Initial Commit

ngx_pagespeed-latest-beta/src/ngx_message_handler.cc

@@ -0,0 +1,116 @@
+// Copyright 2013 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Author: oschaaf@gmail.com (Otto van der Schaaf)
+
+#include "ngx_message_handler.h"
+
+#include <signal.h>
+
+#include "net/instaweb/public/version.h"
+#include "pagespeed/kernel/base/abstract_mutex.h"
+#include "pagespeed/kernel/base/debug.h"
+#include "pagespeed/kernel/base/posix_timer.h"
+#include "pagespeed/kernel/base/string_util.h"
+#include "pagespeed/kernel/base/time_util.h"
+#include "pagespeed/kernel/sharedmem/shared_circular_buffer.h"
+
+namespace {
+
+// This will be prefixed to every logged message.
+const char kModuleName[] = "ngx_pagespeed";
+
+// If set, the crash handler will use this to output a backtrace using
+// ngx_log_error.
+ngx_log_t* global_log = NULL;
+
+}  // namespace
+
+extern "C" {
+  static void signal_handler(int sig) {
+    // Try to output the backtrace to the log file. Since this may end up
+    // crashing/deadlocking/etc. we set an alarm() to abort us if it comes to
+    // that.
+    alarm(2);
+    if (global_log != NULL) {
+      ngx_log_error(NGX_LOG_ALERT, global_log, 0, "Trapped signal [%d]\n%s",
+                    sig, net_instaweb::StackTraceString().c_str());
+    } else {
+      fprintf(stderr, "Trapped signal [%d]\n%s\n",
+              sig, net_instaweb::StackTraceString().c_str());
+    }
+    kill(getpid(), SIGKILL);
+  }
+}  // extern "C"
+
+namespace net_instaweb {
+
+NgxMessageHandler::NgxMessageHandler(Timer* timer, AbstractMutex* mutex)
+    : SystemMessageHandler(timer, mutex),
+      log_(NULL) {
+}
+
+// Installs a signal handler for common crash signals, that tries to print
+// out a backtrace.
+void NgxMessageHandler::InstallCrashHandler(ngx_log_t* log) {
+  global_log = log;
+  signal(SIGTRAP, signal_handler);  // On check failures
+  signal(SIGABRT, signal_handler);
+  signal(SIGFPE, signal_handler);
+  signal(SIGSEGV, signal_handler);
+}
+
+ngx_uint_t NgxMessageHandler::GetNgxLogLevel(MessageType type) {
+  switch (type) {
+    case kInfo:
+      return NGX_LOG_INFO;
+    case kWarning:
+      return NGX_LOG_WARN;
+    case kError:
+      return NGX_LOG_ERR;
+    case kFatal:
+      return NGX_LOG_ALERT;
+  }
+
+  // This should never fall through, but some compilers seem to complain if
+  // we don't include this.
+  return NGX_LOG_ALERT;
+}
+
+void NgxMessageHandler::MessageSImpl(MessageType type,
+                                     const GoogleString& message) {
+  if (log_ != NULL) {
+    ngx_uint_t log_level = GetNgxLogLevel(type);
+    ngx_log_error(log_level, log_, 0/*ngx_err_t*/, "[%s %s] %s",
+                  kModuleName, kModPagespeedVersion, message.c_str());
+  } else {
+    GoogleMessageHandler::MessageSImpl(type, message);
+  }
+  AddMessageToBuffer(type, message);
+}
+
+void NgxMessageHandler::FileMessageSImpl(
+    MessageType type, const char* file, int line, const GoogleString& message) {
+  if (log_ != NULL) {
+    ngx_uint_t log_level = GetNgxLogLevel(type);
+    ngx_log_error(log_level, log_, 0/*ngx_err_t*/, "[%s %s] %s:%d:%s",
+                  kModuleName, kModPagespeedVersion, file, line,
+                  message.c_str());
+  } else {
+    GoogleMessageHandler::FileMessageSImpl(type, file, line, message);
+  }
+  AddMessageToBuffer(type, file, line, message);
+}
+
+}  // namespace net_instaweb