54 lines
805 B
C
54 lines
805 B
C
/* $Source$
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* $State$
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* $Revision$
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include "libsys.h"
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#define OUT_OF_MEMORY (void*)(-1) /* sbrk returns this on failure */
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static char* current = NULL;
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int brk(void* end)
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{
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int e = _syscall(__NR_brk, (quad) end, 0, 0);
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if (e == -1)
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errno = ENOMEM;
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else
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current = end;
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return e;
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}
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void* sbrk(int increment)
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{
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char* old;
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char* new;
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if (!current)
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current = (char*) _syscall(__NR_brk, 0, 0, 0);
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if (increment == 0)
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return current;
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old = current;
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new = old + increment;
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if ((increment > 0) && (new <= old))
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goto out_of_memory;
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else if ((increment < 0) && (new >= old))
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goto out_of_memory;
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if (brk(new) < 0)
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goto out_of_memory;
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return old;
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out_of_memory:
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errno = ENOMEM;
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return OUT_OF_MEMORY;
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}
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