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 // Copyright (c) 2007, 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.

 //

 // Author: Alfred Peng

 #ifndef CLIENT_SOLARIS_HANDLER_EXCEPTION_HANDLER_H__

 #define CLIENT_SOLARIS_HANDLER_EXCEPTION_HANDLER_H__

 #include <map>

 #include <string>

 #include <vector>

 #include "client/solaris/handler/minidump_generator.h"

 namespace google_breakpad {

 using std::string;

 //

 // ExceptionHandler

 //

 // ExceptionHandler can write a minidump file when an exception occurs,

 // or when WriteMinidump() is called explicitly by your program.

 //

 // To have the exception handler write minidumps when an uncaught exception

 // (crash) occurs, you should create an instance early in the execution

 // of your program, and keep it around for the entire time you want to

 // have crash handling active (typically, until shutdown).

 // (NOTE): There should be only one this kind of exception handler

 // object per process.

 //

 // If you want to write minidumps without installing the exception handler,

 // you can create an ExceptionHandler with install_handler set to false,

 // then call WriteMinidump.  You can also use this technique if you want to

 // use different minidump callbacks for different call sites.

 //

 // In either case, a callback function is called when a minidump is written,

 // which receives the unqiue id of the minidump.  The caller can use this

 // id to collect and write additional application state, and to launch an

 // external crash-reporting application.

 //

 // Caller should try to make the callbacks as crash-friendly as possible,

 // it should avoid use heap memory allocation as much as possible.

 //

 class ExceptionHandler {

  public:

   // A callback function to run before Breakpad 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, Breakpad will continue processing,

   // attempting to write a minidump.  If a FilterCallback returns false,

   // Breakpad  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_path>/<minidump_id>.dmp.  context is the parameter supplied

   // by the user as callback_context when the handler was created.  succeeded

   // indicates whether a minidump file was successfully written.

   //

   // If an exception occurred and the callback returns true, Breakpad will

   // treat the exception as fully-handled, suppressing any other handlers from

   // being notified of the exception.  If the callback returns false, Breakpad

   // will treat the exception as unhandled, and allow another handler to handle

   // it. If there are no other handlers, Breakpad will report the exception to

   // the system as unhandled, allowing a debugger or native crash dialog the

   // opportunity to handle the exception.  Most callback implementations

   // should normally return the value of |succeeded|, or when they wish to

   // not report an exception of handled, false.  Callbacks will rarely want to

   // return true directly (unless |succeeded| is true).

   typedef bool (*MinidumpCallback)(const char *dump_path,

                                    const char *minidump_id,

                                    void *context,

                                    bool succeeded);

   // Creates a new ExceptionHandler instance to handle writing minidumps.

   // Before writing a minidump, the optional filter callback will be called.

   // Its return value determines whether or not Breakpad should write a

   // minidump.  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();

   }

   // 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:

   // Setup crash handler.

   void SetupHandler();

   // Setup signal handler for a signal.

   void SetupHandler(int signo);

   // Teardown the handler for a signal.

   void TeardownHandler(int signo);

   // Teardown all handlers.

   void TeardownAllHandlers();

   // Runs the main loop for the exception handler thread.

   static void* ExceptionHandlerThreadMain(void *lpParameter);

   // Signal handler.

   static void HandleException(int signo);

   // Write all the information to the dump file.

   // If called from a signal handler, sighandler_ebp is the ebp of

   // that signal handler's frame, and sig_ctx is an out parameter

   // that will be set to point at the ucontext_t that was placed

   // on the stack by the kernel.  You can pass zero and NULL

   // for the second and third parameters if you are not calling

   // this from a signal handler.

   bool InternalWriteMinidump(int signo, uintptr_t sighandler_ebp,

                              ucontext_t **sig_ctx);

  private:

   // The callbacks before and after writing the dump file.

   FilterCallback filter_;

   MinidumpCallback callback_;

   void *callback_context_;

   // The directory in which a minidump will be written, set by the dump_path

   // argument to the constructor, or set_dump_path.

   string dump_path_;

   // C style dump path. Keep this when setting dump path, since calling

   // c_str() of std::string when crashing may not be safe.

   const char *dump_path_c_;

   // True if the ExceptionHandler installed an unhandled exception filter

   // when created (with an install_handler parameter set to true).

   bool installed_handler_;

   // Keep the previous handlers for the signal.

   typedef void (*sighandler_t)(int);

   std::map<int, sighandler_t> old_handlers_;

   // The global exception handler stack. This is need becuase there may exist

   // multiple ExceptionHandler instances in a process. Each will have itself

   // registered in this stack.

   static std::vector<ExceptionHandler *> *handler_stack_;

   // The index of the handler that should handle the next exception.

   static int handler_stack_index_;

   static pthread_mutex_t handler_stack_mutex_;

   // The minidump generator.

   MinidumpGenerator minidump_generator_;

   // disallow copy ctor and operator=

   explicit ExceptionHandler(const ExceptionHandler &);

   void operator=(const ExceptionHandler &);

 };

 }  // namespace google_breakpad

 #endif  // CLIENT_SOLARIS_HANDLER_EXCEPTION_HANDLER_H__