mirror of
https://github.com/chromium/crashpad.git
synced 2025-03-10 06:36:02 +00:00
1c37daa5ac
This is a reland of 460943dd9a71dc76f68182a8ede766d5543e5341
Original change's description:
> The DoubleForkAndExec() function was taking over 622 milliseconds to run
> on macOS 11 (BigSur) on Intel i5-1038NG7. I did some debugging by adding
> some custom traces and found that the fork() syscall is the bottleneck
> here, i.e., the first fork() takes around 359 milliseconds and the
> nested fork() takes around 263 milliseconds. Replacing the nested fork()
> and exec() with posix_spawn() reduces the time consumption to 257
> milliseconds!
>
> See https://github.com/libuv/libuv/pull/3064 to know why fork() is so
> slow on macOS and why posix_spawn() is a better replacement.
>
> Another point to note is that even base::LaunchProcess() from Chromium
> calls posix_spawnp() on macOS -
> 8f8d82dea0:base/process/launch_mac.cc;l=295-296
The reland isolates the change to non-Android POSIX systems because
posix_spawn and posix_spawnp are available in Android NDK 28, but
Chromium is building with version 23.
Change-Id: If44629f5445bb0e3d0a1d3698b85f047d1cbf04f
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3721655
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>
70 lines
3.5 KiB
C++
70 lines
3.5 KiB
C++
// Copyright 2017 The Crashpad Authors. All rights reserved.
|
||
//
|
||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
// you may not use this file except in compliance with the License.
|
||
// You may obtain a copy of the License at
|
||
//
|
||
// http://www.apache.org/licenses/LICENSE-2.0
|
||
//
|
||
// Unless required by applicable law or agreed to in writing, software
|
||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
// See the License for the specific language governing permissions and
|
||
// limitations under the License.
|
||
|
||
#ifndef CRASHPAD_UTIL_POSIX_SPAWN_SUBPROCESS_H_
|
||
#define CRASHPAD_UTIL_POSIX_SPAWN_SUBPROCESS_H_
|
||
|
||
#include <string>
|
||
#include <vector>
|
||
|
||
namespace crashpad {
|
||
|
||
//! \brief Spawns a subprocess.
|
||
//!
|
||
//! A grandchild process will be started through the
|
||
//! `fork()`-and-`posix_spawn()` pattern where supported, and
|
||
//! double-`fork()`-and-`execv()` pattern elsewhere. This allows the grandchild
|
||
//! to fully disassociate from the parent. The grandchild will not be a member
|
||
//! of the parent’s process group or session and will not have a controlling
|
||
//! terminal, providing isolation from signals not intended for it. The
|
||
//! grandchild’s parent process, in terms of the process tree hierarchy, will be
|
||
//! the process with process ID 1, relieving any other process of the
|
||
//! responsibility to reap it via `waitpid()`. Aside from the three file
|
||
//! descriptors associated with the standard input/output streams and any file
|
||
//! descriptor passed in \a preserve_fd, the grandchild will not inherit any
|
||
//! file descriptors from the parent process.
|
||
//!
|
||
//! \param[in] argv The argument vector to start the grandchild process with.
|
||
//! `argv[0]` is used as the path to the executable.
|
||
//! \param[in] envp A vector of environment variables of the form `var=value` to
|
||
//! be passed to the spawned process. If this value is `nullptr`, the
|
||
//! current environment is used.
|
||
//! \param[in] preserve_fd A file descriptor to be inherited by the grandchild
|
||
//! process. This file descriptor is inherited in addition to the three file
|
||
//! descriptors associated with the standard input/output streams. Use `-1`
|
||
//! if no additional file descriptors are to be inherited.
|
||
//! \param[in] use_path Whether to consult the `PATH` environment variable when
|
||
//! requested to start an executable at a non-absolute path.
|
||
//! \param[in] child_function If not `nullptr`, this function will be called in
|
||
//! the intermediate child process. Take note that this function will run in
|
||
//! the context of a forked process, and must be safe for that purpose.
|
||
//!
|
||
//! \return `true` on success, and `false` on failure with a message logged.
|
||
//! Only failures that occur in the parent process that indicate a definite
|
||
//! failure to start the the grandchild are reported in the return value.
|
||
//! Failures in the intermediate child or grandchild processes cannot be
|
||
//! reported in the return value, and are addressed by logging a message and
|
||
//! terminating. The caller assumes the responsibility for detecting such
|
||
//! failures, for example, by observing a failure to perform a successful
|
||
//! handshake with the grandchild process.
|
||
bool SpawnSubprocess(const std::vector<std::string>& argv,
|
||
const std::vector<std::string>* envp,
|
||
int preserve_fd,
|
||
bool use_path,
|
||
void (*child_function)());
|
||
|
||
} // namespace crashpad
|
||
|
||
#endif // CRASHPAD_UTIL_POSIX_SPAWN_SUBPROCESS_H_
|