, int>) = %zu", sizeof(Tuple3<int, int, int>));
109
110 PASS();
111}
112
113TEST slab_growth() {
114 // TODO: All slabs should start out at 32
115
116 auto li = Alloc<List<int>>();
117 log("li->items_ %p", li->slab_);
118
119 // At some point it moves
120 for (int i = 0; i < 20; ++i) {
121 li->append(42);
122 int size = 8 + (sizeof(int) * li->capacity_);
123 log("%2d. cap %2d, size %3d, li->slab_ %p", i, li->capacity_, size,
124 li->slab_);
125 }
126
127 log("---");
128
129 auto lp = Alloc<List<BigStr *>>();
130 log("lp->items_ %p", lp->slab_);
131
132 // At some point it moves
133 for (int i = 0; i < 20; ++i) {
134 lp->append(kEmptyString);
135 int size = 8 + (sizeof(BigStr *) * lp->capacity_);
136 log("%2d. cap %2d, size %3d, lp->slab_ %p", i, lp->capacity_, size,
137 lp->slab_);
138 }
139
140 PASS();
141}
142
143TEST malloc_address_test() {
144 struct timespec start, end;
145 if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &start) < 0) {
146 FAIL("clock_gettime failed");
147 }
148
149 // glibc gives us blocks of 32 bytes!
150 // 1. diff = -240
151 // 2. diff = 94064
152 // 3. diff = 32
153 // 4. diff = 32
154 // 5. diff = 32
155
156 // tcmalloc has tighter packing!
157 // 1. diff = -8
158 // 2. diff = 32
159 // 3. diff = 8
160 // 4. diff = 8
161 // 5. diff = 8
162
163 // 2023-08: If I pass 4096, I get 4112, so 16 byte diff
164 // 2023-08: If I pass 4080, I get 4096
165
166 // int alloc_size = 24 * 682; // 16368 is close to 16384 - 16 bytes again
167 int alloc_size = 48 * 341; // heap 2 is the same size
168
169 // int alloc_size = 4080;
170 // int alloc_size = 1;
171
172#define NUM_ALLOCS 20
173 char *p[NUM_ALLOCS];
174 for (int i = 0; i < NUM_ALLOCS; ++i) {
175 p[i] = static_cast<char *>(malloc(alloc_size));
176 if (i != 0) {
177 char *prev = p[i - 1];
178 log("%2d. diff = %d", i, p[i] - prev);
179 }
180 }
181
182 for (int i = 0; i < NUM_ALLOCS; ++i) {
183 free(p[i]);
184 }
185
186 if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &end) < 0) {
187 FAIL("clock_gettime failed");
188 }
189
190 log("start %d %d", start.tv_sec, start.tv_nsec);
191 log("end %d %d", end.tv_sec, end.tv_nsec);
192
193 PASS();
194}
195
196GREATEST_MAIN_DEFS();
197
198int main(int argc, char **argv) {
199 gHeap.Init();
200
201 GREATEST_MAIN_BEGIN();
202
203 RUN_TEST(sizeof_syntax);
204 RUN_TEST(sizeof_core_types);
205 RUN_TEST(slab_growth);
206 RUN_TEST(malloc_address_test);
207
208 gHeap.CleanProcessExit();
209
210 GREATEST_MAIN_END();
211 return 0;
212}