Kernel: Added preliminary support for address arbiters.

AddressArbiter: Added documentation comment, fixed whitespace issue.

AddressArbiter: Fixed incorrect comment, reordered if-statement to be more clear.

SVC: Removed trailing whitespace.

src/core/hle/kernel/address_arbiter.cpp

@@ -0,0 +1,87 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#include "common/common_types.h"
+
+#include "core/mem_map.h"
+
+#include "core/hle/hle.h"
+#include "core/hle/kernel/address_arbiter.h"
+#include "core/hle/kernel/thread.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Kernel namespace
+
+namespace Kernel {
+
+class AddressArbiter : public Object {
+public:
+    const char* GetTypeName() const { return "Arbiter"; }
+    const char* GetName() const { return name.c_str(); }
+
+    static Kernel::HandleType GetStaticHandleType() { return HandleType::AddressArbiter; }
+    Kernel::HandleType GetHandleType() const { return HandleType::AddressArbiter; }
+
+    std::string name;   ///< Name of address arbiter object (optional)
+
+    /**
+     * Wait for kernel object to synchronize
+     * @param wait Boolean wait set if current thread should wait as a result of sync operation
+     * @return Result of operation, 0 on success, otherwise error code
+     */
+    Result WaitSynchronization(bool* wait) {
+        // TODO(bunnei): ImplementMe
+        ERROR_LOG(OSHLE, "(UNIMPLEMENTED)");
+        return 0;
+    }
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+/// Arbitrate an address
+Result ArbitrateAddress(Handle handle, ArbitrationType type, u32 address, s32 value) {
+    switch (type) {
+
+    // Signal thread(s) waiting for arbitrate address...
+    case ArbitrationType::Signal:
+        // Negative value means resume all threads
+        if (value < 0) {
+            ArbitrateAllThreads(handle, address);
+        } else {
+            // Resume first N threads
+            for(int i = 0; i < value; i++)
+                ArbitrateHighestPriorityThread(handle, address);
+        }
+        HLE::Reschedule(__func__);
+
+    // Wait current thread (acquire the arbiter)...
+    case ArbitrationType::WaitIfLessThan:
+        if ((s32)Memory::Read32(address) <= value) {
+            Kernel::WaitCurrentThread(WAITTYPE_ARB, handle);
+            HLE::Reschedule(__func__);
+        }
+
+    default:
+        ERROR_LOG(KERNEL, "unknown type=%d", type);
+        return -1;
+    }
+    return 0;
+}
+
+/// Create an address arbiter
+AddressArbiter* CreateAddressArbiter(Handle& handle, const std::string& name) {
+    AddressArbiter* address_arbiter = new AddressArbiter;
+    handle = Kernel::g_object_pool.Create(address_arbiter);
+    address_arbiter->name = name;
+    return address_arbiter;
+}
+
+/// Create an address arbiter
+Handle CreateAddressArbiter(const std::string& name) {
+    Handle handle;
+    CreateAddressArbiter(handle, name);
+    return handle;
+}
+
+} // namespace Kernel

src/core/hle/kernel/address_arbiter.h

@@ -0,0 +1,36 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+#include "core/hle/kernel/kernel.h"
+
+// Address arbiters are an underlying kernel synchronization object that can be created/used via
+// supervisor calls (SVCs). They function as sort of a global lock. Typically, games/other CTR
+// applications use them as an underlying mechanism to implement thread-safe barriers, events, and
+// semphores. 
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Kernel namespace
+
+namespace Kernel {
+
+/// Address arbitration types
+enum class ArbitrationType : u32 {
+    Signal,
+    WaitIfLessThan,
+    DecrementAndWaitIfLessThan,
+    WaitIfLessThanWithTimeout,
+    DecrementAndWaitIfLessThanWithTimeout,
+};
+
+/// Arbitrate an address
+Result ArbitrateAddress(Handle handle, ArbitrationType type, u32 address, s32 value);
+
+/// Create an address arbiter
+Handle CreateAddressArbiter(const std::string& name = "Unknown");
+
+} // namespace FileSys

src/core/hle/kernel/kernel.h

@@ -26,7 +26,7 @@ enum class HandleType : u32 {
     Redirection     = 6,
     Thread          = 7,
     Process         = 8,
-    Arbiter         = 9,
+    AddressArbiter  = 9,
     File            = 10,
     Semaphore       = 11,
     Archive         = 12,