PDF: remove unnecessary mutexes.

We now force all SkPDFObjects to stay on one thread.

TBR=mtklein@google.com

Review URL: https://codereview.chromium.org/942153002

7 files changed, 4 insertions, 29 deletions

diff --git a/src/pdf/SkPDFFont.h b/src/pdf/SkPDFFont.h
index 105ae8d25e..6ff4c7b15e 100644
--- a/src/pdf/SkPDFFont.h
+++ b/src/pdf/SkPDFFont.h
@@ -14,7 +14,6 @@
 #include "SkBitSet.h"
 #include "SkPDFTypes.h"
 #include "SkTDArray.h"
-#include "SkThread.h"
 #include "SkTypeface.h"
 
 class SkPaint;
diff --git a/src/pdf/SkPDFGraphicState.h b/src/pdf/SkPDFGraphicState.h
index b26e4a00cb..2c9198c142 100644
--- a/src/pdf/SkPDFGraphicState.h
+++ b/src/pdf/SkPDFGraphicState.h
@@ -13,7 +13,6 @@
 #include "SkPaint.h"
 #include "SkPDFTypes.h"
 #include "SkTemplates.h"
-#include "SkThread.h"
 
 class SkPDFFormXObject;
 
diff --git a/src/pdf/SkPDFShader.cpp b/src/pdf/SkPDFShader.cpp
index 21d767d700..d7605b3362 100644
--- a/src/pdf/SkPDFShader.cpp
+++ b/src/pdf/SkPDFShader.cpp
@@ -20,7 +20,6 @@
 #include "SkScalar.h"
 #include "SkStream.h"
 #include "SkTemplates.h"
-#include "SkThread.h"
 #include "SkTSet.h"
 #include "SkTypes.h"
 
@@ -583,7 +582,6 @@ SkPDFObject* SkPDFShader::GetPDFShader(SkPDFCanon* canon,
                                        const SkMatrix& matrix,
                                        const SkIRect& surfaceBBox,
                                        SkScalar rasterScale) {
-    // There is only one mutex becasue we don't know which one we'll need.
     SkAutoTDelete<SkPDFShader::State> state(
             SkNEW_ARGS(State, (shader, matrix, surfaceBBox, rasterScale)));
     return get_pdf_shader_by_state(canon, dpi, &state);
diff --git a/src/pdf/SkPDFStream.cpp b/src/pdf/SkPDFStream.cpp
index 4aeb2dbe1e..ae3fe4abc4 100644
--- a/src/pdf/SkPDFStream.cpp
+++ b/src/pdf/SkPDFStream.cpp
@@ -41,7 +41,6 @@ SkPDFStream::SkPDFStream(const SkPDFStream& pdfStream)
 SkPDFStream::~SkPDFStream() {}
 
 void SkPDFStream::emitObject(SkWStream* stream, SkPDFCatalog* catalog) {
-    SkAutoMutexAcquire lock(fMutex);  // multiple threads could be calling emit
     if (!this->populate(catalog)) {
         return fSubstitute->emitObject(stream, catalog);
     }
diff --git a/src/pdf/SkPDFStream.h b/src/pdf/SkPDFStream.h
index cf9316ff14..90c6bcacb6 100644
--- a/src/pdf/SkPDFStream.h
+++ b/src/pdf/SkPDFStream.h
@@ -39,8 +39,7 @@ public:
 
     virtual ~SkPDFStream();
 
-    // The SkPDFObject interface.  This two method uses a mutex to
-    // allow multiple threads to call at the same time.
+    // The SkPDFObject interface.
     virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog) SK_OVERRIDE;
 
 protected:
@@ -90,9 +89,6 @@ private:
     // Indicates what form (or if) the stream has been requested.
     State fState;
 
-    // Mutex guards fState, fDataStream, and fSubstitute in public interface.
-    SkMutex fMutex;
-
     SkAutoTDelete<SkStreamRewindable> fDataStream;
     SkAutoTUnref<SkPDFStream> fSubstitute;
 
diff --git a/src/pdf/SkPDFTypes.cpp b/src/pdf/SkPDFTypes.cpp
index 7902e599ce..43cd68450f 100644
--- a/src/pdf/SkPDFTypes.cpp
+++ b/src/pdf/SkPDFTypes.cpp
@@ -312,15 +312,10 @@ SkPDFDict::~SkPDFDict() {
 }
 
 int SkPDFDict::size() const {
-    SkAutoMutexAcquire lock(fMutex);
     return fValue.count();
 }
 
 void SkPDFDict::emitObject(SkWStream* stream, SkPDFCatalog* catalog) {
-    SkAutoMutexAcquire lock(fMutex); // If another thread triggers a
-                                     // resize while this thread is in
-                                     // the for-loop, we can be left
-                                     // with a bad fValue[i] reference.
     stream->writeText("<<");
     for (int i = 0; i < fValue.count(); i++) {
         SkASSERT(fValue[i].key);
@@ -348,9 +343,6 @@ void SkPDFDict::addResources(SkTSet<SkPDFObject*>* resourceSet,
 SkPDFObject*  SkPDFDict::append(SkPDFName* key, SkPDFObject* value) {
     SkASSERT(key);
     SkASSERT(value);
-    SkAutoMutexAcquire lock(fMutex); // If the SkTDArray resizes while
-                                     // two threads access array, one
-                                     // is left with a bad pointer.
     *(fValue.append()) = Rec(key, value);
     return value;
 }
@@ -376,7 +368,6 @@ void SkPDFDict::insertName(const char key[], const char name[]) {
 }
 
 void SkPDFDict::clear() {
-    SkAutoMutexAcquire lock(fMutex);
     for (int i = 0; i < fValue.count(); i++) {
         SkASSERT(fValue[i].key);
         SkASSERT(fValue[i].value);
@@ -389,7 +380,6 @@ void SkPDFDict::clear() {
 void SkPDFDict::remove(const char key[]) {
     SkASSERT(key);
     SkPDFName name(key);
-    SkAutoMutexAcquire lock(fMutex);
     for (int i = 0; i < fValue.count(); i++) {
         SkASSERT(fValue[i].key);
         if (*(fValue[i].key) == name) {
@@ -403,12 +393,8 @@ void SkPDFDict::remove(const char key[]) {
 }
 
 void SkPDFDict::mergeFrom(const SkPDFDict& other) {
-    SkAutoMutexAcquire lockOther(other.fMutex);
-    SkTDArray<Rec> copy(other.fValue);
-    lockOther.release();  // Do not hold both mutexes at once.
-
-    SkAutoMutexAcquire lock(fMutex);
-    for (int i = 0; i < copy.count(); i++) {
-        *(fValue.append()) = Rec(SkRef(copy[i].key), SkRef(copy[i].value));
+    for (int i = 0; i < other.fValue.count(); i++) {
+        *(fValue.append()) =
+                Rec(SkRef(other.fValue[i].key), SkRef(other.fValue[i].value));
     }
 }
diff --git a/src/pdf/SkPDFTypes.h b/src/pdf/SkPDFTypes.h
index 54c59f28be..7a72a38c78 100644
--- a/src/pdf/SkPDFTypes.h
+++ b/src/pdf/SkPDFTypes.h
@@ -10,7 +10,6 @@
 #ifndef SkPDFTypes_DEFINED
 #define SkPDFTypes_DEFINED
 
-#include "SkMutex.h"
 #include "SkRefCnt.h"
 #include "SkScalar.h"
 #include "SkString.h"
@@ -384,7 +383,6 @@ private:
 
     static const int kMaxLen = 4095;
 
-    mutable SkMutex fMutex;  // protects modifications to fValue
     SkTDArray<struct Rec> fValue;
 
     SkPDFObject* append(SkPDFName* key, SkPDFObject* value);