8f55767619
By making m_in job local (i.e., each job has its own copy of m_in instead of refering to the global m_in) we don't have to store and restore m_in on every thread yield. This reduces overhead. Moreover, remove the assumption that m_in is preserved. Do_XXX functions have to copy the system call parameters as soon as possible and only pass those copies to other functions. Furthermore, this patch cleans up some code and uses better types in a lot of places.
396 lines
12 KiB
C
396 lines
12 KiB
C
#include "fs.h"
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#include "glo.h"
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#include "fproc.h"
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#include "threads.h"
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#include "job.h"
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#include <assert.h>
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static void append_job(struct job *job, void *(*func)(void *arg));
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static void get_work(struct worker_thread *worker);
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static void *worker_main(void *arg);
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static void worker_sleep(struct worker_thread *worker);
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static void worker_wake(struct worker_thread *worker);
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static int worker_waiting_for(struct worker_thread *worker, endpoint_t
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proc_e);
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static int init = 0;
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static mthread_attr_t tattr;
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#ifdef MKCOVERAGE
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# define TH_STACKSIZE (10 * 1024)
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#else
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# define TH_STACKSIZE (7 * 1024)
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#endif
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#define ASSERTW(w) assert((w) == &sys_worker || (w) == &dl_worker || \
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((w) >= &workers[0] && (w) < &workers[NR_WTHREADS]));
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/*===========================================================================*
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* worker_init *
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*===========================================================================*/
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void worker_init(struct worker_thread *wp)
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{
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/* Initialize worker thread */
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if (!init) {
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threads_init();
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if (mthread_attr_init(&tattr) != 0)
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panic("failed to initialize attribute");
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if (mthread_attr_setstacksize(&tattr, TH_STACKSIZE) != 0)
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panic("couldn't set default thread stack size");
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if (mthread_attr_setdetachstate(&tattr, MTHREAD_CREATE_DETACHED) != 0)
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panic("couldn't set default thread detach state");
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invalid_thread_id = mthread_self(); /* Assuming we're the main thread*/
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pending = 0;
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init = 1;
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}
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ASSERTW(wp);
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wp->w_job.j_func = NULL; /* Mark not in use */
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wp->w_next = NULL;
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if (mutex_init(&wp->w_event_mutex, NULL) != 0)
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panic("failed to initialize mutex");
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if (cond_init(&wp->w_event, NULL) != 0)
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panic("failed to initialize conditional variable");
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if (mthread_create(&wp->w_tid, &tattr, worker_main, (void *) wp) != 0)
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panic("unable to start thread");
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yield();
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}
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/*===========================================================================*
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* get_work *
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*===========================================================================*/
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static void get_work(struct worker_thread *worker)
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{
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/* Find new work to do. Work can be 'queued', 'pending', or absent. In the
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* latter case wait for new work to come in. */
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struct job *new_job;
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struct fproc *rfp;
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ASSERTW(worker);
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self = worker;
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/* Do we have queued work to do? */
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if ((new_job = worker->w_job.j_next) != NULL) {
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worker->w_job = *new_job;
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free(new_job);
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return;
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} else if (worker != &sys_worker && worker != &dl_worker && pending > 0) {
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/* Find pending work */
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for (rfp = &fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
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if (rfp->fp_flags & FP_PENDING) {
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worker->w_job = rfp->fp_job;
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rfp->fp_job.j_func = NULL;
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rfp->fp_flags &= ~FP_PENDING; /* No longer pending */
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pending--;
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assert(pending >= 0);
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return;
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}
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}
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panic("Pending work inconsistency");
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}
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/* Wait for work to come to us */
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worker_sleep(worker);
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}
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/*===========================================================================*
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* worker_available *
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*===========================================================================*/
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int worker_available(void)
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{
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int busy, i;
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busy = 0;
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for (i = 0; i < NR_WTHREADS; i++) {
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if (workers[i].w_job.j_func != NULL)
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busy++;
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}
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return(NR_WTHREADS - busy);
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}
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/*===========================================================================*
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* worker_main *
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*===========================================================================*/
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static void *worker_main(void *arg)
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{
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/* Worker thread main loop */
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struct worker_thread *me;
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me = (struct worker_thread *) arg;
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ASSERTW(me);
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while(TRUE) {
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get_work(me);
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/* Register ourselves in fproc table if possible */
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if (me->w_job.j_fp != NULL) {
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me->w_job.j_fp->fp_wtid = me->w_tid;
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}
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/* Carry out work */
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me->w_job.j_func(&me->w_job);
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/* Deregister if possible */
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if (me->w_job.j_fp != NULL) {
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me->w_job.j_fp->fp_wtid = invalid_thread_id;
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}
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/* Mark ourselves as done */
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me->w_job.j_func = NULL;
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me->w_job.j_fp = NULL;
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}
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return(NULL); /* Unreachable */
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}
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/*===========================================================================*
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* dl_worker_start *
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*===========================================================================*/
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void dl_worker_start(void *(*func)(void *arg))
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{
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/* Start the deadlock resolving worker. This worker is reserved to run in case
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* all other workers are busy and we have to have an additional worker to come
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* to the rescue. */
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assert(dl_worker.w_job.j_func == NULL);
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if (dl_worker.w_job.j_func == NULL) {
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dl_worker.w_job.j_fp = fp;
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dl_worker.w_job.j_m_in = m_in;
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dl_worker.w_job.j_func = func;
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worker_wake(&dl_worker);
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}
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}
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/*===========================================================================*
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* sys_worker_start *
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*===========================================================================*/
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void sys_worker_start(void *(*func)(void *arg))
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{
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/* Carry out work for the system (i.e., kernel or PM). If this thread is idle
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* do it right away, else create new job and append it to the queue. */
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if (sys_worker.w_job.j_func == NULL) {
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sys_worker.w_job.j_fp = fp;
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sys_worker.w_job.j_m_in = m_in;
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sys_worker.w_job.j_func = func;
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worker_wake(&sys_worker);
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} else {
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append_job(&sys_worker.w_job, func);
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}
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}
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/*===========================================================================*
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* append_job *
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*===========================================================================*/
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static void append_job(struct job *job, void *(*func)(void *arg))
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{
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/* Append a job */
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struct job *new_job, *tail;
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/* Create new job */
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new_job = calloc(1, sizeof(struct job));
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assert(new_job != NULL);
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new_job->j_fp = fp;
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new_job->j_m_in = m_in;
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new_job->j_func = func;
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new_job->j_next = NULL;
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new_job->j_err_code = OK;
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/* Append to queue */
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tail = job;
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while (tail->j_next != NULL) tail = tail->j_next;
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tail->j_next = new_job;
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}
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/*===========================================================================*
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* worker_start *
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*===========================================================================*/
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void worker_start(void *(*func)(void *arg))
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{
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/* Find an available worker or wait for one */
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int i;
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struct worker_thread *worker;
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if (fp->fp_flags & FP_DROP_WORK) {
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return; /* This process is not allowed to accept new work */
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}
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worker = NULL;
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for (i = 0; i < NR_WTHREADS; i++) {
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if (workers[i].w_job.j_func == NULL) {
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worker = &workers[i];
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break;
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}
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}
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if (worker != NULL) {
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worker->w_job.j_fp = fp;
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worker->w_job.j_m_in = m_in;
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worker->w_job.j_func = func;
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worker->w_job.j_next = NULL;
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worker->w_job.j_err_code = OK;
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worker_wake(worker);
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return;
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}
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/* No worker threads available, let's wait for one to finish. */
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/* If this process already has a job scheduled, forget about this new
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* job;
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* - the new job is do_dummy and we have already scheduled an actual job
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* - the new job is an actual job and we have already scheduled do_dummy in
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* order to exit this proc, so doing the new job is pointless. */
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if (fp->fp_job.j_func == NULL) {
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assert(!(fp->fp_flags & FP_PENDING));
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fp->fp_job.j_fp = fp;
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fp->fp_job.j_m_in = m_in;
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fp->fp_job.j_func = func;
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fp->fp_job.j_next = NULL;
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fp->fp_job.j_err_code = OK;
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fp->fp_flags |= FP_PENDING;
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pending++;
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}
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}
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/*===========================================================================*
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* worker_sleep *
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*===========================================================================*/
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static void worker_sleep(struct worker_thread *worker)
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{
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ASSERTW(worker);
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assert(self == worker);
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if (mutex_lock(&worker->w_event_mutex) != 0)
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panic("unable to lock event mutex");
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if (cond_wait(&worker->w_event, &worker->w_event_mutex) != 0)
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panic("could not wait on conditional variable");
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if (mutex_unlock(&worker->w_event_mutex) != 0)
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panic("unable to unlock event mutex");
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self = worker;
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}
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/*===========================================================================*
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* worker_wake *
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*===========================================================================*/
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static void worker_wake(struct worker_thread *worker)
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{
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/* Signal a worker to wake up */
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ASSERTW(worker);
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if (mutex_lock(&worker->w_event_mutex) != 0)
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panic("unable to lock event mutex");
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if (cond_signal(&worker->w_event) != 0)
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panic("unable to signal conditional variable");
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if (mutex_unlock(&worker->w_event_mutex) != 0)
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panic("unable to unlock event mutex");
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}
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/*===========================================================================*
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* worker_wait *
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*===========================================================================*/
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void worker_wait(void)
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{
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self->w_job.j_err_code = err_code;
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assert(fp == self->w_job.j_fp);
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worker_sleep(self);
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/* We continue here after waking up */
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fp = self->w_job.j_fp; /* Restore global data */
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err_code = self->w_job.j_err_code;
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assert(self->w_next == NULL);
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}
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/*===========================================================================*
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* worker_signal *
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*===========================================================================*/
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void worker_signal(struct worker_thread *worker)
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{
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ASSERTW(worker); /* Make sure we have a valid thread */
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worker_wake(worker);
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}
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/*===========================================================================*
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* worker_stop *
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*===========================================================================*/
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void worker_stop(struct worker_thread *worker)
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{
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ASSERTW(worker); /* Make sure we have a valid thread */
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if (worker->w_job.j_fp)
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worker->w_job.j_fp->fp_sendrec->m_type = EIO;
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else
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worker->w_job.j_m_in.m_type = EIO;
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worker_wake(worker);
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}
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/*===========================================================================*
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* worker_stop_by_endpt *
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*===========================================================================*/
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void worker_stop_by_endpt(endpoint_t proc_e)
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{
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struct worker_thread *worker;
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int i;
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if (proc_e == NONE) return;
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if (worker_waiting_for(&sys_worker, proc_e)) worker_stop(&sys_worker);
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if (worker_waiting_for(&dl_worker, proc_e)) worker_stop(&dl_worker);
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for (i = 0; i < NR_WTHREADS; i++) {
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worker = &workers[i];
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if (worker_waiting_for(worker, proc_e))
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worker_stop(worker);
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}
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}
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/*===========================================================================*
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* worker_get *
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*===========================================================================*/
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struct worker_thread *worker_get(thread_t worker_tid)
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{
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int i;
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struct worker_thread *worker;
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worker = NULL;
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if (worker_tid == sys_worker.w_tid)
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worker = &sys_worker;
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else if (worker_tid == dl_worker.w_tid)
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worker = &dl_worker;
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else {
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for (i = 0; i < NR_WTHREADS; i++) {
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if (workers[i].w_tid == worker_tid) {
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worker = &workers[i];
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break;
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}
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}
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}
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return(worker);
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}
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/*===========================================================================*
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* worker_getjob *
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*===========================================================================*/
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struct job *worker_getjob(thread_t worker_tid)
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{
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struct worker_thread *worker;
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if ((worker = worker_get(worker_tid)) != NULL)
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return(&worker->w_job);
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return(NULL);
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}
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/*===========================================================================*
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* worker_waiting_for *
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*===========================================================================*/
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static int worker_waiting_for(struct worker_thread *worker, endpoint_t proc_e)
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{
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ASSERTW(worker); /* Make sure we have a valid thread */
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if (worker->w_job.j_func != NULL) {
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if (worker->w_job.j_fp != NULL) {
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return(worker->w_job.j_fp->fp_task == proc_e);
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}
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}
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return(0);
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}
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