Add Mac exception handler and generator. Fixes issue #69. Reviewed by mmentovai.

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@98 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/mac/handler/exception_handler.h

@@ -0,0 +1,188 @@
+// Copyright (c) 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// exception_handler.h:  MacOS exception handler
+// This class can install a Mach exception port handler to trap most common
+// programming errors.  If an exception occurs, a minidump file will be
+// generated which contains detailed information about the process and the
+// exception.
+
+#ifndef CLIENT_MAC_HANDLER_EXCEPTION_HANDLER_H__
+#define CLIENT_MAC_HANDLER_EXCEPTION_HANDLER_H__
+
+#include <mach/mach.h>
+
+#include <string>
+
+namespace google_airbag {
+
+using std::string;
+
+struct ExceptionParameters;
+
+class ExceptionHandler {
+ public:
+  // A callback function to run before Airbag performs any substantial
+  // processing of an exception.  A FilterCallback is called before writing
+  // a minidump.  context is the parameter supplied by the user as
+  // callback_context when the handler was created.
+  //
+  // If a FilterCallback returns true, Airbag will continue processing,
+  // attempting to write a minidump.  If a FilterCallback returns false, Airbag
+  // will immediately report the exception as unhandled without writing a
+  // minidump, allowing another handler the opportunity to handle it.
+  typedef bool (*FilterCallback)(void *context);
+  
+  // A callback function to run after the minidump has been written.
+  // |minidump_id| is a unique id for the dump, so the minidump
+  // file is <dump_dir>/<minidump_id>.dmp.
+  // |context| is the value passed into the constructor. 
+  // |succeeded| indicates whether a minidump file was successfully written.
+  // Return true if the exception was fully handled and airbag should exit.
+  // Return false to allow any other exception handlers to process the 
+  // exception.
+  typedef bool (*MinidumpCallback)(const char *dump_dir,
+                                   const char *minidump_id,
+                                   void *context, bool succeeded);
+
+  // Creates a new ExceptionHandler instance to handle writing minidumps.
+  // Minidump files will be written to dump_path, and the optional callback
+  // is called after writing the dump file, as described above.
+  // If install_handler is true, then a minidump will be written whenever
+  // an unhandled exception occurs.  If it is false, minidumps will only
+  // be written when WriteMinidump is called.
+  ExceptionHandler(const string &dump_path, 
+                   FilterCallback filter, MinidumpCallback callback,
+                   void *callback_context, bool install_handler);
+  ~ExceptionHandler();
+
+  // Get and set the minidump path.
+  string dump_path() const { return dump_path_; }
+  void set_dump_path(const string &dump_path) {
+    dump_path_ = dump_path;
+    dump_path_c_ = dump_path_.c_str();
+    UpdateNextID();  // Necessary to put dump_path_ in next_minidump_path_.
+  }
+  
+  // Writes a minidump immediately.  This can be used to capture the
+  // execution state independently of a crash.  Returns true on success.
+  bool WriteMinidump();
+
+  // Convenience form of WriteMinidump which does not require an
+  // ExceptionHandler instance.
+  static bool WriteMinidump(const string &dump_path, MinidumpCallback callback,
+                            void *callback_context);
+
+ private:
+  // Install the mach exception handler
+  bool InstallHandler();
+
+  // Uninstall the mach exception handler (if any)
+  bool UninstallHandler();
+      
+  // Setup the handler thread, and if |install_handler| is true, install the
+  // mach exception port handler
+  bool Setup(bool install_handler);
+    
+  // Uninstall the mach exception handler (if any) and terminate the helper
+  // thread
+  bool Teardown();
+
+  // Send an "empty" mach message to the exception handler.  Return true on
+  // success, false otherwise
+  bool SendEmptyMachMessage();
+
+  // All minidump writing goes through this one routine
+  bool WriteMinidumpWithException(int exception_type, int exception_code,
+                                  mach_port_t thread_name);
+
+  // When installed, this static function will be call from a newly created
+  // pthread with |this| as the argument
+  static void *WaitForMessage(void *exception_handler_class);
+
+  // disallow copy ctor and operator=
+  explicit ExceptionHandler(const ExceptionHandler &);
+  void operator=(const ExceptionHandler &);
+
+  // Generates a new ID and stores it in next_minidump_id_, and stores the
+  // path of the next minidump to be written in next_minidump_path_.
+  void UpdateNextID();
+  
+  // The destination directory for the minidump
+  string dump_path_;
+  
+  // The basename of the next minidump w/o extension
+  string next_minidump_id_;
+  
+  // The full path to the next minidump to be written, including extension
+  string next_minidump_path_;
+  
+  // Pointers to the UTF-8 versions of above
+  const char *dump_path_c_;
+  const char *next_minidump_id_c_;
+  const char *next_minidump_path_c_;
+
+  // The callback function and pointer to be passed back after the minidump
+  // has been written
+  FilterCallback filter_;
+  MinidumpCallback callback_;
+  void *callback_context_;
+
+  // The thread that is created for the handler
+  pthread_t handler_thread_;
+
+  // The port that is waiting on an exception message to be sent, if the
+  // handler is installed
+  mach_port_t handler_port_;
+
+  // These variables save the previous exception handler's data so that it
+  // can be re-installed when this handler is uninstalled
+  ExceptionParameters *previous_;
+
+  // True, if we've installed the exception handler
+  bool installed_exception_handler_;
+  
+  // True, if we're in the process of uninstalling the exception handler and
+  // the thread.
+  bool is_in_teardown_;
+  
+  // Save the last result of the last minidump
+  bool last_minidump_write_result_;
+  
+  // A mutex for use when writing out a minidump that was requested on a 
+  // thread other than the exception handler.
+  pthread_mutex_t minidump_write_mutex_;
+  
+  // True, if we're using the mutext to indicate when mindump writing occurs
+  bool use_minidump_write_mutex_;
+};
+
+}  // namespace google_airbag
+
+#endif  // CLIENT_MAC_HANDLER_EXCEPTION_HANDLER_H__