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#define FUTEX_HT_SIZE   1024    /* keep it a power of 2 */
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#define FUTEX_HT_SIZE   1024    /* keep it a power of 2 */
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static void futex_initialize(futex_t *futex);
 54 
static void futex_initialize(futex_t *futex);
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 55 
 
- 
 
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static futex_t *futex_find(__address paddr);
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static index_t futex_ht_hash(__native *key);
 57 
static index_t futex_ht_hash(__native *key);
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static bool futex_ht_compare(__native *key, count_t keys, link_t *item);
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static bool futex_ht_compare(__native *key, count_t keys, link_t *item);
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static void futex_ht_remove_callback(link_t *item);
 59 
static void futex_ht_remove_callback(link_t *item);
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/** Read-write lock protecting global futex hash table. */
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/** Read-write lock protecting global futex hash table. */
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 */
 100 
 */
100 
__native sys_futex_sleep_timeout(__address uaddr, __u32 usec, int trydown)
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__native sys_futex_sleep_timeout(__address uaddr, __u32 usec, int trydown)
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{
 102 
{
102 
    futex_t *futex;
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    futex_t *futex;
103 
    __address paddr;
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    __address paddr;
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    link_t *item;
 - 
 
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    pte_t *t;
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    pte_t *t;
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    ipl_t ipl;
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    ipl_t ipl;
107 
   
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    ipl = interrupts_disable();
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    ipl = interrupts_disable();
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    paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
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    paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
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    page_table_unlock(AS, true);
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    page_table_unlock(AS, true);
122 
   
 122 
   
123 
    interrupts_restore(ipl);   
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    interrupts_restore(ipl);   
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 124 
 
125 
    /*
 - 
 
126 
     * Find the respective futex structure
 - 
 
127 
     * or allocate new one if it does not exist already.
 - 
 
128 
     */
 - 
 
129 
    rwlock_read_lock(&futex_ht_lock);
 - 
 
130 
    item = hash_table_find(&futex_ht, &paddr);
 - 
 
131 
    if (item) {
 - 
 
132 
        futex = hash_table_get_instance(item, futex_t, ht_link);
 - 
 
133 
        rwlock_read_unlock(&futex_ht_lock);
 - 
 
134 
    } else {
 - 
 
135 
        /*
 - 
 
136 
         * Upgrade to writer is not currently supported,
 - 
 
137 
         * Therefore, it is necessary to release the read lock
 - 
 
138 
         * and reacquire it as a writer.
 - 
 
139 
         */
 - 
 
140 
        rwlock_read_unlock(&futex_ht_lock);
 - 
 
141 
 
 - 
 
142 
        rwlock_write_lock(&futex_ht_lock);
 - 
 
143 
        /*
 - 
 
144 
         * Detect possible race condition by searching
 - 
 
145 
         * the hash table once again with write access.
 - 
 
146 
         */
 - 
 
147 
        item = hash_table_find(&futex_ht, &paddr);
 - 
 
148 
        if (item) {
 - 
 
149 
            futex = hash_table_get_instance(item, futex_t, ht_link);
 - 
 
150 
            rwlock_write_unlock(&futex_ht_lock);
 - 
 
151 
        } else {
 - 
 
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            futex = (futex_t *) malloc(sizeof(futex_t), 0);
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            futex_initialize(futex);
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            futex->paddr = paddr;
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    futex = futex_find(paddr);
155 
            hash_table_insert(&futex_ht, &paddr, &futex->ht_link);
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            rwlock_write_unlock(&futex_ht_lock);
 - 
 
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        }
 - 
 
158 
    }
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159 
   
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    return (__native) waitq_sleep_timeout(&futex->wq, usec, trydown);
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    return (__native) waitq_sleep_timeout(&futex->wq, usec, trydown);
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}
 128 
}
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163 
/** Wakeup one thread waiting in futex wait queue.
 130 
/** Wakeup one thread waiting in futex wait queue.
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 * @return ENOENT if there is no futex associated with the address
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 * @return ENOENT if there is no futex associated with the address
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 *     or if there is no physical mapping for uaddr.
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 *     or if there is no physical mapping for uaddr.
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 */
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 */
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__native sys_futex_wakeup(__address uaddr)
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__native sys_futex_wakeup(__address uaddr)
171 
{
 138 
{
172 
    futex_t *futex = NULL;
 139 
    futex_t *futex;
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    __address paddr;
 140 
    __address paddr;
174 
    link_t *item;
 - 
 
175 
    pte_t *t;
 141 
    pte_t *t;
176 
    ipl_t ipl;
 142 
    ipl_t ipl;
177 
   
 143 
   
178 
    ipl = interrupts_disable();
 144 
    ipl = interrupts_disable();
179 
   
 145 
   
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    paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
 156 
    paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
191 
    page_table_unlock(AS, true);
 157 
    page_table_unlock(AS, true);
192 
   
 158 
   
193 
    interrupts_restore(ipl);
 159 
    interrupts_restore(ipl);
194 
 
 160 
 
- 
 
 161 
    futex = futex_find(paddr);
- 
 
 162 
       
- 
 
 163 
    waitq_wakeup(&futex->wq, WAKEUP_FIRST);
- 
 
 164 
   
- 
 
 165 
    return 0;
- 
 
 166 
}
- 
 
 167 
 
- 
 
 168 
/** Find kernel address of the futex structure corresponding to paddr.
- 
 
 169 
 *
- 
 
 170 
 * If the structure does not exist alreay, a new one is created.
- 
 
 171 
 *
- 
 
 172 
 * @param paddr Physical address of the userspace futex counter.
- 
 
 173 
 *
- 
 
 174 
 * @return Address of the kernel futex structure.
- 
 
 175 
 */
- 
 
 176 
futex_t *futex_find(__address paddr)
- 
 
 177 
{
- 
 
 178 
    link_t *item;
- 
 
 179 
    futex_t *futex;
- 
 
 180 
   
195 
    /*
 181 
    /*
196 
     * Find the respective futex structure.
 182 
     * Find the respective futex structure
- 
 
 183 
     * or allocate new one if it does not exist already.
197 
     */
 184 
     */
198 
    rwlock_read_lock(&futex_ht_lock);
 185 
    rwlock_read_lock(&futex_ht_lock);
199 
    item = hash_table_find(&futex_ht, &paddr);
 186 
    item = hash_table_find(&futex_ht, &paddr);
200 
    if (item) {
 187 
    if (item) {
201 
        futex = hash_table_get_instance(item, futex_t, ht_link);
 188 
        futex = hash_table_get_instance(item, futex_t, ht_link);
- 
 
 189 
        rwlock_read_unlock(&futex_ht_lock);
- 
 
 190 
    } else {
202 
    }
 191 
        /*
- 
 
 192 
         * Upgrade to writer is not currently supported,
- 
 
 193 
         * Therefore, it is necessary to release the read lock
- 
 
 194 
         * and reacquire it as a writer.
- 
 
 195 
         */
203 
    rwlock_read_unlock(&futex_ht_lock);
 196 
        rwlock_read_unlock(&futex_ht_lock);
204 
 
 197 
 
- 
 
 198 
        rwlock_write_lock(&futex_ht_lock);
- 
 
 199 
        /*
- 
 
 200 
         * Avoid possible race condition by searching
- 
 
 201 
         * the hash table once again with write access.
- 
 
 202 
         */
- 
 
 203 
        item = hash_table_find(&futex_ht, &paddr);
205 
    if (!futex)
 204 
        if (item) {
- 
 
 205 
            futex = hash_table_get_instance(item, futex_t, ht_link);
- 
 
 206 
            rwlock_write_unlock(&futex_ht_lock);
- 
 
 207 
        } else {
- 
 
 208 
            futex = (futex_t *) malloc(sizeof(futex_t), 0);
206 
        return (__native) ENOENT;  
 209 
            futex_initialize(futex);
- 
 
 210 
            futex->paddr = paddr;
- 
 
 211 
            hash_table_insert(&futex_ht, &paddr, &futex->ht_link);
- 
 
 212 
            rwlock_write_unlock(&futex_ht_lock);
207 
       
 213 
        }
208 
    waitq_wakeup(&futex->wq, WAKEUP_FIRST);
 - 
 
- 
 
 214 
    }
209 
   
 215 
   
210 
    return 0;
 216 
    return futex;
211 
}
 217 
}
212 
 
 218 
 
213 
/** Compute hash index into futex hash table.
 219 
/** Compute hash index into futex hash table.
214 
 *
 220 
 *
215 
 * @param key Address where the key (i.e. physical address of futex counter) is stored.
 221 
 * @param key Address where the key (i.e. physical address of futex counter) is stored.