Add a skia method to perform an atomic add.
Complements sk_atomic_inc for when you want to increase by more than one.
This time, use the correct atomic add function on Windows.
Reviewed at https://codereview.appspot.com/6399050/
Review URL: https://codereview.appspot.com/6407048
git-svn-id: http://skia.googlecode.com/svn/trunk@4623 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/tests.gyp b/gyp/tests.gyp
index c6e2786..8ea4ee8 100644
--- a/gyp/tests.gyp
+++ b/gyp/tests.gyp
@@ -18,6 +18,7 @@
'sources': [
'../tests/AAClipTest.cpp',
'../tests/AnnotationTest.cpp',
+ '../tests/AtomicTest.cpp',
'../tests/BitmapCopyTest.cpp',
'../tests/BitmapGetColorTest.cpp',
'../tests/BitSetTest.cpp',
diff --git a/include/core/SkThread.h b/include/core/SkThread.h
index 2fd5052..5b1fc1c 100644
--- a/include/core/SkThread.h
+++ b/include/core/SkThread.h
@@ -16,6 +16,7 @@
/****** SkThread_platform needs to define the following...
int32_t sk_atomic_inc(int32_t*);
+int32_t sk_atomic_add(int32_t*, int32_t);
int32_t sk_atomic_dec(int32_t*);
int32_t sk_atomic_conditional_inc(int32_t*);
diff --git a/include/core/SkThread_platform.h b/include/core/SkThread_platform.h
index cb05c50..ce7a871 100644
--- a/include/core/SkThread_platform.h
+++ b/include/core/SkThread_platform.h
@@ -23,6 +23,10 @@
return __sync_fetch_and_add(addr, 1);
}
+static inline __attribute__((always_inline)) int32_t sk_atomic_add(int32_t *addr, int32_t inc) {
+ return __sync_fetch_and_add(addr, inc);
+}
+
static inline __attribute__((always_inline)) int32_t sk_atomic_dec(int32_t *addr) {
return __sync_fetch_and_add(addr, -1);
}
@@ -54,8 +58,9 @@
*/
#include <utils/Atomic.h>
-#define sk_atomic_inc(addr) android_atomic_inc(addr)
-#define sk_atomic_dec(addr) android_atomic_dec(addr)
+#define sk_atomic_inc(addr) android_atomic_inc(addr)
+#define sk_atomic_add(addr, inc) android_atomic_add(inc, addr)
+#define sk_atomic_dec(addr) android_atomic_dec(addr)
void sk_membar_aquire__after_atomic_dec() {
//HACK: Android is actually using full memory barriers.
// Should this change, uncomment below.
@@ -92,6 +97,14 @@
*/
SK_API int32_t sk_atomic_inc(int32_t* addr);
+/** Implemented by the porting layer, this function adds inc to the int
+ specified by the address (in a thread-safe manner), and returns the
+ previous value.
+ No additional memory barrier is required.
+ This must act as a compiler barrier.
+ */
+SK_API int32_t sk_atomic_add(int32_t* addr, int32_t inc);
+
/** Implemented by the porting layer, this function subtracts one from the int
specified by the address (in a thread-safe manner), and returns the
previous value.
diff --git a/src/ports/SkThread_none.cpp b/src/ports/SkThread_none.cpp
index 56bbbae..1122c95 100644
--- a/src/ports/SkThread_none.cpp
+++ b/src/ports/SkThread_none.cpp
@@ -16,6 +16,12 @@
return value;
}
+int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
+ int32_t value = *addr;
+ *addr = value + inc;
+ return value;
+}
+
int32_t sk_atomic_dec(int32_t* addr) {
int32_t value = *addr;
*addr = value - 1;
diff --git a/src/ports/SkThread_pthread.cpp b/src/ports/SkThread_pthread.cpp
index d0bb3ac..ad243b9 100644
--- a/src/ports/SkThread_pthread.cpp
+++ b/src/ports/SkThread_pthread.cpp
@@ -35,6 +35,11 @@
return __sync_fetch_and_add(addr, 1);
}
+int32_t sk_atomic_add(int32_t* addr, int32_t inc)
+{
+ return __sync_fetch_and_add(addr, inc);
+}
+
int32_t sk_atomic_dec(int32_t* addr)
{
return __sync_fetch_and_add(addr, -1);
@@ -74,6 +79,15 @@
return value;
}
+int32_t sk_atomic_add(int32_t* addr, int32_t inc)
+{
+ SkAutoMutexAcquire ac(gAtomicMutex);
+
+ int32_t value = *addr;
+ *addr = value + inc;
+ return value;
+}
+
int32_t sk_atomic_dec(int32_t* addr)
{
SkAutoMutexAcquire ac(gAtomicMutex);
diff --git a/src/ports/SkThread_win.cpp b/src/ports/SkThread_win.cpp
index e833314..91a5ceb 100644
--- a/src/ports/SkThread_win.cpp
+++ b/src/ports/SkThread_win.cpp
@@ -16,7 +16,7 @@
//intrinsic, include intrin.h and put the function in a #pragma intrinsic
//directive.
//The pragma appears to be unnecessary, but doesn't hurt.
-#pragma intrinsic(_InterlockedIncrement, _InterlockedDecrement)
+#pragma intrinsic(_InterlockedIncrement, _InterlockedExchangeAdd, _InterlockedDecrement)
#pragma intrinsic(_InterlockedCompareExchange)
int32_t sk_atomic_inc(int32_t* addr) {
@@ -24,6 +24,11 @@
return _InterlockedIncrement(reinterpret_cast<LONG*>(addr)) - 1;
}
+int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
+ return _InterlockedExchangeAdd(reinterpret_cast<LONG*>(addr),
+ static_cast<LONG>(inc));
+}
+
int32_t sk_atomic_dec(int32_t* addr) {
return _InterlockedDecrement(reinterpret_cast<LONG*>(addr)) + 1;
}
diff --git a/tests/AtomicTest.cpp b/tests/AtomicTest.cpp
new file mode 100644
index 0000000..5275e84
--- /dev/null
+++ b/tests/AtomicTest.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkThread.h"
+#include "SkThreadUtils.h"
+#include "SkTypes.h"
+#include "Test.h"
+
+struct AddInfo {
+ int32_t valueToAdd;
+ int timesToAdd;
+ unsigned int processorAffinity;
+};
+
+static int32_t base = 0;
+
+static AddInfo gAdds[] = {
+ { 3, 100, 23 },
+ { 2, 200, 2 },
+ { 7, 150, 17 },
+};
+
+static void addABunchOfTimes(void* data) {
+ AddInfo* addInfo = static_cast<AddInfo*>(data);
+ for (int i = 0; i < addInfo->timesToAdd; i++) {
+ sk_atomic_add(&base, addInfo->valueToAdd);
+ }
+}
+
+static void test_atomicAddTests(skiatest::Reporter* reporter) {
+ int32_t total = base;
+ SkThread* threads[SK_ARRAY_COUNT(gAdds)];
+ for (size_t i = 0; i < SK_ARRAY_COUNT(gAdds); i++) {
+ total += gAdds[i].valueToAdd * gAdds[i].timesToAdd;
+ }
+ // Start the threads
+ for (size_t i = 0; i < SK_ARRAY_COUNT(gAdds); i++) {
+ threads[i] = new SkThread(addABunchOfTimes, &gAdds[i]);
+ threads[i]->setProcessorAffinity(gAdds[i].processorAffinity);
+ threads[i]->start();
+ }
+
+ // Now end the threads
+ for (size_t i = 0; i < SK_ARRAY_COUNT(gAdds); i++) {
+ threads[i]->join();
+ delete threads[i];
+ }
+ REPORTER_ASSERT(reporter, total == base);
+ // Ensure that the returned value from sk_atomic_add is correct.
+ int32_t valueToModify = 3;
+ const int32_t originalValue = valueToModify;
+ REPORTER_ASSERT(reporter, originalValue == sk_atomic_add(&valueToModify, 7));
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("AtomicAdd", AtomicAddTestClass, test_atomicAddTests)
+