Putting guest thread to sleep inside handler

src/core/hle/kernel/hle_ipc.cpp

@@ -7,6 +7,7 @@
 #include "common/common_funcs.h"
 #include "common/common_types.h"
 #include "core/hle/ipc_helpers.h"
+#include "core/hle/kernel/event.h"
 #include "core/hle/kernel/handle_table.h"
 #include "core/hle/kernel/hle_ipc.h"
 #include "core/hle/kernel/kernel.h"
@@ -25,6 +26,39 @@ void SessionRequestHandler::ClientDisconnected(SharedPtr<ServerSession> server_s
     boost::range::remove_erase(connected_sessions, server_session);
 }
 
+SharedPtr<Event> HLERequestContext::SleepClientThread(SharedPtr<Thread> thread,
+                                                      const std::string& reason, u64 timeout,
+                                                      WakeupCallback&& callback) {
+    // Put the client thread to sleep until the wait event is signaled or the timeout expires.
+    thread->wakeup_callback = [ context = *this, callback ](
+        ThreadWakeupReason reason, SharedPtr<Thread> thread, SharedPtr<WaitObject> object) mutable {
+        ASSERT(thread->status == THREADSTATUS_WAIT_HLE_EVENT);
+        callback(thread, context, reason);
+
+        auto& process = thread->owner_process;
+        // We must copy the entire command buffer *plus* the entire static buffers area, since
+        // the translation might need to read from it in order to retrieve the StaticBuffer
+        // target addresses.
+        std::array<u32, IPC::COMMAND_BUFFER_LENGTH + 2 * IPC::MAX_STATIC_BUFFERS> cmd_buff;
+        Memory::ReadBlock(*process, thread->GetCommandBufferAddress(), cmd_buff.data(),
+                          cmd_buff.size() * sizeof(u32));
+        context.WriteToOutgoingCommandBuffer(cmd_buff.data(), *process, Kernel::g_handle_table);
+        // Copy the translated command buffer back into the thread's command buffer area.
+        Memory::WriteBlock(*process, thread->GetCommandBufferAddress(), cmd_buff.data(),
+                           cmd_buff.size() * sizeof(u32));
+    };
+
+    auto event = Kernel::Event::Create(Kernel::ResetType::OneShot, "HLE Pause Event: " + reason);
+    thread->status = THREADSTATUS_WAIT_HLE_EVENT;
+    thread->wait_objects = {event};
+    event->AddWaitingThread(thread);
+
+    if (timeout > 0)
+        thread->WakeAfterDelay(timeout);
+
+    return event;
+}
+
 HLERequestContext::HLERequestContext(SharedPtr<Kernel::ServerSession> server_session)
     : server_session(std::move(server_session)) {
     cmd_buf[0] = 0;

src/core/hle/kernel/hle_ipc.h

@@ -7,6 +7,7 @@
 #include <array>
 #include <memory>
 #include <vector>
+#include <string>
 #include <boost/container/small_vector.hpp>
 #include "common/common_types.h"
 #include "common/swap.h"
@@ -24,6 +25,8 @@ class Domain;
 class HandleTable;
 class HLERequestContext;
 class Process;
+class Thread;
+class Event;
 
 /**
  * Interface implemented by HLE Session handlers.
@@ -102,6 +105,23 @@ public:
         return server_session;
     }
 
+    using WakeupCallback = std::function<void(SharedPtr<Thread> thread, HLERequestContext& context,
+                                              ThreadWakeupReason reason)>;
+
+    /*
+     * Puts the specified guest thread to sleep until the returned event is signaled or until the
+     * specified timeout expires.
+     * @param thread Thread to be put to sleep.
+     * @param reason Reason for pausing the thread, to be used for debugging purposes.
+     * @param timeout Timeout in nanoseconds after which the thread will be awoken and the callback
+     * invoked with a Timeout reason.
+     * @param callback Callback to be invoked when the thread is resumed. This callback must write
+     * the entire command response once again, regardless of the state of it before this function
+     * was called.
+     * @returns Event that when signaled will resume the thread and call the callback function.
+     */
+    SharedPtr<Event> SleepClientThread(SharedPtr<Thread> thread, const std::string& reason,
+                                       u64 timeout, WakeupCallback&& callback);
     void ParseCommandBuffer(u32_le* src_cmdbuf, bool incoming);
 
     /// Populates this context with data from the requesting process/thread.

src/core/hle/kernel/thread.cpp

@@ -247,7 +247,8 @@ static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
     bool resume = true;
 
     if (thread->status == THREADSTATUS_WAIT_SYNCH_ANY ||
-        thread->status == THREADSTATUS_WAIT_SYNCH_ALL || thread->status == THREADSTATUS_WAIT_ARB) {
+        thread->status == THREADSTATUS_WAIT_SYNCH_ALL || thread->status == THREADSTATUS_WAIT_ARB
+        || thread->status == THREADSTATUS_WAIT_HLE_EVENT) {
 
         // Remove the thread from each of its waiting objects' waitlists
         for (auto& object : thread->wait_objects)

src/core/hle/service/service.cpp

@@ -150,9 +150,15 @@ ResultCode ServiceFrameworkBase::HandleSyncRequest(Kernel::HLERequestContext& co
     }
 
     u32* cmd_buf = (u32*)Memory::GetPointer(Kernel::GetCurrentThread()->GetTLSAddress());
-    context.WriteToOutgoingCommandBuffer(cmd_buf, *Kernel::g_current_process,
-                                         Kernel::g_handle_table);
-
+    auto thread = Kernel::GetCurrentThread();
+    ASSERT(thread->status == THREADSTATUS_RUNNING || thread->status == THREADSTATUS_WAIT_HLE_EVENT);
+    // Only write the response immediately if the thread is still running. If the HLE handler put
+    // the thread to sleep then the writing of the command buffer will be deferred to the wakeup
+    // callback.
+    if (thread->status == THREADSTATUS_RUNNING) {
+        context.WriteToOutgoingCommandBuffer(cmd_buf, *Kernel::g_current_process,
+                                             Kernel::g_handle_table);
+    }
     return RESULT_SUCCESS;
 }