Notify observers when a task port is received.

BUG=582468

Review URL: https://codereview.chromium.org/1781943003

Cr-Commit-Position: refs/heads/master@{#380493}

5 files changed, 72 insertions, 8 deletions

diff --git a/base/mac/mach_port_broker.mm b/base/mac/mach_port_broker.mm
index 3d563ba..bd47017 100644
--- a/base/mac/mach_port_broker.mm
+++ b/base/mac/mach_port_broker.mm
@@ -163,8 +163,11 @@ void MachPortBroker::HandleRequest() {
   mach_port_t child_task_port = msg.child_task_port.name;
 
   // Take the lock and update the broker information.
-  base::AutoLock lock(lock_);
-  FinalizePid(child_pid, child_task_port);
+  {
+    base::AutoLock lock(lock_);
+    FinalizePid(child_pid, child_task_port);
+  }
+  NotifyObservers(child_pid);
 }
 
 void MachPortBroker::FinalizePid(base::ProcessHandle pid,
diff --git a/base/mac/mach_port_broker_unittest.cc b/base/mac/mach_port_broker_unittest.cc
index 2188ea3..c15afb6 100644
--- a/base/mac/mach_port_broker_unittest.cc
+++ b/base/mac/mach_port_broker_unittest.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
 #include "base/test/multiprocess_test.h"
 #include "base/test/test_timeouts.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -17,9 +18,18 @@ namespace {
 const char kBootstrapPortName[] = "thisisatest";
 }
 
-class MachPortBrokerTest : public testing::Test {
+class MachPortBrokerTest : public testing::Test,
+                           public base::PortProvider::Observer {
  public:
-  MachPortBrokerTest() : broker_(kBootstrapPortName) {}
+  MachPortBrokerTest()
+      : broker_(kBootstrapPortName),
+        event_(true, false),
+        received_process_(kNullProcessHandle) {
+    broker_.AddObserver(this);
+  }
+  ~MachPortBrokerTest() override {
+    broker_.RemoveObserver(this);
+  }
 
   // Helper function to acquire/release locks and call |PlaceholderForPid()|.
   void AddPlaceholderForPid(base::ProcessHandle pid) {
@@ -34,8 +44,20 @@ class MachPortBrokerTest : public testing::Test {
     broker_.FinalizePid(pid, task_port);
   }
 
+  void WaitForTaskPort() {
+    event_.Wait();
+  }
+
+  // base::PortProvider::Observer:
+  void OnReceivedTaskPort(ProcessHandle process) override {
+    received_process_ = process;
+    event_.Signal();
+  }
+
  protected:
   MachPortBroker broker_;
+  WaitableEvent event_;
+  ProcessHandle received_process_;
 };
 
 TEST_F(MachPortBrokerTest, Locks) {
@@ -77,6 +99,9 @@ TEST_F(MachPortBrokerTest, ReceivePortFromChild) {
   broker_.AddPlaceholderForPid(test_child_process.Handle());
   broker_.GetLock().Release();
 
+  WaitForTaskPort();
+  EXPECT_EQ(test_child_process.Handle(), received_process_);
+
   int rv = -1;
   ASSERT_TRUE(test_child_process.WaitForExitWithTimeout(
       TestTimeouts::action_timeout(), &rv));
diff --git a/content/browser/mach_broker_mac.h b/content/browser/mach_broker_mac.h
index 32199c6..32ff5d6 100644
--- a/content/browser/mach_broker_mac.h
+++ b/content/browser/mach_broker_mac.h
@@ -24,7 +24,8 @@ namespace content {
 // access to mach task ports for content child processes.
 class CONTENT_EXPORT MachBroker : public base::PortProvider,
                                   public BrowserChildProcessObserver,
-                                  public NotificationObserver {
+                                  public NotificationObserver,
+                                  public base::PortProvider::Observer {
  public:
   // For use in child processes. This will send the task port of the current
   // process over Mach IPC to the port registered by name (via this class) in
@@ -74,6 +75,9 @@ class CONTENT_EXPORT MachBroker : public base::PortProvider,
   MachBroker();
   ~MachBroker() override;
 
+  // Implement |base::PortProvider::Observer|.
+  void OnReceivedTaskPort(base::ProcessHandle process) override;
+
   // Removes all mappings belonging to |child_process_id| from the broker.
   void InvalidateChildProcessId(int child_process_id);
 
diff --git a/content/browser/mach_broker_mac.mm b/content/browser/mach_broker_mac.mm
index 57237aa..dfbf71f 100644
--- a/content/browser/mach_broker_mac.mm
+++ b/content/browser/mach_broker_mac.mm
@@ -99,9 +99,17 @@ std::string MachBroker::GetMachPortName() {
   return base::MachPortBroker::GetMachPortName(kBootstrapName, is_child);
 }
 
-MachBroker::MachBroker() : initialized_(false), broker_(kBootstrapName) {}
+MachBroker::MachBroker() : initialized_(false), broker_(kBootstrapName) {
+  broker_.AddObserver(this);
+}
+
+MachBroker::~MachBroker() {
+  broker_.RemoveObserver(this);
+}
 
-MachBroker::~MachBroker() {}
+void MachBroker::OnReceivedTaskPort(base::ProcessHandle process) {
+  NotifyObservers(process);
+}
 
 void MachBroker::InvalidateChildProcessId(int child_process_id) {
   base::AutoLock lock(GetLock());
diff --git a/content/browser/mach_broker_mac_unittest.cc b/content/browser/mach_broker_mac_unittest.cc
index 21a4c4d..65eaa91 100644
--- a/content/browser/mach_broker_mac_unittest.cc
+++ b/content/browser/mach_broker_mac_unittest.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
 #include "base/test/multiprocess_test.h"
 #include "base/test/test_timeouts.h"
 #include "content/public/test/test_browser_thread_bundle.h"
@@ -14,8 +15,17 @@
 
 namespace content {
 
-class MachBrokerTest : public testing::Test {
+class MachBrokerTest : public testing::Test,
+                       public base::PortProvider::Observer {
  public:
+  MachBrokerTest()
+      : event_(true, false), received_process_(base::kNullProcessHandle) {
+    broker_.AddObserver(this);
+  }
+  ~MachBrokerTest() override {
+    broker_.RemoveObserver(this);
+  }
+
   // Helper function to acquire/release locks and call |PlaceholderForPid()|.
   void AddPlaceholderForPid(base::ProcessHandle pid, int child_process_id) {
     base::AutoLock lock(broker_.GetLock());
@@ -47,8 +57,20 @@ class MachBrokerTest : public testing::Test {
     EXPECT_EQ(0, rv);
   }
 
+  void WaitForTaskPort() {
+    event_.Wait();
+  }
+
+  // base::PortProvider::Observer:
+  void OnReceivedTaskPort(base::ProcessHandle process) override {
+    received_process_ = process;
+    event_.Signal();
+  }
+
  protected:
   MachBroker broker_;
+  base::WaitableEvent event_;
+  base::ProcessHandle received_process_;
   TestBrowserThreadBundle thread_bundle_;
 };
 
@@ -68,6 +90,8 @@ TEST_F(MachBrokerTest, AddChildProcess) {
     broker_.EnsureRunning();
   }
   base::Process child_process = LaunchTestChild("MachBrokerTestChild", 7);
+  WaitForTaskPort();
+  EXPECT_EQ(child_process.Handle(), received_process_);
   WaitForChildExit(child_process);
 
   EXPECT_NE(static_cast<mach_port_t>(MACH_PORT_NULL),