tls-demo.c

#include <windows.h>
#include <stdlib.h>

struct m_thread_info {
	DWORD tid;
};
typedef struct m_thread_info *pthread_t;

static DWORD mpv_tls_index = FLS_OUT_OF_INDEXES;

BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved)
{
	switch (reason) {
	case DLL_PROCESS_ATTACH:
		mpv_tls_index = FlsAlloc(NULL);
		if (mpv_tls_index == FLS_OUT_OF_INDEXES)
			return FALSE;
		break;
	case DLL_PROCESS_DETACH:
		if (mpv_tls_index != FLS_OUT_OF_INDEXES)
			FlsFree(mpv_tls_index);
		break;
	case DLL_THREAD_ATTACH: {
		struct m_thread_info *td = malloc(sizeof td);
		*td = (struct m_thread_info) { GetCurrentThreadId() };
		FlsSetValue(mpv_tls_index, td);
		break;
	}
	case DLL_THREAD_DETACH: {
		struct m_thread_info *td = FlsGetValue(mpv_tls_index);
		free(td);
		break;
	}
	}

	return TRUE;
}

pthread_t pthread_self(void)
{
	return FlsGetValue(mpv_tls_index);
}