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windows: Use a real synchronization primitive for CD detection thread…
… init.

Before we were waiting on a volatile int in a tight loop with a Sleep(50).
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icculus committed Aug 5, 2017
1 parent befc894 commit be9bf023d0497a4300f508e491e980c31ff27188
Showing with 17 additions and 13 deletions.
  1. +17 −13 src/physfs_platform_windows.c
@@ -234,8 +234,7 @@ static inline PHYSFS_ErrorCode errcodeFromWinApi(void)
#define deinitCDThread()
#else
static HANDLE detectCDThreadHandle = NULL;
static HWND detectCDHwnd = 0;
static volatile int initialDiscDetectionComplete = 0;
static HWND detectCDHwnd = NULL;
static volatile DWORD drivesWithMediaBitmap = 0;

typedef BOOL (WINAPI *fnSTEM)(DWORD, LPDWORD b);
@@ -309,8 +308,9 @@ static LRESULT CALLBACK detectCDWndProc(HWND hwnd, UINT msg,
} /* detectCDWndProc */


static DWORD WINAPI detectCDThread(LPVOID lpParameter)
static DWORD WINAPI detectCDThread(LPVOID arg)
{
HANDLE initialDiscDetectionComplete = *((HANDLE *) arg);
const char *classname = "PhysicsFSDetectCDCatcher";
const char *winname = "PhysicsFSDetectCDMsgWindow";
HINSTANCE hInstance = GetModuleHandleW(NULL);
@@ -326,7 +326,7 @@ static DWORD WINAPI detectCDThread(LPVOID lpParameter)
class_atom = RegisterClassExA(&wce);
if (class_atom == 0)
{
initialDiscDetectionComplete = 1; /* let main thread go on. */
SetEvent(initialDiscDetectionComplete); /* let main thread go on. */
return 0;
} /* if */

@@ -336,7 +336,7 @@ static DWORD WINAPI detectCDThread(LPVOID lpParameter)

if (detectCDHwnd == NULL)
{
initialDiscDetectionComplete = 1; /* let main thread go on. */
SetEvent(initialDiscDetectionComplete); /* let main thread go on. */
UnregisterClassA(classname, hInstance);
return 0;
} /* if */
@@ -345,8 +345,8 @@ static DWORD WINAPI detectCDThread(LPVOID lpParameter)

/* Do initial detection, possibly blocking awhile... */
drivesWithMediaBitmap = pollDiscDrives();
/* !!! FIXME: atomic operation, please. */
initialDiscDetectionComplete = 1; /* let main thread go on. */

SetEvent(initialDiscDetectionComplete); /* let main thread go on. */

do
{
@@ -390,13 +390,18 @@ static void detectAvailableCDs(PHYSFS_StringCallback cb, void *data)
*/
if (!detectCDThreadHandle)
{
initialDiscDetectionComplete = 0;
detectCDThreadHandle = CreateThread(NULL,0,detectCDThread,NULL,0,NULL);
if (detectCDThreadHandle == NULL)
HANDLE initialDetectDone = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!initialDetectDone)
return; /* oh well. */

while (!initialDiscDetectionComplete)
Sleep(50);
detectCDThreadHandle = CreateThread(NULL, 0, detectCDThread,
&initialDetectDone, 0, NULL);
if (detectCDThreadHandle)
WaitForSingleObject(initialDetectDone, INFINITE);
CloseHandle(initialDetectDone);

if (!detectCDThreadHandle)
return; /* oh well. */
} /* if */

drives = drivesWithMediaBitmap; /* whatever the thread has seen, we take. */
@@ -418,7 +423,6 @@ static void deinitCDThread(void)
PostMessageW(detectCDHwnd, WM_QUIT, 0, 0);
CloseHandle(detectCDThreadHandle);
detectCDThreadHandle = NULL;
initialDiscDetectionComplete = 0;
drivesWithMediaBitmap = 0;
} /* if */
} /* deinitCDThread */

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