support fetching current interpreter from TLS under useithreads
[perl.git] / win32 / win32thread.h
1 #ifndef _WIN32THREAD_H
2 #define _WIN32THREAD_H
3
4 #include "win32.h"
5
6 typedef struct win32_cond { LONG waiters; HANDLE sem; } perl_cond;
7 typedef DWORD perl_key;
8 typedef HANDLE perl_os_thread;
9
10 #ifndef DONT_USE_CRITICAL_SECTION
11
12 /* Critical Sections used instead of mutexes: lightweight,
13  * but can't be communicated to child processes, and can't get
14  * HANDLE to it for use elsewhere.
15  */
16 typedef CRITICAL_SECTION perl_mutex;
17 #define MUTEX_INIT(m) InitializeCriticalSection(m)
18 #define MUTEX_LOCK(m) EnterCriticalSection(m)
19 #define MUTEX_UNLOCK(m) LeaveCriticalSection(m)
20 #define MUTEX_LOCK_NOCONTEXT(m) EnterCriticalSection(m)
21 #define MUTEX_UNLOCK_NOCONTEXT(m) LeaveCriticalSection(m)
22 #define MUTEX_DESTROY(m) DeleteCriticalSection(m)
23
24 #else
25
26 typedef HANDLE perl_mutex;
27 #  define MUTEX_INIT(m) \
28     STMT_START {                                                \
29         if ((*(m) = CreateMutex(NULL,FALSE,NULL)) == NULL)      \
30             Perl_croak(aTHX_ "panic: MUTEX_INIT");              \
31     } STMT_END
32
33 #  define MUTEX_LOCK(m) \
34     STMT_START {                                                \
35         if (WaitForSingleObject(*(m),INFINITE) == WAIT_FAILED)  \
36             Perl_croak(aTHX_ "panic: MUTEX_LOCK");              \
37     } STMT_END
38
39 #  define MUTEX_UNLOCK(m) \
40     STMT_START {                                                \
41         if (ReleaseMutex(*(m)) == 0)                            \
42             Perl_croak(aTHX_ "panic: MUTEX_UNLOCK");            \
43     } STMT_END
44
45 #  define MUTEX_LOCK_NOCONTEXT(m) \
46     STMT_START {                                                \
47         if (WaitForSingleObject(*(m),INFINITE) == WAIT_FAILED)  \
48             Perl_croak_nocontext("panic: MUTEX_LOCK");          \
49     } STMT_END
50
51 #  define MUTEX_UNLOCK_NOCONTEXT(m) \
52     STMT_START {                                                \
53         if (ReleaseMutex(*(m)) == 0)                            \
54             Perl_croak_nocontext("panic: MUTEX_UNLOCK");        \
55     } STMT_END
56
57 #  define MUTEX_DESTROY(m) \
58     STMT_START {                                                \
59         if (CloseHandle(*(m)) == 0)                             \
60             Perl_croak(aTHX_ "panic: MUTEX_DESTROY");           \
61     } STMT_END
62
63 #endif
64
65 /* These macros assume that the mutex associated with the condition
66  * will always be held before COND_{SIGNAL,BROADCAST,WAIT,DESTROY},
67  * so there's no separate mutex protecting access to (c)->waiters
68  */
69 #define COND_INIT(c) \
70     STMT_START {                                                \
71         (c)->waiters = 0;                                       \
72         (c)->sem = CreateSemaphore(NULL,0,LONG_MAX,NULL);       \
73         if ((c)->sem == NULL)                                   \
74             Perl_croak(aTHX_ "panic: COND_INIT (%ld)",GetLastError());  \
75     } STMT_END
76
77 #define COND_SIGNAL(c) \
78     STMT_START {                                                \
79         if ((c)->waiters > 0 &&                                 \
80             ReleaseSemaphore((c)->sem,1,NULL) == 0)             \
81             Perl_croak(aTHX_ "panic: COND_SIGNAL (%ld)",GetLastError());        \
82     } STMT_END
83
84 #define COND_BROADCAST(c) \
85     STMT_START {                                                \
86         if ((c)->waiters > 0 &&                                 \
87             ReleaseSemaphore((c)->sem,(c)->waiters,NULL) == 0)  \
88             Perl_croak(aTHX_ "panic: COND_BROADCAST (%ld)",GetLastError());\
89     } STMT_END
90
91 #define COND_WAIT(c, m) \
92     STMT_START {                                                \
93         (c)->waiters++;                                         \
94         MUTEX_UNLOCK(m);                                        \
95         /* Note that there's no race here, since a              \
96          * COND_BROADCAST() on another thread will have seen the\
97          * right number of waiters (i.e. including this one) */ \
98         if (WaitForSingleObject((c)->sem,INFINITE)==WAIT_FAILED)\
99             Perl_croak(aTHX_ "panic: COND_WAIT (%ld)",GetLastError());  \
100         /* XXX there may be an inconsequential race here */     \
101         MUTEX_LOCK(m);                                          \
102         (c)->waiters--;                                         \
103     } STMT_END
104
105 #define COND_DESTROY(c) \
106     STMT_START {                                                \
107         (c)->waiters = 0;                                       \
108         if (CloseHandle((c)->sem) == 0)                         \
109             Perl_croak(aTHX_ "panic: COND_DESTROY (%ld)",GetLastError());       \
110     } STMT_END
111
112 #define DETACH(t) \
113     STMT_START {                                                \
114         if (CloseHandle((t)->self) == 0) {                      \
115             MUTEX_UNLOCK(&(t)->mutex);                          \
116             Perl_croak(aTHX_ "panic: DETACH");                          \
117         }                                                       \
118     } STMT_END
119
120
121 #define THREAD_CREATE(t, f)     Perl_thread_create(t, f)
122 #define THREAD_POST_CREATE(t)   NOOP
123
124 /* XXX Docs mention that the RTL versions of thread creation routines
125  * should be used, but that advice only seems applicable when the RTL
126  * is not in a DLL.  RTL DLLs in both Borland and VC seem to do all of
127  * the init/deinit required upon DLL_THREAD_ATTACH/DETACH.  So we seem
128  * to be completely safe using straight Win32 API calls, rather than
129  * the much braindamaged RTL calls.
130  *
131  * _beginthread() in the RTLs call CloseHandle() just after the thread
132  * function returns, which means: 1) we have a race on our hands
133  * 2) it is impossible to implement join() semantics.
134  *
135  * IOW, do *NOT* turn on USE_RTL_THREAD_API!  It is here
136  * for experimental purposes only. GSAR 98-01-02
137  */
138 #ifdef USE_RTL_THREAD_API
139 #  include <process.h>
140 #  if defined(__BORLANDC__)
141      /* Borland RTL doesn't allow a return value from thread function! */
142 #    define THREAD_RET_TYPE     void _USERENTRY
143 #    define THREAD_RET_CAST(p)  ((void)(thr->i.retv = (void *)(p)))
144 #  elif defined (_MSC_VER)
145 #    define THREAD_RET_TYPE     unsigned __stdcall
146 #    define THREAD_RET_CAST(p)  ((unsigned)(p))
147 #  else
148      /* CRTDLL.DLL doesn't allow a return value from thread function! */
149 #    define THREAD_RET_TYPE     void __cdecl
150 #    define THREAD_RET_CAST(p)  ((void)(thr->i.retv = (void *)(p)))
151 #  endif
152 #else   /* !USE_RTL_THREAD_API */
153 #  define THREAD_RET_TYPE       DWORD WINAPI
154 #  define THREAD_RET_CAST(p)    ((DWORD)(p))
155 #endif  /* !USE_RTL_THREAD_API */
156
157 typedef THREAD_RET_TYPE thread_func_t(void *);
158
159
160 START_EXTERN_C
161
162 #if defined(PERLDLL) && defined(USE_DECLSPEC_THREAD) && (!defined(__BORLANDC__) || defined(_DLL))
163 extern __declspec(thread) void *PL_current_context;
164 #define PERL_SET_CONTEXT(t)             (PL_current_context = t)
165 #define PERL_GET_CONTEXT                PL_current_context
166 #else
167 #define PERL_GET_CONTEXT                Perl_get_context()
168 #define PERL_SET_CONTEXT(t)             Perl_set_context(t)
169 #endif
170
171 #define PERL_GET_CONTEXT_DEFINED
172
173 #if defined(USE_THREADS)
174 struct perl_thread;
175 int Perl_thread_create (struct perl_thread *thr, thread_func_t *fn);
176 void Perl_set_thread_self (struct perl_thread *thr);
177 void Perl_init_thread_intern (struct perl_thread *t);
178
179 #define SET_THREAD_SELF(thr) Perl_set_thread_self(thr)
180
181 #endif /* USE_THREADS */
182
183 END_EXTERN_C
184
185 #define INIT_THREADS            NOOP
186 #define ALLOC_THREAD_KEY \
187     STMT_START {                                                        \
188         if ((PL_thr_key = TlsAlloc()) == TLS_OUT_OF_INDEXES)            \
189             Perl_croak_nocontext("panic: TlsAlloc");                    \
190     } STMT_END
191
192 #if defined(USE_RTL_THREAD_API) && !defined(_MSC_VER)
193 #define JOIN(t, avp)                                                    \
194     STMT_START {                                                        \
195         if ((WaitForSingleObject((t)->self,INFINITE) == WAIT_FAILED)    \
196              || (GetExitCodeThread((t)->self,(LPDWORD)(avp)) == 0)      \
197              || (CloseHandle((t)->self) == 0))                          \
198             Perl_croak(aTHX_ "panic: JOIN");                                    \
199         *avp = (AV *)((t)->i.retv);                                     \
200     } STMT_END
201 #else   /* !USE_RTL_THREAD_API || _MSC_VER */
202 #define JOIN(t, avp)                                                    \
203     STMT_START {                                                        \
204         if ((WaitForSingleObject((t)->self,INFINITE) == WAIT_FAILED)    \
205              || (GetExitCodeThread((t)->self,(LPDWORD)(avp)) == 0)      \
206              || (CloseHandle((t)->self) == 0))                          \
207             Perl_croak(aTHX_ "panic: JOIN");                            \
208     } STMT_END
209 #endif  /* !USE_RTL_THREAD_API || _MSC_VER */
210
211 #define YIELD                   Sleep(0)
212
213 #endif /* _WIN32THREAD_H */
214