exile.h/exile.hpp

202 sor
6.1 KiB
C++

#include "exile.h"
#include <functional>
#include <iostream>
#include <string>
#include <tuple>
#include <memory>
#include <sys/wait.h>
#ifndef EXILE_MMAP_SIZE
#define EXILE_MMAP_SIZE 128 * 1024 * 1024 //128MB
#endif
template<typename T, typename U, typename ... Args>
class launch_arg
{
static_assert(std::is_trivially_copyable_v<T>);
static_assert(!std::is_pointer_v<T>);
public:
struct exile_policy *policy;
T *result_shm;
U fn;
std::tuple<Args...> args;
launch_arg(struct exile_policy *policy, T *result_shm, U fn, Args && ... args) : policy(policy),
result_shm(result_shm), fn(fn), args(std::forward<Args>(args)...) {}
};
template<typename T, typename U, typename ... Args>
class launch_arg_serializer
{
static_assert(std::is_copy_constructible_v<T>);
public:
struct exile_policy *policy;
char *serialize_buffer;
size_t n;
U fn;
std::tuple<Args...> args;
const std::function<size_t (const T &, char *, size_t n)> &serializer;
const std::function<T(const char * buf, size_t n)> &deserializer;
launch_arg_serializer(struct exile_policy *policy, char *serialize_buffer, size_t n, const std::function<size_t (const T &, char *, size_t)> &serializer, const std::function<T(const char *, size_t)> &deserializer, U fn, Args && ... args) : policy(policy), serialize_buffer(serialize_buffer), n(n), fn(fn), args(std::forward<Args>(args)...), serializer(serializer), deserializer(deserializer) {}
};
template<typename T, typename U, typename ... Args>
int exile_clone_handle_trivial(void * arg)
{
static_assert(std::is_trivially_copyable_v<T>);
static_assert(!std::is_pointer_v<T>);
launch_arg<T, U, Args...> *launchargs = (launch_arg<T, U, Args...> *) arg;
int ret = exile_enable_policy(launchargs->policy);
if(ret != 0)
{
EXILE_LOG_ERROR("exile_enable_policy() failed: %s\n", strerror(errno));
return 1;
}
T result = std::apply(launchargs->fn, launchargs->args);
std::cout << result;
memcpy(launchargs->result_shm, &result, sizeof(T));
return 0;
}
template<typename T, typename U, typename ... Args>
int exile_clone_handle_serializer(void * arg)
{
static_assert(std::is_copy_constructible_v<T>);
launch_arg_serializer<T, U, Args...> *launchargs = (launch_arg_serializer<T, U, Args...> *) arg;
int ret = exile_enable_policy(launchargs->policy);
if(ret != 0)
{
EXILE_LOG_ERROR("exile_enable_policy() failed: %s\n", strerror(errno));
return 1;
}
T result = std::apply(launchargs->fn, launchargs->args);
/* TODO: exception handling */
/* TODO: ugly :S */
char *target = launchargs->serialize_buffer + sizeof(size_t);
size_t n = launchargs->n - sizeof(size_t);
size_t size = launchargs->serializer(result, target, n);
memcpy(launchargs->serialize_buffer, &size, sizeof(size_t));
return 0;
}
inline int do_clone(int (*clonefn)(void *), void *launcharg)
{
struct rlimit rlimit;
int ret = getrlimit(RLIMIT_STACK, &rlimit);
if(ret != 0)
{
EXILE_LOG_ERROR("Failed to get stack size: %s\n", strerror(errno));
return ret;
}
size_t size = rlimit.rlim_cur;
char *stack = (char *) calloc(1, size);
char *stackbegin = stack;
if(stack == NULL)
{
EXILE_LOG_ERROR("Failed to allocate stack memory for child\n");
return 1;
}
stack += size;
ret = clone(clonefn, stack, 17 /* SIGCHLD */, launcharg);
int status = 0;
waitpid(ret, &status, __WALL);
free(stackbegin);
if(WIFEXITED(status))
{
return WEXITSTATUS(status);
}
/* TODO: exception or what? */
return 23;
}
template<typename T, typename U, typename ... Args>
typename std::enable_if_t<std::is_trivially_copyable_v<T> && !std::is_pointer_v<T>, T> exile_launch(struct exile_policy *policy, U fn, Args && ... args)
{
size_t mapsize = sizeof(T);
T * sharedbuf = (T *) mmap(NULL, mapsize , PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
if(sharedbuf == NULL)
{
throw std::runtime_error(std::string("mmap failed: ") + strerror(errno));
}
std::shared_ptr<void> deleter(nullptr, [sharedbuf, mapsize](...){ munmap(sharedbuf, mapsize); });
launch_arg<T, U, Args...> launcharg(policy, sharedbuf, fn, std::forward<Args>(args)...);
int (*clonefn)(void *) = &exile_clone_handle_trivial<T, U, Args...>;
/* TODO: exception or what? */
int ret = do_clone(clonefn, &launcharg);
if(ret == 0)
{
return *sharedbuf;
}
throw std::runtime_error(std::string("clone() failed: " + std::to_string(ret)));
return T();
}
template<typename T, typename U, typename ... Args>
typename std::enable_if_t<std::is_pointer_v<T> || (!std::is_trivially_copyable_v<T> && std::is_copy_constructible_v<T>), T>
exile_launch(struct exile_policy *policy, const std::function<size_t (const T &, char *, size_t)> &serializer, const std::function<T(const char *, size_t)> &deserializer, U fn, Args && ... args)
{
size_t mapsize = EXILE_MMAP_SIZE;
char *sharedbuf = (char *) mmap(NULL, mapsize , PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
if(sharedbuf == NULL)
{
throw std::runtime_error(std::string("mmap failed: ") + strerror(errno));
}
std::shared_ptr<void> deleter(nullptr, [sharedbuf, mapsize](...){ munmap(sharedbuf, mapsize); });
launch_arg_serializer<T, U, Args...> launcharg(policy, sharedbuf, mapsize, serializer, deserializer, fn, std::forward<Args>(args)...);
int (*clonefn)(void *) = &exile_clone_handle_serializer<T, U, Args...>;
/* TODO: exception or what? */
int ret = do_clone(clonefn, &launcharg);
if(ret == 0)
{
size_t size = 0;
memcpy(&size, sharedbuf, sizeof(size));
return deserializer(sharedbuf + sizeof(size_t), size);
}
throw std::runtime_error(std::string("clone() failed: " + std::to_string(ret)));
return T();
}
template<class T>
std::basic_string<typename T::value_type> deserialize_stdstring(const char *buf, size_t n)
{
return std::basic_string<typename T::value_type> { buf, n };
}
template<class T>
size_t serialize_stdstring(const std::basic_string<typename T::value_type> &t, char *buf, size_t n)
{
if(n < t.size())
{
return 0;
}
memcpy(buf, t.data(), t.size());
return t.size();
}
template<typename T, typename U, typename ... Args>
std::basic_string<typename T::value_type> exile_launch(struct exile_policy *policy, U fn, Args && ... args)
{
return exile_launch<T, U, Args...>(policy, &serialize_stdstring<T>, &deserialize_stdstring<T>, fn, std::forward<Args>(args) ...);
}