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Ignore whitespace Rev 2480 → Rev 2481

/trunk/uspace/lib/libc/include/psthread.h
49,9 → 49,10
#define PSTHREAD_SERIALIZED 1
 
typedef enum {
PS_SLEEP,
PS_PREEMPT,
PS_TO_MANAGER,
PS_FROM_MANAGER,
PS_PREEMPT,
PS_FROM_DEAD
} pschange_type;
 
65,8 → 66,9
int (*func)(void *);
tcb_t *tcb;
 
struct psthread_data *waiter;
int finished;
struct psthread_data *clean_after_me;
struct psthread_data *joiner;
int joinee_retval;
int retval;
int flags;
};
87,11 → 89,10
void psthread_inc_sercount(void);
void psthread_dec_sercount(void);
 
static inline int psthread_schedule_next() {
static inline int psthread_schedule_next(void) {
return psthread_schedule_next_adv(PS_PREEMPT);
}
 
 
#endif
 
/** @}
/trunk/uspace/lib/libc/generic/psthread.c
1,5 → 1,6
/*
* Copyright (c) 2006 Ondrej Palkovsky
* Copyright (c) 2007 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
44,7 → 45,7
#include <async.h>
 
#ifndef PSTHREAD_INITIAL_STACK_PAGES_NO
#define PSTHREAD_INITIAL_STACK_PAGES_NO 1
#define PSTHREAD_INITIAL_STACK_PAGES_NO 1
#endif
 
static LIST_INITIALIZE(ready_list);
55,7 → 56,7
 
static atomic_t psthread_futex = FUTEX_INITIALIZER;
/** Count of real threads that are in async_serialized mode */
static int serialized_threads; /* Protected by async_futex */
static int serialized_threads; /* Protected by async_futex */
/** Thread-local count of serialization. If >0, we must not preempt */
static __thread int serialization_count;
/** Counter of threads residing in async_manager */
62,7 → 63,7
static int threads_in_manager;
 
/** Setup psthread information into TCB structure */
psthread_data_t * psthread_setup()
psthread_data_t *psthread_setup(void)
{
psthread_data_t *pt;
tcb_t *tcb;
89,7 → 90,14
free(pt);
}
 
/** Function that is called on entry to new pseudo thread */
/** Function that spans the whole life-cycle of a pseudo thread.
*
* Each pseudo thread begins execution in this function.
* Then the function implementing the pseudo thread logic is called.
* After its return, the return value is saved for a potentional
* joiner. If the joiner exists, it is woken up. The pseudo thread
* then switches to another pseudo thread, which cleans up after it.
*/
void psthread_main(void)
{
psthread_data_t *pt = __tcb_get()->pst_data;
96,11 → 104,16
 
pt->retval = pt->func(pt->arg);
 
pt->finished = 1;
if (pt->waiter)
list_append(&pt->waiter->link, &ready_list);
/*
* If there is a joiner, wake it up and save our return value.
*/
if (pt->joiner) {
list_append(&pt->joiner->link, &ready_list);
pt->joiner->joinee_retval = pt->retval;
}
 
psthread_schedule_next_adv(PS_FROM_DEAD);
/* not reached */
}
 
/** Schedule next userspace pseudo thread.
108,8 → 121,11
* If calling with PS_TO_MANAGER parameter, the async_futex should be
* held.
*
* @param ctype Type of switch.
* @return 0 if there is no ready pseudo thread, 1 otherwise.
* @param ctype One of PS_SLEEP, PS_PREEMPT, PS_TO_MANAGER,
* PS_FROM_MANAGER, PS_FROM_DEAD. The parameter describes
* the circumstances of the switch.
* @return Return 0 if there is no ready pseudo thread,
* return 1 otherwise.
*/
int psthread_schedule_next_adv(pschange_type ctype)
{
120,12 → 136,20
 
if (ctype == PS_PREEMPT && list_empty(&ready_list))
goto ret_0;
if (ctype == PS_SLEEP) {
if (list_empty(&ready_list) && list_empty(&serialized_list))
goto ret_0;
}
 
if (ctype == PS_FROM_MANAGER) {
if (list_empty(&ready_list) && list_empty(&serialized_list))
goto ret_0;
/* Do not preempt if there is not sufficient count of thread managers */
if (list_empty(&serialized_list) && threads_in_manager <= serialized_threads) {
/*
* Do not preempt if there is not sufficient count of thread
* managers.
*/
if (list_empty(&serialized_list) && threads_in_manager <=
serialized_threads) {
goto ret_0;
}
}
138,45 → 162,70
}
}
srcpt = __tcb_get()->pst_data;
if (ctype != PS_FROM_DEAD) {
/* Save current state */
srcpt = __tcb_get()->pst_data;
if (!context_save(&srcpt->ctx)) {
if (serialization_count)
srcpt->flags &= ~PSTHREAD_SERIALIZED;
return 1; // futex_up already done here
if (srcpt->clean_after_me) {
/*
* Cleanup after the dead pseudo thread from
* which we restored context here.
*/
free(srcpt->clean_after_me->stack);
psthread_teardown(srcpt->clean_after_me);
srcpt->clean_after_me = NULL;
}
return 1; /* futex_up already done here */
}
 
/* Save myself to correct run list */
/* Save myself to the correct run list */
if (ctype == PS_PREEMPT)
list_append(&srcpt->link, &ready_list);
else if (ctype == PS_FROM_MANAGER) {
list_append(&srcpt->link, &manager_list);
threads_in_manager--;
} /* If ctype == PS_TO_MANAGER, don't save ourselves to any list, we should
* already be somewhere, or we will be lost */
} else
srcpt = NULL; /* Avoid GCC warning, if ctype == PS_FROM_DEAD, srcpt is not used */
} else {
/*
* If ctype == PS_TO_MANAGER, don't save ourselves to
* any list, we should already be somewhere, or we will
* be lost.
*
* The ctype == PS_SLEEP case is similar. The pseudo
* thread has an external refernce which can be used to
* wake it up once that time has come.
*/
}
}
 
/* Choose new thread to run */
if (ctype == PS_TO_MANAGER || ctype == PS_FROM_DEAD) {
dstpt = list_get_instance(manager_list.next,psthread_data_t, link);
dstpt = list_get_instance(manager_list.next, psthread_data_t,
link);
if (serialization_count && ctype == PS_TO_MANAGER) {
serialized_threads++;
srcpt->flags |= PSTHREAD_SERIALIZED;
}
threads_in_manager++;
 
if (ctype == PS_FROM_DEAD)
dstpt->clean_after_me = srcpt;
} else {
if (!list_empty(&serialized_list)) {
dstpt = list_get_instance(serialized_list.next, psthread_data_t, link);
dstpt = list_get_instance(serialized_list.next,
psthread_data_t, link);
serialized_threads--;
} else
dstpt = list_get_instance(ready_list.next, psthread_data_t, link);
} else {
dstpt = list_get_instance(ready_list.next,
psthread_data_t, link);
}
}
list_remove(&dstpt->link);
 
futex_up(&psthread_futex);
context_restore(&dstpt->ctx);
/* not reached */
 
ret_0:
futex_up(&psthread_futex);
185,36 → 234,40
 
/** Wait for uspace pseudo thread to finish.
*
* @param psthrid Pseudo thread to wait for.
* Each pseudo thread can be only joined by one other pseudo thread. Moreover,
* the joiner must be from the same thread as the joinee.
*
* @return Value returned by the finished thread.
* @param psthrid Pseudo thread to join.
*
* @return Value returned by the finished thread.
*/
int psthread_join(pstid_t psthrid)
{
volatile psthread_data_t *pt;
volatile int retval;
psthread_data_t *pt;
psthread_data_t *cur;
 
/* Handle psthrid = Kernel address -> it is wait for call */
pt = (psthread_data_t *) psthrid;
 
/* TODO */
printf("join unsupported\n");
_exit(1);
/*
* The joiner is running so the joinee isn't.
*/
cur = __tcb_get()->pst_data;
pt->joiner = cur;
psthread_schedule_next_adv(PS_SLEEP);
 
retval = pt->retval;
 
free(pt->stack);
psthread_teardown((void *)pt);
 
return retval;
/*
* The joinee fills in the return value.
*/
return cur->joinee_retval;
}
 
/** Create a userspace pseudo thread.
*
* @param func Pseudo thread function.
* @param arg Argument to pass to func.
* @param func Pseudo thread function.
* @param arg Argument to pass to func.
*
* @return 0 on failure, TLS of the new pseudo thread.
* @return Return 0 on failure or TLS of the new pseudo thread.
*/
pstid_t psthread_create(int (*func)(void *), void *arg)
{
223,7 → 276,8
pt = psthread_setup();
if (!pt)
return 0;
pt->stack = (char *) malloc(PSTHREAD_INITIAL_STACK_PAGES_NO*getpagesize());
pt->stack = (char *) malloc(PSTHREAD_INITIAL_STACK_PAGES_NO *
getpagesize());
 
if (!pt->stack) {
psthread_teardown(pt);
232,17 → 286,24
 
pt->arg= arg;
pt->func = func;
pt->finished = 0;
pt->waiter = NULL;
pt->clean_after_me = NULL;
pt->joiner = NULL;
pt->joinee_retval = 0;
pt->retval = 0;
pt->flags = 0;
 
context_save(&pt->ctx);
context_set(&pt->ctx, FADDR(psthread_main), pt->stack, PSTHREAD_INITIAL_STACK_PAGES_NO*getpagesize(), pt->tcb);
context_set(&pt->ctx, FADDR(psthread_main), pt->stack,
PSTHREAD_INITIAL_STACK_PAGES_NO * getpagesize(), pt->tcb);
 
return (pstid_t )pt;
return (pstid_t) pt;
}
 
/** Add a thread to ready list */
/** Add a thread to the ready list.
*
* @param psthrid Pinter to the pseudo thread structure of the
* pseudo thread to be added.
*/
void psthread_add_ready(pstid_t psthrid)
{
psthread_data_t *pt;
256,7 → 317,11
futex_up(&psthread_futex);
}
 
/** Add a thread to manager list */
/** Add a pseudo thread to the manager list.
*
* @param psthrid Pinter to the pseudo thread structure of the
* pseudo thread to be added.
*/
void psthread_add_manager(pstid_t psthrid)
{
psthread_data_t *pt;
269,7 → 334,7
}
 
/** Remove one manager from manager list */
void psthread_remove_manager()
void psthread_remove_manager(void)
{
futex_down(&psthread_futex);
if (list_empty(&manager_list)) {
280,19 → 345,22
futex_up(&psthread_futex);
}
 
/** Return thread id of current running thread */
/** Return thread id of the currently running thread.
*
* @return Pseudo thread ID of the currently running pseudo thread.
*/
pstid_t psthread_get_id(void)
{
return (pstid_t)__tcb_get()->pst_data;
return (pstid_t) __tcb_get()->pst_data;
}
 
/** Disable preemption
*
* If the thread wants to send several message in row and does not want
* to be preempted, it should start async_serialize_start() in the beginning
* of communication and async_serialize_end() in the end. If it is a
* true multithreaded application, it should protect the communication channel
* by a futex as well. Interrupt messages will can still be preempted.
* If the thread wants to send several message in a row and does not want to be
* preempted, it should start async_serialize_start() in the beginning of
* communication and async_serialize_end() in the end. If it is a true
* multithreaded application, it should protect the communication channel by a
* futex as well. Interrupt messages can still be preempted.
*/
void psthread_inc_sercount(void)
{
299,6 → 367,7
serialization_count++;
}
 
/** Restore the preemption counter to the previous state. */
void psthread_dec_sercount(void)
{
serialization_count--;
306,3 → 375,4
 
/** @}
*/