0
@@ -1,3 +1,8 @@
0
+/**
0
+ * This file implements an APR bucket which understands the request handler's
0
+ * (= the dispatcher's) protocol.
0
+ * See http://www.apachetutor.org/dev/brigades for information on APR buckets.
0
+ */
0
 #ifndef _DISPATCHER_BUCKET_H_
0
 #define _DISPATCHER_BUCKET_H_
0
 

0
@@ -1,10 +1,9 @@
0
 #ifndef _PASSENGER_EXCEPTIONS_H_
0
 #define _PASSENGER_EXCEPTIONS_H_
0
 
0
-#include <apr_strings.h>
0
 #include <exception>
0
 #include <string>
0
-#include <cstring>
0
+#include <sstream>
0
 
0
 namespace Passenger {
0
 
0
@@ -16,14 +15,9 @@ private:
0
   int m_code;
0
 public:
0
   SystemException(const string &message, int errorCode) {
0
-    char buffer[10];
0
-    
0
-    msg.assign(message);
0
-    msg.append(": ");
0
-    msg.append(strerror(errorCode));
0
-    if (apr_snprintf(buffer, sizeof(buffer), " (%d)", errorCode) > 0) {
0
-      msg.append(buffer);
0
-    }
0
+    stringstream str(message);
0
+    str << ":" << strerror(errorCode) << " (" << errorCode << ")";
0
+    msg = str.str();
0
     m_code = errorCode;
0
   }
0
   

0
@@ -279,7 +279,7 @@ public:
0
       
0
       return OK;
0
     } catch (const exception &e) {
0
-      ap_log_rerror(APLOG_MARK, APLOG_ERR, APR_EGENERAL, r, "mod_passenger unknown error: %s", e.what());
0
+      ap_log_rerror(APLOG_MARK, APLOG_ERR, APR_EGENERAL, r, "mod_passenger: unknown uncaught error: %s", e.what());
0
       return HTTP_INTERNAL_SERVER_ERROR;
0
     }
0
   }

0
@@ -8,10 +8,10 @@ LIBTOOL_OBJECTS=Configuration.o,Hooks.o,DispatcherBucket.o,Utils.o
0
 .PHONY: all install clean start restart stop
0
 
0
 all: $(OBJECTS)
0
-  $(APXS) -c mod_rails.c -Wc,$(LIBTOOL_OBJECTS) -Wl,-lstdc++
0
+  $(APXS) -c mod_rails.c -Wc,$(LIBTOOL_OBJECTS) -Wl,-lstdc++,-lboost_thread
0
 
0
 install: $(OBJECTS)
0
-  $(APXS) -i -c mod_rails.c -Wc,$(LIBTOOL_OBJECTS) -Wl,-lstdc++
0
+  $(APXS) -i -c mod_rails.c -Wc,$(LIBTOOL_OBJECTS) -Wl,-lstdc++,-lboost_thread
0
 
0
 Configuration.o: Configuration.cpp
0
   $(CXX) $(CXXFLAGS) -c Configuration.cpp

0
@@ -4,6 +4,7 @@
0
 #include <string>
0
 #include <list>
0
 #include <boost/shared_ptr.hpp>
0
+#include <boost/thread/mutex.hpp>
0
 
0
 #include <sys/types.h>
0
 #include <sys/wait.h>
0
@@ -16,6 +17,7 @@
0
 #include "Application.h"
0
 #include "MessageChannel.h"
0
 #include "Exceptions.h"
0
+#include "Utils.h"
0
 
0
 namespace Passenger {
0
 
0
@@ -26,12 +28,17 @@ using namespace boost;
0
  * This class is responsible for spawning new instances of Ruby on Rails applications.
0
  * Use the spawn() method to do so.
0
  *
0
+ * This class is fully thread-safe.
0
+ *
0
  * <h2>Implementation details</h2>
0
  * Internally, it makes use of a spawn server, which is written in Ruby. This server
0
  * is automatically started when a SpawnManager instance is created, and automatically
0
  * shutdown when that instance is destroyed. Spawning requests are sent to the server,
0
  * and details about the spawned process is returned.
0
  *
0
+ * If the spawn server dies during the middle of an operation, it will be restarted.
0
+ * See spawn() for full details.
0
+ *
0
  * The communication channel with the server is anonymous, i.e. no other processes
0
  * can access the communication channel, so communication is guaranteed to be safe
0
  * (unless, of course, if the spawn server itself is a trojan).
0
@@ -47,34 +54,35 @@ using namespace boost;
0
  */
0
 class SpawnManager {
0
 private:
0
+  string spawnServerCommand;
0
+  string logFile;
0
+  string environment;
0
+  string rubyCommand;
0
+  
0
+  mutex lock;
0
+  
0
   MessageChannel channel;
0
   pid_t pid;
0
+  bool serverNeedsRestart;
0
 
0
-public:
0
   /**
0
-   * Construct a new SpawnManager.
0
+   * Restarts the spawn server.
0
    *
0
-   * @param spawnServerCommand The filename of the spawn server to use.
0
-   * @param logFile Specify a log file that the spawn manager should use.
0
-   *            Messages on its standard output and standard error channels
0
-   *            will be written to this log file. If an empty string is
0
-   *            specified, no log file will be used, and the spawn server
0
-   *            will use the same standard output/error channels as the
0
-   *            current process.
0
-   * @param environment The RAILS_ENV environment that all RoR applications
0
-   *            should use. If an empty string is specified, the current value
0
-   *            of the RAILS_ENV environment variable will be used.
0
-   * @param rubyCommand The Ruby interpreter's command.
0
-   * @param SystemException An error occured while trying to setup the spawn server.
0
+   * @throws SystemException An error occured while trying to setup the spawn server.
0
    * @throws IOException The specified log file could not be opened.
0
    */
0
-  SpawnManager(const string &spawnServerCommand,
0
-               const string &logFile = "",
0
-               const string &environment = "production",
0
-               const string &rubyCommand = "ruby") {
0
+  void restartServer() {
0
+    if (pid != 0) {
0
+      channel.close();
0
+      // TODO: should not wait infinitely
0
+      waitpid(pid, NULL, 0);
0
+      pid = 0;
0
+    }
0
+    
0
     int fds[2];
0
     FILE *logFileHandle = NULL;
0
     
0
+    serverNeedsRestart = true;
0
     if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1) {
0
       throw SystemException("Cannot create a Unix socket", errno);
0
     }
0
@@ -90,68 +98,160 @@ public:
0
 
0
     pid = fork();
0
     if (pid == 0) {
0
-      pid = fork();
0
-      if (pid == 0) {
0
-        if (!logFile.empty()) {
0
-          dup2(fileno(logFileHandle), STDERR_FILENO);
0
-          fclose(logFileHandle);
0
-        }
0
-        dup2(STDERR_FILENO, STDOUT_FILENO);
0
-        if (!environment.empty()) {
0
-          setenv("RAILS_ENV", environment.c_str(), true);
0
-        }
0
-        dup2(fds[1], STDIN_FILENO);
0
-        close(fds[0]);
0
-        close(fds[1]);
0
-        
0
-        // Close all other file descriptors
0
-        for (int i = sysconf(_SC_OPEN_MAX); i >= 0; i--) {
0
-          if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO) {
0
-            close(i);
0
-          }
0
+      if (!logFile.empty()) {
0
+        dup2(fileno(logFileHandle), STDERR_FILENO);
0
+        fclose(logFileHandle);
0
+      }
0
+      dup2(STDERR_FILENO, STDOUT_FILENO);
0
+      if (!environment.empty()) {
0
+        setenv("RAILS_ENV", environment.c_str(), true);
0
+      }
0
+      dup2(fds[1], STDIN_FILENO);
0
+      close(fds[0]);
0
+      close(fds[1]);
0
+      
0
+      // Close all other file descriptors
0
+      for (int i = sysconf(_SC_OPEN_MAX); i >= 0; i--) {
0
+        if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO) {
0
+          close(i);
0
         }
0
-        
0
-        execlp(rubyCommand.c_str(), rubyCommand.c_str(), spawnServerCommand.c_str(), NULL);
0
-        fprintf(stderr, "Unable to run %s: %s\n", rubyCommand.c_str(), strerror(errno));
0
-        _exit(1);
0
-      } else if (pid == -1) {
0
-        fprintf(stderr, "Unable to fork a process: %s\n", strerror(errno));
0
-        _exit(0);
0
-      } else {
0
-        _exit(0);
0
       }
0
+      
0
+      execlp(rubyCommand.c_str(), rubyCommand.c_str(), spawnServerCommand.c_str(), NULL);
0
+      fprintf(stderr, "Unable to run %s: %s\n", rubyCommand.c_str(), strerror(errno));
0
+      _exit(1);
0
     } else if (pid == -1) {
0
       close(fds[0]);
0
       close(fds[1]);
0
       if (logFileHandle != NULL) {
0
         fclose(logFileHandle);
0
       }
0
+      pid = 0;
0
       throw SystemException("Unable to fork a process", errno);
0
     } else {
0
       close(fds[1]);
0
       if (!logFile.empty()) {
0
         fclose(logFileHandle);
0
       }
0
-      waitpid(pid, NULL, 0);
0
       channel = MessageChannel(fds[0]);
0
+      serverNeedsRestart = false;
0
+    }
0
+  }
0
+
0
+public:
0
+  /**
0
+   * Thrown when SpawnManager tried to restart the spawn server, but failed.
0
+   * Use getSubException() to find out more details about the failure.
0
+   */
0
+  class RestartException: public exception {
0
+  private:
0
+    shared_ptr<exception> m_subexception;
0
+  public:
0
+    RestartException(shared_ptr<exception> subexception)
0
+      : m_subexception(subexception) {}
0
+    
0
+    virtual ~RestartException() throw() {}
0
+    
0
+    virtual const char *what() const throw() {
0
+      return m_subexception->what();
0
+    }
0
+  
0
+    /**
0
+     * An exception which contains more details about why the restart failed.
0
+     */
0
+    shared_ptr<exception> getSubException() const throw() {
0
+      return m_subexception;
0
     }
0
+  };
0
+
0
+  /**
0
+   * Construct a new SpawnManager.
0
+   *
0
+   * @param spawnServerCommand The filename of the spawn server to use.
0
+   * @param logFile Specify a log file that the spawn manager should use.
0
+   *            Messages on its standard output and standard error channels
0
+   *            will be written to this log file. If an empty string is
0
+   *            specified, no log file will be used, and the spawn server
0
+   *            will use the same standard output/error channels as the
0
+   *            current process.
0
+   * @param environment The RAILS_ENV environment that all RoR applications
0
+   *            should use. If an empty string is specified, the current value
0
+   *            of the RAILS_ENV environment variable will be used.
0
+   * @param rubyCommand The Ruby interpreter's command.
0
+   * @throws SystemException An error occured while trying to setup the spawn server.
0
+   * @throws IOException The specified log file could not be opened.
0
+   */
0
+  SpawnManager(const string &spawnServerCommand,
0
+               const string &logFile = "",
0
+               const string &environment = "production",
0
+               const string &rubyCommand = "ruby") {
0
+    this->spawnServerCommand = spawnServerCommand;
0
+    this->logFile = logFile;
0
+    this->environment = environment;
0
+    this->rubyCommand = rubyCommand;
0
+    pid = 0;
0
+    restartServer();
0
   }
0
   
0
   ~SpawnManager() throw() {
0
-    channel.close();
0
+    if (pid != 0) {
0
+      channel.close();
0
+      waitpid(pid, NULL, 0);
0
+    }
0
   }
0
   
0
-  ApplicationPtr spawn(const string &appRoot, const string &username = "") {
0
+  /**
0
+   * Spawn a new instance of a Ruby on Rails application.
0
+   *
0
+   * If something went wrong in the server during the spawning process,
0
+   * then an IOException or a SystemException will be thrown. The server will
0
+   * be restarted next time spawn() is called. If the server crashes during
0
+   * the restart, a RestartException will be thrown.
0
+   *
0
+   * @param appRoot The application root of a RoR application, i.e. the folder that
0
+   *             contains 'app/', 'public/', 'config/', etc. This must be a valid directory,
0
+   *             but the path does not have to be absolute.
0
+   * @param user The user
0
+   * @return A smart pointer to an Application object, which represents the application
0
+   *         instance that has been spawned. Use this object to communicate with the
0
+   *         spawned application.
0
+   * @throws IOException Something went wrong during spawning.
0
+   * @throws SystemException Something went wrong during spawning.
0
+   * @throws RestartException An attempt to restart the spawn server was made, but that failed.
0
+   */
0
+  ApplicationPtr spawn(const string &appRoot, const string &user = "", const string &group = "") {
0
     vector<string> args;
0
+    mutex::scoped_lock l(lock);
0
+    
0
+    if (serverNeedsRestart) {
0
+      try {
0
+        P_TRACE("Restarting spawn server.");
0
+        restartServer();
0
+      } catch (const IOException &e) {
0
+        P_TRACE("Failed to restart spawn server: " << e.what());
0
+        shared_ptr<IOException> copy(new IOException(e));
0
+        throw RestartException(copy);
0
+      } catch (const SystemException &e) {
0
+        P_TRACE("Failed to restart spawn server: " << e.what());
0
+        shared_ptr<SystemException> copy(new SystemException(e));
0
+        throw RestartException(copy);
0
+      }
0
+    }
0
   
0
-    channel.write("spawn_application", appRoot.c_str(), username.c_str(), NULL);
0
-    if (!channel.read(args)) {
0
-      throw IOException("The spawn manager server has exited unexpectedly.");
0
+    try {
0
+      channel.write("spawn_application", appRoot.c_str(), user.c_str(), group.c_str(), NULL);
0
+      if (!channel.read(args)) {
0
+        throw IOException("The spawn server has exited unexpectedly.");
0
+      }
0
+      pid_t pid = atoi(args.front().c_str());
0
+      int reader = channel.readFileDescriptor();
0
+      int writer = channel.readFileDescriptor();
0
+      return ApplicationPtr(new Application(appRoot, pid, reader, writer));
0
+    } catch (const exception &e) {
0
+      P_TRACE("Spawn server died. Will restart it next time.");
0
+      serverNeedsRestart = true;
0
+      throw;
0
     }
0
-    pid_t pid = atoi(args.front().c_str());
0
-    int reader = channel.readFileDescriptor();
0
-    int writer = channel.readFileDescriptor();
0
-    return ApplicationPtr(new Application(appRoot, pid, reader, writer));
0
   }
0
 };
0
 

0
@@ -31,20 +31,22 @@ class ApplicationSpawner < AbstractServer
0
   # or a directory that doesn't appear to be a Rails application root directory,
0
   # then an ArgumentError will be raised.
0
   #
0
-  # You may optionally specify _username_. If specified, ApplicationSpawner will
0
-  # switch very spawned instance to the given user. This only works if
0
+  # You may optionally specify _user_ and _group_. If specified, ApplicationSpawner will
0
+  # switch very spawned instance to the given user and group. This only works if
0
   # ApplicationSpawner is running as root (or has the capability to change the
0
   # current process's user).
0
-  # If given an invalid username, then an ArgumentError will be raised.
0
-  # If the current process's user cannot be changed, then a UserChangeError
0
+  # If given an invalid user or group, then an ArgumentError will be raised.
0
+  # If the current process's user/group cannot be changed, then a UserChangeError
0
   # will be raised.
0
-  def initialize(app_root, username = nil)
0
+  def initialize(app_root, user = nil, group = nil)
0
     super()
0
     @app_root = normalize_path(app_root)
0
-    @username = username
0
+    @user = user
0
+    @group = group
0
     self.time = Time.now
0
     assert_valid_app_root(@app_root)
0
-    assert_valid_username(@username) unless @username.nil?
0
+    assert_valid_username(@user) unless @user.nil?
0
+    assert_valid_groupname(@group) unless @group.nil?
0
     define_message_handler(:spawn_application, :handle_spawn_application)
0
   end
0
   

0
@@ -65,12 +65,13 @@ class FrameworkSpawner < AbstractServer
0
   # or a problem in the Ruby on Rails framework), then a ApplicationSpawner::SpawnError
0
   # will be raised. The application's exception message will be printed to standard
0
   # error.
0
-  def spawn_application(app_root, username = nil)
0
+  def spawn_application(app_root, user = nil, group = nil)
0
     app_root = normalize_path(app_root)
0
     assert_valid_app_root(app_root)
0
-    assert_valid_username(username) unless username.nil?
0
+    assert_valid_username(user) unless user.nil?
0
+    assert_valid_groupname(group) unless group.nil?
0
     begin
0
-      send_to_server("spawn_application", app_root, username)
0
+      send_to_server("spawn_application", app_root, user, group)
0
       pid = recv_from_server
0
       reader = recv_io_from_server
0
       writer = recv_io_from_server
0
@@ -152,11 +153,13 @@ private
0
     end
0
   end
0
 
0
-  def handle_spawn_application(app_root, username)
0
+  def handle_spawn_application(app_root, user, group)
0
+    user = nil if user && user.empty?
0
+    group = nil if group && group.empty?
0
     @spawners_lock.synchronize do
0
       spawner = @spawners[app_root]
0
       if spawner.nil?
0
-        spawner = ApplicationSpawner.new(app_root, username.empty? ? nil : username)
0
+        spawner = ApplicationSpawner.new(app_root, user, group)
0
         spawner.file_descriptors_to_close = [@child_socket.fileno]
0
         spawner.start
0
         @spawners[app_root] = spawner

0
@@ -24,7 +24,6 @@ class RequestHandler
0
     
0
     def self.write(io, data)
0
       io.write([data.size].pack('n') << data)
0
-      io.flush
0
     end
0
   end
0
 
0
@@ -76,6 +75,7 @@ class RequestHandler
0
     write_chunk("\r\n")
0
     write_chunk(content)
0
     write_chunk("")
0
+    @writer.flush
0
   end
0
 
0
 private

0
@@ -34,7 +34,7 @@ class SpawnManager
0
     end
0
   end
0
 
0
-  def spawn_application(app_root, username = nil)
0
+  def spawn_application(app_root, user = nil, group = nil)
0
     framework_version = Application.get_framework_version(app_root)
0
     spawner = nil
0
     @lock.synchronize do
0
@@ -46,7 +46,7 @@ class SpawnManager
0
       end
0
     end
0
     spawner.time = Time.now
0
-    return spawner.spawn_application(app_root, username)
0
+    return spawner.spawn_application(app_root, user, group)
0
   end
0
   
0
   def server_main(unix_socket)
0
@@ -116,9 +116,10 @@ private
0
     @previous_signal_handlers = {}
0
   end
0
 
0
-  def handle_spawn_application(app_root, username = nil)
0
-    username = nil if username && username.empty?
0
-    app = spawn_application(app_root, username)
0
+  def handle_spawn_application(app_root, user, group)
0
+    user = nil if user && user.empty?
0
+    group = nil if group && group.empty?
0
+    app = spawn_application(app_root, user, group)
0
     @channel.write(app.pid)
0
     @channel.send_io(app.reader)
0
     @channel.send_io(app.writer)

0
@@ -26,8 +26,13 @@ private
0
   end
0
   
0
   def assert_valid_username(username)
0
-    # If username does not exist then getpwnam() will throw an ArgumentError.
0
-    username.nil? || !Etc.getpwnam(username).nil?
0
+    # If username does not exist then getpwnam() will raise an ArgumentError.
0
+    username && Etc.getpwnam(username)
0
+  end
0
+  
0
+  def assert_valid_groupname(groupname)
0
+    # If groupname does not exist then getgrnam() will raise an ArgumentError.
0
+    groupname && Etc.getgrnam(groupname)
0
   end
0
   
0
   def print_exception(current_location, exception)