diff options
Diffstat (limited to 'contrib/gcc/gthr-win32.h')
| -rw-r--r-- | contrib/gcc/gthr-win32.h | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/contrib/gcc/gthr-win32.h b/contrib/gcc/gthr-win32.h new file mode 100644 index 0000000..97d5a82 --- /dev/null +++ b/contrib/gcc/gthr-win32.h @@ -0,0 +1,509 @@ +/* Threads compatibility routines for libgcc2 and libobjc. */ +/* Compile this one with gcc. */ +/* Copyright (C) 1999, 2000, 2002 Free Software Foundation, Inc. + Contributed by Mumit Khan <khan@xraylith.wisc.edu>. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA +02111-1307, USA. */ + +/* As a special exception, if you link this library with other files, + some of which are compiled with GCC, to produce an executable, + this library does not by itself cause the resulting executable + to be covered by the GNU General Public License. + This exception does not however invalidate any other reasons why + the executable file might be covered by the GNU General Public License. */ + +#ifndef GCC_GTHR_WIN32_H +#define GCC_GTHR_WIN32_H + +/* Windows32 threads specific definitions. The windows32 threading model + does not map well into pthread-inspired gcc's threading model, and so + there are caveats one needs to be aware of. + + 1. The destructor supplied to __gthread_key_create is ignored for + generic x86-win32 ports. This will certainly cause memory leaks + due to unreclaimed eh contexts (sizeof (eh_context) is at least + 24 bytes for x86 currently). + + This memory leak may be significant for long-running applications + that make heavy use of C++ EH. + + However, Mingw runtime (version 0.3 or newer) provides a mechanism + to emulate pthreads key dtors; the runtime provides a special DLL, + linked in if -mthreads option is specified, that runs the dtors in + the reverse order of registration when each thread exits. If + -mthreads option is not given, a stub is linked in instead of the + DLL, which results in memory leak. Other x86-win32 ports can use + the same technique of course to avoid the leak. + + 2. The error codes returned are non-POSIX like, and cast into ints. + This may cause incorrect error return due to truncation values on + hw where sizeof (DWORD) > sizeof (int). + + 3. We might consider using Critical Sections instead of Windows32 + mutexes for better performance, but emulating __gthread_mutex_trylock + interface becomes more complicated (Win9x does not support + TryEnterCriticalSectioni, while NT does). + + The basic framework should work well enough. In the long term, GCC + needs to use Structured Exception Handling on Windows32. */ + +#define __GTHREADS 1 + +#include <errno.h> +#ifdef __MINGW32__ +#include <_mingw.h> +#endif + +#ifdef _LIBOBJC + +/* This is necessary to prevent windef.h (included from windows.h) from + defining it's own BOOL as a typedef. */ +#ifndef __OBJC__ +#define __OBJC__ +#endif +#include <windows.h> +/* Now undef the windows BOOL. */ +#undef BOOL + +/* Key structure for maintaining thread specific storage */ +static DWORD __gthread_objc_data_tls = (DWORD)-1; + +/* Backend initialization functions */ + +/* Initialize the threads subsystem. */ +int +__gthread_objc_init_thread_system(void) +{ + /* Initialize the thread storage key */ + if ((__gthread_objc_data_tls = TlsAlloc()) != (DWORD)-1) + return 0; + else + return -1; +} + +/* Close the threads subsystem. */ +int +__gthread_objc_close_thread_system(void) +{ + if (__gthread_objc_data_tls != (DWORD)-1) + TlsFree(__gthread_objc_data_tls); + return 0; +} + +/* Backend thread functions */ + +/* Create a new thread of execution. */ +objc_thread_t +__gthread_objc_thread_detach(void (*func)(void *arg), void *arg) +{ + DWORD thread_id = 0; + HANDLE win32_handle; + + if (!(win32_handle = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)func, + arg, 0, &thread_id))) + thread_id = 0; + + return (objc_thread_t)thread_id; +} + +/* Set the current thread's priority. */ +int +__gthread_objc_thread_set_priority(int priority) +{ + int sys_priority = 0; + + switch (priority) + { + case OBJC_THREAD_INTERACTIVE_PRIORITY: + sys_priority = THREAD_PRIORITY_NORMAL; + break; + default: + case OBJC_THREAD_BACKGROUND_PRIORITY: + sys_priority = THREAD_PRIORITY_BELOW_NORMAL; + break; + case OBJC_THREAD_LOW_PRIORITY: + sys_priority = THREAD_PRIORITY_LOWEST; + break; + } + + /* Change priority */ + if (SetThreadPriority(GetCurrentThread(), sys_priority)) + return 0; + else + return -1; +} + +/* Return the current thread's priority. */ +int +__gthread_objc_thread_get_priority(void) +{ + int sys_priority; + + sys_priority = GetThreadPriority(GetCurrentThread()); + + switch (sys_priority) + { + case THREAD_PRIORITY_HIGHEST: + case THREAD_PRIORITY_TIME_CRITICAL: + case THREAD_PRIORITY_ABOVE_NORMAL: + case THREAD_PRIORITY_NORMAL: + return OBJC_THREAD_INTERACTIVE_PRIORITY; + + default: + case THREAD_PRIORITY_BELOW_NORMAL: + return OBJC_THREAD_BACKGROUND_PRIORITY; + + case THREAD_PRIORITY_IDLE: + case THREAD_PRIORITY_LOWEST: + return OBJC_THREAD_LOW_PRIORITY; + } + + /* Couldn't get priority. */ + return -1; +} + +/* Yield our process time to another thread. */ +void +__gthread_objc_thread_yield(void) +{ + Sleep(0); +} + +/* Terminate the current thread. */ +int +__gthread_objc_thread_exit(void) +{ + /* exit the thread */ + ExitThread(__objc_thread_exit_status); + + /* Failed if we reached here */ + return -1; +} + +/* Returns an integer value which uniquely describes a thread. */ +objc_thread_t +__gthread_objc_thread_id(void) +{ + return (objc_thread_t)GetCurrentThreadId(); +} + +/* Sets the thread's local storage pointer. */ +int +__gthread_objc_thread_set_data(void *value) +{ + if (TlsSetValue(__gthread_objc_data_tls, value)) + return 0; + else + return -1; +} + +/* Returns the thread's local storage pointer. */ +void * +__gthread_objc_thread_get_data(void) +{ + DWORD lasterror; + void *ptr; + + lasterror = GetLastError(); + + ptr = TlsGetValue(__gthread_objc_data_tls); /* Return thread data. */ + + SetLastError( lasterror ); + + return ptr; +} + +/* Backend mutex functions */ + +/* Allocate a mutex. */ +int +__gthread_objc_mutex_allocate(objc_mutex_t mutex) +{ + if ((mutex->backend = (void *)CreateMutex(NULL, 0, NULL)) == NULL) + return -1; + else + return 0; +} + +/* Deallocate a mutex. */ +int +__gthread_objc_mutex_deallocate(objc_mutex_t mutex) +{ + CloseHandle((HANDLE)(mutex->backend)); + return 0; +} + +/* Grab a lock on a mutex. */ +int +__gthread_objc_mutex_lock(objc_mutex_t mutex) +{ + int status; + + status = WaitForSingleObject((HANDLE)(mutex->backend), INFINITE); + if (status != WAIT_OBJECT_0 && status != WAIT_ABANDONED) + return -1; + else + return 0; +} + +/* Try to grab a lock on a mutex. */ +int +__gthread_objc_mutex_trylock(objc_mutex_t mutex) +{ + int status; + + status = WaitForSingleObject((HANDLE)(mutex->backend), 0); + if (status != WAIT_OBJECT_0 && status != WAIT_ABANDONED) + return -1; + else + return 0; +} + +/* Unlock the mutex */ +int +__gthread_objc_mutex_unlock(objc_mutex_t mutex) +{ + if (ReleaseMutex((HANDLE)(mutex->backend)) == 0) + return -1; + else + return 0; +} + +/* Backend condition mutex functions */ + +/* Allocate a condition. */ +int +__gthread_objc_condition_allocate(objc_condition_t condition) +{ + /* Unimplemented. */ + return -1; +} + +/* Deallocate a condition. */ +int +__gthread_objc_condition_deallocate(objc_condition_t condition) +{ + /* Unimplemented. */ + return -1; +} + +/* Wait on the condition */ +int +__gthread_objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex) +{ + /* Unimplemented. */ + return -1; +} + +/* Wake up all threads waiting on this condition. */ +int +__gthread_objc_condition_broadcast(objc_condition_t condition) +{ + /* Unimplemented. */ + return -1; +} + +/* Wake up one thread waiting on this condition. */ +int +__gthread_objc_condition_signal(objc_condition_t condition) +{ + /* Unimplemented. */ + return -1; +} + +#else /* _LIBOBJC */ + +#include <windows.h> + +typedef DWORD __gthread_key_t; + +typedef struct { + int done; + long started; +} __gthread_once_t; + +typedef HANDLE __gthread_mutex_t; + +#define __GTHREAD_ONCE_INIT {FALSE, -1} +#define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function + +#if __MINGW32_MAJOR_VERSION >= 1 || \ + (__MINGW32_MAJOR_VERSION == 0 && __MINGW32_MINOR_VERSION > 2) +#define MINGW32_SUPPORTS_MT_EH 1 +#ifdef __cplusplus +extern "C" { +#endif +extern int __mingwthr_key_dtor (DWORD, void (*) (void *)); +#ifdef __cplusplus +} +#endif + +/* Mingw runtime >= v0.3 provides a magic variable that is set to non-zero + if -mthreads option was specified, or 0 otherwise. This is to get around + the lack of weak symbols in PE-COFF. */ +extern int _CRT_MT; +#endif + +static inline int +__gthread_active_p (void) +{ +#ifdef MINGW32_SUPPORTS_MT_EH + return _CRT_MT; +#else + return 1; +#endif +} + +static inline int +__gthread_once (__gthread_once_t *once, void (*func) (void)) +{ + if (! __gthread_active_p ()) + return -1; + else if (once == NULL || func == NULL) + return EINVAL; + + if (! once->done) + { + if (InterlockedIncrement (&(once->started)) == 0) + { + (*func) (); + once->done = TRUE; + } + else + { + /* Another thread is currently executing the code, so wait for it + to finish; yield the CPU in the meantime. If performance + does become an issue, the solution is to use an Event that + we wait on here (and set above), but that implies a place to + create the event before this routine is called. */ + while (! once->done) + Sleep (0); + } + } + + return 0; +} + +/* Windows32 thread local keys don't support destructors; this leads to + leaks, especially in threaded applications making extensive use of + C++ EH. Mingw uses a thread-support DLL to work-around this problem. */ +static inline int +__gthread_key_create (__gthread_key_t *key, void (*dtor) (void *)) +{ + int status = 0; + DWORD tls_index = TlsAlloc (); + if (tls_index != 0xFFFFFFFF) + { + *key = tls_index; +#ifdef MINGW32_SUPPORTS_MT_EH + /* Mingw runtime will run the dtors in reverse order for each thread + when the thread exits. */ + status = __mingwthr_key_dtor (*key, dtor); +#endif + } + else + status = (int) GetLastError (); + return status; +} + +/* Currently, this routine is called only for Mingw runtime, and if + -mthreads option is chosen to link in the thread support DLL. */ +static inline int +__gthread_key_dtor (__gthread_key_t key, void *ptr) +{ + /* Nothing needed. */ + return 0; +} + +static inline int +__gthread_key_delete (__gthread_key_t key) +{ + return (TlsFree (key) != 0) ? 0 : (int) GetLastError (); +} + +static inline void * +__gthread_getspecific (__gthread_key_t key) +{ + DWORD lasterror; + void *ptr; + + lasterror = GetLastError(); + + ptr = TlsGetValue(key); + + SetLastError( lasterror ); + + return ptr; +} + +static inline int +__gthread_setspecific (__gthread_key_t key, const void *ptr) +{ + return (TlsSetValue (key, (void*) ptr) != 0) ? 0 : (int) GetLastError (); +} + +static inline void +__gthread_mutex_init_function (__gthread_mutex_t *mutex) +{ + /* Create unnamed mutex with default security attr and no initial owner. */ + *mutex = CreateMutex (NULL, 0, NULL); +} + +static inline int +__gthread_mutex_lock (__gthread_mutex_t *mutex) +{ + int status = 0; + + if (__gthread_active_p ()) + { + if (WaitForSingleObject (*mutex, INFINITE) == WAIT_OBJECT_0) + status = 0; + else + status = 1; + } + return status; +} + +static inline int +__gthread_mutex_trylock (__gthread_mutex_t *mutex) +{ + int status = 0; + + if (__gthread_active_p ()) + { + if (WaitForSingleObject (*mutex, 0) == WAIT_OBJECT_0) + status = 0; + else + status = 1; + } + return status; +} + +static inline int +__gthread_mutex_unlock (__gthread_mutex_t *mutex) +{ + if (__gthread_active_p ()) + return (ReleaseMutex (*mutex) != 0) ? 0 : 1; + else + return 0; +} + +#endif /* _LIBOBJC */ + +#endif /* ! GCC_GTHR_WIN32_H */ + |
