1 files changed, 213 insertions, 0 deletions
diff --git a/js/src/jit/IonCompileTask.cpp b/js/src/jit/IonCompileTask.cpp
new file mode 100644
index 0000000000..0e612f308b
--- /dev/null
+++ b/js/src/jit/IonCompileTask.cpp
@@ -0,0 +1,213 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jit/IonCompileTask.h"
+
+#include "jit/CodeGenerator.h"
+#include "jit/Ion.h"
+#include "jit/JitRuntime.h"
+#include "jit/JitScript.h"
+#include "jit/WarpSnapshot.h"
+#include "vm/HelperThreadState.h"
+#include "vm/JSScript.h"
+
+#include "vm/JSScript-inl.h"
+#include "vm/Realm-inl.h"
+
+using namespace js;
+using namespace js::jit;
+
+void IonCompileTask::runHelperThreadTask(AutoLockHelperThreadState& locked) {
+  // The build is taken by this thread. Unfreeze the LifoAlloc to allow
+  // mutations.
+  alloc().lifoAlloc()->setReadWrite();
+
+  {
+    AutoUnlockHelperThreadState unlock(locked);
+    runTask();
+  }
+
+  FinishOffThreadIonCompile(this, locked);
+
+  JSRuntime* rt = script()->runtimeFromAnyThread();
+
+  // Ping the main thread so that the compiled code can be incorporated at the
+  // next interrupt callback.
+  //
+  // This must happen before the current task is reset. DestroyContext
+  // cancels in progress Ion compilations before destroying its target
+  // context, and after we reset the current task we are no longer considered
+  // to be Ion compiling.
+  rt->mainContextFromAnyThread()->requestInterrupt(
+      InterruptReason::AttachIonCompilations);
+}
+
+void IonCompileTask::runTask() {
+  // This is the entry point when ion compiles are run offthread.
+
+  jit::JitContext jctx(mirGen_.realm->runtime());
+  setBackgroundCodegen(jit::CompileBackEnd(&mirGen_, snapshot_));
+}
+
+void IonCompileTask::trace(JSTracer* trc) {
+  if (!mirGen_.runtime->runtimeMatches(trc->runtime())) {
+    return;
+  }
+
+  snapshot_->trace(trc);
+}
+
+IonCompileTask::IonCompileTask(JSContext* cx, MIRGenerator& mirGen,
+                               WarpSnapshot* snapshot)
+    : mirGen_(mirGen),
+      snapshot_(snapshot),
+      isExecuting_(cx->isExecutingRef()) {}
+
+size_t IonCompileTask::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
+  // See js::jit::FreeIonCompileTask.
+  // The IonCompileTask and most of its contents live in the LifoAlloc we point
+  // to.
+
+  size_t result = alloc().lifoAlloc()->sizeOfIncludingThis(mallocSizeOf);
+
+  if (backgroundCodegen_) {
+    result += mallocSizeOf(backgroundCodegen_);
+  }
+
+  return result;
+}
+
+static inline bool TooManyUnlinkedTasks(JSRuntime* rt) {
+  static const size_t MaxUnlinkedTasks = 100;
+  return rt->jitRuntime()->ionLazyLinkListSize() > MaxUnlinkedTasks;
+}
+
+static void MoveFinishedTasksToLazyLinkList(
+    JSRuntime* rt, const AutoLockHelperThreadState& lock) {
+  // Incorporate any off thread compilations for the runtime which have
+  // finished, failed or have been cancelled.
+
+  GlobalHelperThreadState::IonCompileTaskVector& finished =
+      HelperThreadState().ionFinishedList(lock);
+
+  for (size_t i = 0; i < finished.length(); i++) {
+    // Find a finished task for the runtime.
+    IonCompileTask* task = finished[i];
+    if (task->script()->runtimeFromAnyThread() != rt) {
+      continue;
+    }
+
+    HelperThreadState().remove(finished, &i);
+    rt->jitRuntime()->numFinishedOffThreadTasksRef(lock)--;
+
+    JSScript* script = task->script();
+    MOZ_ASSERT(script->hasBaselineScript());
+    script->baselineScript()->setPendingIonCompileTask(rt, script, task);
+    rt->jitRuntime()->ionLazyLinkListAdd(rt, task);
+  }
+}
+
+static void EagerlyLinkExcessTasks(JSContext* cx,
+                                   AutoLockHelperThreadState& lock) {
+  JSRuntime* rt = cx->runtime();
+  MOZ_ASSERT(TooManyUnlinkedTasks(rt));
+
+  do {
+    jit::IonCompileTask* task = rt->jitRuntime()->ionLazyLinkList(rt).getLast();
+    RootedScript script(cx, task->script());
+
+    AutoUnlockHelperThreadState unlock(lock);
+    AutoRealm ar(cx, script);
+    jit::LinkIonScript(cx, script);
+  } while (TooManyUnlinkedTasks(rt));
+}
+
+void jit::AttachFinishedCompilations(JSContext* cx) {
+  JSRuntime* rt = cx->runtime();
+  MOZ_ASSERT(CurrentThreadCanAccessRuntime(rt));
+
+  if (!rt->jitRuntime() || !rt->jitRuntime()->numFinishedOffThreadTasks()) {
+    return;
+  }
+
+  AutoLockHelperThreadState lock;
+
+  while (true) {
+    MoveFinishedTasksToLazyLinkList(rt, lock);
+
+    if (!TooManyUnlinkedTasks(rt)) {
+      break;
+    }
+
+    EagerlyLinkExcessTasks(cx, lock);
+
+    // Linking releases the lock so we must now check the finished list
+    // again.
+  }
+
+  MOZ_ASSERT(!rt->jitRuntime()->numFinishedOffThreadTasks());
+}
+
+static void FreeIonCompileTask(IonCompileTask* task) {
+  // The task is allocated into its LifoAlloc, so destroying that will
+  // destroy the task and all other data accumulated during compilation,
+  // except any final codegen (which includes an assembler and needs to be
+  // explicitly destroyed).
+  js_delete(task->backgroundCodegen());
+  js_delete(task->alloc().lifoAlloc());
+}
+
+void jit::FreeIonCompileTasks(const IonFreeCompileTasks& tasks) {
+  MOZ_ASSERT(!tasks.empty());
+  for (auto* task : tasks) {
+    FreeIonCompileTask(task);
+  }
+}
+
+void IonFreeTask::runHelperThreadTask(AutoLockHelperThreadState& locked) {
+  {
+    AutoUnlockHelperThreadState unlock(locked);
+    jit::FreeIonCompileTasks(compileTasks());
+  }
+
+  js_delete(this);
+}
+
+void jit::FinishOffThreadTask(JSRuntime* runtime,
+                              AutoStartIonFreeTask& freeTask,
+                              IonCompileTask* task) {
+  MOZ_ASSERT(runtime);
+  MOZ_ASSERT(CurrentThreadCanAccessRuntime(runtime));
+
+  JSScript* script = task->script();
+
+  // Clean the references to the pending IonCompileTask, if we just finished it.
+  if (script->baselineScript()->hasPendingIonCompileTask() &&
+      script->baselineScript()->pendingIonCompileTask() == task) {
+    script->baselineScript()->removePendingIonCompileTask(runtime, script);
+  }
+
+  // If the task is still in one of the helper thread lists, then remove it.
+  if (task->isInList()) {
+    runtime->jitRuntime()->ionLazyLinkListRemove(runtime, task);
+  }
+
+  // Clean up if compilation did not succeed.
+  if (script->isIonCompilingOffThread()) {
+    script->jitScript()->clearIsIonCompilingOffThread(script);
+
+    const AbortReasonOr<Ok>& status = task->mirGen().getOffThreadStatus();
+    if (status.isErr() && status.inspectErr() == AbortReason::Disable) {
+      script->disableIon();
+    }
+  }
+
+  // Try to free the Ion LifoAlloc off-thread. Free on the main thread if this
+  // OOMs.
+  if (!freeTask.addIonCompileToFreeTaskBatch(task)) {
+    FreeIonCompileTask(task);
+  }
+}