Allow setting the panic hook with parity-clib (#9292)

* Allow setting the panic hook with parity-clib

* Make all FFI functions unsafe

* Fix comment

* Fix concern
This commit is contained in:
Pierre Krieger 2018-08-10 11:06:30 +02:00 committed by Marek Kotewicz
parent 30e40079ca
commit 1564fae011
7 changed files with 168 additions and 143 deletions

1
Cargo.lock generated
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@ -1947,6 +1947,7 @@ source = "git+https://github.com/paritytech/parity-common#0045887fecd2fec39e56c9
name = "parity-clib"
version = "1.12.0"
dependencies = [
"panic_hook 0.1.0",
"parity-ethereum 2.1.0",
]

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@ -10,6 +10,7 @@ name = "parity"
crate-type = ["cdylib", "staticlib"]
[dependencies]
panic_hook = { path = "../util/panic_hook" }
parity-ethereum = { path = "../", default-features = false }
[features]

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@ -102,6 +102,23 @@ void parity_destroy(void* parity);
///
int parity_rpc(void* parity, const char* rpc, size_t len, char* out_str, size_t* out_len);
/// Sets a callback to call when a panic happens in the Rust code.
///
/// The callback takes as parameter the custom param (the one passed to this function), plus the
/// panic message. You are expected to log the panic message somehow, in order to communicate it to
/// the user. A panic always indicates a bug in Parity.
///
/// Note that this method sets the panic hook for the whole program, and not just for Parity. In
/// other words, if you use multiple Rust libraries at once (and not just Parity), then a panic
/// in any Rust code will call this callback as well.
///
/// ## Thread safety
///
/// The callback can be called from any thread and multiple times simultaneously. Make sure that
/// your code is thread safe.
///
int parity_set_panic_hook(void (*cb)(void* param, const char* msg, size_t msg_len), void* param);
#ifdef __cplusplus
}
#endif

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@ -18,6 +18,7 @@
//! duplicating documentation.
extern crate parity_ethereum;
extern crate panic_hook;
use std::os::raw::{c_char, c_void, c_int};
use std::panic;
@ -33,132 +34,132 @@ pub struct ParityParams {
}
#[no_mangle]
pub extern fn parity_config_from_cli(args: *const *const c_char, args_lens: *const usize, len: usize, output: *mut *mut c_void) -> c_int {
unsafe {
panic::catch_unwind(|| {
*output = ptr::null_mut();
pub unsafe extern fn parity_config_from_cli(args: *const *const c_char, args_lens: *const usize, len: usize, output: *mut *mut c_void) -> c_int {
panic::catch_unwind(|| {
*output = ptr::null_mut();
let args = {
let arg_ptrs = slice::from_raw_parts(args, len);
let arg_lens = slice::from_raw_parts(args_lens, len);
let args = {
let arg_ptrs = slice::from_raw_parts(args, len);
let arg_lens = slice::from_raw_parts(args_lens, len);
let mut args = Vec::with_capacity(len + 1);
args.push("parity".to_owned());
let mut args = Vec::with_capacity(len + 1);
args.push("parity".to_owned());
for (&arg, &len) in arg_ptrs.iter().zip(arg_lens.iter()) {
let string = slice::from_raw_parts(arg as *const u8, len);
match String::from_utf8(string.to_owned()) {
Ok(a) => args.push(a),
Err(_) => return 1,
};
}
args
};
match parity_ethereum::Configuration::parse_cli(&args) {
Ok(mut cfg) => {
// Always disable the auto-updater when used as a library.
cfg.args.arg_auto_update = "none".to_owned();
let cfg = Box::into_raw(Box::new(cfg));
*output = cfg as *mut _;
0
},
Err(_) => {
1
},
}
}).unwrap_or(1)
}
}
#[no_mangle]
pub extern fn parity_config_destroy(cfg: *mut c_void) {
unsafe {
let _ = panic::catch_unwind(|| {
let _cfg = Box::from_raw(cfg as *mut parity_ethereum::Configuration);
});
}
}
#[no_mangle]
pub extern fn parity_start(cfg: *const ParityParams, output: *mut *mut c_void) -> c_int {
unsafe {
panic::catch_unwind(|| {
*output = ptr::null_mut();
let cfg: &ParityParams = &*cfg;
let config = Box::from_raw(cfg.configuration as *mut parity_ethereum::Configuration);
let on_client_restart_cb = {
struct Cb(Option<extern "C" fn(*mut c_void, *const c_char, usize)>, *mut c_void);
unsafe impl Send for Cb {}
unsafe impl Sync for Cb {}
impl Cb {
fn call(&self, new_chain: String) {
if let Some(ref cb) = self.0 {
cb(self.1, new_chain.as_bytes().as_ptr() as *const _, new_chain.len())
}
}
}
let cb = Cb(cfg.on_client_restart_cb, cfg.on_client_restart_cb_custom);
move |new_chain: String| { cb.call(new_chain); }
};
let action = match parity_ethereum::start(*config, on_client_restart_cb, || {}) {
Ok(action) => action,
Err(_) => return 1,
};
match action {
parity_ethereum::ExecutionAction::Instant(Some(s)) => { println!("{}", s); 0 },
parity_ethereum::ExecutionAction::Instant(None) => 0,
parity_ethereum::ExecutionAction::Running(client) => {
*output = Box::into_raw(Box::<parity_ethereum::RunningClient>::new(client)) as *mut c_void;
0
}
}
}).unwrap_or(1)
}
}
#[no_mangle]
pub extern fn parity_destroy(client: *mut c_void) {
unsafe {
let _ = panic::catch_unwind(|| {
let client = Box::from_raw(client as *mut parity_ethereum::RunningClient);
client.shutdown();
});
}
}
#[no_mangle]
pub extern fn parity_rpc(client: *mut c_void, query: *const char, len: usize, out_str: *mut c_char, out_len: *mut usize) -> c_int {
unsafe {
panic::catch_unwind(|| {
let client: &mut parity_ethereum::RunningClient = &mut *(client as *mut parity_ethereum::RunningClient);
let query_str = {
let string = slice::from_raw_parts(query as *const u8, len);
match str::from_utf8(string) {
Ok(a) => a,
for (&arg, &len) in arg_ptrs.iter().zip(arg_lens.iter()) {
let string = slice::from_raw_parts(arg as *const u8, len);
match String::from_utf8(string.to_owned()) {
Ok(a) => args.push(a),
Err(_) => return 1,
}
};
if let Some(output) = client.rpc_query_sync(query_str) {
let q_out_len = output.as_bytes().len();
if *out_len < q_out_len {
return 1;
}
ptr::copy_nonoverlapping(output.as_bytes().as_ptr(), out_str as *mut u8, q_out_len);
*out_len = q_out_len;
0
} else {
1
};
}
}).unwrap_or(1)
args
};
match parity_ethereum::Configuration::parse_cli(&args) {
Ok(mut cfg) => {
// Always disable the auto-updater when used as a library.
cfg.args.arg_auto_update = "none".to_owned();
let cfg = Box::into_raw(Box::new(cfg));
*output = cfg as *mut _;
0
},
Err(_) => {
1
},
}
}).unwrap_or(1)
}
#[no_mangle]
pub unsafe extern fn parity_config_destroy(cfg: *mut c_void) {
let _ = panic::catch_unwind(|| {
let _cfg = Box::from_raw(cfg as *mut parity_ethereum::Configuration);
});
}
#[no_mangle]
pub unsafe extern fn parity_start(cfg: *const ParityParams, output: *mut *mut c_void) -> c_int {
panic::catch_unwind(|| {
*output = ptr::null_mut();
let cfg: &ParityParams = &*cfg;
let config = Box::from_raw(cfg.configuration as *mut parity_ethereum::Configuration);
let on_client_restart_cb = {
let cb = CallbackStr(cfg.on_client_restart_cb, cfg.on_client_restart_cb_custom);
move |new_chain: String| { cb.call(&new_chain); }
};
let action = match parity_ethereum::start(*config, on_client_restart_cb, || {}) {
Ok(action) => action,
Err(_) => return 1,
};
match action {
parity_ethereum::ExecutionAction::Instant(Some(s)) => { println!("{}", s); 0 },
parity_ethereum::ExecutionAction::Instant(None) => 0,
parity_ethereum::ExecutionAction::Running(client) => {
*output = Box::into_raw(Box::<parity_ethereum::RunningClient>::new(client)) as *mut c_void;
0
}
}
}).unwrap_or(1)
}
#[no_mangle]
pub unsafe extern fn parity_destroy(client: *mut c_void) {
let _ = panic::catch_unwind(|| {
let client = Box::from_raw(client as *mut parity_ethereum::RunningClient);
client.shutdown();
});
}
#[no_mangle]
pub unsafe extern fn parity_rpc(client: *mut c_void, query: *const char, len: usize, out_str: *mut c_char, out_len: *mut usize) -> c_int {
panic::catch_unwind(|| {
let client: &mut parity_ethereum::RunningClient = &mut *(client as *mut parity_ethereum::RunningClient);
let query_str = {
let string = slice::from_raw_parts(query as *const u8, len);
match str::from_utf8(string) {
Ok(a) => a,
Err(_) => return 1,
}
};
if let Some(output) = client.rpc_query_sync(query_str) {
let q_out_len = output.as_bytes().len();
if *out_len < q_out_len {
return 1;
}
ptr::copy_nonoverlapping(output.as_bytes().as_ptr(), out_str as *mut u8, q_out_len);
*out_len = q_out_len;
0
} else {
1
}
}).unwrap_or(1)
}
#[no_mangle]
pub unsafe extern fn parity_set_panic_hook(callback: extern "C" fn(*mut c_void, *const c_char, usize), param: *mut c_void) {
let cb = CallbackStr(Some(callback), param);
panic_hook::set_with(move |panic_msg| {
cb.call(panic_msg);
});
}
// Internal structure for handling callbacks that get passed a string.
struct CallbackStr(Option<extern "C" fn(*mut c_void, *const c_char, usize)>, *mut c_void);
unsafe impl Send for CallbackStr {}
unsafe impl Sync for CallbackStr {}
impl CallbackStr {
fn call(&self, new_chain: &str) {
if let Some(ref cb) = self.0 {
cb(self.1, new_chain.as_bytes().as_ptr() as *const _, new_chain.len())
}
}
}

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@ -57,7 +57,6 @@ extern crate ethcore_transaction as transaction;
extern crate ethereum_types;
extern crate ethkey;
extern crate kvdb;
extern crate panic_hook;
extern crate parity_hash_fetch as hash_fetch;
extern crate parity_ipfs_api;
extern crate parity_local_store as local_store;

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@ -253,7 +253,8 @@ fn main_direct(force_can_restart: bool) -> i32 {
panic_hook::set_with({
let e = exit.clone();
let exiting = exiting.clone();
move || {
move |panic_msg| {
let _ = stdio::stderr().write_all(panic_msg.as_bytes());
if !exiting.swap(true, Ordering::SeqCst) {
*e.0.lock() = ExitStatus {
panicking: true,

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@ -24,16 +24,26 @@ use std::thread;
use std::process;
use backtrace::Backtrace;
/// Set the panic hook
/// Set the panic hook to write to stderr and abort the process when a panic happens.
pub fn set_abort() {
set_with(|| process::abort());
set_with(|msg| {
let _ = io::stderr().write_all(msg.as_bytes());
process::abort()
});
}
/// Set the panic hook with a closure to be called afterwards.
pub fn set_with<F: Fn() + Send + Sync + 'static>(f: F) {
/// Set the panic hook with a closure to be called. The closure receives the panic message.
///
/// Depending on how Parity was compiled, after the closure has been executed, either the process
/// aborts or unwinding starts.
///
/// If you panic within the closure, a double panic happens and the process will stop.
pub fn set_with<F>(f: F)
where F: Fn(&str) + Send + Sync + 'static
{
panic::set_hook(Box::new(move |info| {
panic_hook(info);
f();
let msg = gen_panic_msg(info);
f(&msg);
}));
}
@ -43,7 +53,7 @@ This is a bug. Please report it at:
https://github.com/paritytech/parity-ethereum/issues/new
";
fn panic_hook(info: &PanicInfo) {
fn gen_panic_msg(info: &PanicInfo) -> String {
let location = info.location();
let file = location.as_ref().map(|l| l.file()).unwrap_or("<unknown>");
let line = location.as_ref().map(|l| l.line()).unwrap_or(0);
@ -61,18 +71,13 @@ fn panic_hook(info: &PanicInfo) {
let backtrace = Backtrace::new();
let mut stderr = io::stderr();
format!(r#"
let _ = writeln!(stderr, "");
let _ = writeln!(stderr, "====================");
let _ = writeln!(stderr, "");
let _ = writeln!(stderr, "{:?}", backtrace);
let _ = writeln!(stderr, "");
let _ = writeln!(
stderr,
"Thread '{}' panicked at '{}', {}:{}",
name, msg, file, line
);
====================
let _ = writeln!(stderr, "{}", ABOUT_PANIC);
{backtrace:?}
Thread '{name}' panicked at '{msg}', {file}:{line}
{about}
"#, backtrace = backtrace, name = name, msg = msg, file = file, line = line, about = ABOUT_PANIC)
}