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#include <mlibc/thread-entry.hpp>
#include <mlibc/all-sysdeps.hpp>
#include <mlibc/tcb.hpp>
#include <bits/ensure.h>
#include <sys/mman.h>
#include <errno.h>
#include <stdint.h>
#include <stddef.h>
extern "C" void __mlibc_enter_thread(void *entry, void *user_arg, Tcb *tcb) {
// Wait until our parent sets up the TID.
while(!__atomic_load_n(&tcb->tid, __ATOMIC_RELAXED))
mlibc::sys_futex_wait(&tcb->tid, 0, nullptr);
if(mlibc::sys_tcb_set(tcb))
__ensure(!"sys_tcb_set() failed");
tcb->invokeThreadFunc(entry, user_arg);
auto self = reinterpret_cast<Tcb *>(tcb);
__atomic_store_n(&self->didExit, 1, __ATOMIC_RELEASE);
mlibc::sys_futex_wake(&self->didExit);
mlibc::sys_thread_exit();
}
namespace mlibc {
static constexpr size_t default_stacksize = 0x200000;
int sys_prepare_stack(void **stack, void *entry, void *user_arg, void *tcb, size_t *stack_size, size_t *guard_size, void **stack_base) {
if (!*stack_size)
*stack_size = default_stacksize;
*guard_size = 0;
if (*stack) {
*stack_base = *stack;
} else {
*stack_base = mmap(nullptr, *stack_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if(*stack_base == MAP_FAILED) {
return errno;
}
}
uintptr_t *sp = reinterpret_cast<uintptr_t *>(reinterpret_cast<uintptr_t>(*stack_base) + *stack_size);
*--sp = reinterpret_cast<uintptr_t>(tcb);
*--sp = reinterpret_cast<uintptr_t>(user_arg);
*--sp = reinterpret_cast<uintptr_t>(entry);
*stack = reinterpret_cast<void*>(sp);
return 0;
}
} //namespace mlibc
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