child processes spawn

parity/hypervisor/mod.rs

@@ -16,7 +16,7 @@
 
 //! Parity interprocess hypervisor module
 
-// while not in binary
+// while not included in binary
 #![allow(dead_code)]
 
 pub mod service;
@@ -26,30 +26,74 @@ pub const HYPERVISOR_IPC_URL: &'static str = "ipc:///tmp/parity-internal-hyper-s
 use nanoipc;
 use std::sync::{Arc,RwLock};
 use hypervisor::service::*;
+use std::process::{Command,Child};
+use std::collections::HashMap;
+
+type BinaryId = &'static str;
+
+const BLOCKCHAIN_DB_BINARY: BinaryId = "blockchain";
 
 pub struct Hypervisor {
+	ipc_addr: String,
 	service: Arc<HypervisorService>,
 	ipc_worker: RwLock<nanoipc::Worker<HypervisorService>>,
+	processes: RwLock<HashMap<BinaryId, Child>>,
 }
 
 impl Hypervisor {
 	/// initializes the Hypervisor service with the open ipc socket for incoming clients
-	pub fn init() -> Arc<Hypervisor>{
+	pub fn new() -> Hypervisor {
 		Hypervisor::with_url(HYPERVISOR_IPC_URL)
 	}
 
-	fn with_url(addr: &str) -> Arc<Hypervisor>{
+	fn with_url(addr: &str) -> Hypervisor{
 		Hypervisor::with_url_and_service(addr, HypervisorService::new())
 	}
 
-	fn with_url_and_service(addr: &str, service: Arc<HypervisorService>) -> Arc<Hypervisor> {
-		let mut worker = nanoipc::Worker::new(&service);
-		worker.add_reqrep(addr).expect("Hypervisor ipc worker can not start - critical!");
-
-		Arc::new(Hypervisor{
+	fn with_url_and_service(addr: &str, service: Arc<HypervisorService>) -> Hypervisor {
+		let worker = nanoipc::Worker::new(&service);
+		Hypervisor{
+			ipc_addr: addr.to_owned(),
 			service: service,
 			ipc_worker: RwLock::new(worker),
-		})
+			processes: RwLock::new(HashMap::new()),
+		}
+	}
+
+	/// Since one binary can host multiple modules
+	/// we match binaries
+	fn match_module(module_id: &IpcModuleId) -> Option<BinaryId> {
+		match *module_id {
+			BLOCKCHAIN_MODULE_ID => Some(BLOCKCHAIN_DB_BINARY),
+			// none means the module is inside the main binary
+			_ => None
+		}
+	}
+
+	fn start(&self) {
+		let mut worker = self.ipc_worker.write().unwrap();
+		worker.add_reqrep(&self.ipc_addr).unwrap_or_else(|e| panic!("Hypervisor ipc worker can not start - critical! ({:?})", e));
+
+		for module_id in self.service.module_ids() {
+			self.start_module(module_id);
+		}
+	}
+
+	fn start_module(&self, module_id: IpcModuleId) {
+		Self::match_module(&module_id).map(|binary_id|
+		   {
+				let mut processes = self.processes.write().unwrap();
+				{
+					let process = processes.get(binary_id);
+					if process.is_some() {
+						// already started for another module
+						return;
+					}
+				}
+				let child = Command::new(binary_id).spawn().unwrap_or_else(
+					|e| panic!("Hypervisor cannot start binary: {}", e));
+				processes.insert(binary_id, child);
+			});
 	}
 
 	pub fn modules_ready(&self) -> bool {
@@ -98,6 +142,7 @@ mod tests {
 		});
 
 		let hypervisor = Hypervisor::with_url_and_service(url, HypervisorService::with_modules(vec![test_module_id]));
+		hypervisor.start();
 		hypervisor_ready_local.store(true, Ordering::Relaxed);
 		hypervisor.wait_for_startup();
 

parity/hypervisor/service.rs.in

@@ -21,8 +21,7 @@ use std::collections::HashMap;
 
 pub type IpcModuleId = u64;
 
-pub const _DATABASE_MODULE_ID: IpcModuleId = 1000;
-pub const _BLOCKCHAIN_MODULE_ID: IpcModuleId = 2000;
+pub const BLOCKCHAIN_MODULE_ID: IpcModuleId = 2000;
 
 pub struct HypervisorService {
 	check_list: RwLock<HashMap<IpcModuleId, bool>>,
@@ -55,6 +54,10 @@ impl HypervisorService {
 	pub fn unchecked_count(&self) -> usize {
 		self.check_list.read().unwrap().iter().filter(|&(_, status)| !status).count()
 	}
+
+	pub fn module_ids(&self) -> Vec<IpcModuleId> {
+		self.check_list.read().unwrap().iter().map(|(module_id, _)| module_id).cloned().collect()
+	}
 }
 
 impl ::ipc::IpcConfig for HypervisorService {}