Use libc::pause instead of std::thread::park in wait-for-exit loop · model-checking/verify-rust-std@2e90f6f (original) (raw)
`@@ -10,9 +10,9 @@ cfg_if::cfg_if! {
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`} else if #[cfg(target_os = "linux")] {
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`/// Mitigation for https://github.com/rust-lang/rust/issues/126600
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`///
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``
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/// On unix (where libc::exit may not be thread-safe), ensure that only one Rust thread
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/// calls libc::exit (or returns from main) by calling this function before calling
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/// libc::exit (or returning from main).
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`` +
/// On UNIX-like platforms (where libc::exit may not be thread-safe), ensure that only one
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/// Rust thread calls libc::exit (or returns from main) by calling this function before
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/// calling libc::exit (or returning from main).
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`///
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`/// Technically not enough to ensure soundness, since other code directly calling
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`/// libc::exit will still race with this.
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`@@ -23,7 +23,7 @@ cfg_if::cfg_if! {
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`/// This function will return only the first time it is called in a process.
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`///
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`/// * If it is called again on the same thread as the first call, it will abort.
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``
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/// * If it is called again on a different thread, it will thread::park() in a loop
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`+
/// * If it is called again on a different thread, it will wait in a loop
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`/// (waiting for the process to exit).
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`pub(crate) fn unique_thread_exit() {
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`let this_thread_id = unsafe { libc::gettid() };
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`@@ -52,9 +52,10 @@ cfg_if::cfg_if! {
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`}
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`Err(_) => {
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`` // This is not the first thread to call unique_thread_exit.
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``
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// Park until the process exits.
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// Pause until the process exits.
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`loop {
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``
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crate::thread::park();
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// Safety: libc::pause is safe to call.
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unsafe { libc::pause(); }
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`}
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`}
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`}
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`@@ -77,10 +78,12 @@ cfg_if::cfg_if! {
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` core::panicking::panic_nounwind("std::process::exit called re-entrantly")
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`} else {
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`` // This is not the first thread to call unique_thread_exit.
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`+
// Pause until the process exits.
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`// Park until the process exits.
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` drop(exiting_thread_id);
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`loop {
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``
`-
crate::thread::park();
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// Safety: libc::pause is safe to call.
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unsafe { libc::pause(); }
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`}
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`}
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`}
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