/*

 * Copyright 1998-2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

#include "util.h"

#include "eventHandler.h"

#include "threadControl.h"

#include "commonRef.h"

#include "eventHelper.h"

#include "stepControl.h"

#include "invoker.h"

#include "bag.h"

#define HANDLING_EVENT(node) ((node)->current_ei != 0)

/*

 * Collection of info for properly handling co-located events.

 * If the ei field is non-zero, then one of the possible

 * co-located events has been posted and the other fields describe

 * the event's location.

 */

typedef struct CoLocatedEventInfo_ {

    EventIndex ei;

    jclass    clazz;

    jmethodID method;

    jlocation location;

} CoLocatedEventInfo;

/**

 * The main data structure in threadControl is the ThreadNode.

 * This is a per-thread structure that is allocated on the

 * first event that occurs in a thread. It is freed after the

 * thread's thread end event has completed processing. The

 * structure contains state information on its thread including

 * suspend counts. It also acts as a repository for other

 * per-thread state such as the current method invocation or

 * current step.

 *

 * suspendCount is the number of outstanding suspends

 * from the debugger. suspends from the app itself are

 * not included in this count.

 */

typedef struct ThreadNode {

    jthread thread;

    unsigned int toBeResumed : 1;

    unsigned int pendingInterrupt : 1;

    unsigned int isDebugThread : 1;

    unsigned int suspendOnStart : 1;

    unsigned int isStarted : 1;

    unsigned int popFrameEvent : 1;

    unsigned int popFrameProceed : 1;

    unsigned int popFrameThread : 1;

    EventIndex current_ei;

    jobject pendingStop;

    jint suspendCount;

    jint resumeFrameDepth; /* !=0 => This thread is in a call to Thread.resume() */

    jvmtiEventMode instructionStepMode;

    StepRequest currentStep;

    InvokeRequest currentInvoke;

    struct bag *eventBag;

    CoLocatedEventInfo cleInfo;

    struct ThreadNode *next;

    struct ThreadNode *prev;

    jlong frameGeneration;

    struct ThreadList *list;  /* Tells us what list this thread is in */

} ThreadNode;

static jint suspendAllCount;

typedef struct ThreadList {

    ThreadNode *first;

} ThreadList;

/*

 * popFrameEventLock is used to notify that the event has been received

 */

static jrawMonitorID popFrameEventLock = NULL;

/*

 * popFrameProceedLock is used to assure that the event thread is

 * re-suspended immediately after the event is acknowledged.

 */

static jrawMonitorID popFrameProceedLock = NULL;

static jrawMonitorID threadLock;

static jlocation resumeLocation;

static HandlerNode *breakpointHandlerNode;

static HandlerNode *framePopHandlerNode;

static HandlerNode *catchHandlerNode;

static jvmtiError threadControl_removeDebugThread(jthread thread);

/*

 * Threads which have issued thread start events and not yet issued thread

 * end events are maintained in the "runningThreads" list. All other threads known

 * to this module are kept in the "otherThreads" list.

 */

static ThreadList runningThreads;

static ThreadList otherThreads;

#define MAX_DEBUG_THREADS 10

static int debugThreadCount;

static jthread debugThreads[MAX_DEBUG_THREADS];

typedef struct DeferredEventMode {

    EventIndex ei;

    jvmtiEventMode mode;

    jthread thread;

    struct DeferredEventMode *next;

} DeferredEventMode;

typedef struct {

    DeferredEventMode *first;

    DeferredEventMode *last;

} DeferredEventModeList;

static DeferredEventModeList deferredEventModes;

static jint

getStackDepth(jthread thread)

{

    jint count = 0;

    jvmtiError error;

    error = JVMTI_FUNC_PTR(gdata->jvmti,GetFrameCount)

                        (gdata->jvmti, thread, &count);

    if (error != JVMTI_ERROR_NONE) {

        EXIT_ERROR(error, "getting frame count");

    }

    return count;

}

/* Get the state of the thread direct from JVMTI */

static jvmtiError

threadState(jthread thread, jint *pstate)

{

    *pstate = 0;

    return JVMTI_FUNC_PTR(gdata->jvmti,GetThreadState)

                        (gdata->jvmti, thread, pstate);

}

/* Set TLS on a specific jthread to the ThreadNode* */

static void

setThreadLocalStorage(jthread thread, ThreadNode *node)

{

    jvmtiError  error;

    error = JVMTI_FUNC_PTR(gdata->jvmti,SetThreadLocalStorage)

            (gdata->jvmti, thread, (void*)node);

    if ( error == JVMTI_ERROR_THREAD_NOT_ALIVE ) {

        /* Just return, thread hasn't started yet */

        return;

    } else if ( error != JVMTI_ERROR_NONE ) {

        /* The jthread object must be valid, so this must be a fatal error */

        EXIT_ERROR(error, "cannot set thread local storage");

    }

}

/* Get TLS on a specific jthread, which is the ThreadNode* */

static ThreadNode *

getThreadLocalStorage(jthread thread)

{

    jvmtiError  error;

    ThreadNode *node;

    node = NULL;

    error = JVMTI_FUNC_PTR(gdata->jvmti,GetThreadLocalStorage)

            (gdata->jvmti, thread, (void**)&node);

    if ( error == JVMTI_ERROR_THREAD_NOT_ALIVE ) {

        /* Just return NULL, thread hasn't started yet */

        return NULL;

    } else if ( error != JVMTI_ERROR_NONE ) {

        /* The jthread object must be valid, so this must be a fatal error */

        EXIT_ERROR(error, "cannot get thread local storage");

    }

    return node;

}

/* Search list for nodes that don't have TLS set and match this thread.

 *   It assumed that this logic is never dealing with terminated threads,

 *   since the ThreadEnd events always delete the ThreadNode while the

 *   jthread is still alive.  So we can only look at the ThreadNode's that

 *   have never had their TLS set, making the search much faster.

 *   But keep in mind, this kind of search should rarely be needed.

 */

static ThreadNode *

nonTlsSearch(JNIEnv *env, ThreadList *list, jthread thread)

{

    ThreadNode *node;

    for (node = list->first; node != NULL; node = node->next) {

        if (isSameObject(env, node->thread, thread)) {

            break;

        }

    }

    return node;

}

/*

 * These functions maintain the linked list of currently running threads.

 * All assume that the threadLock is held before calling.

 * If list==NULL, search both lists.

 */

static ThreadNode *

findThread(ThreadList *list, jthread thread)

{

    ThreadNode *node;

    /* Get thread local storage for quick thread -> node access */

    node = getThreadLocalStorage(thread);

    /* In some rare cases we might get NULL, so we check the list manually for

     *   any threads that we could match.

     */

    if ( node == NULL ) {

        JNIEnv *env;

        env = getEnv();

        if ( list != NULL ) {

            node = nonTlsSearch(env, list, thread);

        } else {

            node = nonTlsSearch(env, &runningThreads, thread);

            if ( node == NULL ) {

                node = nonTlsSearch(env, &otherThreads, thread);

            }

        }

        if ( node != NULL ) {

            /* Here we make another attempt to set TLS, it's ok if this fails */

            setThreadLocalStorage(thread, (void*)node);

        }

    }

    /* If a list is supplied, only return ones in this list */

    if ( node != NULL && list != NULL && node->list != list ) {

        return NULL;

    }

    return node;

}

/* Remove a ThreadNode from a ThreadList */

static void

removeNode(ThreadList *list, ThreadNode *node)

{

    ThreadNode *prev;

    ThreadNode *next;

    prev = node->prev;

    next = node->next;

    if ( prev != NULL ) {

        prev->next = next;

    }

    if ( next != NULL ) {

        next->prev = prev;

    }

    if ( prev == NULL ) {

        list->first = next;

    }

    node->next = NULL;

    node->prev = NULL;

    node->list = NULL;

}

/* Add a ThreadNode to a ThreadList */

static void

addNode(ThreadList *list, ThreadNode *node)

{

    node->next = NULL;

    node->prev = NULL;

    node->list = NULL;

    if ( list->first == NULL ) {

        list->first = node;

    } else {

        list->first->prev = node;

        node->next = list->first;

        list->first = node;

    }

    node->list = list;

}

static ThreadNode *

insertThread(JNIEnv *env, ThreadList *list, jthread thread)

{

    ThreadNode *node;

    struct bag *eventBag;

    node = findThread(list, thread);

    if (node == NULL) {

        node = jvmtiAllocate(sizeof(*node));

        if (node == NULL) {

            EXIT_ERROR(AGENT_ERROR_OUT_OF_MEMORY,"thread table entry");

            return NULL;

        }

        (void)memset(node, 0, sizeof(*node));

        eventBag = eventHelper_createEventBag();

        if (eventBag == NULL) {

            jvmtiDeallocate(node);

            EXIT_ERROR(AGENT_ERROR_OUT_OF_MEMORY,"thread table entry");

            return NULL;

        }

        /*

         * Init all flags false, all refs NULL, all counts 0

         */

        saveGlobalRef(env, thread, &(node->thread));

        if (node->thread == NULL) {

            jvmtiDeallocate(node);

            bagDestroyBag(eventBag);

            EXIT_ERROR(AGENT_ERROR_OUT_OF_MEMORY,"thread table entry");

            return NULL;

        }

        /*

         * Remember if it is a debug thread

         */

        if (threadControl_isDebugThread(node->thread)) {

            node->isDebugThread = JNI_TRUE;

        } else if (suspendAllCount > 0){

            /*

             * If there is a pending suspendAll, all new threads should

             * be initialized as if they were suspended by the suspendAll,

             * and the thread will need to be suspended when it starts.

             */

            node->suspendCount = suspendAllCount;

            node->suspendOnStart = JNI_TRUE;

        }

        node->current_ei = 0;

        node->instructionStepMode = JVMTI_DISABLE;

        node->eventBag = eventBag;

        addNode(list, node);

        /* Set thread local storage for quick thread -> node access.

         *   Some threads may not be in a state that allows setting of TLS,

         *   which is ok, see findThread, it deals with threads without TLS set.

         */

        setThreadLocalStorage(node->thread, (void*)node);

    }

    return node;

}

static void

clearThread(JNIEnv *env, ThreadNode *node)

{

    if (node->pendingStop != NULL) {

        tossGlobalRef(env, &(node->pendingStop));

    }

    stepControl_clearRequest(node->thread, &node->currentStep);

    if (node->isDebugThread) {

        (void)threadControl_removeDebugThread(node->thread);

    }

    /* Clear out TLS on this thread (just a cleanup action) */

    setThreadLocalStorage(node->thread, NULL);

    tossGlobalRef(env, &(node->thread));

    bagDestroyBag(node->eventBag);

    jvmtiDeallocate(node);

}

static void

removeThread(JNIEnv *env, ThreadList *list, jthread thread)

{

    ThreadNode *node;

    node = findThread(list, thread);

    if (node != NULL) {

        removeNode(list, node);

        clearThread(env, node);

    }

}

static void

removeResumed(JNIEnv *env, ThreadList *list)

{

    ThreadNode *node;

    node = list->first;

    while (node != NULL) {

        ThreadNode *temp = node->next;

        if (node->suspendCount == 0) {

            removeThread(env, list, node->thread);

        }

        node = temp;

    }

}

static void

moveNode(ThreadList *source, ThreadList *dest, ThreadNode *node)

{

    removeNode(source, node);

    JDI_ASSERT(findThread(dest, node->thread) == NULL);

    addNode(dest, node);

}

typedef jvmtiError (*ThreadEnumerateFunction)(JNIEnv *, ThreadNode *, void *);

static jvmtiError

enumerateOverThreadList(JNIEnv *env, ThreadList *list,

                        ThreadEnumerateFunction function, void *arg)

{

    ThreadNode *node;

    jvmtiError error = JVMTI_ERROR_NONE;

    for (node = list->first; node != NULL; node = node->next) {

        error = (*function)(env, node, arg);

        if ( error != JVMTI_ERROR_NONE ) {

            break;

        }

    }

    return error;

}

static void

insertEventMode(DeferredEventModeList *list, DeferredEventMode *eventMode)

{

    if (list->last != NULL) {

        list->last->next = eventMode;

    } else {

        list->first = eventMode;

    }

    list->last = eventMode;

}

static void

removeEventMode(DeferredEventModeList *list, DeferredEventMode *eventMode, DeferredEventMode *prev)

{

    if (prev == NULL) {

        list->first = eventMode->next;

    } else {

        prev->next = eventMode->next;

    }

    if (eventMode->next == NULL) {

        list->last = prev;

    }

}

static jvmtiError

addDeferredEventMode(JNIEnv *env, jvmtiEventMode mode, EventIndex ei, jthread thread)

{

    DeferredEventMode *eventMode;

    /*LINTED*/

    eventMode = jvmtiAllocate((jint)sizeof(DeferredEventMode));

    if (eventMode == NULL) {

        return AGENT_ERROR_OUT_OF_MEMORY;

    }

    eventMode->thread = NULL;

    saveGlobalRef(env, thread, &(eventMode->thread));

    eventMode->mode = mode;

    eventMode->ei = ei;

    eventMode->next = NULL;

    insertEventMode(&deferredEventModes, eventMode);

    return JVMTI_ERROR_NONE;

}

static void

freeDeferredEventModes(JNIEnv *env)

{

    DeferredEventMode *eventMode;

    eventMode = deferredEventModes.first;

    while (eventMode != NULL) {

        DeferredEventMode *next;

        next = eventMode->next;

        tossGlobalRef(env, &(eventMode->thread));

        jvmtiDeallocate(eventMode);

        eventMode = next;

    }

    deferredEventModes.first = NULL;

    deferredEventModes.last = NULL;

}

static jvmtiError

threadSetEventNotificationMode(ThreadNode *node,

        jvmtiEventMode mode, EventIndex ei, jthread thread)

{

    jvmtiError error;

    /* record single step mode */

    if (ei == EI_SINGLE_STEP) {

        node->instructionStepMode = mode;

    }

    error = JVMTI_FUNC_PTR(gdata->jvmti,SetEventNotificationMode)

        (gdata->jvmti, mode, eventIndex2jvmti(ei), thread);

    return error;

}

static void

processDeferredEventModes(JNIEnv *env, jthread thread, ThreadNode *node)

{

    jvmtiError error;

    DeferredEventMode *eventMode;

    DeferredEventMode *prev;

    prev = NULL;

    eventMode = deferredEventModes.first;

    while (eventMode != NULL) {

        DeferredEventMode *next = eventMode->next;

        if (isSameObject(env, thread, eventMode->thread)) {

            error = threadSetEventNotificationMode(node,

                    eventMode->mode, eventMode->ei, eventMode->thread);

            if (error != JVMTI_ERROR_NONE) {

                EXIT_ERROR(error, "cannot process deferred thread event notifications at thread start");

            }

            removeEventMode(&deferredEventModes, eventMode, prev);

            tossGlobalRef(env, &(eventMode->thread));

            jvmtiDeallocate(eventMode);

        } else {

            prev = eventMode;

        }

        eventMode = next;