gecko/js/src/jslock.h

320 lines
12 KiB
C

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef jslock_h__
#define jslock_h__
#include "jstypes.h"
#include "jsprvtd.h" /* for JSScope, etc. */
#include "jspubtd.h" /* for JSRuntime, etc. */
#ifdef JS_THREADSAFE
# include "pratom.h"
# include "prlock.h"
# include "prcvar.h"
# include "prthread.h"
#endif
JS_BEGIN_EXTERN_C
#ifdef JS_THREADSAFE
#if (defined(_WIN32) && defined(_M_IX86)) || \
(defined(_WIN64) && (defined(_M_AMD64) || defined(_M_X64))) || \
(defined(__i386) && (defined(__GNUC__) || defined(__SUNPRO_CC))) || \
(defined(__x86_64) && (defined(__GNUC__) || defined(__SUNPRO_CC))) || \
(defined(__sparc) && (defined(__GNUC__) || defined(__SUNPRO_CC))) || \
defined(AIX) || \
defined(USE_ARM_KUSER)
# define JS_HAS_NATIVE_COMPARE_AND_SWAP 1
#else
# define JS_HAS_NATIVE_COMPARE_AND_SWAP 0
#endif
#if defined(JS_USE_ONLY_NSPR_LOCKS) || !JS_HAS_NATIVE_COMPARE_AND_SWAP
# define NSPR_LOCK 1
#else
# undef NSPR_LOCK
#endif
#define Thin_GetWait(W) ((jsword)(W) & 0x1)
#define Thin_SetWait(W) ((jsword)(W) | 0x1)
#define Thin_RemoveWait(W) ((jsword)(W) & ~0x1)
typedef struct JSFatLock JSFatLock;
typedef struct JSThinLock {
jsword owner;
JSFatLock *fat;
} JSThinLock;
#define CX_THINLOCK_ID(cx) ((jsword)(cx)->thread)
#define CURRENT_THREAD_IS_ME(me) (((JSThread *)me)->id == js_CurrentThreadId())
typedef PRLock JSLock;
typedef struct JSTitle JSTitle;
struct JSTitle {
JSContext *ownercx; /* creating context, NULL if shared */
JSThinLock lock; /* binary semaphore protecting title */
union { /* union lockful and lock-free state: */
jsrefcount count; /* lock entry count for reentrancy */
JSTitle *link; /* next link in rt->titleSharingTodo */
} u;
#ifdef JS_DEBUG_TITLE_LOCKS
const char *file[4]; /* file where lock was (re-)taken */
unsigned int line[4]; /* line where lock was (re-)taken */
#endif
};
/*
* Title structure is always allocated as a field of JSScope.
*/
#define TITLE_TO_SCOPE(title) \
((JSScope *)((uint8 *) (title) - offsetof(JSScope, title)))
/*
* Atomic increment and decrement for a reference counter, given jsrefcount *p.
* NB: jsrefcount is int32, aka PRInt32, so that pratom.h functions work.
*/
#define JS_ATOMIC_INCREMENT(p) PR_AtomicIncrement((PRInt32 *)(p))
#define JS_ATOMIC_DECREMENT(p) PR_AtomicDecrement((PRInt32 *)(p))
#define JS_ATOMIC_ADD(p,v) PR_AtomicAdd((PRInt32 *)(p), (PRInt32)(v))
#define JS_ATOMIC_SET(p,v) PR_AtomicSet((PRInt32 *)(p), (PRInt32)(v))
#define js_CurrentThreadId() (jsword)PR_GetCurrentThread()
#define JS_NEW_LOCK() PR_NewLock()
#define JS_DESTROY_LOCK(l) PR_DestroyLock(l)
#define JS_ACQUIRE_LOCK(l) PR_Lock(l)
#define JS_RELEASE_LOCK(l) PR_Unlock(l)
#define JS_NEW_CONDVAR(l) PR_NewCondVar(l)
#define JS_DESTROY_CONDVAR(cv) PR_DestroyCondVar(cv)
#define JS_WAIT_CONDVAR(cv,to) PR_WaitCondVar(cv,to)
#define JS_NO_TIMEOUT PR_INTERVAL_NO_TIMEOUT
#define JS_NOTIFY_CONDVAR(cv) PR_NotifyCondVar(cv)
#define JS_NOTIFY_ALL_CONDVAR(cv) PR_NotifyAllCondVar(cv)
#ifdef JS_DEBUG_TITLE_LOCKS
#define JS_SET_OBJ_INFO(obj_, file_, line_) \
JS_SET_SCOPE_INFO(OBJ_SCOPE(obj_), file_, line_)
#define JS_SET_SCOPE_INFO(scope_, file_, line_) \
js_SetScopeInfo(scope_, file_, line_)
#endif
#define JS_LOCK(cx, tl) js_Lock(cx, tl)
#define JS_UNLOCK(cx, tl) js_Unlock(cx, tl)
#define JS_LOCK_RUNTIME(rt) js_LockRuntime(rt)
#define JS_UNLOCK_RUNTIME(rt) js_UnlockRuntime(rt)
/*
* NB: The JS_LOCK_OBJ and JS_UNLOCK_OBJ macros work *only* on native objects
* (objects for which OBJ_IS_NATIVE returns true). All uses of these macros in
* the engine are predicated on OBJ_IS_NATIVE or equivalent checks. These uses
* are for optimizations above the JSObjectOps layer, under which object locks
* normally hide.
*/
#define CX_OWNS_SCOPE_TITLE(cx,scope) ((scope)->title.ownercx == (cx))
#define JS_LOCK_OBJ(cx,obj) (CX_OWNS_SCOPE_TITLE(cx, OBJ_SCOPE(obj)) \
? (void)0 \
: (js_LockObj(cx, obj), \
JS_SET_OBJ_INFO(obj,__FILE__,__LINE__)))
#define JS_UNLOCK_OBJ(cx,obj) (CX_OWNS_SCOPE_TITLE(cx, OBJ_SCOPE(obj)) \
? (void)0 : js_UnlockObj(cx, obj))
#define JS_LOCK_TITLE(cx,title) \
((title)->ownercx == (cx) ? (void)0 \
: (js_LockTitle(cx, (title)), \
JS_SET_TITLE_INFO(title,__FILE__,__LINE__)))
#define JS_UNLOCK_TITLE(cx,title) ((title)->ownercx == (cx) ? (void)0 \
: js_UnlockTitle(cx, title))
#define JS_LOCK_SCOPE(cx,scope) JS_LOCK_TITLE(cx,&(scope)->title)
#define JS_UNLOCK_SCOPE(cx,scope) JS_UNLOCK_TITLE(cx,&(scope)->title)
#define JS_DROP_ALL_EMPTY_SCOPE_LOCKS(cx,scope) \
JS_BEGIN_MACRO \
JS_ASSERT((scope)->isSharedEmpty()); \
if (!CX_OWNS_SCOPE_TITLE(cx, scope)) \
js_DropAllEmptyScopeLocks(cx, scope); \
JS_END_MACRO
extern void js_Lock(JSContext *cx, JSThinLock *tl);
extern void js_Unlock(JSContext *cx, JSThinLock *tl);
extern void js_LockRuntime(JSRuntime *rt);
extern void js_UnlockRuntime(JSRuntime *rt);
extern void js_LockObj(JSContext *cx, JSObject *obj);
extern void js_UnlockObj(JSContext *cx, JSObject *obj);
extern void js_InitTitle(JSContext *cx, JSTitle *title);
extern void js_FinishTitle(JSContext *cx, JSTitle *title);
extern void js_LockTitle(JSContext *cx, JSTitle *title);
extern void js_UnlockTitle(JSContext *cx, JSTitle *title);
extern int js_SetupLocks(int,int);
extern void js_CleanupLocks();
extern void js_DropAllEmptyScopeLocks(JSContext *cx, JSScope *scope);
extern JS_FRIEND_API(jsval)
js_GetSlotThreadSafe(JSContext *, JSObject *, uint32);
extern void js_SetSlotThreadSafe(JSContext *, JSObject *, uint32, jsval);
extern void js_InitLock(JSThinLock *);
extern void js_FinishLock(JSThinLock *);
/*
* This function must be called with the GC lock held.
*/
extern void
js_ShareWaitingTitles(JSContext *cx);
extern void
js_NudgeOtherContexts(JSContext *cx);
#ifdef DEBUG
#define JS_IS_RUNTIME_LOCKED(rt) js_IsRuntimeLocked(rt)
#define JS_IS_OBJ_LOCKED(cx,obj) js_IsObjLocked(cx,obj)
#define JS_IS_TITLE_LOCKED(cx,title) js_IsTitleLocked(cx,title)
extern JSBool js_IsRuntimeLocked(JSRuntime *rt);
extern JSBool js_IsObjLocked(JSContext *cx, JSObject *obj);
extern JSBool js_IsTitleLocked(JSContext *cx, JSTitle *title);
#ifdef JS_DEBUG_TITLE_LOCKS
extern void js_SetScopeInfo(JSScope *scope, const char *file, int line);
#endif
#else
#define JS_IS_RUNTIME_LOCKED(rt) 0
#define JS_IS_OBJ_LOCKED(cx,obj) 1
#define JS_IS_TITLE_LOCKED(cx,title) 1
#endif /* DEBUG */
#else /* !JS_THREADSAFE */
#define JS_ATOMIC_INCREMENT(p) (++*(p))
#define JS_ATOMIC_DECREMENT(p) (--*(p))
#define JS_ATOMIC_ADD(p,v) (*(p) += (v))
#define JS_ATOMIC_SET(p,v) (*(p) = (v))
#define JS_CurrentThreadId() 0
#define JS_NEW_LOCK() NULL
#define JS_DESTROY_LOCK(l) ((void)0)
#define JS_ACQUIRE_LOCK(l) ((void)0)
#define JS_RELEASE_LOCK(l) ((void)0)
#define JS_LOCK(cx, tl) ((void)0)
#define JS_UNLOCK(cx, tl) ((void)0)
#define JS_NEW_CONDVAR(l) NULL
#define JS_DESTROY_CONDVAR(cv) ((void)0)
#define JS_WAIT_CONDVAR(cv,to) ((void)0)
#define JS_NOTIFY_CONDVAR(cv) ((void)0)
#define JS_NOTIFY_ALL_CONDVAR(cv) ((void)0)
#define JS_LOCK_RUNTIME(rt) ((void)0)
#define JS_UNLOCK_RUNTIME(rt) ((void)0)
#define CX_OWNS_SCOPE_TITLE(cx,obj) true
#define JS_LOCK_OBJ(cx,obj) ((void)0)
#define JS_UNLOCK_OBJ(cx,obj) ((void)0)
#define JS_LOCK_SCOPE(cx,scope) ((void)0)
#define JS_UNLOCK_SCOPE(cx,scope) ((void)0)
#define JS_DROP_ALL_EMPTY_SCOPE_LOCKS(cx,scope) ((void)0)
#define JS_IS_RUNTIME_LOCKED(rt) 1
#define JS_IS_OBJ_LOCKED(cx,obj) 1
#define JS_IS_TITLE_LOCKED(cx,title) 1
#endif /* !JS_THREADSAFE */
#define JS_LOCK_RUNTIME_VOID(rt,e) \
JS_BEGIN_MACRO \
JS_LOCK_RUNTIME(rt); \
e; \
JS_UNLOCK_RUNTIME(rt); \
JS_END_MACRO
#define JS_LOCK_GC(rt) JS_ACQUIRE_LOCK((rt)->gcLock)
#define JS_UNLOCK_GC(rt) JS_RELEASE_LOCK((rt)->gcLock)
#define JS_AWAIT_GC_DONE(rt) JS_WAIT_CONDVAR((rt)->gcDone, JS_NO_TIMEOUT)
#define JS_NOTIFY_GC_DONE(rt) JS_NOTIFY_ALL_CONDVAR((rt)->gcDone)
#define JS_AWAIT_REQUEST_DONE(rt) JS_WAIT_CONDVAR((rt)->requestDone, \
JS_NO_TIMEOUT)
#define JS_NOTIFY_REQUEST_DONE(rt) JS_NOTIFY_CONDVAR((rt)->requestDone)
#define CX_OWNS_OBJECT_TITLE(cx,obj) CX_OWNS_SCOPE_TITLE(cx, OBJ_SCOPE(obj))
#ifndef JS_SET_OBJ_INFO
#define JS_SET_OBJ_INFO(obj,f,l) ((void)0)
#endif
#ifndef JS_SET_TITLE_INFO
#define JS_SET_TITLE_INFO(title,f,l) ((void)0)
#endif
#ifdef JS_THREADSAFE
extern JSBool
js_CompareAndSwap(jsword *w, jsword ov, jsword nv);
/* Atomically bitwise-or the mask into the word *w using compare and swap. */
extern void
js_AtomicSetMask(jsword *w, jsword mask);
#define JS_ATOMIC_SET_MASK(w, mask) js_AtomicSetMask(w, mask)
#else
static inline JSBool
js_CompareAndSwap(jsword *w, jsword ov, jsword nv)
{
return (*w == ov) ? *w = nv, JS_TRUE : JS_FALSE;
}
#define JS_ATOMIC_SET_MASK(w, mask) (*(w) |= (mask))
#endif /* JS_THREADSAFE */
JS_END_EXTERN_C
#endif /* jslock_h___ */