From 2c54fd235788822b24d178ed4a7ee236b13f674e Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Fri, 1 Mar 2019 12:24:23 +1100
Subject: [PATCH] [c-host] added platform agnostic thread interface

---
 c-host/app.h              | 10 +++++-
 c-host/windows/platform.c | 66 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/c-host/app.h b/c-host/app.h
index 5004061b..46302ed2 100644
--- a/c-host/app.h
+++ b/c-host/app.h
@@ -27,4 +27,12 @@ int app_main();
 
 unsigned int os_shmemSize();
 bool         os_shmemMmap(void **ptr);
-void         os_shmemUnmap();
\ No newline at end of file
+void         os_shmemUnmap();
+
+// os specific thread functions
+
+typedef struct osThreadHandle osThreadHandle;
+typedef int (*osThreadFunction)(void * opaque);
+
+bool         os_createThread(const char * name, osThreadFunction function, void * opaque, osThreadHandle ** handle);
+bool         os_joinThread  (osThreadHandle * handle, int * resultCode);
\ No newline at end of file
diff --git a/c-host/windows/platform.c b/c-host/windows/platform.c
index a94393e1..18eeb618 100644
--- a/c-host/windows/platform.c
+++ b/c-host/windows/platform.c
@@ -29,6 +29,16 @@ static HANDLE       shmemHandle = INVALID_HANDLE_VALUE;
 static bool         shmemOwned  = false;
 static IVSHMEM_MMAP shmemMap    = {0};
 
+struct osThreadHandle
+{
+  const char       * name;
+  osThreadFunction   function;
+  void             * opaque;
+  HANDLE             handle;
+  DWORD              threadID;
+  int                resultCode;
+};
+
 int WINAPI WinMain(HINSTANCE hInstnace, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
 {
   HDEVINFO                         deviceInfoSet;
@@ -146,4 +156,60 @@ void os_shmemUnmap()
     DEBUG_WINERROR("DeviceIoControl failed", GetLastError());
   else
     shmemOwned = false;
+}
+
+static DWORD WINAPI threadWrapper(LPVOID lpParameter)
+{
+  osThreadHandle * handle = (osThreadHandle *)lpParameter;
+  handle->resultCode = handle->function(handle->opaque);
+  return 0;
+}
+
+bool os_createThread(const char * name, osThreadFunction function, void * opaque, osThreadHandle ** handle)
+{
+  *handle           = (osThreadHandle *)malloc(sizeof(osThreadHandle));
+  (*handle)->name   = name;
+  (*handle)->opaque = opaque;
+  (*handle)->handle = CreateThread(NULL, 0, threadWrapper, *handle, 0, &(*handle)->threadID);
+
+  if (!(*handle)->handle)
+  {
+    free(*handle);
+    *handle = NULL;
+    DEBUG_WINERROR("CreateThread failed", GetLastError());
+    return false;
+  }
+
+  return true;
+}
+
+bool os_joinThread(osThreadHandle * handle, int * resultCode)
+{
+  while(true)
+  {
+    switch(WaitForSingleObject(handle->handle, INFINITE))
+    {
+      case WAIT_OBJECT_0:
+        if (resultCode)
+          *resultCode = handle->resultCode;
+        CloseHandle(handle->handle);
+        free(handle);
+        return true;
+
+      case WAIT_ABANDONED:
+      case WAIT_TIMEOUT:
+        continue;
+
+      case WAIT_FAILED:
+        DEBUG_WINERROR("Wait for thread failed", GetLastError());
+        CloseHandle(handle->handle);
+        free(handle);
+        return false;
+    }
+
+    break;
+  }
+
+  DEBUG_WINERROR("Unknown failure waiting for thread", GetLastError());
+  return false;
 }
\ No newline at end of file