devtools/platform/nsJSInspector.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsJSInspector.h"
   7 #include "mozilla/HoldDropJSObjects.h"
   8 #include "mozilla/SpinEventLoopUntil.h"
   9 #include "mozilla/dom/ScriptSettings.h"
  10 #include "nsTArray.h"
  11
  12 #define JSINSPECTOR_CONTRACTID "@mozilla.org/jsinspector;1"
  13
  14 #define JSINSPECTOR_CID                              \
  15   {                                                  \
  16     0xec5aa99c, 0x7abb, 0x4142, {                    \
  17       0xac, 0x5f, 0xaa, 0xb2, 0x41, 0x9e, 0x38, 0xe2 \
  18     }                                                \
  19   }
  20
  21 namespace mozilla {
  22 namespace jsinspector {
  23
  24 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsJSInspector)
  25   NS_INTERFACE_MAP_ENTRY(nsISupports)
  26   NS_INTERFACE_MAP_ENTRY(nsIJSInspector)
  27 NS_INTERFACE_MAP_END
  28
  29 NS_IMPL_CYCLE_COLLECTION_CLASS(nsJSInspector)
  30
  31 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsJSInspector)
  32 NS_IMPL_CYCLE_COLLECTING_RELEASE(nsJSInspector)
  33
  34 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsJSInspector)
  35 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  36
  37 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsJSInspector)
  38   tmp->mRequestors.Clear();
  39   tmp->mLastRequestor = JS::NullValue();
  40 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  41
  42 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsJSInspector)
  43   for (uint32_t i = 0; i < tmp->mRequestors.Length(); ++i) {
  44     NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mRequestors[i])
  45   }
  46   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mLastRequestor)
  47 NS_IMPL_CYCLE_COLLECTION_TRACE_END
  48
  49 nsJSInspector::nsJSInspector()
  50     : mNestedLoopLevel(0), mRequestors(1), mLastRequestor(JS::NullValue()) {}
  51
  52 nsJSInspector::~nsJSInspector() {
  53   MOZ_ASSERT(mRequestors.Length() == 0);
  54   MOZ_ASSERT(mLastRequestor.isNull());
  55   mozilla::DropJSObjects(this);
  56 }
  57
  58 NS_IMETHODIMP
  59 nsJSInspector::EnterNestedEventLoop(JS::Handle<JS::Value> requestor,
  60                                     uint32_t* out) {
  61   nsresult rv = NS_OK;
  62
  63   mLastRequestor = requestor;
  64   mRequestors.AppendElement(requestor);
  65   mozilla::HoldJSObjects(this);
  66
  67   mozilla::dom::AutoNoJSAPI nojsapi;
  68
  69   uint32_t nestLevel = ++mNestedLoopLevel;
  70   if (!SpinEventLoopUntil("nsJSInspector::EnterNestedEventLoop"_ns,
  71                           [&]() { return mNestedLoopLevel < nestLevel; })) {
  72     rv = NS_ERROR_UNEXPECTED;
  73   }
  74
  75   NS_ASSERTION(mNestedLoopLevel <= nestLevel,
  76                "nested event didn't unwind properly");
  77
  78   if (mNestedLoopLevel == nestLevel) {
  79     mLastRequestor = mRequestors.ElementAt(--mNestedLoopLevel);
  80   }
  81
  82   *out = mNestedLoopLevel;
  83   return rv;
  84 }
  85
  86 NS_IMETHODIMP
  87 nsJSInspector::ExitNestedEventLoop(uint32_t* out) {
  88   if (mNestedLoopLevel > 0) {
  89     mRequestors.RemoveElementAt(--mNestedLoopLevel);
  90     if (mNestedLoopLevel > 0)
  91       mLastRequestor = mRequestors.ElementAt(mNestedLoopLevel - 1);
  92     else
  93       mLastRequestor = JS::NullValue();
  94   } else {
  95     return NS_ERROR_FAILURE;
  96   }
  97
  98   *out = mNestedLoopLevel;
  99
 100   return NS_OK;
 101 }
 102
 103 NS_IMETHODIMP
 104 nsJSInspector::GetEventLoopNestLevel(uint32_t* out) {
 105   *out = mNestedLoopLevel;
 106   return NS_OK;
 107 }
 108
 109 NS_IMETHODIMP
 110 nsJSInspector::GetLastNestRequestor(JS::MutableHandle<JS::Value> out) {
 111   out.set(mLastRequestor);
 112   return NS_OK;
 113 }
 114
 115 }  // namespace jsinspector
 116 }  // namespace mozilla