Issue #1829 - Revert "Issue #1751"

xpcom/threads/SharedThreadPool.h

@@ -87,7 +87,7 @@ public:
   // Use the system default in ASAN builds, because the default is assumed to be
   // larger than the size we want to use and is hopefully sufficient for ASAN.
   static const uint32_t kStackSize = nsIThreadManager::DEFAULT_STACK_SIZE;
-#elif defined(XP_WIN) || defined(LINUX)
+#elif defined(XP_WIN) || defined(XP_MACOSX) || defined(LINUX)
   static const uint32_t kStackSize = (256 * 1024);
 #else
   // All other platforms use their system defaults.

xpcom/threads/nsProcess.h

@@ -19,7 +19,9 @@
 #include "nsIWeakReferenceUtils.h"
 #include "nsIObserver.h"
 #include "nsString.h"
+#ifndef XP_MACOSX
 #include "prproces.h"
+#endif
 #if defined(PROCESSMODEL_WINAPI)
 #include <windows.h>
 #include <shellapi.h>
@@ -71,7 +73,7 @@ private:
   int32_t mExitValue;
 #if defined(PROCESSMODEL_WINAPI)
   HANDLE mProcess;
-#else
+#elif !defined(XP_MACOSX)
   PRProcess* mProcess;
 #endif
 };

xpcom/threads/nsProcessCommon.cpp

@@ -33,12 +33,31 @@
 #include "nsLiteralString.h"
 #include "nsReadableUtils.h"
 #else
+#ifdef XP_MACOSX
+#include <crt_externs.h>
+#include <spawn.h>
+#include <sys/wait.h>
+#include <sys/errno.h>
+#endif
 #include <sys/types.h>
 #include <signal.h>
 #endif
 
 using namespace mozilla;
 
+#ifdef XP_MACOSX
+cpu_type_t pref_cpu_types[2] = {
+#if defined(__i386__)
+  CPU_TYPE_X86,
+#elif defined(__x86_64__)
+  CPU_TYPE_X86_64,
+#elif defined(__ppc__)
+  CPU_TYPE_POWERPC,
+#endif
+  CPU_TYPE_ANY
+};
+#endif
+
 //-------------------------------------------------------------------//
 // nsIProcess implementation
 //-------------------------------------------------------------------//
@@ -55,7 +74,9 @@ nsProcess::nsProcess()
   , mObserver(nullptr)
   , mWeakObserver(nullptr)
   , mExitValue(-1)
+#if !defined(XP_MACOSX)
   , mProcess(nullptr)
+#endif
 {
 }
 
@@ -240,16 +261,34 @@ nsProcess::Monitor(void* aArg)
       return;
     }
   }
+#else
+#ifdef XP_MACOSX
+  int exitCode = -1;
+  int status = 0;
+  pid_t result;
+  do {
+    result = waitpid(process->mPid, &status, 0);
+  } while (result == -1 && errno == EINTR);
+  if (result == process->mPid) {
+    if (WIFEXITED(status)) {
+      exitCode = WEXITSTATUS(status);
+    } else if (WIFSIGNALED(status)) {
+      exitCode = 256; // match NSPR's signal exit status
+    }
+  }
 #else
   int32_t exitCode = -1;
   if (PR_WaitProcess(process->mProcess, &exitCode) != PR_SUCCESS) {
     exitCode = -1;
   }
+#endif
 
   // Lock in case Kill or GetExitCode are called during this
   {
     MutexAutoLock lock(process->mLock);
+#if !defined(XP_MACOSX)
     process->mProcess = nullptr;
+#endif
     process->mExitValue = exitCode;
     if (process->mShutdown) {
       return;
@@ -466,6 +505,34 @@ nsProcess::RunProcess(bool aBlocking, char** aMyArgv, nsIObserver* aObserver,
   }
 
   mPid = GetProcessId(mProcess);
+#elif defined(XP_MACOSX)
+  // Initialize spawn attributes.
+  posix_spawnattr_t spawnattr;
+  if (posix_spawnattr_init(&spawnattr) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Set spawn attributes.
+  size_t attr_count = ArrayLength(pref_cpu_types);
+  size_t attr_ocount = 0;
+  if (posix_spawnattr_setbinpref_np(&spawnattr, attr_count, pref_cpu_types,
+                                    &attr_ocount) != 0 ||
+      attr_ocount != attr_count) {
+    posix_spawnattr_destroy(&spawnattr);
+    return NS_ERROR_FAILURE;
+  }
+
+  // Note: |aMyArgv| is already null-terminated as required by posix_spawnp.
+  pid_t newPid = 0;
+  int result = posix_spawnp(&newPid, aMyArgv[0], nullptr, &spawnattr, aMyArgv,
+                            *_NSGetEnviron());
+  mPid = static_cast<int32_t>(newPid);
+
+  posix_spawnattr_destroy(&spawnattr);
+
+  if (result != 0) {
+    return NS_ERROR_FAILURE;
+  }
 #else
   mProcess = PR_CreateProcess(aMyArgv[0], aMyArgv, nullptr, nullptr);
   if (!mProcess) {
@@ -545,6 +612,10 @@ nsProcess::Kill()
     if (TerminateProcess(mProcess, 0) == 0) {
       return NS_ERROR_FAILURE;
     }
+#elif defined(XP_MACOSX)
+    if (kill(mPid, SIGKILL) != 0) {
+      return NS_ERROR_FAILURE;
+    }
 #else
     if (!mProcess || (PR_KillProcess(mProcess) != PR_SUCCESS)) {
       return NS_ERROR_FAILURE;

xpcom/threads/nsThread.cpp

@@ -52,6 +52,11 @@
 #define HAVE_SCHED_SETAFFINITY
 #endif
 
+#ifdef XP_MACOSX
+#include <mach/mach.h>
+#include <mach/thread_policy.h>
+#endif
+
 #ifdef MOZ_CANARY
 # include <unistd.h>
 # include <execinfo.h>
@@ -370,6 +375,16 @@ SetThreadAffinity(unsigned int cpu)
   sched_setaffinity(0, sizeof(cpus), &cpus);
   // Don't assert sched_setaffinity's return value because it intermittently (?)
   // fails with EINVAL on Linux x64 try runs.
+#elif defined(XP_MACOSX)
+  // OS X does not provide APIs to pin threads to specific processors, but you
+  // can tag threads as belonging to the same "affinity set" and the OS will try
+  // to run them on the same processor. To run threads on different processors,
+  // tag them as belonging to different affinity sets. Tag 0, the default, means
+  // "no affinity" so let's pretend each CPU has its own tag `cpu+1`.
+  thread_affinity_policy_data_t policy;
+  policy.affinity_tag = cpu + 1;
+  MOZ_ALWAYS_TRUE(thread_policy_set(mach_thread_self(), THREAD_AFFINITY_POLICY,
+                                    &policy.affinity_tag, 1) == KERN_SUCCESS);
 #elif defined(XP_WIN)
   MOZ_ALWAYS_TRUE(SetThreadIdealProcessor(GetCurrentThread(), cpu) != -1);
 #endif