duktape-1.5.2/src-separate/duk_hthread_alloc.c

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/*
 *  duk_hthread allocation and freeing.
 */
 
#include "duk_internal.h"
 
/*
 *  Allocate initial stacks for a thread.  Note that 'thr' must be reachable
 *  as a garbage collection may be triggered by the allocation attempts.
 *  Returns zero (without leaking memory) if init fails.
 */
 
DUK_INTERNAL duk_bool_t duk_hthread_init_stacks(duk_heap *heap, duk_hthread *thr) {
    duk_size_t alloc_size;
    duk_size_t i;
 
    DUK_ASSERT(heap != NULL);
    DUK_ASSERT(thr != NULL);
    DUK_ASSERT(thr->valstack == NULL);
    DUK_ASSERT(thr->valstack_end == NULL);
    DUK_ASSERT(thr->valstack_bottom == NULL);
    DUK_ASSERT(thr->valstack_top == NULL);
    DUK_ASSERT(thr->callstack == NULL);
    DUK_ASSERT(thr->catchstack == NULL);
 
    /* valstack */
    alloc_size = sizeof(duk_tval) * DUK_VALSTACK_INITIAL_SIZE;
    thr->valstack = (duk_tval *) DUK_ALLOC(heap, alloc_size);
    if (!thr->valstack) {
        goto fail;
    }
    DUK_MEMZERO(thr->valstack, alloc_size);
    thr->valstack_end = thr->valstack + DUK_VALSTACK_INITIAL_SIZE;
#if !defined(DUK_USE_PREFER_SIZE)
    thr->valstack_size = DUK_VALSTACK_INITIAL_SIZE;
#endif
    thr->valstack_bottom = thr->valstack;
    thr->valstack_top = thr->valstack;
 
    for (i = 0; i < DUK_VALSTACK_INITIAL_SIZE; i++) {
        DUK_TVAL_SET_UNDEFINED(&thr->valstack[i]);
    }
 
    /* callstack */
    alloc_size = sizeof(duk_activation) * DUK_CALLSTACK_INITIAL_SIZE;
    thr->callstack = (duk_activation *) DUK_ALLOC(heap, alloc_size);
    if (!thr->callstack) {
        goto fail;
    }
    DUK_MEMZERO(thr->callstack, alloc_size);
    thr->callstack_size = DUK_CALLSTACK_INITIAL_SIZE;
    DUK_ASSERT(thr->callstack_top == 0);
 
    /* catchstack */
    alloc_size = sizeof(duk_catcher) * DUK_CATCHSTACK_INITIAL_SIZE;
    thr->catchstack = (duk_catcher *) DUK_ALLOC(heap, alloc_size);
    if (!thr->catchstack) {
        goto fail;
    }
    DUK_MEMZERO(thr->catchstack, alloc_size);
    thr->catchstack_size = DUK_CATCHSTACK_INITIAL_SIZE;
    DUK_ASSERT(thr->catchstack_top == 0);
 
    return 1;
 
 fail:
    DUK_FREE(heap, thr->valstack);
    DUK_FREE(heap, thr->callstack);
    DUK_FREE(heap, thr->catchstack);
 
    thr->valstack = NULL;
    thr->callstack = NULL;
    thr->catchstack = NULL;
    return 0;
}
 
/* For indirect allocs. */
 
DUK_INTERNAL void *duk_hthread_get_valstack_ptr(duk_heap *heap, void *ud) {
    duk_hthread *thr = (duk_hthread *) ud;
    DUK_UNREF(heap);
    return (void *) thr->valstack;
}
 
DUK_INTERNAL void *duk_hthread_get_callstack_ptr(duk_heap *heap, void *ud) {
    duk_hthread *thr = (duk_hthread *) ud;
    DUK_UNREF(heap);
    return (void *) thr->callstack;
}
 
DUK_INTERNAL void *duk_hthread_get_catchstack_ptr(duk_heap *heap, void *ud) {
    duk_hthread *thr = (duk_hthread *) ud;
    DUK_UNREF(heap);
    return (void *) thr->catchstack;
}