Changes to the process implementation.

runtime/bin/process_macos.cc

Index: runtime/bin/process_macos.cc
diff --git a/runtime/bin/process_macos.cc b/runtime/bin/process_macos.cc
index 3ecf98eaae04b9388f4e85f003d7ff54ed33e114..959318e2cebe6f87ff51d79b261e979e302cd4bf 100644
--- a/runtime/bin/process_macos.cc
+++ b/runtime/bin/process_macos.cc
@@ -24,6 +24,12 @@
 class ProcessInfo {
  public:
   ProcessInfo(pid_t pid, intptr_t fd) : pid_(pid), fd_(fd) { }
+  ~ProcessInfo() {
+    int closed = TEMP_FAILURE_RETRY(close(fd_));
+    if (closed != 0) {
+      FATAL("Failed to close process exit code pipe");
+    }
+  }
   pid_t pid() { return pid_; }
   intptr_t fd() { return fd_; }
   ProcessInfo* next() { return next_; }
@@ -100,6 +106,8 @@ dart::Mutex ProcessInfoList::mutex_;
 // event loop.
 class ExitCodeHandler {
  public:
+  static const char kTerminateByte = 1;
+
   // Ensure that the ExitCodeHandler has been initialized.
   static bool EnsureInitialized() {
     // Multiple isolates could be starting processes at the same
@@ -135,6 +143,18 @@ class ExitCodeHandler {
     return sig_chld_fds_[1];
   }
 
+  static void Terminate() {
+    MutexLocker locker(&mutex_);
+    if (!initialized_) {
+      return;
+    }
+    char data = ExitCodeHandler::kTerminateByte;
+    ssize_t result = TEMP_FAILURE_RETRY(write(WakeUpFd(), &data, 1));
+    if (result < 1) {
+      perror("Failed to write to wake-up fd in SIGCHLD handler");
+    }
+  }
+
  private:
   // GetProcessExitCodes is called on a separate thread when a SIGCHLD
   // signal is received to retrieve the exit codes and post them to
@@ -154,13 +174,13 @@ class ExitCodeHandler {
       }
       intptr_t exit_code_fd = ProcessInfoList::LookupProcessExitFd(pid);
       if (exit_code_fd != 0) {
-        int message[3] = { pid, exit_code, negative };
+        int message[2] = { exit_code, negative };
         ssize_t result =
             FDUtils::WriteToBlocking(exit_code_fd, &message, sizeof(message));
         if (result != sizeof(message) && errno != EPIPE) {
           perror("ExitHandler notification failed");
         }
-        TEMP_FAILURE_RETRY(close(exit_code_fd));
+        ProcessInfoList::RemoveProcess(pid);
       }
     }
   }
@@ -187,6 +207,10 @@ class ExitCodeHandler {
         if (read_bytes < 1) {
           perror("Failed to read from wake-up fd in exit-code handler");
         }
+        // Check if the ExitCodeHandler has been terminated.
+        if (data == ExitCodeHandler::kTerminateByte) {
+          return;
+        }
         // Get the exit code from all processes that have died.
         GetProcessExitCodes();
       }
@@ -487,6 +511,6 @@ bool Process::Kill(intptr_t id) {
 }
 
 
-void Process::Exit(intptr_t id) {
-  ProcessInfoList::RemoveProcess(id);
+void Process::TerminateExitCodeHandler() {
+  ExitCodeHandler::Terminate();
 }