Make POSIX SIGTERM/SIGINT/SIGHUP handler async signal safe.

base/logging.cc

 // Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/logging.h"
 
 #if defined(OS_WIN)
+#include <io.h>
 #include <windows.h>
 typedef HANDLE FileHandle;
 typedef HANDLE MutexHandle;
+// Windows warns on using write().  It prefers _write().
+#define write(fd, buf, count) _write(fd, buf, static_cast<unsigned int>(count))
+// Windows doesn't define STDERR_FILENO.  Define it here.
+#define STDERR_FILENO 2
 #elif defined(OS_MACOSX)
 #include <CoreFoundation/CoreFoundation.h>
 #include <mach/mach.h>
 #include <mach/mach_time.h>
 #include <mach-o/dyld.h>
 #elif defined(OS_LINUX)
 #include <sys/syscall.h>
 #include <time.h>
 #endif
 
 #if defined(OS_POSIX)
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #define MAX_PATH PATH_MAX
 typedef FILE* FileHandle;
 typedef pthread_mutex_t* MutexHandle;
 #endif
 
 #include <ctime>
 #include <iomanip>
 #include <cstring>
 #include <algorithm>
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/debug_util.h"
+#include "base/eintr_wrapper.h"
 #include "base/lock_impl.h"
 #if defined(OS_POSIX)
 #include "base/safe_strerror_posix.h"
 #endif
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 
 namespace logging {
 
@@ skipping 627 matching lines @@
 #endif  // OS_WIN
 
 void CloseLogFile() {
   if (!log_file)
     return;
 
   CloseFile(log_file);
   log_file = NULL;
 }
 
+void RawLog(int level, const char* message) {
+  if (level >= min_log_level) {
+    size_t bytes_written = 0;
+    const size_t message_len = strlen(message);
+    int rv;
+    while (bytes_written < message_len) {
+      rv = HANDLE_EINTR(
+          write(STDERR_FILENO, message + bytes_written,
+                message_len - bytes_written));
+      if (rv < 0) {
+        // Give up, nothing we can do now.
+        break;
+      }
+      bytes_written += rv;
+    }
+
+    if (message_len > 0 && message[message_len - 1] != '\n') {
+      do {
+        rv = HANDLE_EINTR(write(STDERR_FILENO, "\n", 1));
+        if (rv < 0) {
+          // Give up, nothing we can do now.
+          break;
+        }
+      } while (rv != 1);
+    }
+  }
+
+  if (level == LOG_FATAL)
+    DebugUtil::BreakDebugger();
+}
+
 }  // namespace logging
 
 std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
   return out << WideToUTF8(std::wstring(wstr));
 }