[apple/javascriptcore.git] / heap / MachineStackMarker.cpp

/*
 *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 *  Copyright (C) 2007 Eric Seidel <eric@webkit.org>
 *  Copyright (C) 2009 Acision BV. All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "config.h"
#include "MachineStackMarker.h"

#include "ConservativeRoots.h"
#include "Heap.h"
#include "JSArray.h"
#include "JSCInlines.h"
#include "VM.h"
#include <setjmp.h>
#include <stdlib.h>
#include <wtf/StdLibExtras.h>

#if OS(DARWIN)

#include <mach/mach_init.h>
#include <mach/mach_port.h>
#include <mach/task.h>
#include <mach/thread_act.h>
#include <mach/vm_map.h>

#elif OS(WINDOWS)

#include <windows.h>
#include <malloc.h>

#elif OS(UNIX)

#include <sys/mman.h>
#include <unistd.h>

#if OS(SOLARIS)
#include <thread.h>
#else
#include <pthread.h>
#endif

#if HAVE(PTHREAD_NP_H)
#include <pthread_np.h>
#endif

#if USE(PTHREADS) && !OS(WINDOWS) && !OS(DARWIN)
#include <signal.h>
#endif

#endif

using namespace WTF;

namespace JSC {

static inline void swapIfBackwards(void*& begin, void*& end)
{
#if OS(WINCE)
    if (begin <= end)
        return;
    std::swap(begin, end);
#else
UNUSED_PARAM(begin);
UNUSED_PARAM(end);
#endif
}

#if OS(DARWIN)
typedef mach_port_t PlatformThread;
#elif OS(WINDOWS)
typedef HANDLE PlatformThread;
#elif USE(PTHREADS)
typedef pthread_t PlatformThread;
static const int SigThreadSuspendResume = SIGUSR2;

#if defined(SA_RESTART)
static void pthreadSignalHandlerSuspendResume(int)
{
    sigset_t signalSet;
    sigemptyset(&signalSet);
    sigaddset(&signalSet, SigThreadSuspendResume);
    sigsuspend(&signalSet);
}
#endif
#endif

class MachineThreads::Thread {
    WTF_MAKE_FAST_ALLOCATED;
public:
    Thread(const PlatformThread& platThread, void* base)
        : platformThread(platThread)
        , stackBase(base)
    {
#if USE(PTHREADS) && !OS(WINDOWS) && !OS(DARWIN) && defined(SA_RESTART)
        // if we have SA_RESTART, enable SIGUSR2 debugging mechanism
        struct sigaction action;
        action.sa_handler = pthreadSignalHandlerSuspendResume;
        sigemptyset(&action.sa_mask);
        action.sa_flags = SA_RESTART;
        sigaction(SigThreadSuspendResume, &action, 0);

        sigset_t mask;
        sigemptyset(&mask);
        sigaddset(&mask, SigThreadSuspendResume);
        pthread_sigmask(SIG_UNBLOCK, &mask, 0);
#endif
    }

    Thread* next;
    PlatformThread platformThread;
    void* stackBase;
};

MachineThreads::MachineThreads(Heap* heap)
    : m_registeredThreads(0)
    , m_threadSpecific(0)
#if !ASSERT_DISABLED
    , m_heap(heap)
#endif
{
    UNUSED_PARAM(heap);
}

MachineThreads::~MachineThreads()
{
    if (m_threadSpecific)
        threadSpecificKeyDelete(m_threadSpecific);

    MutexLocker registeredThreadsLock(m_registeredThreadsMutex);
    for (Thread* t = m_registeredThreads; t;) {
        Thread* next = t->next;
        delete t;
        t = next;
    }
}

static inline PlatformThread getCurrentPlatformThread()
{
#if OS(DARWIN)
    return pthread_mach_thread_np(pthread_self());
#elif OS(WINDOWS)
    return GetCurrentThread();
#elif USE(PTHREADS)
    return pthread_self();
#endif
}

static inline bool equalThread(const PlatformThread& first, const PlatformThread& second)
{
#if OS(DARWIN) || OS(WINDOWS)
    return first == second;
#elif USE(PTHREADS)
    return !!pthread_equal(first, second);
#else
#error Need a way to compare threads on this platform
#endif
}

void MachineThreads::makeUsableFromMultipleThreads()
{
    if (m_threadSpecific)
        return;

    threadSpecificKeyCreate(&m_threadSpecific, removeThread);
}

void MachineThreads::addCurrentThread()
{
    ASSERT(!m_heap->vm()->hasExclusiveThread() || m_heap->vm()->exclusiveThread() == std::this_thread::get_id());

    if (!m_threadSpecific || threadSpecificGet(m_threadSpecific))
        return;

    threadSpecificSet(m_threadSpecific, this);
    Thread* thread = new Thread(getCurrentPlatformThread(), wtfThreadData().stack().origin());

    MutexLocker lock(m_registeredThreadsMutex);

    thread->next = m_registeredThreads;
    m_registeredThreads = thread;
}

void MachineThreads::removeThread(void* p)
{
    if (p)
        static_cast<MachineThreads*>(p)->removeCurrentThread();
}

void MachineThreads::removeCurrentThread()
{
    PlatformThread currentPlatformThread = getCurrentPlatformThread();

    MutexLocker lock(m_registeredThreadsMutex);

    if (equalThread(currentPlatformThread, m_registeredThreads->platformThread)) {
        Thread* t = m_registeredThreads;
        m_registeredThreads = m_registeredThreads->next;
        delete t;
    } else {
        Thread* last = m_registeredThreads;
        Thread* t;
        for (t = m_registeredThreads->next; t; t = t->next) {
            if (equalThread(t->platformThread, currentPlatformThread)) {
                last->next = t->next;
                break;
            }
            last = t;
        }
        ASSERT(t); // If t is NULL, we never found ourselves in the list.
        delete t;
    }
}

#if COMPILER(GCC)
#define REGISTER_BUFFER_ALIGNMENT __attribute__ ((aligned (sizeof(void*))))
#else
#define REGISTER_BUFFER_ALIGNMENT
#endif

void MachineThreads::gatherFromCurrentThread(ConservativeRoots& conservativeRoots, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks, void* stackCurrent)
{
    // setjmp forces volatile registers onto the stack
    jmp_buf registers REGISTER_BUFFER_ALIGNMENT;
#if COMPILER(MSVC)
#pragma warning(push)
#pragma warning(disable: 4611)
#endif
    setjmp(registers);
#if COMPILER(MSVC)
#pragma warning(pop)
#endif

    void* registersBegin = &registers;
    void* registersEnd = reinterpret_cast<void*>(roundUpToMultipleOf<sizeof(void*)>(reinterpret_cast<uintptr_t>(&registers + 1)));
    swapIfBackwards(registersBegin, registersEnd);
    conservativeRoots.add(registersBegin, registersEnd, jitStubRoutines, codeBlocks);

    void* stackBegin = stackCurrent;
    void* stackEnd = wtfThreadData().stack().origin();
    swapIfBackwards(stackBegin, stackEnd);
    conservativeRoots.add(stackBegin, stackEnd, jitStubRoutines, codeBlocks);
}

static inline void suspendThread(const PlatformThread& platformThread)
{
#if OS(DARWIN)
    thread_suspend(platformThread);
#elif OS(WINDOWS)
    SuspendThread(platformThread);
#elif USE(PTHREADS)
    pthread_kill(platformThread, SigThreadSuspendResume);
#else
#error Need a way to suspend threads on this platform
#endif
}

static inline void resumeThread(const PlatformThread& platformThread)
{
#if OS(DARWIN)
    thread_resume(platformThread);
#elif OS(WINDOWS)
    ResumeThread(platformThread);
#elif USE(PTHREADS)
    pthread_kill(platformThread, SigThreadSuspendResume);
#else
#error Need a way to resume threads on this platform
#endif
}

typedef unsigned long usword_t; // word size, assumed to be either 32 or 64 bit

#if OS(DARWIN)

#if CPU(X86)
typedef i386_thread_state_t PlatformThreadRegisters;
#elif CPU(X86_64)
typedef x86_thread_state64_t PlatformThreadRegisters;
#elif CPU(PPC)
typedef ppc_thread_state_t PlatformThreadRegisters;
#elif CPU(PPC64)
typedef ppc_thread_state64_t PlatformThreadRegisters;
#elif CPU(ARM)
typedef arm_thread_state_t PlatformThreadRegisters;
#elif CPU(ARM64)
typedef arm_thread_state64_t PlatformThreadRegisters;
#else
#error Unknown Architecture
#endif

#elif OS(WINDOWS)
typedef CONTEXT PlatformThreadRegisters;
#elif USE(PTHREADS)
typedef pthread_attr_t PlatformThreadRegisters;
#else
#error Need a thread register struct for this platform
#endif

static size_t getPlatformThreadRegisters(const PlatformThread& platformThread, PlatformThreadRegisters& regs)
{
#if OS(DARWIN)

#if CPU(X86)
    unsigned user_count = sizeof(regs)/sizeof(int);
    thread_state_flavor_t flavor = i386_THREAD_STATE;
#elif CPU(X86_64)
    unsigned user_count = x86_THREAD_STATE64_COUNT;
    thread_state_flavor_t flavor = x86_THREAD_STATE64;
#elif CPU(PPC) 
    unsigned user_count = PPC_THREAD_STATE_COUNT;
    thread_state_flavor_t flavor = PPC_THREAD_STATE;
#elif CPU(PPC64)
    unsigned user_count = PPC_THREAD_STATE64_COUNT;
    thread_state_flavor_t flavor = PPC_THREAD_STATE64;
#elif CPU(ARM)
    unsigned user_count = ARM_THREAD_STATE_COUNT;
    thread_state_flavor_t flavor = ARM_THREAD_STATE;
#elif CPU(ARM64)
    unsigned user_count = ARM_THREAD_STATE64_COUNT;
    thread_state_flavor_t flavor = ARM_THREAD_STATE64;
#else
#error Unknown Architecture
#endif

    kern_return_t result = thread_get_state(platformThread, flavor, (thread_state_t)&regs, &user_count);
    if (result != KERN_SUCCESS) {
        WTFReportFatalError(__FILE__, __LINE__, WTF_PRETTY_FUNCTION, 
                            "JavaScript garbage collection failed because thread_get_state returned an error (%d). This is probably the result of running inside Rosetta, which is not supported.", result);
        CRASH();
    }
    return user_count * sizeof(usword_t);
// end OS(DARWIN)

#elif OS(WINDOWS)
    regs.ContextFlags = CONTEXT_INTEGER | CONTEXT_CONTROL;
    GetThreadContext(platformThread, &regs);
    return sizeof(CONTEXT);
#elif USE(PTHREADS)
    pthread_attr_init(&regs);
#if HAVE(PTHREAD_NP_H) || OS(NETBSD)
#if !OS(OPENBSD)
    // e.g. on FreeBSD 5.4, neundorf@kde.org
    pthread_attr_get_np(platformThread, &regs);
#endif
#else
    // FIXME: this function is non-portable; other POSIX systems may have different np alternatives
    pthread_getattr_np(platformThread, &regs);
#endif
    return 0;
#else
#error Need a way to get thread registers on this platform
#endif
}

static inline void* otherThreadStackPointer(const PlatformThreadRegisters& regs)
{
#if OS(DARWIN)

#if __DARWIN_UNIX03

#if CPU(X86)
    return reinterpret_cast<void*>(regs.__esp);
#elif CPU(X86_64)
    return reinterpret_cast<void*>(regs.__rsp);
#elif CPU(PPC) || CPU(PPC64)
    return reinterpret_cast<void*>(regs.__r1);
#elif CPU(ARM)
    return reinterpret_cast<void*>(regs.__sp);
#elif CPU(ARM64)
    return reinterpret_cast<void*>(regs.__sp);
#else
#error Unknown Architecture
#endif

#else // !__DARWIN_UNIX03

#if CPU(X86)
    return reinterpret_cast<void*>(regs.esp);
#elif CPU(X86_64)
    return reinterpret_cast<void*>(regs.rsp);
#elif CPU(PPC) || CPU(PPC64)
    return reinterpret_cast<void*>(regs.r1);
#else
#error Unknown Architecture
#endif

#endif // __DARWIN_UNIX03

// end OS(DARWIN)
#elif OS(WINDOWS)

#if CPU(ARM)
    return reinterpret_cast<void*>((uintptr_t) regs.Sp);
#elif CPU(MIPS)
    return reinterpret_cast<void*>((uintptr_t) regs.IntSp);
#elif CPU(X86)
    return reinterpret_cast<void*>((uintptr_t) regs.Esp);
#elif CPU(X86_64)
    return reinterpret_cast<void*>((uintptr_t) regs.Rsp);
#else
#error Unknown Architecture
#endif

#elif USE(PTHREADS)
    void* stackBase = 0;
    size_t stackSize = 0;
#if OS(OPENBSD)
    stack_t ss;
    int rc = pthread_stackseg_np(pthread_self(), &ss);
    stackBase = (void*)((size_t) ss.ss_sp - ss.ss_size);
    stackSize = ss.ss_size;
#else
    int rc = pthread_attr_getstack(&regs, &stackBase, &stackSize);
#endif
    (void)rc; // FIXME: Deal with error code somehow? Seems fatal.
    ASSERT(stackBase);
    return static_cast<char*>(stackBase) + stackSize;
#else
#error Need a way to get the stack pointer for another thread on this platform
#endif
}

static void freePlatformThreadRegisters(PlatformThreadRegisters& regs)
{
#if USE(PTHREADS) && !OS(WINDOWS) && !OS(DARWIN)
    pthread_attr_destroy(&regs);
#else
    UNUSED_PARAM(regs);
#endif
}

void MachineThreads::gatherFromOtherThread(ConservativeRoots& conservativeRoots, Thread* thread, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks)
{
    PlatformThreadRegisters regs;
    size_t regSize = getPlatformThreadRegisters(thread->platformThread, regs);

    conservativeRoots.add(static_cast<void*>(&regs), static_cast<void*>(reinterpret_cast<char*>(&regs) + regSize), jitStubRoutines, codeBlocks);

    void* stackPointer = otherThreadStackPointer(regs);
    void* stackBase = thread->stackBase;
    swapIfBackwards(stackPointer, stackBase);
    stackPointer = reinterpret_cast<void*>(WTF::roundUpToMultipleOf<sizeof(void*)>(reinterpret_cast<uintptr_t>(stackPointer)));
    conservativeRoots.add(stackPointer, stackBase, jitStubRoutines, codeBlocks);

    freePlatformThreadRegisters(regs);
}

void MachineThreads::gatherConservativeRoots(ConservativeRoots& conservativeRoots, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks, void* stackCurrent)
{
    gatherFromCurrentThread(conservativeRoots, jitStubRoutines, codeBlocks, stackCurrent);

    if (m_threadSpecific) {
        PlatformThread currentPlatformThread = getCurrentPlatformThread();

        MutexLocker lock(m_registeredThreadsMutex);

#ifndef NDEBUG
        // Forbid malloc during the gather phase. The gather phase suspends
        // threads, so a malloc during gather would risk a deadlock with a
        // thread that had been suspended while holding the malloc lock.
        fastMallocForbid();
#endif
        for (Thread* thread = m_registeredThreads; thread; thread = thread->next) {
            if (!equalThread(thread->platformThread, currentPlatformThread))
                suspendThread(thread->platformThread);
        }

        // It is safe to access the registeredThreads list, because we earlier asserted that locks are being held,
        // and since this is a shared heap, they are real locks.
        for (Thread* thread = m_registeredThreads; thread; thread = thread->next) {
            if (!equalThread(thread->platformThread, currentPlatformThread))
                gatherFromOtherThread(conservativeRoots, thread, jitStubRoutines, codeBlocks);
        }

        for (Thread* thread = m_registeredThreads; thread; thread = thread->next) {
            if (!equalThread(thread->platformThread, currentPlatformThread))
                resumeThread(thread->platformThread);
        }

#ifndef NDEBUG
        fastMallocAllow();
#endif
    }
}

} // namespace JSC
Commit	Line	Data
14957cd0 A	1	/*
	2	* Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
	3	* Copyright (C) 2007 Eric Seidel <eric@webkit.org>
	4	* Copyright (C) 2009 Acision BV. All rights reserved.
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	19	*
	20	*/
	21
	22	#include "config.h"
	23	#include "MachineStackMarker.h"
	24
	25	#include "ConservativeRoots.h"
	26	#include "Heap.h"
	27	#include "JSArray.h"
81345200	28	#include "JSCInlines.h"
93a37866	29	#include "VM.h"
14957cd0 A	30	#include <setjmp.h>
	31	#include <stdlib.h>
	32	#include <wtf/StdLibExtras.h>
	33
14957cd0 A	34	#if OS(DARWIN)
	35
	36	#include <mach/mach_init.h>
	37	#include <mach/mach_port.h>
	38	#include <mach/task.h>
	39	#include <mach/thread_act.h>
	40	#include <mach/vm_map.h>
	41
	42	#elif OS(WINDOWS)
	43
	44	#include <windows.h>
	45	#include <malloc.h>
	46
14957cd0 A	47	#elif OS(UNIX)
14957cd0 A	48
14957cd0	49	#include <sys/mman.h>
14957cd0 A	50	#include <unistd.h>
	51
	52	#if OS(SOLARIS)
	53	#include <thread.h>
	54	#else
	55	#include <pthread.h>
	56	#endif
	57
	58	#if HAVE(PTHREAD_NP_H)
	59	#include <pthread_np.h>
	60	#endif
	61
14957cd0 A	62	#if USE(PTHREADS) && !OS(WINDOWS) && !OS(DARWIN)
14957cd0 A	63	#include <signal.h>
14957cd0 A	64	#endif
	65
	66	#endif
	67
	68	using namespace WTF;
	69
	70	namespace JSC {
	71
	72	static inline void swapIfBackwards(void& begin, void& end)
	73	{
	74	#if OS(WINCE)
	75	if (begin <= end)
	76	return;
	77	std::swap(begin, end);
	78	#else
	79	UNUSED_PARAM(begin);
	80	UNUSED_PARAM(end);
	81	#endif
	82	}
	83
14957cd0 A	84	#if OS(DARWIN)
	85	typedef mach_port_t PlatformThread;
	86	#elif OS(WINDOWS)
	87	typedef HANDLE PlatformThread;
	88	#elif USE(PTHREADS)
	89	typedef pthread_t PlatformThread;
	90	static const int SigThreadSuspendResume = SIGUSR2;
	91
6fe7ccc8	92	#if defined(SA_RESTART)
93a37866	93	static void pthreadSignalHandlerSuspendResume(int)
14957cd0 A	94	{
	95	sigset_t signalSet;
	96	sigemptyset(&signalSet);
	97	sigaddset(&signalSet, SigThreadSuspendResume);
	98	sigsuspend(&signalSet);
	99	}
	100	#endif
6fe7ccc8	101	#endif
14957cd0 A	102
14957cd0 A	103	class MachineThreads::Thread {
93a37866	104	WTF_MAKE_FAST_ALLOCATED;
14957cd0	105	public:
6fe7ccc8 A	106	Thread(const PlatformThread& platThread, void* base)
6fe7ccc8 A	107	: platformThread(platThread)
14957cd0 A	108	, stackBase(base)
14957cd0 A	109	{
6fe7ccc8 A	110	#if USE(PTHREADS) && !OS(WINDOWS) && !OS(DARWIN) && defined(SA_RESTART)
6fe7ccc8 A	111	// if we have SA_RESTART, enable SIGUSR2 debugging mechanism
14957cd0 A	112	struct sigaction action;
	113	action.sa_handler = pthreadSignalHandlerSuspendResume;
	114	sigemptyset(&action.sa_mask);
	115	action.sa_flags = SA_RESTART;
	116	sigaction(SigThreadSuspendResume, &action, 0);
	117
	118	sigset_t mask;
	119	sigemptyset(&mask);
	120	sigaddset(&mask, SigThreadSuspendResume);
	121	pthread_sigmask(SIG_UNBLOCK, &mask, 0);
	122	#endif
	123	}
	124
	125	Thread* next;
14957cd0 A	126	PlatformThread platformThread;
	127	void* stackBase;
	128	};
	129
14957cd0	130	MachineThreads::MachineThreads(Heap* heap)
93a37866	131	: m_registeredThreads(0)
14957cd0	132	, m_threadSpecific(0)
93a37866 A	133	#if !ASSERT_DISABLED
	134	, m_heap(heap)
	135	#endif
14957cd0	136	{
93a37866	137	UNUSED_PARAM(heap);
14957cd0 A	138	}
	139
	140	MachineThreads::~MachineThreads()
	141	{
93a37866 A	142	if (m_threadSpecific)
93a37866 A	143	threadSpecificKeyDelete(m_threadSpecific);
14957cd0 A	144
	145	MutexLocker registeredThreadsLock(m_registeredThreadsMutex);
	146	for (Thread* t = m_registeredThreads; t;) {
	147	Thread* next = t->next;
	148	delete t;
	149	t = next;
	150	}
14957cd0 A	151	}
14957cd0 A	152
14957cd0 A	153	static inline PlatformThread getCurrentPlatformThread()
	154	{
	155	#if OS(DARWIN)
	156	return pthread_mach_thread_np(pthread_self());
	157	#elif OS(WINDOWS)
6fe7ccc8	158	return GetCurrentThread();
14957cd0 A	159	#elif USE(PTHREADS)
	160	return pthread_self();
	161	#endif
	162	}
	163
6fe7ccc8 A	164	static inline bool equalThread(const PlatformThread& first, const PlatformThread& second)
	165	{
	166	#if OS(DARWIN) \|\| OS(WINDOWS)
	167	return first == second;
	168	#elif USE(PTHREADS)
	169	return !!pthread_equal(first, second);
	170	#else
	171	#error Need a way to compare threads on this platform
	172	#endif
	173	}
	174
14957cd0 A	175	void MachineThreads::makeUsableFromMultipleThreads()
	176	{
	177	if (m_threadSpecific)
	178	return;
	179
93a37866	180	threadSpecificKeyCreate(&m_threadSpecific, removeThread);
14957cd0 A	181	}
	182
	183	void MachineThreads::addCurrentThread()
	184	{
81345200	185	ASSERT(!m_heap->vm()->hasExclusiveThread() \|\| m_heap->vm()->exclusiveThread() == std::this_thread::get_id());
14957cd0	186
93a37866	187	if (!m_threadSpecific \|\| threadSpecificGet(m_threadSpecific))
14957cd0 A	188	return;
14957cd0 A	189
93a37866	190	threadSpecificSet(m_threadSpecific, this);
6fe7ccc8	191	Thread* thread = new Thread(getCurrentPlatformThread(), wtfThreadData().stack().origin());
14957cd0 A	192
	193	MutexLocker lock(m_registeredThreadsMutex);
	194
	195	thread->next = m_registeredThreads;
	196	m_registeredThreads = thread;
	197	}
	198
	199	void MachineThreads::removeThread(void* p)
	200	{
	201	if (p)
	202	static_cast<MachineThreads*>(p)->removeCurrentThread();
	203	}
	204
	205	void MachineThreads::removeCurrentThread()
	206	{
6fe7ccc8	207	PlatformThread currentPlatformThread = getCurrentPlatformThread();
14957cd0 A	208
	209	MutexLocker lock(m_registeredThreadsMutex);
	210
6fe7ccc8	211	if (equalThread(currentPlatformThread, m_registeredThreads->platformThread)) {
14957cd0 A	212	Thread* t = m_registeredThreads;
	213	m_registeredThreads = m_registeredThreads->next;
	214	delete t;
	215	} else {
	216	Thread* last = m_registeredThreads;
	217	Thread* t;
	218	for (t = m_registeredThreads->next; t; t = t->next) {
6fe7ccc8	219	if (equalThread(t->platformThread, currentPlatformThread)) {
14957cd0 A	220	last->next = t->next;
	221	break;
	222	}
	223	last = t;
	224	}
	225	ASSERT(t); // If t is NULL, we never found ourselves in the list.
	226	delete t;
	227	}
	228	}
	229
14957cd0 A	230	#if COMPILER(GCC)
	231	#define REGISTER_BUFFER_ALIGNMENT __attribute__ ((aligned (sizeof(void*))))
	232	#else
	233	#define REGISTER_BUFFER_ALIGNMENT
	234	#endif
	235
81345200	236	void MachineThreads::gatherFromCurrentThread(ConservativeRoots& conservativeRoots, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks, void* stackCurrent)
14957cd0 A	237	{
	238	// setjmp forces volatile registers onto the stack
	239	jmp_buf registers REGISTER_BUFFER_ALIGNMENT;
	240	#if COMPILER(MSVC)
	241	#pragma warning(push)
	242	#pragma warning(disable: 4611)
	243	#endif
	244	setjmp(registers);
	245	#if COMPILER(MSVC)
	246	#pragma warning(pop)
	247	#endif
	248
	249	void* registersBegin = &registers;
	250	void* registersEnd = reinterpret_cast<void>(roundUpToMultipleOf<sizeof(void)>(reinterpret_cast<uintptr_t>(&registers + 1)));
	251	swapIfBackwards(registersBegin, registersEnd);
81345200	252	conservativeRoots.add(registersBegin, registersEnd, jitStubRoutines, codeBlocks);
14957cd0 A	253
14957cd0 A	254	void* stackBegin = stackCurrent;
6fe7ccc8	255	void* stackEnd = wtfThreadData().stack().origin();
14957cd0	256	swapIfBackwards(stackBegin, stackEnd);
81345200	257	conservativeRoots.add(stackBegin, stackEnd, jitStubRoutines, codeBlocks);
14957cd0 A	258	}
14957cd0 A	259
14957cd0 A	260	static inline void suspendThread(const PlatformThread& platformThread)
	261	{
	262	#if OS(DARWIN)
	263	thread_suspend(platformThread);
	264	#elif OS(WINDOWS)
	265	SuspendThread(platformThread);
	266	#elif USE(PTHREADS)
	267	pthread_kill(platformThread, SigThreadSuspendResume);
	268	#else
	269	#error Need a way to suspend threads on this platform
	270	#endif
	271	}
	272
	273	static inline void resumeThread(const PlatformThread& platformThread)
	274	{
	275	#if OS(DARWIN)
	276	thread_resume(platformThread);
	277	#elif OS(WINDOWS)
	278	ResumeThread(platformThread);
	279	#elif USE(PTHREADS)
	280	pthread_kill(platformThread, SigThreadSuspendResume);
	281	#else
	282	#error Need a way to resume threads on this platform
	283	#endif
	284	}
	285
	286	typedef unsigned long usword_t; // word size, assumed to be either 32 or 64 bit
	287
	288	#if OS(DARWIN)
	289
	290	#if CPU(X86)
	291	typedef i386_thread_state_t PlatformThreadRegisters;
	292	#elif CPU(X86_64)
	293	typedef x86_thread_state64_t PlatformThreadRegisters;
	294	#elif CPU(PPC)
	295	typedef ppc_thread_state_t PlatformThreadRegisters;
	296	#elif CPU(PPC64)
	297	typedef ppc_thread_state64_t PlatformThreadRegisters;
	298	#elif CPU(ARM)
	299	typedef arm_thread_state_t PlatformThreadRegisters;
93a37866 A	300	#elif CPU(ARM64)
93a37866 A	301	typedef arm_thread_state64_t PlatformThreadRegisters;
14957cd0 A	302	#else
	303	#error Unknown Architecture
	304	#endif
	305
	306	#elif OS(WINDOWS)
	307	typedef CONTEXT PlatformThreadRegisters;
	308	#elif USE(PTHREADS)
	309	typedef pthread_attr_t PlatformThreadRegisters;
	310	#else
	311	#error Need a thread register struct for this platform
	312	#endif
	313
	314	static size_t getPlatformThreadRegisters(const PlatformThread& platformThread, PlatformThreadRegisters& regs)
	315	{
	316	#if OS(DARWIN)
	317
	318	#if CPU(X86)
	319	unsigned user_count = sizeof(regs)/sizeof(int);
	320	thread_state_flavor_t flavor = i386_THREAD_STATE;
	321	#elif CPU(X86_64)
	322	unsigned user_count = x86_THREAD_STATE64_COUNT;
	323	thread_state_flavor_t flavor = x86_THREAD_STATE64;
	324	#elif CPU(PPC)
	325	unsigned user_count = PPC_THREAD_STATE_COUNT;
	326	thread_state_flavor_t flavor = PPC_THREAD_STATE;
	327	#elif CPU(PPC64)
	328	unsigned user_count = PPC_THREAD_STATE64_COUNT;
	329	thread_state_flavor_t flavor = PPC_THREAD_STATE64;
	330	#elif CPU(ARM)
	331	unsigned user_count = ARM_THREAD_STATE_COUNT;
	332	thread_state_flavor_t flavor = ARM_THREAD_STATE;
93a37866 A	333	#elif CPU(ARM64)
	334	unsigned user_count = ARM_THREAD_STATE64_COUNT;
	335	thread_state_flavor_t flavor = ARM_THREAD_STATE64;
14957cd0 A	336	#else
	337	#error Unknown Architecture
	338	#endif
	339
	340	kern_return_t result = thread_get_state(platformThread, flavor, (thread_state_t)&regs, &user_count);
	341	if (result != KERN_SUCCESS) {
	342	WTFReportFatalError(__FILE__, __LINE__, WTF_PRETTY_FUNCTION,
	343	"JavaScript garbage collection failed because thread_get_state returned an error (%d). This is probably the result of running inside Rosetta, which is not supported.", result);
	344	CRASH();
	345	}
	346	return user_count * sizeof(usword_t);
	347	// end OS(DARWIN)
	348
	349	#elif OS(WINDOWS)
6fe7ccc8	350	regs.ContextFlags = CONTEXT_INTEGER \| CONTEXT_CONTROL;
14957cd0 A	351	GetThreadContext(platformThread, &regs);
	352	return sizeof(CONTEXT);
	353	#elif USE(PTHREADS)
	354	pthread_attr_init(&regs);
	355	#if HAVE(PTHREAD_NP_H) \|\| OS(NETBSD)
81345200	356	#if !OS(OPENBSD)
14957cd0 A	357	// e.g. on FreeBSD 5.4, neundorf@kde.org
14957cd0 A	358	pthread_attr_get_np(platformThread, &regs);
81345200	359	#endif
14957cd0 A	360	#else
	361	// FIXME: this function is non-portable; other POSIX systems may have different np alternatives
	362	pthread_getattr_np(platformThread, &regs);
	363	#endif
	364	return 0;
	365	#else
	366	#error Need a way to get thread registers on this platform
	367	#endif
	368	}
	369
	370	static inline void* otherThreadStackPointer(const PlatformThreadRegisters& regs)
	371	{
	372	#if OS(DARWIN)
	373
	374	#if __DARWIN_UNIX03
	375
	376	#if CPU(X86)
	377	return reinterpret_cast<void*>(regs.__esp);
	378	#elif CPU(X86_64)
	379	return reinterpret_cast<void*>(regs.__rsp);
	380	#elif CPU(PPC) \|\| CPU(PPC64)
	381	return reinterpret_cast<void*>(regs.__r1);
	382	#elif CPU(ARM)
	383	return reinterpret_cast<void*>(regs.__sp);
93a37866 A	384	#elif CPU(ARM64)
93a37866 A	385	return reinterpret_cast<void*>(regs.__sp);
14957cd0 A	386	#else
	387	#error Unknown Architecture
	388	#endif
	389
	390	#else // !__DARWIN_UNIX03
	391
	392	#if CPU(X86)
	393	return reinterpret_cast<void*>(regs.esp);
	394	#elif CPU(X86_64)
	395	return reinterpret_cast<void*>(regs.rsp);
	396	#elif CPU(PPC) \|\| CPU(PPC64)
	397	return reinterpret_cast<void*>(regs.r1);
	398	#else
	399	#error Unknown Architecture
	400	#endif
	401
	402	#endif // __DARWIN_UNIX03
	403
	404	// end OS(DARWIN)
6fe7ccc8 A	405	#elif OS(WINDOWS)
	406
	407	#if CPU(ARM)
	408	return reinterpret_cast<void*>((uintptr_t) regs.Sp);
	409	#elif CPU(MIPS)
	410	return reinterpret_cast<void*>((uintptr_t) regs.IntSp);
	411	#elif CPU(X86)
14957cd0	412	return reinterpret_cast<void*>((uintptr_t) regs.Esp);
6fe7ccc8	413	#elif CPU(X86_64)
14957cd0	414	return reinterpret_cast<void*>((uintptr_t) regs.Rsp);
6fe7ccc8 A	415	#else
	416	#error Unknown Architecture
	417	#endif
	418
14957cd0 A	419	#elif USE(PTHREADS)
	420	void* stackBase = 0;
	421	size_t stackSize = 0;
81345200 A	422	#if OS(OPENBSD)
	423	stack_t ss;
	424	int rc = pthread_stackseg_np(pthread_self(), &ss);
	425	stackBase = (void*)((size_t) ss.ss_sp - ss.ss_size);
	426	stackSize = ss.ss_size;
	427	#else
14957cd0	428	int rc = pthread_attr_getstack(&regs, &stackBase, &stackSize);
81345200	429	#endif
14957cd0 A	430	(void)rc; // FIXME: Deal with error code somehow? Seems fatal.
	431	ASSERT(stackBase);
	432	return static_cast<char*>(stackBase) + stackSize;
	433	#else
	434	#error Need a way to get the stack pointer for another thread on this platform
	435	#endif
	436	}
	437
	438	static void freePlatformThreadRegisters(PlatformThreadRegisters& regs)
	439	{
81345200	440	#if USE(PTHREADS) && !OS(WINDOWS) && !OS(DARWIN)
14957cd0 A	441	pthread_attr_destroy(&regs);
	442	#else
	443	UNUSED_PARAM(regs);
	444	#endif
	445	}
	446
81345200	447	void MachineThreads::gatherFromOtherThread(ConservativeRoots& conservativeRoots, Thread* thread, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks)
14957cd0	448	{
14957cd0 A	449	PlatformThreadRegisters regs;
	450	size_t regSize = getPlatformThreadRegisters(thread->platformThread, regs);
	451
81345200	452	conservativeRoots.add(static_cast<void>(&regs), static_cast<void>(reinterpret_cast<char*>(&regs) + regSize), jitStubRoutines, codeBlocks);
14957cd0 A	453
	454	void* stackPointer = otherThreadStackPointer(regs);
	455	void* stackBase = thread->stackBase;
	456	swapIfBackwards(stackPointer, stackBase);
81345200 A	457	stackPointer = reinterpret_cast<void>(WTF::roundUpToMultipleOf<sizeof(void)>(reinterpret_cast<uintptr_t>(stackPointer)));
81345200 A	458	conservativeRoots.add(stackPointer, stackBase, jitStubRoutines, codeBlocks);
14957cd0	459
14957cd0 A	460	freePlatformThreadRegisters(regs);
	461	}
	462
81345200	463	void MachineThreads::gatherConservativeRoots(ConservativeRoots& conservativeRoots, JITStubRoutineSet& jitStubRoutines, CodeBlockSet& codeBlocks, void* stackCurrent)
14957cd0	464	{
81345200	465	gatherFromCurrentThread(conservativeRoots, jitStubRoutines, codeBlocks, stackCurrent);
14957cd0	466
14957cd0	467	if (m_threadSpecific) {
6fe7ccc8	468	PlatformThread currentPlatformThread = getCurrentPlatformThread();
14957cd0 A	469
	470	MutexLocker lock(m_registeredThreadsMutex);
	471
	472	#ifndef NDEBUG
	473	// Forbid malloc during the gather phase. The gather phase suspends
	474	// threads, so a malloc during gather would risk a deadlock with a
	475	// thread that had been suspended while holding the malloc lock.
	476	fastMallocForbid();
	477	#endif
93a37866 A	478	for (Thread* thread = m_registeredThreads; thread; thread = thread->next) {
	479	if (!equalThread(thread->platformThread, currentPlatformThread))
	480	suspendThread(thread->platformThread);
	481	}
	482
14957cd0 A	483	// It is safe to access the registeredThreads list, because we earlier asserted that locks are being held,
	484	// and since this is a shared heap, they are real locks.
	485	for (Thread* thread = m_registeredThreads; thread; thread = thread->next) {
6fe7ccc8	486	if (!equalThread(thread->platformThread, currentPlatformThread))
81345200	487	gatherFromOtherThread(conservativeRoots, thread, jitStubRoutines, codeBlocks);
14957cd0	488	}
93a37866 A	489
	490	for (Thread* thread = m_registeredThreads; thread; thread = thread->next) {
	491	if (!equalThread(thread->platformThread, currentPlatformThread))
	492	resumeThread(thread->platformThread);
	493	}
	494
14957cd0 A	495	#ifndef NDEBUG
	496	fastMallocAllow();
	497	#endif
	498	}
14957cd0 A	499	}
	500
	501	} // namespace JSC