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#include <stdlib.h>
#define nth_bit(x, n) ((x >> n) & 1)
#define Fn(N, Np1) \
void* a##N(int x) { return ( nth_bit(x, N) ? a##Np1(x) : a##Np1(x) ); }
// This test allocates a lot of heap memory, and every allocation features a
// different stack trace -- the stack traces are effectively a
// representation of the number 'i', where each function represents a bit in
// 'i', and if it's a 1 the first function is called, and if it's a 0 the
// second function is called.
void* a999(int x)
{
return malloc(100);
}
Fn(17, 999)
Fn(16, 17)
Fn(15, 16)
Fn(14, 15)
Fn(13, 14)
Fn(12, 13)
Fn(11, 12)
Fn(10, 11)
Fn( 9, 10)
Fn( 8, 9)
Fn( 7, 8)
Fn( 6, 7)
Fn( 5, 6)
Fn( 4, 5)
Fn( 3, 4)
Fn( 2, 3)
Fn( 1, 2)
Fn( 0, 1)
int main(void)
{
int i;
// Create a large XTree.
for (i = 0; i < (1 << 18); i++)
a0(i);
// Do a lot of allocations so it gets dup'd a lot of times.
for (i = 0; i < 100000; i++) {
free(a1(234));
free(a2(111));
}
return 0;
}
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