iop: Support wating on message boxes

game/sce/iop.cpp

@@ -196,9 +196,7 @@ s32 SendMbx(s32 mbxid, void* sendmsg) {
 }
 
 s32 ReceiveMbx(MsgPacket** recvmsg, int mbxid) {
-  ASSERT(false);
-  // TODO
-  return 0;
+  return iop->kernel.ReceiveMbx((void**)recvmsg, mbxid);
 }
 
 s32 PollMbx(MsgPacket** recvmsg, int mbxid) {

game/sce/iop.h

@@ -30,6 +30,12 @@
 #define SA_THFIFO 0
 #define SA_THPRI 1
 
+// Message box attributes
+#define MBA_THFIFO 0x000
+#define MBA_THPRI 0x001
+#define MBA_MSFIFO 0x000
+#define MBA_MSPRI 0x004
+
 class IOP;
 
 namespace iop {

game/system/IOP_Kernel.cpp

@@ -103,6 +103,12 @@ void IOP_Kernel::iWakeupThread(s32 id) {
   wakeup_queue.push(id);
 }
 
+s32 IOP_Kernel::CreateSema(s32 attr, s32 option, s32 init_count, s32 max_count) {
+  s32 id = semas.size();
+  semas.emplace_back((Semaphore::attribute)attr, option, init_count, max_count);
+  return id;
+}
+
 s32 IOP_Kernel::WaitSema(s32 id) {
   auto& sema = semas.at(id);
   if (sema.count > 0) {
@@ -159,6 +165,81 @@ s32 IOP_Kernel::PollSema(s32 id) {
   return KE_SEMA_ZERO;
 }
 
+/*!
+ * Create a message box
+ */
+s32 IOP_Kernel::CreateMbx() {
+  s32 id = mbxs.size();
+  mbxs.emplace_back();
+  return id;
+}
+
+s32 IOP_Kernel::ReceiveMbx(void** msg, s32 mbx) {
+  ASSERT(mbx < (s32)mbxs.size());
+  s32 gotSomething = mbxs[mbx].messages.empty() ? 0 : 1;
+  if (!gotSomething) {
+    /* Was empty, wait until there's messages */
+    mbxs[mbx].wait_list.push_back(_currentThread);
+    _currentThread->state = IopThread::State::Wait;
+    _currentThread->waitType = IopThread::Wait::MsgBox;
+    leaveThread();
+  }
+
+  ASSERT(mbxs[mbx].messages.empty() == false);
+
+  void* thing = mbxs[mbx].messages.front();
+  if (msg) {
+    *msg = thing;
+  }
+
+  mbxs[mbx].messages.pop();
+
+  return KE_OK;
+}
+
+/*!
+ * Set msg to thing if its there and pop it.
+ * Returns if it got something.
+ */
+s32 IOP_Kernel::PollMbx(void** msg, s32 mbx) {
+  ASSERT(mbx < (s32)mbxs.size());
+  s32 gotSomething = mbxs[mbx].messages.empty() ? 0 : 1;
+  if (gotSomething) {
+    void* thing = mbxs[mbx].messages.front();
+
+    if (msg) {
+      *msg = thing;
+    }
+
+    mbxs[mbx].messages.pop();
+  }
+
+  return gotSomething ? KE_OK : KE_MBOX_NOMSG;
+}
+
+s32 IOP_Kernel::PeekMbx(s32 mbx) {
+  return !mbxs[mbx].messages.empty();
+}
+
+/*!
+ * Push something into a mbx
+ */
+s32 IOP_Kernel::SendMbx(s32 mbx, void* value) {
+  ASSERT(mbx < (s32)mbxs.size());
+  mbxs[mbx].messages.push(value);
+
+  IopThread* to_run = nullptr;
+  if (!mbxs[mbx].wait_list.empty()) {
+    to_run = mbxs[mbx].wait_list.front();
+    mbxs[mbx].wait_list.pop_front();
+
+    to_run->waitType = IopThread::Wait::None;
+    to_run->state = IopThread::State::Ready;
+  }
+
+  return KE_OK;
+}
+
 /*!
  * Return to kernel from a thread, not to be called from the kernel thread.
  */

game/system/IOP_Kernel.h

@@ -57,6 +57,7 @@ struct IopThread {
     None,
     Semaphore,
     Delay,
+    MsgBox,
   };
 
   IopThread(std::string n, void (*f)(), s32 ID, u32 priority)
@@ -91,6 +92,11 @@ struct Semaphore {
   std::list<IopThread*> wait_list;
 };
 
+struct MsgBox {
+  std::queue<void*> messages;
+  std::list<IopThread*> wait_list;
+};
+
 class IOP_Kernel {
  public:
   IOP_Kernel() {
@@ -122,52 +128,13 @@ class IOP_Kernel {
     return _currentThread->thID;
   }
 
-  /*!
-   * Create a message box
-   */
-  s32 CreateMbx() {
-    s32 id = mbxs.size();
-    mbxs.emplace_back();
-    return id;
-  }
-
-  /*!
-   * Set msg to thing if its there and pop it.
-   * Returns if it got something.
-   */
-  s32 PollMbx(void** msg, s32 mbx) {
-    ASSERT(mbx < (s32)mbxs.size());
-    s32 gotSomething = mbxs[mbx].empty() ? 0 : 1;
-    if (gotSomething) {
-      void* thing = mbxs[mbx].front();
-
-      if (msg) {
-        *msg = thing;
-      }
-
-      mbxs[mbx].pop();
-    }
-
-    return gotSomething ? KE_OK : KE_MBOX_NOMSG;
-  }
-
-  s32 PeekMbx(s32 mbx) { return !mbxs[mbx].empty(); }
-
-  /*!
-   * Push something into a mbx
-   */
-  s32 SendMbx(s32 mbx, void* value) {
-    ASSERT(mbx < (s32)mbxs.size());
-    mbxs[mbx].push(value);
-    return 0;
-  }
-
-  s32 CreateSema(s32 attr, s32 option, s32 init_count, s32 max_count) {
-    s32 id = semas.size();
-    semas.emplace_back((Semaphore::attribute)attr, option, init_count, max_count);
-    return id;
-  }
+  s32 CreateMbx();
+  s32 ReceiveMbx(void** msg, s32 mbx);
+  s32 PollMbx(void** msg, s32 mbx);
+  s32 PeekMbx(s32 mbx);
+  s32 SendMbx(s32 mbx, void* value);
 
+  s32 CreateSema(s32 attr, s32 option, s32 init_count, s32 max_count);
   s32 WaitSema(s32 id);
   s32 SignalSema(s32 id);
   s32 PollSema(s32 id);
@@ -205,7 +172,7 @@ class IOP_Kernel {
   s32 _nextThID = 0;
   IopThread* _currentThread = nullptr;
   std::vector<IopThread> threads;
-  std::vector<std::queue<void*>> mbxs;
+  std::vector<MsgBox> mbxs;
   std::vector<SifRecord> sif_records;
   std::vector<Semaphore> semas;
   std::queue<int> wakeup_queue;