Allow dumping live processes on OS X

R=mark at http://breakpad.appspot.com/148001/show

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@647 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/mac/handler/exception_handler.cc

@@ -33,6 +33,7 @@
 #include "client/mac/handler/exception_handler.h"
 #include "client/mac/handler/minidump_generator.h"
 #include "common/mac/macho_utilities.h"
+#include "common/mac/scoped_task_suspend-inl.h"
 
 #ifndef USE_PROTECTED_ALLOCATIONS
 #define USE_PROTECTED_ALLOCATIONS 0
@@ -301,6 +302,37 @@ bool ExceptionHandler::WriteMinidump(const string &dump_path,
   return handler.WriteMinidump();
 }
 
+// static
+bool ExceptionHandler::WriteMinidumpForChild(mach_port_t child,
+					     mach_port_t child_blamed_thread,
+					     const string &dump_path,
+					     MinidumpCallback callback,
+					     void *callback_context) {
+  ScopedTaskSuspend suspend(child);
+
+  MinidumpGenerator generator(child, MACH_PORT_NULL);
+  string dump_id;
+  string dump_filename = generator.UniqueNameInDirectory(dump_path, &dump_id);
+
+  generator.SetExceptionInformation(EXC_BREAKPOINT,
+#if defined (__i386__) || defined(__x86_64__)
+				    EXC_I386_BPT,
+#elif defined (__ppc__) || defined (__ppc64__)
+				    EXC_PPC_BREAKPOINT,
+#else
+  #error architecture not supported
+#endif
+				    0,
+				    child_blamed_thread);
+  bool result = generator.Write(dump_filename.c_str());
+
+  if (callback) {
+    return callback(dump_path.c_str(), dump_id.c_str(),
+		    callback_context, result);
+  }
+  return result;
+}
+
 bool ExceptionHandler::WriteMinidumpWithException(int exception_type,
                                                   int exception_code,
                                                   int exception_subcode,

src/client/mac/handler/exception_handler.h

@@ -121,6 +121,14 @@ class ExceptionHandler {
   static bool WriteMinidump(const string &dump_path, MinidumpCallback callback,
                             void *callback_context);
 
+  // Write a minidump of child immediately. This can be used to capture
+  // the execution state of a child process independently of a crash.
+  static bool WriteMinidumpForChild(mach_port_t child,
+				    mach_port_t child_blamed_thread,
+				    const std::string &dump_path,
+				    MinidumpCallback callback,
+				    void *callback_context);
+
   // Returns whether out-of-process dump generation is used or not.
   bool IsOutOfProcess() const {
     return crash_generation_client_.get() != NULL;

src/client/mac/handler/minidump_generator.cc

@@ -536,7 +536,10 @@ bool MinidumpGenerator::WriteThreadListStream(
     return false;
 
   // Don't include the generator thread
-  non_generator_thread_count = thread_count - 1;
+  if (handler_thread_ != MACH_PORT_NULL)
+    non_generator_thread_count = thread_count - 1;
+  else
+    non_generator_thread_count = thread_count;
   if (!list.AllocateObjectAndArray(non_generator_thread_count,
                                    sizeof(MDRawThread)))
     return false;