add hg and python

1 files changed, 364 insertions, 0 deletions

diff --git a/sys/src/cmd/python/Python/thread_nt.h b/sys/src/cmd/python/Python/thread_nt.h
new file mode 100644
index 000000000..67f5ed517
--- /dev/null
+++ b/sys/src/cmd/python/Python/thread_nt.h
@@ -0,0 +1,364 @@
+
+/* 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 ;
+
+typedef PVOID WINAPI interlocked_cmp_xchg_t(PVOID *dest, PVOID exc, PVOID comperand) ;
+
+/* Sorry mate, but we haven't got InterlockedCompareExchange in Win95! */
+static PVOID WINAPI
+interlocked_cmp_xchg(PVOID *dest, PVOID exc, PVOID comperand)
+{
+	static LONG spinlock = 0 ;
+	PVOID result ;
+	DWORD dwSleep = 0;
+
+	/* Acqire spinlock (yielding control to other threads if cant aquire for the moment) */
+	while(InterlockedExchange(&spinlock, 1))
+	{
+		// Using Sleep(0) can cause a priority inversion.
+		// Sleep(0) only yields the processor if there's
+		// another thread of the same priority that's
+		// ready to run.  If a high-priority thread is
+		// trying to acquire the lock, which is held by
+		// a low-priority thread, then the low-priority
+		// thread may never get scheduled and hence never
+		// free the lock.  NT attempts to avoid priority
+		// inversions by temporarily boosting the priority
+		// of low-priority runnable threads, but the problem
+		// can still occur if there's a medium-priority
+		// thread that's always runnable.  If Sleep(1) is used,
+		// then the thread unconditionally yields the CPU.  We
+		// only do this for the second and subsequent even
+		// iterations, since a millisecond is a long time to wait
+		// if the thread can be scheduled in again sooner
+		// (~100,000 instructions).
+		// Avoid priority inversion: 0, 1, 0, 1,...
+		Sleep(dwSleep);
+		dwSleep = !dwSleep;
+	}
+	result = *dest ;
+	if (result == comperand)
+		*dest = exc ;
+	/* Release spinlock */
+	spinlock = 0 ;
+	return result ;
+} ;
+
+static interlocked_cmp_xchg_t *ixchg;
+
+BOOL
+InitializeNonRecursiveMutex(PNRMUTEX mutex)
+{
+	if (!ixchg)
+	{
+		/* Sorely, Win95 has no InterlockedCompareExchange API (Win98 has), so we have to use emulation */
+		HANDLE kernel = GetModuleHandle("kernel32.dll") ;
+		if (!kernel || (ixchg = (interlocked_cmp_xchg_t *)GetProcAddress(kernel, "InterlockedCompareExchange")) == NULL)
+			ixchg = interlocked_cmp_xchg ;
+	}
+
+	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 */
+}
+
+#ifdef InterlockedCompareExchange
+#undef InterlockedCompareExchange
+#endif
+#define InterlockedCompareExchange(dest,exchange,comperand) (ixchg((dest), (exchange), (comperand)))
+
+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((PVOID *)&mutex->owned, (PVOID)0, (PVOID)-1) != (PVOID)-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, _pythread_stacksize, &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(), rv, errno));
+		obj.id = -1;
+	}
+	else {
+		dprintf(("%ld: PyThread_start_new_thread succeeded: %p\n",
+		         PyThread_get_thread_ident(), 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: %l\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)