diff --git a/components/gfx/font_cache_thread.rs b/components/gfx/font_cache_thread.rs index fec14cfdb9d..fdb48e519fe 100644 --- a/components/gfx/font_cache_thread.rs +++ b/components/gfx/font_cache_thread.rs @@ -112,6 +112,7 @@ pub enum Command { AddWebFont(LowercaseString, EffectiveSources, IpcSender<()>), AddDownloadedWebFont(LowercaseString, ServoUrl, Vec, IpcSender<()>), Exit(IpcSender<()>), + Ping, } /// Reply messages sent from the font cache thread to the FontContext caller. @@ -204,6 +205,7 @@ impl FontCache { templates.add_template(Atom::from(url.to_string()), Some(bytes)); drop(result.send(())); } + Command::Ping => (), Command::Exit(result) => { let _ = result.send(()); break; @@ -472,10 +474,13 @@ impl FontSource for FontCacheThread { self.chan.send(Command::GetFontInstance(key, size, response_chan)) .expect("failed to send message to font cache thread"); - let instance_key = response_port.recv() - .expect("failed to receive response to font request"); - - instance_key + let instance_key = response_port.recv(); + if instance_key.is_err() { + let font_thread_has_closed = self.chan.send(Command::Ping).is_err(); + assert!(font_thread_has_closed, "Failed to receive a response from live font cache"); + panic!("Font cache thread has already exited."); + } + instance_key.unwrap() } fn find_font_template(&mut self, family: SingleFontFamily, desc: FontTemplateDescriptor) @@ -485,10 +490,15 @@ impl FontSource for FontCacheThread { self.chan.send(Command::GetFontTemplate(family, desc, response_chan)) .expect("failed to send message to font cache thread"); - let reply = response_port.recv() - .expect("failed to receive response to font request"); + let reply = response_port.recv(); - match reply { + if reply.is_err() { + let font_thread_has_closed = self.chan.send(Command::Ping).is_err(); + assert!(font_thread_has_closed, "Failed to receive a response from live font cache"); + panic!("Font cache thread has already exited."); + } + + match reply.unwrap() { Reply::GetFontTemplateReply(data) => { data } @@ -502,10 +512,14 @@ impl FontSource for FontCacheThread { self.chan.send(Command::GetLastResortFontTemplate(desc, response_chan)) .expect("failed to send message to font cache thread"); - let reply = response_port.recv() - .expect("failed to receive response to font request"); + let reply = response_port.recv(); + if reply.is_err() { + let font_thread_has_closed = self.chan.send(Command::Ping).is_err(); + assert!(font_thread_has_closed, "Failed to receive a response from live font cache"); + panic!("Font cache thread has already exited."); + } - match reply { + match reply.unwrap() { Reply::GetFontTemplateReply(data) => { data.unwrap() }