condvar.c

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#include <condvar.h>
#include <tpa.h>
#include <vm.h>
#include <log.h>
#include <scheduler.h>
#include <unused_param.h>
 
struct condvar_data {
    uint64_t wait_count;
};
 
static tpa_t*   condvars;
static uint64_t next_condvar = 1;
 
void init_condvar(void) {
    condvars = tpa_new(&kernel_alloc, sizeof(struct condvar_data), 4080, 0);
}
 
void sc_handle_locking_create_condvar(uint64_t* cv, uint64_t* e) {
    if(!next_condvar) {
        *e = 12; // ENOMEM TODO: errno.h
        logw("condvar", "CondVar namespace overflow!");
        return;
    }
 
    struct condvar_data data = {
        .wait_count = 0,
    };
 
    tpa_set(condvars, next_condvar, &data);
 
    logd("condvar", "Created new condvar %u", next_condvar);
    *cv = next_condvar++;
    *e  = 0;
}
 
void sc_handle_locking_destroy_condvar(uint64_t condvar, uint64_t* e) {
    struct condvar_data* data = tpa_get(condvars, condvar);
 
    if(!data) {
        *e = 22; // EINVAL
        return;
    }
    else if(data->wait_count) {
        *e = 16; // EBUSY
        return;
    }
 
    tpa_set(condvars, condvar, 0);
    logd("condvar", "Created new condvar %u", next_condvar);
    *e  = 0;
}
 
void sc_handle_locking_signal_condvar(uint64_t condvar, uint64_t amount, uint64_t* e) {
    struct condvar_data* data = tpa_get(condvars, condvar);
 
    if(!data) {
        *e = 22; // EINVAL
        return;
    }
    else if(data->wait_count) {
        *e = 0;
 
        union wait_data wd;
        wd.condvar = condvar;
        scheduler_waitable_done(wait_reason_condvar, wd, amount);
        //XXX: update wait_count
    }
}
 
void sc_handle_locking_wait_condvar(uint64_t condvar, uint64_t timeout, uint64_t* e) {
    UNUSED_PARAM(timeout);
 
    struct condvar_data* data = tpa_get(condvars, condvar);
 
    if(!data) {
        *e = 22; // EINVAL
        return;
    }
 
    *e = 0;
    ++data->wait_count;
 
    union wait_data wd;
    wd.condvar = condvar;
    scheduler_wait_for(-1, wait_reason_condvar, wd);
}