/* This code implemented by Dag.Gruneau@elsa.preseco.comm.se */

/* Fast NonRecursiveMutex support by Yakov Markovitch, markovitch@iso.ru */

/* Eliminated some memory leaks, gsw@agere.com */

#include <windows.h>

#include <limits.h>

#ifdef HAVE_PROCESS_H

#include <process.h>

#endif

typedef struct NRMUTEX {

	LONG   owned ;

	DWORD  thread_id ;

	HANDLE hevent ;

} NRMUTEX, *PNRMUTEX ;

BOOL

InitializeNonRecursiveMutex(PNRMUTEX mutex)

{

	mutex->owned = -1 ;  /* No threads have entered NonRecursiveMutex */

	mutex->thread_id = 0 ;

	mutex->hevent = CreateEvent(NULL, FALSE, FALSE, NULL) ;

	return mutex->hevent != NULL ;	/* TRUE if the mutex is created */

}

VOID

DeleteNonRecursiveMutex(PNRMUTEX mutex)

{

	/* No in-use check */

	CloseHandle(mutex->hevent) ;

	mutex->hevent = NULL ; /* Just in case */

}

DWORD

EnterNonRecursiveMutex(PNRMUTEX mutex, BOOL wait)

{

	/* Assume that the thread waits successfully */

	DWORD ret ;

	/* InterlockedIncrement(&mutex->owned) == 0 means that no thread currently owns the mutex */

	if (!wait)

	{

		if (InterlockedCompareExchange(&mutex->owned, 0, -1) != -1)

			return WAIT_TIMEOUT ;

		ret = WAIT_OBJECT_0 ;

	}

	else

		ret = InterlockedIncrement(&mutex->owned) ?

			/* Some thread owns the mutex, let's wait... */

			WaitForSingleObject(mutex->hevent, INFINITE) : WAIT_OBJECT_0 ;

	mutex->thread_id = GetCurrentThreadId() ; /* We own it */

	return ret ;

}

BOOL

LeaveNonRecursiveMutex(PNRMUTEX mutex)

{

	/* We don't own the mutex */

	mutex->thread_id = 0 ;

	return

		InterlockedDecrement(&mutex->owned) < 0 ||

		SetEvent(mutex->hevent) ; /* Other threads are waiting, wake one on them up */

}

PNRMUTEX

AllocNonRecursiveMutex(void)

{

	PNRMUTEX mutex = (PNRMUTEX)malloc(sizeof(NRMUTEX)) ;

	if (mutex && !InitializeNonRecursiveMutex(mutex))

	{

		free(mutex) ;

		mutex = NULL ;

	}

	return mutex ;

}

void

FreeNonRecursiveMutex(PNRMUTEX mutex)

{

	if (mutex)

	{

		DeleteNonRecursiveMutex(mutex) ;

		free(mutex) ;

	}

}

long PyThread_get_thread_ident(void);

/*

 * Initialization of the C package, should not be needed.

 */

static void

PyThread__init_thread(void)

{

}

/*

 * Thread support.

 */

typedef struct {

	void (*func)(void*);

	void *arg;

	long id;

	HANDLE done;

} callobj;

static int

bootstrap(void *call)

{

	callobj *obj = (callobj*)call;

	/* copy callobj since other thread might free it before we're done */

	void (*func)(void*) = obj->func;

	void *arg = obj->arg;

	obj->id = PyThread_get_thread_ident();

	ReleaseSemaphore(obj->done, 1, NULL);

	func(arg);

	return 0;

}

long

PyThread_start_new_thread(void (*func)(void *), void *arg)

{

	Py_uintptr_t rv;

	callobj obj;

	dprintf(("%ld: PyThread_start_new_thread called\n",

		 PyThread_get_thread_ident()));

	if (!initialized)

		PyThread_init_thread();

	obj.id = -1;	/* guilty until proved innocent */

	obj.func = func;

	obj.arg = arg;

	obj.done = CreateSemaphore(NULL, 0, 1, NULL);

	if (obj.done == NULL)

		return -1;

	rv = _beginthread(bootstrap,

			  Py_SAFE_DOWNCAST(_pythread_stacksize,

					   Py_ssize_t, int),

			  &obj);

	if (rv == (Py_uintptr_t)-1) {

		/* I've seen errno == EAGAIN here, which means "there are

		 * too many threads".

		 */

		dprintf(("%ld: PyThread_start_new_thread failed: %p errno %d\n",

		         PyThread_get_thread_ident(), (void*)rv, errno));

		obj.id = -1;

	}

	else {

		dprintf(("%ld: PyThread_start_new_thread succeeded: %p\n",

		         PyThread_get_thread_ident(), (void*)rv));

		/* wait for thread to initialize, so we can get its id */

		WaitForSingleObject(obj.done, INFINITE);

		assert(obj.id != -1);

	}

	CloseHandle((HANDLE)obj.done);

	return obj.id;

}

/*

 * Return the thread Id instead of an handle. The Id is said to uniquely identify the

 * thread in the system

 */

long

PyThread_get_thread_ident(void)

{

	if (!initialized)

		PyThread_init_thread();

	return GetCurrentThreadId();

}

static void

do_PyThread_exit_thread(int no_cleanup)

{

	dprintf(("%ld: PyThread_exit_thread called\n", PyThread_get_thread_ident()));

	if (!initialized)

		if (no_cleanup)

			_exit(0);

		else

			exit(0);

	_endthread();

}

void

PyThread_exit_thread(void)

{

	do_PyThread_exit_thread(0);

}

void

PyThread__exit_thread(void)

{

	do_PyThread_exit_thread(1);

}

#ifndef NO_EXIT_PROG

static void

do_PyThread_exit_prog(int status, int no_cleanup)

{

	dprintf(("PyThread_exit_prog(%d) called\n", status));

	if (!initialized)

		if (no_cleanup)

			_exit(status);

		else

			exit(status);

}

void

PyThread_exit_prog(int status)

{

	do_PyThread_exit_prog(status, 0);

}

void

PyThread__exit_prog(int status)

{

	do_PyThread_exit_prog(status, 1);

}

#endif /* NO_EXIT_PROG */

/*

 * Lock support. It has too be implemented as semaphores.

 * I [Dag] tried to implement it with mutex but I could find a way to

 * tell whether a thread already own the lock or not.

 */

PyThread_type_lock

PyThread_allocate_lock(void)

{

	PNRMUTEX aLock;

	dprintf(("PyThread_allocate_lock called\n"));

	if (!initialized)

		PyThread_init_thread();

	aLock = AllocNonRecursiveMutex() ;

	dprintf(("%ld: PyThread_allocate_lock() -> %p\n", PyThread_get_thread_ident(), aLock));

	return (PyThread_type_lock) aLock;

}

void

PyThread_free_lock(PyThread_type_lock aLock)

{

	dprintf(("%ld: PyThread_free_lock(%p) called\n", PyThread_get_thread_ident(),aLock));

	FreeNonRecursiveMutex(aLock) ;

}

/*

 * Return 1 on success if the lock was acquired

 *

 * and 0 if the lock was not acquired. This means a 0 is returned

 * if the lock has already been acquired by this thread!

 */

int

PyThread_acquire_lock(PyThread_type_lock aLock, int waitflag)

{

	int success ;

	dprintf(("%ld: PyThread_acquire_lock(%p, %d) called\n", PyThread_get_thread_ident(),aLock, waitflag));

	success = aLock && EnterNonRecursiveMutex((PNRMUTEX) aLock, (waitflag ? INFINITE : 0)) == WAIT_OBJECT_0 ;

	dprintf(("%ld: PyThread_acquire_lock(%p, %d) -> %d\n", PyThread_get_thread_ident(),aLock, waitflag, success));

	return success;

}

void

PyThread_release_lock(PyThread_type_lock aLock)

{

	dprintf(("%ld: PyThread_release_lock(%p) called\n", PyThread_get_thread_ident(),aLock));

	if (!(aLock && LeaveNonRecursiveMutex((PNRMUTEX) aLock)))

		dprintf(("%ld: Could not PyThread_release_lock(%p) error: %ld\n", PyThread_get_thread_ident(), aLock, GetLastError()));

}

/* minimum/maximum thread stack sizes supported */

#define THREAD_MIN_STACKSIZE	0x8000		/* 32kB */

#define THREAD_MAX_STACKSIZE	0x10000000	/* 256MB */

/* set the thread stack size.

 * Return 0 if size is valid, -1 otherwise.

 */

static int

_pythread_nt_set_stacksize(size_t size)

{

	/* set to default */

	if (size == 0) {

		_pythread_stacksize = 0;

		return 0;

	}

	/* valid range? */

	if (size >= THREAD_MIN_STACKSIZE && size < THREAD_MAX_STACKSIZE) {

		_pythread_stacksize = size;

		return 0;

	}

	return -1;

}

#define THREAD_SET_STACKSIZE(x)	_pythread_nt_set_stacksize(x)