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/*
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Atomic.h>
#include <LibPthread/pthread.h>
#include <errno.h>
#include <unistd.h>
#ifndef _DYNAMIC_LOADER
extern "C" {
static constexpr int max_keys = PTHREAD_KEYS_MAX;
struct KeyTable {
KeyDestructor destructors[max_keys] { nullptr };
int next { 0 };
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
};
struct SpecificTable {
void* values[max_keys] { nullptr };
};
static KeyTable s_keys;
# ifndef X86_64_NO_TLS
__thread
# endif
SpecificTable t_specifics;
int __pthread_key_create(pthread_key_t* key, KeyDestructor destructor)
{
int ret = 0;
__pthread_mutex_lock(&s_keys.mutex);
if (s_keys.next >= max_keys) {
ret = EAGAIN;
} else {
*key = s_keys.next++;
s_keys.destructors[*key] = destructor;
ret = 0;
}
__pthread_mutex_unlock(&s_keys.mutex);
return ret;
}
int pthread_key_create(pthread_key_t*, KeyDestructor) __attribute__((weak, alias("__pthread_key_create")));
int __pthread_key_delete(pthread_key_t key)
{
if (key < 0 || key >= max_keys)
return EINVAL;
__pthread_mutex_lock(&s_keys.mutex);
s_keys.destructors[key] = nullptr;
__pthread_mutex_unlock(&s_keys.mutex);
return 0;
}
int pthread_key_delete(pthread_key_t) __attribute__((weak, alias("__pthread_key_delete")));
void* __pthread_getspecific(pthread_key_t key)
{
if (key < 0)
return nullptr;
if (key >= max_keys)
return nullptr;
return t_specifics.values[key];
}
void* pthread_getspecific(pthread_key_t) __attribute__((weak, alias("__pthread_getspecific")));
int __pthread_setspecific(pthread_key_t key, const void* value)
{
if (key < 0)
return EINVAL;
if (key >= max_keys)
return EINVAL;
t_specifics.values[key] = const_cast<void*>(value);
return 0;
}
int pthread_setspecific(pthread_key_t, const void*) __attribute__((weak, alias("__pthread_setspecific")));
void __pthread_key_destroy_for_current_thread()
{
// This function will either be called during exit_thread, for a pthread, or
// during global program shutdown for the main thread.
__pthread_mutex_lock(&s_keys.mutex);
size_t num_used_keys = s_keys.next;
// Dr. POSIX accounts for weird key destructors setting their own key again.
// Or even, setting other unrelated keys? Odd, but whatever the Doc says goes.
for (size_t destruct_iteration = 0; destruct_iteration < PTHREAD_DESTRUCTOR_ITERATIONS; ++destruct_iteration) {
bool any_nonnull_destructors = false;
for (size_t key_index = 0; key_index < num_used_keys; ++key_index) {
void* value = exchange(t_specifics.values[key_index], nullptr);
if (value && s_keys.destructors[key_index]) {
any_nonnull_destructors = true;
(*s_keys.destructors[key_index])(value);
}
}
if (!any_nonnull_destructors)
break;
}
__pthread_mutex_unlock(&s_keys.mutex);
}
}
#endif
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