Mac: for branded Google Chrome, handle SIGTERM in renderer to clean up Breakpad.

Test:
1. Build a (branded) Google Chrome.
2. From the command-line, run: "launchctl bslist | wc -l" and note the number.
3. Start Google Chrome on a fresh profile.
4. Once a browser window has opened, do #2 again, and note the number -- it should have increased (by 2).
5. Close the tab, and do #2 again. The number should have decreased by 1.
6. Open tabs, navigate, etc., and do #2 between each stage. Whenever a new (e.g., renderer) process is started, the number should increase (e.g., when you go to a "new" site). When a process is terminated (e.g., you close the last tab for a particular site), the number should decrease.
7. Quit, and do #2 again. Hopefully, the number should be the same as the first time.

(Note: when a renderer crashes, the number will not decrease -- so the number after quitting will not be the same as before starting. This is why this is only a stopgap. For comparison, do this on a branded Google Chrome without this patch; typically, the numbers will not decrease on renderer termination.)

BUG=28547
TEST=See above.

Review URL: http://codereview.chromium.org/484007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34318 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 137 insertions, 0 deletions

diff --git a/chrome/renderer/renderer_main.cc b/chrome/renderer/renderer_main.cc
index c8f89c9..d4e2c5f 100644
--- a/chrome/renderer/renderer_main.cc
+++ b/chrome/renderer/renderer_main.cc
@@ -28,10 +28,122 @@
 #include "grit/generated_resources.h"
 #include "net/base/net_module.h"
 
+#if defined(OS_MACOSX)
+#include "base/eintr_wrapper.h"
+#include "chrome/app/breakpad_mac.h"
+#include <signal.h>
+#include <unistd.h>
+#endif  // OS_MACOSX
+
 #if defined(USE_LINUX_BREAKPAD)
 #include "chrome/app/breakpad_linux.h"
 #endif
 
+#if defined(OS_MACOSX)
+namespace {
+
+// TODO(viettrungluu): crbug.com/28547: The following signal handling is needed,
+// as a stopgap, to avoid leaking due to not releasing Breakpad properly.
+// Without this problem, this could all be eliminated. Remove when Breakpad is
+// fixed?
+// TODO(viettrungluu): Code taken from browser_main.cc (with a bit of editing).
+// The code should be properly shared (or this code should be eliminated).
+int g_shutdown_pipe_write_fd = -1;
+
+void SIGTERMHandler(int signal) {
+  RAW_CHECK(signal == SIGTERM);
+  RAW_LOG(INFO, "Handling SIGTERM in renderer.");
+
+  // Reinstall the default handler.  We had one shot at graceful shutdown.
+  struct sigaction action;
+  memset(&action, 0, sizeof(action));
+  action.sa_handler = SIG_DFL;
+  CHECK(sigaction(signal, &action, NULL) == 0);
+
+  RAW_CHECK(g_shutdown_pipe_write_fd != -1);
+  size_t bytes_written = 0;
+  do {
+    int rv = HANDLE_EINTR(
+        write(g_shutdown_pipe_write_fd,
+              reinterpret_cast<const char*>(&signal) + bytes_written,
+              sizeof(signal) - bytes_written));
+    RAW_CHECK(rv >= 0);
+    bytes_written += rv;
+  } while (bytes_written < sizeof(signal));
+
+  RAW_LOG(INFO, "Wrote signal to shutdown pipe.");
+}
+
+class ShutdownDetector : public PlatformThread::Delegate {
+ public:
+  explicit ShutdownDetector(int shutdown_fd) : shutdown_fd_(shutdown_fd) {
+    CHECK(shutdown_fd_ != -1);
+  }
+
+  virtual void ThreadMain() {
+    int signal;
+    size_t bytes_read = 0;
+    ssize_t ret;
+    do {
+      ret = HANDLE_EINTR(
+          read(shutdown_fd_,
+               reinterpret_cast<char*>(&signal) + bytes_read,
+               sizeof(signal) - bytes_read));
+      if (ret < 0) {
+        NOTREACHED() << "Unexpected error: " << strerror(errno);
+        break;
+      } else if (ret == 0) {
+        NOTREACHED() << "Unexpected closure of shutdown pipe.";
+        break;
+      }
+      bytes_read += ret;
+    } while (bytes_read < sizeof(signal));
+
+    if (bytes_read == sizeof(signal))
+      LOG(INFO) << "Handling shutdown for signal " << signal << ".";
+    else
+      LOG(INFO) << "Handling shutdown for unknown signal.";
+
+    // Clean up Breakpad if necessary.
+    if (IsCrashReporterEnabled()) {
+      LOG(INFO) << "Cleaning up Breakpad.";
+      DestructCrashReporter();
+    } else {
+      LOG(INFO) << "Breakpad not enabled; no clean-up needed.";
+    }
+
+    // Something went seriously wrong, so get out.
+    if (bytes_read != sizeof(signal)) {
+      LOG(WARNING) << "Failed to get signal. Quitting ungracefully.";
+      _exit(1);
+    }
+
+    // Re-raise the signal.
+    kill(getpid(), signal);
+
+    // The signal may be handled on another thread. Give that a chance to
+    // happen.
+    sleep(3);
+
+    // We really should be dead by now.  For whatever reason, we're not. Exit
+    // immediately, with the exit status set to the signal number with bit 8
+    // set.  On the systems that we care about, this exit status is what is
+    // normally used to indicate an exit by this signal's default handler.
+    // This mechanism isn't a de jure standard, but even in the worst case, it
+    // should at least result in an immediate exit.
+    LOG(WARNING) << "Still here, exiting really ungracefully.";
+    _exit(signal | (1 << 7));
+  }
+
+ private:
+  const int shutdown_fd_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShutdownDetector);
+};
+
+}  // namespace
+#endif  // OS_MACOSX
+
 // This function provides some ways to test crash and assertion handling
 // behavior of the renderer.
 static void HandleRendererErrorTestParameters(const CommandLine& command_line) {
@@ -56,6 +168,31 @@ int RendererMain(const MainFunctionParams& parameters) {
   const CommandLine& parsed_command_line = parameters.command_line_;
   base::ScopedNSAutoreleasePool* pool = parameters.autorelease_pool_;
 
+#if defined(OS_MACOSX)
+  // TODO(viettrungluu): Code taken from browser_main.cc.
+  int pipefd[2];
+  int ret = pipe(pipefd);
+  if (ret < 0) {
+    PLOG(DFATAL) << "Failed to create pipe";
+  } else {
+    int shutdown_pipe_read_fd = pipefd[0];
+    g_shutdown_pipe_write_fd = pipefd[1];
+    const size_t kShutdownDetectorThreadStackSize = 4096;
+    if (!PlatformThread::CreateNonJoinable(
+        kShutdownDetectorThreadStackSize,
+        new ShutdownDetector(shutdown_pipe_read_fd))) {
+      LOG(DFATAL) << "Failed to create shutdown detector task.";
+    }
+  }
+
+  // crbug.com/28547: When Breakpad is in use, handle SIGTERM to avoid leaking
+  // Mach ports.
+  struct sigaction action;
+  memset(&action, 0, sizeof(action));
+  action.sa_handler = SIGTERMHandler;
+  CHECK(sigaction(SIGTERM, &action, NULL) == 0);
+#endif  // OS_MACOSX
+
 #if defined(USE_LINUX_BREAKPAD)
   // Needs to be called after we have chrome::DIR_USER_DATA.
   InitCrashReporter();