Files
kaguya 9a9b91c940 user: implement mlibc as the libc, finally.
It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>
2026-05-02 03:31:49 -04:00

136 lines
3.8 KiB
C++

#include <pthread.h>
#include <stdlib.h>
#include <sys/auxv.h>
#include <frg/eternal.hpp>
#include <bits/ensure.h>
#include <mlibc/all-sysdeps.hpp>
#include <mlibc/allocator.hpp>
#include <mlibc/debug.hpp>
#include <mlibc/elf/startup.h>
#include <mlibc/posix-pipe.hpp>
#include <protocols/posix/data.hpp>
#include <protocols/posix/supercalls.hpp>
extern "C" uintptr_t *__dlapi_entrystack();
extern "C" void __dlapi_enter(uintptr_t *);
// declared in posix-pipe.hpp
thread_local Queue globalQueue;
// TODO: clock tracker page and file table don't need to be thread-local!
thread_local HelHandle __mlibc_posix_lane;
thread_local void *__mlibc_clk_tracker_page;
namespace {
thread_local unsigned __mlibc_gsf_nesting;
thread_local posix::ThreadPage *__mlibc_cached_thread_page;
thread_local HelHandle *cachedFileTable;
// This construction is a bit weird: Even though the variables above
// are thread_local we still protect their initialization with a pthread_once_t
// (instead of using a C++ constructor).
// We do this in order to able to clear the pthread_once_t after a fork.
thread_local pthread_once_t has_cached_infos = PTHREAD_ONCE_INIT;
void actuallyCacheInfos() {
posix::ManagarmProcessData data;
HEL_CHECK(
helSyscall1(kHelCallSuper + posix::superGetProcessData, reinterpret_cast<HelWord>(&data))
);
__mlibc_posix_lane = data.posixLane;
__mlibc_cached_thread_page = data.threadPage;
cachedFileTable = data.fileTable;
__mlibc_clk_tracker_page = data.clockTrackerPage;
}
} // namespace
SignalGuard::SignalGuard() {
pthread_once(&has_cached_infos, &actuallyCacheInfos);
if (!__mlibc_cached_thread_page)
return;
if (!__mlibc_gsf_nesting)
__atomic_store_n(&__mlibc_cached_thread_page->globalSignalFlag, 1, __ATOMIC_RELAXED);
__mlibc_gsf_nesting++;
}
SignalGuard::~SignalGuard() {
pthread_once(&has_cached_infos, &actuallyCacheInfos);
if (!__mlibc_cached_thread_page)
return;
__ensure(__mlibc_gsf_nesting > 0);
__mlibc_gsf_nesting--;
if (!__mlibc_gsf_nesting) {
unsigned int result =
__atomic_exchange_n(&__mlibc_cached_thread_page->globalSignalFlag, 0, __ATOMIC_RELAXED);
if (result == 2) {
HEL_CHECK(helSyscall0(kHelCallSuper + posix::superSigRaise));
} else {
__ensure(result == 1);
}
}
}
MemoryAllocator &getSysdepsAllocator() {
// use frg::eternal to prevent a call to __cxa_atexit().
// this is necessary because __cxa_atexit() call this function.
static frg::eternal<VirtualAllocator> virtualAllocator;
static frg::eternal<MemoryPool> heap{virtualAllocator.get()};
static frg::eternal<MemoryAllocator> singleton{&heap.get()};
return singleton.get();
}
HelHandle getPosixLane() {
cacheFileTable();
return __mlibc_posix_lane;
}
HelHandle *cacheFileTable() {
// TODO: Make sure that this is signal-safe (it is called e.g. by sys_clock_get()).
pthread_once(&has_cached_infos, &actuallyCacheInfos);
return cachedFileTable;
}
HelHandle getHandleForFd(int fd) {
if (fd >= 512)
return 0;
return cacheFileTable()[fd];
}
void clearCachedInfos() { has_cached_infos = PTHREAD_ONCE_INIT; }
void resetCancellationId() {
pthread_once(&has_cached_infos, &actuallyCacheInfos);
__atomic_store_n(&__mlibc_cached_thread_page->cancellationId, 0, __ATOMIC_RELEASE);
}
void setCancellationId(uint64_t id, HelHandle handle, int fd) {
pthread_once(&has_cached_infos, &actuallyCacheInfos);
__mlibc_cached_thread_page->lane = handle;
__mlibc_cached_thread_page->fd = fd;
__atomic_store_n(&__mlibc_cached_thread_page->cancellationId, id, __ATOMIC_RELEASE);
}
namespace {
thread_local uint64_t cancellationId = 1;
} // namespace
uint64_t allocateCancellationId() { return cancellationId++; }
extern char **environ;
extern "C" void
__mlibc_entry(uintptr_t *entry_stack, int (*main_fn)(int argc, char *argv[], char *env[])) {
__dlapi_enter(entry_stack);
auto result = main_fn(mlibc::entry_stack.argc, mlibc::entry_stack.argv, environ);
exit(result);
}