commit dda8551a22added0340e1ad7445d36279b5c82bb
parent 1cba3966756b2a305eefe19f86ff2227258c1095
Author: Simon Kornblith <simon@simonster.com>
Date: Tue, 28 Jun 2011 03:59:18 +0000
Fix additional race condition and make IPC more resilient to hanging on shutdown
Diffstat:
1 file changed, 75 insertions(+), 54 deletions(-)
diff --git a/chrome/content/zotero/xpcom/ipc.js b/chrome/content/zotero/xpcom/ipc.js
@@ -24,7 +24,7 @@
*/
Zotero.IPC = new function() {
- var _libc, _libcPath, _instancePipe, _user32;
+ var _libc, _libcPath, _instancePipe, _user32, open, write, close, instancePipeOpen;
/**
* Initialize pipe for communication with connector
@@ -44,19 +44,58 @@ Zotero.IPC = new function() {
/**
* Parses input received via instance pipe
*/
- this.parsePipeInput = function(msg) {
- // remove a newline if there is one
- if(msg[msg.length-1] === "\n") msg = msg.substr(0, msg.length-1);
-
- Zotero.debug('IPC: Received "'+msg+'"');
-
- if(msg === "releaseLock" && !Zotero.isConnector) {
- switchConnectorMode(true);
- } else if(msg === "lockReleased") {
- Zotero.onDBLockReleased();
- } else if(msg === "initComplete") {
- Zotero.onInitComplete();
+ this.parsePipeInput = function(msgs) {
+ for each(var msg in msgs.split("\n")) {
+ if(!msg) continue;
+ Zotero.debug('IPC: Received "'+msg+'"');
+
+ if(msg === "releaseLock" && !Zotero.isConnector) {
+ switchConnectorMode(true);
+ } else if(msg === "lockReleased") {
+ Zotero.onDBLockReleased();
+ } else if(msg === "initComplete") {
+ Zotero.onInitComplete();
+ }
+ }
+ }
+
+ /**
+ * Writes safely to a file, avoiding blocking
+ * @param {String} path The path of the file
+ * @param {String} string The string to write to the file
+ * @return {Boolean} True if write succeeded; false otherwise
+ */
+ this.safePipeWrite = function(path, string) {
+ if(!open) {
+ // safely write to instance pipes
+ var lib = Zotero.IPC.getLibc();
+ if(!lib) return false;
+
+ // int open(const char *path, int oflag);
+ if(Zotero.isFx36) {
+ open = lib.declare("open", ctypes.default_abi, ctypes.int32_t, ctypes.string, ctypes.int32_t);
+ } else {
+ open = lib.declare("open", ctypes.default_abi, ctypes.int, ctypes.char.ptr, ctypes.int);
+ }
+ // ssize_t write(int fildes, const void *buf, size_t nbyte);
+ if(Zotero.isFx36) {
+ write = lib.declare("write", ctypes.default_abi, ctypes.int32_t, ctypes.int32_t, ctypes.string, ctypes.uint32_t);
+ } else {
+ write = lib.declare("write", ctypes.default_abi, ctypes.ssize_t, ctypes.int, ctypes.char.ptr, ctypes.size_t);
+ }
+ // int close(int filedes);
+ if(Zotero.isFx36) {
+ close = lib.declare("close", ctypes.default_abi, ctypes.int32_t, ctypes.int32_t);
+ } else {
+ close = lib.declare("close", ctypes.default_abi, ctypes.int, ctypes.int);
+ }
}
+
+ var fd = open(path, 0x0004 | 0x0001); // O_NONBLOCK | O_WRONLY
+ if(fd === -1) return false;
+ write(fd, string, string.length);
+ close(fd);
+ return true;
}
/**
@@ -145,6 +184,13 @@ Zotero.IPC = new function() {
user32.close();
return false;
} else { // communicate via pipes
+ // make sure instance pipe is open and accepting input, or ignore if it has been deleted
+ if(!instancePipeOpen && _instancePipe.exists()) {
+ while(!Zotero.IPC.safePipeWrite(_instancePipe.path, "test\n")) {
+ Zotero.wait();
+ }
+ instancePipeOpen = true;
+ }
// look for other Zotero instances
var pipes = [];
@@ -160,37 +206,13 @@ Zotero.IPC = new function() {
}
if(!pipes.length) return false;
-
- // safely write to instance pipes
- var lib = this.getLibc();
- if(!lib) return false;
-
- // int open(const char *path, int oflag);
- if(Zotero.isFx36) {
- var open = lib.declare("open", ctypes.default_abi, ctypes.int32_t, ctypes.string, ctypes.int32_t);
- } else {
- var open = lib.declare("open", ctypes.default_abi, ctypes.int, ctypes.char.ptr, ctypes.int);
- }
- // ssize_t write(int fildes, const void *buf, size_t nbyte);
- if(Zotero.isFx36) {
- } else {
- var write = lib.declare("write", ctypes.default_abi, ctypes.ssize_t, ctypes.int, ctypes.char.ptr, ctypes.size_t);
- }
- // int close(int filedes);
- if(Zotero.isFx36) {
- } else {
- var close = lib.declare("close", ctypes.default_abi, ctypes.int, ctypes.int);
- }
-
var success = false;
for each(var pipe in pipes) {
- var fd = open(pipe.path, 0x0004 | 0x0001); // O_NONBLOCK | O_WRONLY
- if(fd !== -1) {
- Zotero.debug('IPC: Broadcasting "'+msg+'" to instance '+pipe.leafName);
+ Zotero.debug('IPC: Trying to broadcast "'+msg+'" to instance '+pipe.leafName);
+ if(Zotero.IPC.safePipeWrite(pipe.path, msg+"\n")) {
success = true;
- write(fd, msg+"\n", msg.length);
- close(fd);
} else {
+ Zotero.debug('IPC: Removing defunct pipe '+pipe.leafName);
try {
pipe.remove(true);
} catch(e) {};
@@ -320,13 +342,19 @@ Zotero.IPC.Pipe = new function() {
* deletes it
*/
this.writeShutdownMessage = function(file) {
+ // Make sure pipe actually exists
+ if(!file.exists()) {
+ Zotero.debug("IPC: Not closing pipe "+file.path+": already deleted");
+ return;
+ }
+
+ // Keep trying to write to pipe until we succeed, in case pipe is not yet open
Zotero.debug("IPC: Closing pipe "+file.path);
- var oStream = Components.classes["@mozilla.org/network/file-output-stream;1"].
- getService(Components.interfaces.nsIFileOutputStream);
- oStream.init(file, 0x02 | 0x10, 0, 0);
- const cmd = "Zotero shutdown\n";
- oStream.write(cmd, cmd.length);
- oStream.close();
+ while(!Zotero.IPC.safePipeWrite(file.path, "Zotero shutdown\n")) {
+ Zotero.wait();
+ }
+
+ // Delete pipe
file.remove(false);
}
}
@@ -405,14 +433,7 @@ Zotero.IPC.Pipe.WorkerThread = function(file, callback) {
worker.postMessage({"path":file.path, "libc":Zotero.IPC.getLibcPath()});
// add shutdown listener
- Zotero.addShutdownListener(function() {
- // wait for pending events to complete (so that we don't try to close the pipe before it
- // finishes opening)
- while(Zotero.mainThread.processNextEvent(false)) {};
-
- // close pipe
- Zotero.IPC.Pipe.writeShutdownMessage(file)
- });
+ Zotero.addShutdownListener(Zotero.IPC.Pipe.writeShutdownMessage.bind(null, file));
}
Zotero.IPC.Pipe.WorkerThread.prototype = {
