swapcontext_test.cc [plain text]
#include <stdio.h>
#include <ucontext.h>
#include <unistd.h>
ucontext_t orig_context;
ucontext_t child_context;
void Child(int mode) {
char x[32] = {0}; printf("Child: %p\n", x);
if (mode == 1) {
if (swapcontext(&child_context, &orig_context) < 0) {
perror("swapcontext");
_exit(0);
}
}
}
int Run(int arg, int mode) {
const int kStackSize = 1 << 20;
char child_stack[kStackSize + 1];
printf("Child stack: %p\n", child_stack);
getcontext(&child_context);
child_context.uc_stack.ss_sp = child_stack;
child_context.uc_stack.ss_size = kStackSize / 2;
if (mode == 0) {
child_context.uc_link = &orig_context;
}
makecontext(&child_context, (void (*)())Child, 1, mode);
if (swapcontext(&orig_context, &child_context) < 0) {
perror("swapcontext");
return 0;
}
for (int i = 0; i < kStackSize; i++) {
child_stack[i] = i;
}
return child_stack[arg];
}
int main(int argc, char **argv) {
int ret = 0;
ret += Run(argc - 1, 0);
printf("Test1 passed\n");
ret += Run(argc - 1, 1);
printf("Test2 passed\n");
return ret;
}