Getting service process on Mac to handle having things moved/changed underneath it.

chrome/common/service_process_util_mac.mm

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/service_process_util_posix.h"
 
 #import <Foundation/Foundation.h>
 #include <launch.h>
 
 #include "base/command_line.h"
 #include "base/file_path.h"
+#include "base/file_util.h"
 #include "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/path_service.h"
 #include "base/scoped_nsobject.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/version.h"
 #include "chrome/common/child_process_host.h"
@@ skipping 52 matching lines @@
                                                        error:&err]) {
     LOG(ERROR) << "GetUserAgentPath: " << err;
   }
 
   NSString* plist_file_path =
       [launch_agents_path
            stringByAppendingPathComponent:GetServiceProcessLaunchDFileName()];
   return [NSURL fileURLWithPath:plist_file_path isDirectory:NO];
 }
 
-}
+class ExecPathComponentWatcherDelegate 
+    : public base::FilePathComponentWatcher::Delegate {
+ public:
+  ExecPathComponentWatcherDelegate(Task* shutdown_task) 
+      : shutdown_task_(shutdown_task) { }
+  virtual ~ExecPathComponentWatcherDelegate();
+  virtual void OnFilePathComponentsChanged(const FilePath& old_path,
+                                           const FilePath& new_path) OVERRIDE;
+
+private:
+  Task* shutdown_task_;
+};
+
+}  // namespace
 
 // Gets the name of the service process IPC channel.
 IPC::ChannelHandle GetServiceProcessChannel() {
   std::string socket_path;
   scoped_nsobject<NSDictionary> dictionary(
       base::mac::CFToNSCast(GTMCopyLaunchdExports()));
   NSString *ns_socket_path =
       [dictionary objectForKey:GetServiceProcessLaunchDSocketEnvVar()];
   if (ns_socket_path) {
     socket_path = base::SysNSStringToUTF8(ns_socket_path);
@@ skipping 64 matching lines @@
   if (!InitializeState()) {
     return false;
   }
   CFErrorRef err = NULL;
   state_->launchd_conf_.reset(GTMSMJobCheckIn(&err));
   if (!state_->launchd_conf_.get()) {
     LOG(ERROR) << "InitializePlatformState: " << err;
     CFRelease(err);
     return false;
   }
+  
+  
+  return true;
+}
+
+bool ServiceProcessState::SignalReadyPlatformSpecific(Task* shutdown_task) {
+  NSDictionary *ns_launchd_conf = base::mac::CFToNSCast(state_->launchd_conf_);
+  NSString *exe_path = [ns_launchd_conf objectForKey:@ LAUNCH_JOBKEY_PROGRAM];
+  if (!exe_path) {
+    return false;
+  }
+  
+  FilePath executable_path = FilePath([exe_path fileSystemRepresentation]);
+  if (!state_->executable_watcher_.Watch(
+      executable_path, new ExecPathComponentWatcherDelegate(shutdown_task))) {
+    return false;
+  }
   return true;
 }
 
 IPC::ChannelHandle ServiceProcessState::GetServiceProcessChannel() {
   CHECK(state_);
   NSDictionary *ns_launchd_conf = base::mac::CFToNSCast(state_->launchd_conf_);
   NSDictionary* socket_dict =
       [ns_launchd_conf objectForKey:@ LAUNCH_JOBKEY_SOCKETS];
   NSArray* sockets =
       [socket_dict objectForKey:GetServiceProcessLaunchDSocketKey()];
@@ skipping 116 matching lines @@
 
   base::mac::ScopedNSAutoreleasePool pool;
   NSURL* plist_url = GetUserAgentPath();
   SInt32 error = 0;
   if (!CFURLDestroyResource(reinterpret_cast<CFURLRef>(plist_url), &error)) {
     LOG(ERROR) << "RemoveFromAutoRun: " << error;
     return false;
   }
   return true;
 }
+
+ExecPathComponentWatcherDelegate::~ExecPathComponentWatcherDelegate() { }
+void ExecPathComponentWatcherDelegate::OnFilePathComponentsChanged(
+    const FilePath& old_path, const FilePath& new_path) {
+  bool needs_shutdown = false;
+  bool needs_plist_rewrite = false;
+  bool needs_plist_deletion = false;
+  
+  if (access(new_path.value().c_str(), W_OK) != 0) {
+    // Can we execute it?
+    needs_shutdown = true;
+    needs_plist_deletion = true;    
+  } else if (file_util::IsInTrash(new_path)) {
+    // Is it in the trash?
+    needs_shutdown = true;
+    needs_plist_deletion = true;    
+  } else if (!file_util::AreReferringToSameObject(old_path, new_path)) {
+    // Did it get moved?
+    needs_plist_rewrite = true;
+  }
+  
+  if (needs_shutdown) {
+    MessageLoop::current()->PostTask(FROM_HERE, shutdown_task_);
+  }
+}
+