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fix(parity-clib): grumbles that were not addressed in #9920 (#10154)

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* fix(remove needless unsafe blocks)

* style(nits)

* fix(parity-clib): eliminate repetitive event loops

* revert(java bindings): safe rust -> unsafe rust

These functions can still end up with `UB` thus should be unsafe

* fix(grumbles): make Callback trait `pub (crate)`
This commit is contained in:
Niklas Adolfsson 2019-02-11 15:27:46 +01:00 committed by Afri Schoedon
parent 751d15e4be
commit c84e5745fa
2 changed files with 116 additions and 163 deletions
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102
parity-clib/src/java.rs
View File

@ -15,34 +15,31 @@
// along with Parity Ethereum. If not, see <http://www.gnu.org/licenses/>.
use std::{mem, ptr};
use std::ffi::c_void;
use std::sync::Arc;
use std::time::Duration;
use std::thread;
use std::os::raw::c_void;
use {parity_config_from_cli, parity_destroy, parity_set_logger, parity_start, parity_unsubscribe_ws, ParityParams, error};
use {Callback, parity_config_from_cli, parity_destroy, parity_rpc_worker, parity_start, parity_set_logger,
parity_unsubscribe_ws, parity_ws_worker, ParityParams};
use futures::{Future, Stream};
use futures::sync::mpsc;
use jni::{JavaVM, JNIEnv};
use jni::objects::{JClass, JString, JObject, JValue, GlobalRef};
use jni::sys::{jlong, jobjectArray, va_list};
use tokio_current_thread::CurrentThread;
use parity_ethereum::{RunningClient, PubSubSession};
use parity_ethereum::RunningClient;
type CheckedQuery<'a> = (&'a RunningClient, String, JavaVM, GlobalRef);
// Creates a Java callback to a static method named `void callback(Object)`
struct Callback<'a> {
struct JavaCallback<'a> {
jvm: JavaVM,
callback: GlobalRef,
method_name: &'a str,
method_descriptor: &'a str,
}
unsafe impl<'a> Send for Callback<'a> {}
unsafe impl<'a> Sync for Callback<'a> {}
impl<'a> Callback<'a> {
unsafe impl<'a> Send for JavaCallback<'a> {}
unsafe impl<'a> Sync for JavaCallback<'a> {}
impl<'a> JavaCallback<'a> {
fn new(jvm: JavaVM, callback: GlobalRef) -> Self {
Self {
jvm,
@ -51,7 +48,9 @@ impl<'a> Callback<'a> {
method_descriptor: "(Ljava/lang/Object;)V",
}
}
}
impl<'a> Callback for JavaCallback<'a> {
fn call(&self, msg: &str) {
let env = self.jvm.attach_current_thread().expect("JavaVM should have an environment; qed");
let java_str = env.new_string(msg.to_string()).expect("Rust String is valid JString; qed");
@ -63,13 +62,13 @@ impl<'a> Callback<'a> {
#[no_mangle]
pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_configFromCli(env: JNIEnv, _: JClass, cli: jobjectArray) -> jlong {
let cli_len = env.get_array_length(cli).expect("invalid Java bindings");
let cli_len = env.get_array_length(cli).expect("invalid Java bindings") as usize;
let mut jni_strings = Vec::with_capacity(cli_len as usize);
let mut opts = Vec::with_capacity(cli_len as usize);
let mut opts_lens = Vec::with_capacity(cli_len as usize);
let mut jni_strings = Vec::with_capacity(cli_len);
let mut opts = Vec::with_capacity(cli_len);
let mut opts_lens = Vec::with_capacity(cli_len);
for n in 0..cli_len {
for n in 0..cli_len as i32 {
let elem = env.get_object_array_element(cli, n).expect("invalid Java bindings");
let elem_str: JString = elem.into();
match env.get_string(elem_str) {
@ -77,7 +76,7 @@ pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_configFromCli(env:
opts.push(s.as_ptr());
opts_lens.push(s.to_bytes().len());
jni_strings.push(s);
},
}
Err(err) => {
let _ = env.throw_new("java/lang/Exception", err.to_string());
return 0
@ -86,7 +85,7 @@ pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_configFromCli(env:
}
let mut out = ptr::null_mut();
match parity_config_from_cli(opts.as_ptr(), opts_lens.as_ptr(), cli_len as usize, &mut out) {
match parity_config_from_cli(opts.as_ptr(), opts_lens.as_ptr(), cli_len, &mut out) {
0 => out as jlong,
_ => {
let _ = env.throw_new("java/lang/Exception", "failed to create config object");
@ -120,7 +119,7 @@ pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_build(
_ => {
let _ = env.throw_new("java/lang/Exception", "failed to start Parity");
0
},
}
}
}
@ -129,7 +128,7 @@ pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_destroy(_env: JNIEn
parity_destroy(parity);
}
unsafe fn async_checker<'a>(client: va_list, rpc: JString, callback: JObject, env: &JNIEnv<'a>)
unsafe fn java_query_checker<'a>(client: va_list, rpc: JString, callback: JObject, env: &JNIEnv<'a>)
-> Result<CheckedQuery<'a>, String> {
let query: String = env.get_string(rpc)
.map(Into::into)
@ -151,26 +150,10 @@ pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_rpcQueryNative(
callback: JObject,
)
{
let _ = async_checker(parity, rpc, callback, &env)
let _ = java_query_checker(parity, rpc, callback, &env)
.map(|(client, query, jvm, global_ref)| {
let callback = Arc::new(Callback::new(jvm, global_ref));
let cb = callback.clone();
let future = client.rpc_query(&query, None).map(move |response| {
let response = response.unwrap_or_else(|| error::EMPTY.to_string());
callback.call(&response);
});
let _handle = thread::Builder::new()
.name("rpc_query".to_string())
.spawn(move || {
let mut current_thread = CurrentThread::new();
current_thread.spawn(future);
let _ = current_thread.run_timeout(Duration::from_millis(timeout_ms as u64))
.map_err(|_e| {
cb.call(error::TIMEOUT);
});
})
.expect("rpc-query thread shouldn't fail; qed");
let callback = Arc::new(JavaCallback::new(jvm, global_ref));
parity_rpc_worker(client, &query, callback, timeout_ms as u64);
})
.map_err(|e| {
let _ = env.throw_new("java/lang/Exception", e);
@ -186,43 +169,10 @@ pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_subscribeWebSocketN
callback: JObject,
) -> va_list {
async_checker(parity, rpc, callback, &env)
java_query_checker(parity, rpc, callback, &env)
.map(move |(client, query, jvm, global_ref)| {
let callback = Arc::new(Callback::new(jvm, global_ref));
let (tx, mut rx) = mpsc::channel(1);
let session = Arc::new(PubSubSession::new(tx));
let weak_session = Arc::downgrade(&session);
let query_future = client.rpc_query(&query, Some(session.clone()));;
let _handle = thread::Builder::new()
.name("ws-subscriber".into())
.spawn(move || {
// Wait for subscription ID
// Note this may block forever and can't be destroyed using the session object
// However, this will likely timeout or be catched the RPC layer
if let Ok(Some(response)) = query_future.wait() {
callback.call(&response);
} else {
callback.call(error::SUBSCRIBE);
return;
};
loop {
for response in rx.by_ref().wait() {
if let Ok(r) = response {
callback.call(&r);
}
}
let rc = weak_session.upgrade().map_or(0,|session| Arc::strong_count(&session));
// No subscription left, then terminate
if rc <= 1 {
break;
}
}
})
.expect("rpc-subscriber thread shouldn't fail; qed");
Arc::into_raw(session) as va_list
let callback = Arc::new(JavaCallback::new(jvm, global_ref));
parity_ws_worker(client, &query, callback) as va_list
})
.unwrap_or_else(|e| {
let _ = env.throw_new("java/lang/Exception", e);

173
parity-clib/src/lib.rs
View File

@ -40,7 +40,7 @@ use futures::sync::mpsc;
use parity_ethereum::{PubSubSession, RunningClient};
use tokio_current_thread::CurrentThread;
type Callback = Option<extern "C" fn(*mut c_void, *const c_char, usize)>;
type CCallback = Option<extern "C" fn(*mut c_void, *const c_char, usize)>;
type CheckedQuery<'a> = (&'a RunningClient, &'static str);
pub mod error {
@ -52,11 +52,33 @@ pub mod error {
#[repr(C)]
pub struct ParityParams {
pub configuration: *mut c_void,
pub on_client_restart_cb: Callback,
pub on_client_restart_cb: CCallback,
pub on_client_restart_cb_custom: *mut c_void,
pub logger: *mut c_void
}
/// Trait representing a callback that passes a string
pub(crate) trait Callback: Send + Sync {
fn call(&self, msg: &str);
}
// Internal structure for handling callbacks that get passed a string.
struct CallbackStr {
user_data: *mut c_void,
function: CCallback,
}
unsafe impl Send for CallbackStr {}
unsafe impl Sync for CallbackStr {}
impl Callback for CallbackStr {
fn call(&self, msg: &str) {
if let Some(ref cb) = self.function {
let cstr = CString::new(msg).expect("valid string with no nul bytes in the middle; qed").into_raw();
cb(self.user_data, cstr, msg.len())
}
}
}
#[no_mangle]
pub unsafe extern fn parity_config_from_cli(
args: *const *const c_char,
@ -112,7 +134,6 @@ pub unsafe extern fn parity_start(cfg: *const ParityParams, output: *mut *mut c_
panic::catch_unwind(|| {
*output = ptr::null_mut();
let cfg: &ParityParams = &*cfg;
let logger = Arc::from_raw(cfg.logger as *mut parity_ethereum::RotatingLogger);
let config = Box::from_raw(cfg.configuration as *mut parity_ethereum::Configuration);
@ -121,7 +142,7 @@ pub unsafe extern fn parity_start(cfg: *const ParityParams, output: *mut *mut c_
user_data: cfg.on_client_restart_cb_custom,
function: cfg.on_client_restart_cb,
};
move |new_chain: String| { cb.call(new_chain.as_bytes()); }
move |new_chain: String| { cb.call(&new_chain); }
};
let action = match parity_ethereum::start(*config, logger, on_client_restart_cb, || {}) {
@ -133,7 +154,7 @@ pub unsafe extern fn parity_start(cfg: *const ParityParams, output: *mut *mut c_
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;
*output = Box::into_raw(Box::new(client)) as *mut c_void;
0
}
}
@ -148,47 +169,19 @@ pub unsafe extern fn parity_destroy(client: *mut c_void) {
});
}
unsafe fn parity_rpc_query_checker<'a>(client: *const c_void, query: *const c_char, len: usize)
-> Option<CheckedQuery<'a>>
{
let query_str = {
let string = slice::from_raw_parts(query as *const u8, len);
str::from_utf8(string).ok()?
};
let client: &RunningClient = &*(client as *const RunningClient);
Some((client, query_str))
}
#[no_mangle]
pub unsafe extern fn parity_rpc(
client: *const c_void,
query: *const c_char,
len: usize,
timeout_ms: usize,
callback: Callback,
callback: CCallback,
user_data: *mut c_void,
) -> c_int {
panic::catch_unwind(|| {
if let Some((client, query)) = parity_rpc_query_checker(client, query, len) {
let client = client as &RunningClient;
let callback = Arc::new(CallbackStr {user_data, function: callback} );
let cb = callback.clone();
let query = client.rpc_query(query, None).map(move |response| {
let response = response.unwrap_or_else(|| error::EMPTY.to_string());
callback.call(response.as_bytes());
});
let _handle = thread::Builder::new()
.name("rpc_query".to_string())
.spawn(move || {
let mut current_thread = CurrentThread::new();
current_thread.spawn(query);
let _ = current_thread.run_timeout(Duration::from_millis(timeout_ms as u64))
.map_err(|_e| {
cb.call(error::TIMEOUT.as_bytes());
});
})
.expect("rpc-query thread shouldn't fail; qed");
parity_rpc_worker(client, query, callback, timeout_ms as u64);
0
} else {
1
@ -201,47 +194,13 @@ pub unsafe extern fn parity_subscribe_ws(
client: *const c_void,
query: *const c_char,
len: usize,
callback: Callback,
callback: CCallback,
user_data: *mut c_void,
) -> *const c_void {
panic::catch_unwind(|| {
if let Some((client, query)) = parity_rpc_query_checker(client, query, len) {
let (tx, mut rx) = mpsc::channel(1);
let session = Arc::new(PubSubSession::new(tx));
let query_future = client.rpc_query(query, Some(session.clone()));
let weak_session = Arc::downgrade(&session);
let cb = CallbackStr { user_data, function: callback};
let _handle = thread::Builder::new()
.name("ws-subscriber".into())
.spawn(move || {
// Wait for subscription ID
// Note this may block forever and be can't destroyed using the session object
// However, this will likely timeout or be catched the RPC layer
if let Ok(Some(response)) = query_future.wait() {
cb.call(response.as_bytes());
} else {
cb.call(error::SUBSCRIBE.as_bytes());
return;
}
loop {
for response in rx.by_ref().wait() {
if let Ok(r) = response {
cb.call(r.as_bytes());
}
}
let rc = weak_session.upgrade().map_or(0,|session| Arc::strong_count(&session));
// No subscription left, then terminate
if rc <= 1 {
break;
}
}
})
.expect("rpc-subscriber thread shouldn't fail; qed");
Arc::into_raw(session) as *const c_void
let callback = Arc::new(CallbackStr { user_data, function: callback});
parity_ws_worker(client, query, callback)
} else {
ptr::null()
}
@ -257,10 +216,10 @@ pub unsafe extern fn parity_unsubscribe_ws(session: *const c_void) {
}
#[no_mangle]
pub unsafe extern fn parity_set_panic_hook(callback: Callback, param: *mut c_void) {
pub extern fn parity_set_panic_hook(callback: CCallback, param: *mut c_void) {
let cb = CallbackStr {user_data: param, function: callback};
panic_hook::set_with(move |panic_msg| {
cb.call(panic_msg.as_bytes());
cb.call(panic_msg);
});
}
@ -283,19 +242,63 @@ pub unsafe extern fn parity_set_logger(
*logger = Arc::into_raw(parity_ethereum::setup_log(&logger_cfg).expect("Logger initialized only once; qed")) as *mut _;
}
// Internal structure for handling callbacks that get passed a string.
struct CallbackStr {
user_data: *mut c_void,
function: Callback,
// WebSocket event loop
fn parity_ws_worker(client: &RunningClient, query: &str, callback: Arc<Callback>) -> *const c_void {
let (tx, mut rx) = mpsc::channel(1);
let session = Arc::new(PubSubSession::new(tx));
let query_future = client.rpc_query(query, Some(session.clone()));
let weak_session = Arc::downgrade(&session);
let _handle = thread::Builder::new()
.name("ws-subscriber".into())
.spawn(move || {
// Wait for subscription ID
// Note this may block forever and be can't destroyed using the session object
// However, this will likely timeout or be catched the RPC layer
if let Ok(Some(response)) = query_future.wait() {
callback.call(&response);
} else {
callback.call(error::SUBSCRIBE);
return;
}
unsafe impl Send for CallbackStr {}
unsafe impl Sync for CallbackStr {}
impl CallbackStr {
fn call(&self, msg: &[u8]) {
if let Some(ref cb) = self.function {
let cstr = CString::new(msg).expect("valid string with no null bytes in the middle; qed").into_raw();
cb(self.user_data, cstr, msg.len())
while weak_session.upgrade().map_or(0, |session| Arc::strong_count(&session)) > 1 {
for response in rx.by_ref().wait() {
if let Ok(r) = response {
callback.call(&r);
}
}
}
})
.expect("rpc-subscriber thread shouldn't fail; qed");
Arc::into_raw(session) as *const c_void
}
// RPC event loop that runs for at most `timeout_ms`
fn parity_rpc_worker(client: &RunningClient, query: &str, callback: Arc<Callback>, timeout_ms: u64) {
let cb = callback.clone();
let query = client.rpc_query(query, None).map(move |response| {
let response = response.unwrap_or_else(|| error::EMPTY.to_string());
callback.call(&response);
});
let _handle = thread::Builder::new()
.name("rpc_query".to_string())
.spawn(move || {
let mut current_thread = CurrentThread::new();
current_thread.spawn(query);
let _ = current_thread
.run_timeout(Duration::from_millis(timeout_ms))
.map_err(|_e| {
cb.call(error::TIMEOUT);
});
})
.expect("rpc-query thread shouldn't fail; qed");
}
unsafe fn parity_rpc_query_checker<'a>(client: *const c_void, query: *const c_char, len: usize)
-> Option<CheckedQuery<'a>>
{
let query_str = str::from_utf8(slice::from_raw_parts(query as *const u8, len)).ok()?;
let client: &RunningClient = &*(client as *const RunningClient);
Some((client, query_str))
}