1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2  *
3  * ***** BEGIN LICENSE BLOCK *****
4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5  *
6  * The contents of this file are subject to the Mozilla Public License Version
7  * 1.1 (the "License"); you may not use this file except in compliance with
8  * the License. You may obtain a copy of the License at
9  * http://www.mozilla.org/MPL/
10  *
11  * Software distributed under the License is distributed on an "AS IS" basis,
12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13  * for the specific language governing rights and limitations under the
14  * License.
15  *
16  * The Original Code is Mozilla Communicator client code, released
17  * March 31, 1998.
18  *
19  * The Initial Developer of the Original Code is
20  * Netscape Communications Corporation.
21  * Portions created by the Initial Developer are Copyright (C) 1998
22  * the Initial Developer. All Rights Reserved.
23  *
24  * Contributor(s):
25  *
26  * Alternatively, the contents of this file may be used under the terms of
27  * either of the GNU General Public License Version 2 or later (the "GPL"),
28  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29  * in which case the provisions of the GPL or the LGPL are applicable instead
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35  * the provisions above, a recipient may use your version of this file under
36  * the terms of any one of the MPL, the GPL or the LGPL.
37  *
38  * ***** END LICENSE BLOCK ***** */
39 #ifndef jslock_h__
40 #define jslock_h__
41 
42 #ifdef JS_THREADSAFE
43 
44 #include "jstypes.h"
45 #include "pratom.h"
46 #include "prlock.h"
47 #include "prcvar.h"
48 #include "prthread.h"
49 
50 #include "jsprvtd.h"    /* for JSScope, etc. */
51 #include "jspubtd.h"    /* for JSRuntime, etc. */
52 
53 #define Thin_GetWait(W) ((jsword)(W) & 0x1)
54 #define Thin_SetWait(W) ((jsword)(W) | 0x1)
55 #define Thin_RemoveWait(W) ((jsword)(W) & ~0x1)
56 
57 typedef struct JSFatLock JSFatLock;
58 
59 struct JSFatLock {
60     int         susp;
61     PRLock      *slock;
62     PRCondVar   *svar;
63     JSFatLock   *next;
64     JSFatLock   **prevp;
65 };
66 
67 typedef struct JSThinLock {
68     jsword      owner;
69     JSFatLock   *fat;
70 } JSThinLock;
71 
72 #define CX_THINLOCK_ID(cx)       ((jsword)(cx)->thread)
73 #define CURRENT_THREAD_IS_ME(me) (((JSThread *)me)->id == js_CurrentThreadId())
74 
75 typedef PRLock JSLock;
76 
77 typedef struct JSFatLockTable {
78     JSFatLock   *free;
79     JSFatLock   *taken;
80 } JSFatLockTable;
81 
82 /*
83  * Atomic increment and decrement for a reference counter, given jsrefcount *p.
84  * NB: jsrefcount is int32, aka PRInt32, so that pratom.h functions work.
85  */
86 #define JS_ATOMIC_INCREMENT(p)      PR_AtomicIncrement((PRInt32 *)(p))
87 #define JS_ATOMIC_DECREMENT(p)      PR_AtomicDecrement((PRInt32 *)(p))
88 #define JS_ATOMIC_ADD(p,v)          PR_AtomicAdd((PRInt32 *)(p), (PRInt32)(v))
89 
90 #define js_CurrentThreadId()        (jsword)PR_GetCurrentThread()
91 #define JS_NEW_LOCK()               PR_NewLock()
92 #define JS_DESTROY_LOCK(l)          PR_DestroyLock(l)
93 #define JS_ACQUIRE_LOCK(l)          PR_Lock(l)
94 #define JS_RELEASE_LOCK(l)          PR_Unlock(l)
95 #define JS_LOCK0(P,M)               js_Lock(P,M)
96 #define JS_UNLOCK0(P,M)             js_Unlock(P,M)
97 
98 #define JS_NEW_CONDVAR(l)           PR_NewCondVar(l)
99 #define JS_DESTROY_CONDVAR(cv)      PR_DestroyCondVar(cv)
100 #define JS_WAIT_CONDVAR(cv,to)      PR_WaitCondVar(cv,to)
101 #define JS_NO_TIMEOUT               PR_INTERVAL_NO_TIMEOUT
102 #define JS_NOTIFY_CONDVAR(cv)       PR_NotifyCondVar(cv)
103 #define JS_NOTIFY_ALL_CONDVAR(cv)   PR_NotifyAllCondVar(cv)
104 
105 /*
106  * Include jsscope.h so JS_LOCK_OBJ macro callers don't have to include it.
107  * Since there is a JSThinLock member in JSScope, we can't nest this include
108  * much earlier (see JSThinLock's typedef, above).  Yes, that means there is
109  * an #include cycle between jslock.h and jsscope.h: moderate-sized XXX here,
110  * to be fixed by moving JS_LOCK_SCOPE to jsscope.h, JS_LOCK_OBJ to jsobj.h,
111  * and so on.
112  */
113 #include "jsscope.h"
114 
115 #define JS_LOCK_RUNTIME(rt)         js_LockRuntime(rt)
116 #define JS_UNLOCK_RUNTIME(rt)       js_UnlockRuntime(rt)
117 
118 /*
119  * NB: The JS_LOCK_OBJ and JS_UNLOCK_OBJ macros work *only* on native objects
120  * (objects for which OBJ_IS_NATIVE returns true).  All uses of these macros in
121  * the engine are predicated on OBJ_IS_NATIVE or equivalent checks.  These uses
122  * are for optimizations above the JSObjectOps layer, under which object locks
123  * normally hide.
124  */
125 #define JS_LOCK_OBJ(cx,obj)         ((OBJ_SCOPE(obj)->ownercx == (cx))        \
126                                      ? (void)0                                \
127                                      : (js_LockObj(cx, obj)))
128 #define JS_UNLOCK_OBJ(cx,obj)       ((OBJ_SCOPE(obj)->ownercx == (cx))        \
129                                      ? (void)0 : js_UnlockObj(cx, obj))
130 
131 #define JS_LOCK_SCOPE(cx,scope)     ((scope)->ownercx == (cx) ? (void)0       \
132                                      : js_LockScope(cx, scope))
133 #define JS_UNLOCK_SCOPE(cx,scope)   ((scope)->ownercx == (cx) ? (void)0       \
134                                      : js_UnlockScope(cx, scope))
135 #define JS_TRANSFER_SCOPE_LOCK(cx, scope, newscope)                           \
136                                     js_TransferScopeLock(cx, scope, newscope)
137 
138 extern void js_LockRuntime(JSRuntime *rt);
139 extern void js_UnlockRuntime(JSRuntime *rt);
140 extern void js_LockObj(JSContext *cx, JSObject *obj);
141 extern void js_UnlockObj(JSContext *cx, JSObject *obj);
142 extern void js_LockScope(JSContext *cx, JSScope *scope);
143 extern void js_UnlockScope(JSContext *cx, JSScope *scope);
144 extern int js_SetupLocks(int,int);
145 extern void js_CleanupLocks();
146 extern void js_TransferScopeLock(JSContext *, JSScope *, JSScope *);
147 extern JS_FRIEND_API(jsval)
148 js_GetSlotThreadSafe(JSContext *, JSObject *, uint32);
149 extern void js_SetSlotThreadSafe(JSContext *, JSObject *, uint32, jsval);
150 extern void js_InitLock(JSThinLock *);
151 extern void js_FinishLock(JSThinLock *);
152 extern void js_FinishSharingScope(JSRuntime *rt, JSScope *scope);
153 
154 #ifdef DEBUG
155 
156 #define JS_IS_RUNTIME_LOCKED(rt)        js_IsRuntimeLocked(rt)
157 #define JS_IS_OBJ_LOCKED(cx,obj)        js_IsObjLocked(cx,obj)
158 #define JS_IS_SCOPE_LOCKED(cx,scope)    js_IsScopeLocked(cx,scope)
159 
160 extern JSBool js_IsRuntimeLocked(JSRuntime *rt);
161 extern JSBool js_IsObjLocked(JSContext *cx, JSObject *obj);
162 extern JSBool js_IsScopeLocked(JSContext *cx, JSScope *scope);
163 
164 #else
165 
166 #define JS_IS_RUNTIME_LOCKED(rt)        0
167 #define JS_IS_OBJ_LOCKED(cx,obj)        1
168 #define JS_IS_SCOPE_LOCKED(cx,scope)    1
169 
170 #endif /* DEBUG */
171 
172 #define JS_LOCK_OBJ_VOID(cx, obj, e)                                          \
173     JS_BEGIN_MACRO                                                            \
174         JS_LOCK_OBJ(cx, obj);                                                 \
175         e;                                                                    \
176         JS_UNLOCK_OBJ(cx, obj);                                               \
177     JS_END_MACRO
178 
179 #define JS_LOCK_VOID(cx, e)                                                   \
180     JS_BEGIN_MACRO                                                            \
181         JSRuntime *_rt = (cx)->runtime;                                       \
182         JS_LOCK_RUNTIME_VOID(_rt, e);                                         \
183     JS_END_MACRO
184 
185 /* FIXME: bug 353962 hackaround */
186 #define JS_USE_ONLY_NSPR_LOCKS  1
187 
188 #if defined(JS_USE_ONLY_NSPR_LOCKS) ||                                        \
189     !( (defined(_WIN32) && defined(_M_IX86)) ||                               \
190        (defined(__GNUC__) && defined(__i386__)) ||                            \
191        ((defined(__USLC__) || defined(_SCO_DS)) && defined(i386)) ||          \
192        (defined(SOLARIS) && defined(sparc) && defined(ULTRA_SPARC)) ||        \
193        defined(AIX) )
194 
195 #define NSPR_LOCK 1
196 
197 #undef JS_LOCK0
198 #undef JS_UNLOCK0
199 #define JS_LOCK0(P,M)   (JS_ACQUIRE_LOCK(((JSLock*)(P)->fat)), (P)->owner = (M))
200 #define JS_UNLOCK0(P,M) ((P)->owner = 0, JS_RELEASE_LOCK(((JSLock*)(P)->fat)))
201 
202 #else  /* arch-tests */
203 
204 #undef NSPR_LOCK
205 
206 extern JS_INLINE void js_Lock(JSThinLock *tl, jsword me);
207 extern JS_INLINE void js_Unlock(JSThinLock *tl, jsword me);
208 
209 #endif /* arch-tests */
210 
211 #else  /* !JS_THREADSAFE */
212 
213 #define JS_ATOMIC_INCREMENT(p)      (++*(p))
214 #define JS_ATOMIC_DECREMENT(p)      (--*(p))
215 #define JS_ATOMIC_ADD(p,v)          (*(p) += (v))
216 
217 #define JS_CurrentThreadId() 0
218 #define JS_NEW_LOCK()               NULL
219 #define JS_DESTROY_LOCK(l)          ((void)0)
220 #define JS_ACQUIRE_LOCK(l)          ((void)0)
221 #define JS_RELEASE_LOCK(l)          ((void)0)
222 #define JS_LOCK0(P,M)               ((void)0)
223 #define JS_UNLOCK0(P,M)             ((void)0)
224 
225 #define JS_NEW_CONDVAR(l)           NULL
226 #define JS_DESTROY_CONDVAR(cv)      ((void)0)
227 #define JS_WAIT_CONDVAR(cv,to)      ((void)0)
228 #define JS_NOTIFY_CONDVAR(cv)       ((void)0)
229 #define JS_NOTIFY_ALL_CONDVAR(cv)   ((void)0)
230 
231 #define JS_LOCK_RUNTIME(rt)         ((void)0)
232 #define JS_UNLOCK_RUNTIME(rt)       ((void)0)
233 #define JS_LOCK_OBJ(cx,obj)         ((void)0)
234 #define JS_UNLOCK_OBJ(cx,obj)       ((void)0)
235 #define JS_LOCK_OBJ_VOID(cx,obj,e)  (e)
236 #define JS_LOCK_SCOPE(cx,scope)     ((void)0)
237 #define JS_UNLOCK_SCOPE(cx,scope)   ((void)0)
238 #define JS_TRANSFER_SCOPE_LOCK(c,o,n) ((void)0)
239 
240 #define JS_IS_RUNTIME_LOCKED(rt)        1
241 #define JS_IS_OBJ_LOCKED(cx,obj)        1
242 #define JS_IS_SCOPE_LOCKED(cx,scope)    1
243 #define JS_LOCK_VOID(cx, e)             JS_LOCK_RUNTIME_VOID((cx)->runtime, e)
244 
245 #endif /* !JS_THREADSAFE */
246 
247 #define JS_LOCK_RUNTIME_VOID(rt,e)                                            \
248     JS_BEGIN_MACRO                                                            \
249         JS_LOCK_RUNTIME(rt);                                                  \
250         e;                                                                    \
251         JS_UNLOCK_RUNTIME(rt);                                                \
252     JS_END_MACRO
253 
254 #define JS_LOCK_GC(rt)              JS_ACQUIRE_LOCK((rt)->gcLock)
255 #define JS_UNLOCK_GC(rt)            JS_RELEASE_LOCK((rt)->gcLock)
256 #define JS_LOCK_GC_VOID(rt,e)       (JS_LOCK_GC(rt), (e), JS_UNLOCK_GC(rt))
257 #define JS_AWAIT_GC_DONE(rt)        JS_WAIT_CONDVAR((rt)->gcDone, JS_NO_TIMEOUT)
258 #define JS_NOTIFY_GC_DONE(rt)       JS_NOTIFY_ALL_CONDVAR((rt)->gcDone)
259 #define JS_AWAIT_REQUEST_DONE(rt)   JS_WAIT_CONDVAR((rt)->requestDone,        \
260                                                     JS_NO_TIMEOUT)
261 #define JS_NOTIFY_REQUEST_DONE(rt)  JS_NOTIFY_CONDVAR((rt)->requestDone)
262 
263 #define JS_LOCK(P,CX)               JS_LOCK0(P, CX_THINLOCK_ID(CX))
264 #define JS_UNLOCK(P,CX)             JS_UNLOCK0(P, CX_THINLOCK_ID(CX))
265 
266 #endif /* jslock_h___ */
267