Bug 1050122 - Part 1: Enable Nuwa on debug builds, and kill it if the preference is false. r=khuey

b2g/app/B2GLoader.cpp

@@ -219,6 +219,13 @@ RunProcesses(int argc, const char *argv[], FdArray& aReservedFds)
                                     aReservedFds);
   }
 
+  // Reap zombie child process.
+  struct sigaction sa;
+  sa.sa_handler = SIG_IGN;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = 0;
+  sigaction(SIGCHLD, &sa, nullptr);
+
   // The b2g process
   int childPid = pid;
   XRE_ProcLoaderClientInit(childPid, parentSock, aReservedFds);

b2g/app/b2g.js

@@ -800,13 +800,11 @@ pref("hal.processPriorityManager.gonk.notifyLowMemUnderKB", 14336);
 // blocked on a poll(), and this pref has no effect.)
 pref("gonk.systemMemoryPressureRecoveryPollMS", 5000);
 
-#ifndef DEBUG
 // Enable pre-launching content processes for improved startup time
 // (hiding latency).
 pref("dom.ipc.processPrelaunch.enabled", true);
 // Wait this long before pre-launching a new subprocess.
 pref("dom.ipc.processPrelaunch.delayMs", 5000);
-#endif
 
 pref("dom.ipc.reuse_parent_app", false);
 

ipc/glue/ProcessUtils_linux.cpp

@@ -31,6 +31,7 @@
 #include "mozilla/unused.h"
 #include "base/process_util.h"
 #include "base/eintr_wrapper.h"
+#include "mozilla/Preferences.h"
 
 #include "prenv.h"
 
@@ -204,6 +205,14 @@ ProcLoaderClientGeckoInit()
   MOZ_ASSERT(!sProcLoaderClientGeckoInitialized,
              "call ProcLoaderClientGeckoInit() more than once");
 
+  if (!Preferences::GetBool("dom.ipc.processPrelaunch.enabled", false)) {
+    kill(sProcLoaderPid, SIGKILL);
+    sProcLoaderPid = 0;
+    close(sProcLoaderChannelFd);
+    sProcLoaderChannelFd = -1;
+    return;
+  }
+
   sProcLoaderClientGeckoInitialized = true;
 
   TransportDescriptor fd;