4 files changed, 38 insertions, 3 deletions

diff --git a/src/core/hle/kernel/errors.h b/src/core/hle/kernel/errors.h
index b3b60e7df..64aa61460 100644
--- a/src/core/hle/kernel/errors.h
+++ b/src/core/hle/kernel/errors.h
@@ -13,6 +13,7 @@ enum {
     OutOfHandles = 19,
     SessionClosedByRemote = 26,
     PortNameTooLong = 30,
+    NoPendingSessions = 35,
     WrongPermission = 46,
     InvalidBufferDescriptor = 48,
     MaxConnectionsReached = 52,
@@ -94,5 +95,9 @@ constexpr ResultCode ERR_OUT_OF_RANGE_KERNEL(ErrorDescription::OutOfRange, Error
                                              ErrorLevel::Permanent); // 0xD8E007FD
 constexpr ResultCode RESULT_TIMEOUT(ErrorDescription::Timeout, ErrorModule::OS,
                                     ErrorSummary::StatusChanged, ErrorLevel::Info);
+/// Returned when Accept() is called on a port with no sessions to be accepted.
+constexpr ResultCode ERR_NO_PENDING_SESSIONS(ErrCodes::NoPendingSessions, ErrorModule::OS,
+                                             ErrorSummary::WouldBlock,
+                                             ErrorLevel::Permanent); // 0xD8401823
 
 } // namespace Kernel
diff --git a/src/core/hle/kernel/server_port.cpp b/src/core/hle/kernel/server_port.cpp
index 4d20c39a1..49a9cdfa3 100644
--- a/src/core/hle/kernel/server_port.cpp
+++ b/src/core/hle/kernel/server_port.cpp
@@ -5,8 +5,10 @@
 #include <tuple>
 #include "common/assert.h"
 #include "core/hle/kernel/client_port.h"
+#include "core/hle/kernel/errors.h"
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/server_port.h"
+#include "core/hle/kernel/server_session.h"
 #include "core/hle/kernel/thread.h"
 
 namespace Kernel {
@@ -14,6 +16,16 @@ namespace Kernel {
 ServerPort::ServerPort() {}
 ServerPort::~ServerPort() {}
 
+ResultVal<SharedPtr<ServerSession>> ServerPort::Accept() {
+    if (pending_sessions.empty()) {
+        return ERR_NO_PENDING_SESSIONS;
+    }
+
+    auto session = std::move(pending_sessions.back());
+    pending_sessions.pop_back();
+    return MakeResult(std::move(session));
+}
+
 bool ServerPort::ShouldWait(Thread* thread) const {
     // If there are no pending sessions, we wait until a new one is added.
     return pending_sessions.size() == 0;
diff --git a/src/core/hle/kernel/server_port.h b/src/core/hle/kernel/server_port.h
index f1419cd46..6fe7c7f2f 100644
--- a/src/core/hle/kernel/server_port.h
+++ b/src/core/hle/kernel/server_port.h
@@ -14,6 +14,7 @@
 namespace Kernel {
 
 class ClientPort;
+class ServerSession;
 class SessionRequestHandler;
 
 class ServerPort final : public WaitObject {
@@ -41,6 +42,12 @@ public:
     }
 
     /**
+     * Accepts a pending incoming connection on this port. If there are no pending sessions, will
+     * return ERR_NO_PENDING_SESSIONS.
+     */
+    ResultVal<SharedPtr<ServerSession>> Accept();
+
+    /**
      * Sets the HLE handler template for the port. ServerSessions crated by connecting to this port
      * will inherit a reference to this handler.
      */
@@ -50,8 +57,8 @@ public:
 
     std::string name; ///< Name of port (optional)
 
-    std::vector<SharedPtr<WaitObject>>
-        pending_sessions; ///< ServerSessions waiting to be accepted by the port
+    /// ServerSessions waiting to be accepted by the port
+    std::vector<SharedPtr<ServerSession>> pending_sessions;
 
     /// This session's HLE request handler template (optional)
     /// ServerSessions created from this port inherit a reference to this handler.
diff --git a/src/core/hle/svc.cpp b/src/core/hle/svc.cpp
index 2e11d41ce..c05401143 100644
--- a/src/core/hle/svc.cpp
+++ b/src/core/hle/svc.cpp
@@ -971,6 +971,17 @@ static ResultCode CreateSession(Handle* server_session, Handle* client_session)
     return RESULT_SUCCESS;
 }
 
+static ResultCode AcceptSession(Handle* out_server_session, Handle server_port_handle) {
+    using Kernel::ServerPort;
+    SharedPtr<ServerPort> server_port = Kernel::g_handle_table.Get<ServerPort>(server_port_handle);
+    if (server_port == nullptr)
+        return ERR_INVALID_HANDLE;
+
+    CASCADE_RESULT(auto session, server_port->Accept());
+    CASCADE_RESULT(*out_server_session, Kernel::g_handle_table.Create(std::move(session)));
+    return RESULT_SUCCESS;
+}
+
 static ResultCode GetSystemInfo(s64* out, u32 type, s32 param) {
     using Kernel::MemoryRegion;
 
@@ -1147,7 +1158,7 @@ static const FunctionDef SVC_Table[] = {
     {0x47, HLE::Wrap<CreatePort>, "CreatePort"},
     {0x48, HLE::Wrap<CreateSessionToPort>, "CreateSessionToPort"},
     {0x49, HLE::Wrap<CreateSession>, "CreateSession"},
-    {0x4A, nullptr, "AcceptSession"},
+    {0x4A, HLE::Wrap<AcceptSession>, "AcceptSession"},
     {0x4B, nullptr, "ReplyAndReceive1"},
     {0x4C, nullptr, "ReplyAndReceive2"},
     {0x4D, nullptr, "ReplyAndReceive3"},