1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
#include <stdlib.h>
#include <stdio.h>
#include <alloca.h>
#include <emscripten.h>
#include <emscripten/stack.h>
#include <assert.h>
#include <string.h>
void __attribute__((noinline)) DoSomething(char *addr) {
memset(addr, 42, 13);
}
void TestStackValidity() {
uintptr_t base = emscripten_stack_get_base();
uintptr_t end = emscripten_stack_get_end();
uintptr_t used = labs((intptr_t)base - (intptr_t)emscripten_stack_get_current());
uintptr_t free = labs((intptr_t)end - (intptr_t)emscripten_stack_get_current());
uintptr_t free2 = emscripten_stack_get_free();
uintptr_t total = labs((intptr_t)end - (intptr_t)base);
assert(used + free == total);
assert(free == free2);
}
int increment = 256 * 1024;
int main() {
emscripten_stack_init();
TestStackValidity();
uintptr_t origFree = emscripten_stack_get_free();
uintptr_t prevFree = emscripten_stack_get_free();
printf("Stack used: %lu\n", origFree - emscripten_stack_get_free());
for (int i = 0; i < 10; ++i) {
int increment_noopt = emscripten_random() >= 0 ? increment : 2;
char *p = alloca(increment_noopt);
DoSomething(p);
uintptr_t free = emscripten_stack_get_free();
assert(prevFree - free == increment);
prevFree = free;
// Print something from the allocationed region to prevent whole program
// optimizations from elminiating the alloca completely.
printf("Val: %d\n", p[10]);
printf("Stack used: %zu\n", origFree - emscripten_stack_get_free());
TestStackValidity();
}
return 0;
}
|
