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authorNick Desaulniers <nickdesaulniers@users.noreply.github.com>2024-01-23 15:38:12 -0800
committerGitHub <noreply@github.com>2024-01-23 15:38:12 -0800
commit6a3ace20c80191159009668fff82fc3feeeca0a6 (patch)
tree3dafb5d132669c45e2caeebea05e837dec6781c8
parent22da8096020fcf54bae2f885882bbd088a4dcd9b (diff)
[libc] remove redundant call_once (#79226)
Missed cleanup from https://reviews.llvm.org/D134716. Fixes: #79220
-rw-r--r--libc/src/threads/linux/call_once.cpp67
-rw-r--r--libc/src/threads/linux/thread_start_args.h.def11
2 files changed, 0 insertions, 78 deletions
diff --git a/libc/src/threads/linux/call_once.cpp b/libc/src/threads/linux/call_once.cpp
deleted file mode 100644
index 5cdd8ebfd190..000000000000
--- a/libc/src/threads/linux/call_once.cpp
+++ /dev/null
@@ -1,67 +0,0 @@
-//===-- Linux implementation of the call_once function --------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "Futex.h"
-
-#include "src/__support/CPP/atomic.h"
-#include "src/__support/OSUtil/syscall.h" // For syscall functions.
-#include "src/__support/common.h"
-#include "src/threads/call_once.h"
-#include "src/threads/linux/Futex.h"
-
-#include <limits.h>
-#include <linux/futex.h>
-#include <sys/syscall.h> // For syscall numbers.
-#include <threads.h> // For call_once related type definition.
-
-namespace LIBC_NAMESPACE {
-
-static constexpr FutexWordType START = 0x11;
-static constexpr FutexWordType WAITING = 0x22;
-static constexpr FutexWordType FINISH = 0x33;
-static constexpr once_flag ONCE_FLAG_INIT_VAL = ONCE_FLAG_INIT;
-
-LLVM_LIBC_FUNCTION(void, call_once,
- (once_flag * flag, __call_once_func_t func)) {
- auto *futex_word = reinterpret_cast<cpp::Atomic<FutexWordType> *>(flag);
- static_assert(sizeof(*futex_word) == sizeof(once_flag));
-
- FutexWordType not_called = ONCE_FLAG_INIT_VAL.__word;
-
- // The C standard wording says:
- //
- // The completion of the function func synchronizes with all
- // previous or subsequent calls to call_once with the same
- // flag variable.
- //
- // What this means is that, the call_once call can return only after
- // the called function |func| returns. So, we use futexes to synchronize
- // calls with the same flag value.
- if (futex_word->compare_exchange_strong(not_called, START)) {
- func();
- auto status = futex_word->exchange(FINISH);
- if (status == WAITING) {
- LIBC_NAMESPACE::syscall_impl(FUTEX_SYSCALL_ID, &futex_word->val,
- FUTEX_WAKE_PRIVATE,
- INT_MAX, // Wake all waiters.
- 0, 0, 0);
- }
- return;
- }
-
- FutexWordType status = START;
- if (futex_word->compare_exchange_strong(status, WAITING) ||
- status == WAITING) {
- LIBC_NAMESPACE::syscall_impl(
- FUTEX_SYSCALL_ID, &futex_word->val, FUTEX_WAIT_PRIVATE,
- WAITING, // Block only if status is still |WAITING|.
- 0, 0, 0);
- }
-}
-
-} // namespace LIBC_NAMESPACE
diff --git a/libc/src/threads/linux/thread_start_args.h.def b/libc/src/threads/linux/thread_start_args.h.def
deleted file mode 100644
index cc990a37548b..000000000000
--- a/libc/src/threads/linux/thread_start_args.h.def
+++ /dev/null
@@ -1,11 +0,0 @@
-//===-- Implementation of the get_start_args_addr function ------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include <stdint.h>
-
-%%include_file(${thread_start_args})