WebSVN – HelenOS-historic – Diff – //kernel/trunk/generic/src/synch/futex.c



 */
 
/**
 * Kernel backend for futexes.
 * Deallocation of orphaned kernel-side futex structures is not currently implemented.
 
 */
 
#include <synch/futex.h>
#include <synch/rwlock.h>
#include <synch/spinlock.h>
#include <synch/synch.h>
#include <mm/frame.h>
#include <mm/page.h>
#include <mm/slab.h>
#include <proc/thread.h>
#include <genarch/mm/page_pt.h>
#include <genarch/mm/page_ht.h>
#include <adt/hash_table.h>
#include <adt/list.h>
#include <arch.h>

}
 
/** Sleep in futex wait queue.
 *
 * @param uaddr Userspace address of the futex counter.
 * @param usec If non-zero, number of microseconds this thread is willing to sleep.
 * @param trydown If usec is zero and trydown is non-zero, conditional operation will be attempted.
 *
 * @return One of ESYNCH_TIMEOUT, ESYNCH_OK_ATOMIC and ESYNCH_OK_BLOCKED. See synch.h.
 *     If there is no physical mapping for uaddr ENOENT is returned.
 */
__native sys_futex_sleep_timeout(__address uaddr, __u32 usec, int trydown)
{
    futex_t *futex;
    __address paddr;
    link_t *item;
    pte_t *t;
    ipl_t ipl;
   
    ipl = interrupts_disable();
 
    /*
     * Find physical address of futex counter.
     */
    page_table_lock(AS, true);
    t = page_mapping_find(AS, ALIGN_DOWN(uaddr, PAGE_SIZE));
    if (!t || !PTE_VALID(t) || !PTE_PRESENT(t)) {
        page_table_unlock(AS, true);
        interrupts_restore(ipl);
        return (__native) ENOENT;
    }
    paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
    page_table_unlock(AS, true);
   
    interrupts_restore(ipl);   
 
    /*
     * Find the respective futex structure
     * or allocate new one if it does not exist already.
     */
    rwlock_read_lock(&futex_ht_lock);

            hash_table_insert(&futex_ht, &paddr, &futex->ht_link);
            rwlock_write_unlock(&futex_ht_lock);
        }
    }
   
    return (__native) waitq_sleep_timeout(&futex->wq, usec, trydown);
}
 
/** Wakeup one thread waiting in futex wait queue.
 *
 * @param uaddr Userspace address of the futex counter.

{
    futex_t *futex = NULL;
    __address paddr;
    link_t *item;
    pte_t *t;
    ipl_t ipl;
   
    ipl = interrupts_disable();
   
    /*
     * Find physical address of futex counter.
     */
    page_table_lock(AS, true);
    t = page_mapping_find(AS, ALIGN_DOWN(uaddr, PAGE_SIZE));
    if (!t || !PTE_VALID(t) || !PTE_PRESENT(t)) {
        page_table_unlock(AS, true);
        interrupts_restore(ipl);
        return (__native) ENOENT;
    }
    paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
    page_table_unlock(AS, true);
   
    interrupts_restore(ipl);
 
    /*
     * Find the respective futex structure.
     */
    rwlock_read_lock(&futex_ht_lock);
    item = hash_table_find(&futex_ht, &paddr);
    if (item) {
        futex = hash_table_get_instance(item, futex_t, ht_link);
    }
    rwlock_read_unlock(&futex_ht_lock);
 
    if (!futex)
        return (__native) ENOENT;  
       
    waitq_wakeup(&futex->wq, WAKEUP_FIRST);
   

Rev 1109	Rev 1117
Line 27...	Line 27...
27	*/	27	*/
28		28
29	/**	29	/**
30	* Kernel backend for futexes.	30	* Kernel backend for futexes.
31	* Deallocation of orphaned kernel-side futex structures is not currently implemented.	31	* Deallocation of orphaned kernel-side futex structures is not currently implemented.
32	* Timeouting futexes are currently not implemented.	-
33	*/	32	*/
34		33
35	#include <synch/futex.h>	34	#include <synch/futex.h>
36	#include <synch/rwlock.h>	35	#include <synch/rwlock.h>
-		36	#include <synch/spinlock.h>
37	#include <synch/synch.h>	37	#include <synch/synch.h>
38	#include <mm/frame.h>	38	#include <mm/frame.h>
39	#include <mm/page.h>	39	#include <mm/page.h>
40	#include <mm/slab.h>	40	#include <mm/slab.h>
-		41	#include <proc/thread.h>
41	#include <genarch/mm/page_pt.h>	42	#include <genarch/mm/page_pt.h>
42	#include <genarch/mm/page_ht.h>	43	#include <genarch/mm/page_ht.h>
43	#include <adt/hash_table.h>	44	#include <adt/hash_table.h>
44	#include <adt/list.h>	45	#include <adt/list.h>
45	#include <arch.h>	46	#include <arch.h>
Line 88...	Line 89...
88	}	89	}
89		90
90	/** Sleep in futex wait queue.	91	/** Sleep in futex wait queue.
91	*	92	*
92	* @param uaddr Userspace address of the futex counter.	93	* @param uaddr Userspace address of the futex counter.
-		94	* @param usec If non-zero, number of microseconds this thread is willing to sleep.
-		95	* @param trydown If usec is zero and trydown is non-zero, conditional operation will be attempted.
93	*	96	*
94	* @return One of ESYNCH_OK_ATOMIC and ESYNCH_OK_BLOCKED. See synch.h.	97	* @return One of ESYNCH_TIMEOUT, ESYNCH_OK_ATOMIC and ESYNCH_OK_BLOCKED. See synch.h.
95	* If there is no physical mapping for uaddr ENOENT is returned.	98	* If there is no physical mapping for uaddr ENOENT is returned.
96	*/	99	*/
97	__native sys_futex_sleep(__address uaddr)	100	__native sys_futex_sleep_timeout(__address uaddr, __u32 usec, int trydown)
98	{	101	{
99	futex_t *futex;	102	futex_t *futex;
100	__address paddr;	103	__address paddr;
101	link_t *item;	104	link_t *item;
102	pte_t *t;	105	pte_t *t;
-		106	ipl_t ipl;
103		107
-		108	ipl = interrupts_disable();
-		109
104	/*	110	/*
105	* Find physical address of futex counter.	111	* Find physical address of futex counter.
106	*/	112	*/
107	page_table_lock(AS, true);	113	page_table_lock(AS, true);
108	t = page_mapping_find(AS, ALIGN_DOWN(uaddr, PAGE_SIZE));	114	t = page_mapping_find(AS, ALIGN_DOWN(uaddr, PAGE_SIZE));
109	if (!t \|\| !PTE_VALID(t) \|\| !PTE_PRESENT(t)) {	115	if (!t \|\| !PTE_VALID(t) \|\| !PTE_PRESENT(t)) {
110	page_table_unlock(AS, true);	116	page_table_unlock(AS, true);
-		117	interrupts_restore(ipl);
111	return (__native) ENOENT;	118	return (__native) ENOENT;
112	}	119	}
113	paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));	120	paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
114	page_table_unlock(AS, true);	121	page_table_unlock(AS, true);
115		122
-		123	interrupts_restore(ipl);
-		124
116	/*	125	/*
117	* Find the respective futex structure	126	* Find the respective futex structure
118	* or allocate new one if it does not exist already.	127	* or allocate new one if it does not exist already.
119	*/	128	*/
120	rwlock_read_lock(&futex_ht_lock);	129	rwlock_read_lock(&futex_ht_lock);
Line 146...	Line 155...
146	hash_table_insert(&futex_ht, &paddr, &futex->ht_link);	155	hash_table_insert(&futex_ht, &paddr, &futex->ht_link);
147	rwlock_write_unlock(&futex_ht_lock);	156	rwlock_write_unlock(&futex_ht_lock);
148	}	157	}
149	}	158	}
150		159
151	return (__native) waitq_sleep(&futex->wq);	160	return (__native) waitq_sleep_timeout(&futex->wq, usec, trydown);
152	}	161	}
153		162
154	/** Wakeup one thread waiting in futex wait queue.	163	/** Wakeup one thread waiting in futex wait queue.
155	*	164	*
156	* @param uaddr Userspace address of the futex counter.	165	* @param uaddr Userspace address of the futex counter.
Line 162...	Line 171...
162	{	171	{
163	futex_t *futex = NULL;	172	futex_t *futex = NULL;
164	__address paddr;	173	__address paddr;
165	link_t *item;	174	link_t *item;
166	pte_t *t;	175	pte_t *t;
-		176	ipl_t ipl;
-		177
-		178	ipl = interrupts_disable();
167		179
168	/*	180	/*
169	* Find physical address of futex counter.	181	* Find physical address of futex counter.
170	*/	182	*/
171	page_table_lock(AS, true);	183	page_table_lock(AS, true);
172	t = page_mapping_find(AS, ALIGN_DOWN(uaddr, PAGE_SIZE));	184	t = page_mapping_find(AS, ALIGN_DOWN(uaddr, PAGE_SIZE));
173	if (!t \|\| !PTE_VALID(t) \|\| !PTE_PRESENT(t)) {	185	if (!t \|\| !PTE_VALID(t) \|\| !PTE_PRESENT(t)) {
174	page_table_unlock(AS, true);	186	page_table_unlock(AS, true);
-		187	interrupts_restore(ipl);
175	return (__native) ENOENT;	188	return (__native) ENOENT;
176	}	189	}
177	paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));	190	paddr = PFN2ADDR(PTE_GET_FRAME(t)) + (uaddr - ALIGN_DOWN(uaddr, PAGE_SIZE));
178	page_table_unlock(AS, true);	191	page_table_unlock(AS, true);
179		192
-		193	interrupts_restore(ipl);
-		194
180	/*	195	/*
181	* Find the respective futex structure.	196	* Find the respective futex structure.
182	*/	197	*/
183	rwlock_read_lock(&futex_ht_lock);	198	rwlock_read_lock(&futex_ht_lock);
184	item = hash_table_find(&futex_ht, &paddr);	199	item = hash_table_find(&futex_ht, &paddr);
185	if (item) {	200	if (item) {
186	futex = hash_table_get_instance(item, futex_t, ht_link);	201	futex = hash_table_get_instance(item, futex_t, ht_link);
187	}	202	}
188	rwlock_read_unlock(&futex_ht_lock);	203	rwlock_read_unlock(&futex_ht_lock);
189		204
190	if (!futex)	205	if (!futex)
191	return (__native) ENOENT;	206	return (__native) ENOENT;
192		207
193	waitq_wakeup(&futex->wq, WAKEUP_FIRST);	208	waitq_wakeup(&futex->wq, WAKEUP_FIRST);
194		209

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(root)//kernel/trunk/generic/src/synch/futex.c – Rev 1109 → 1117