bwbe_c52@uhura.cc.rochester.edu (Brent Benson) (03/02/90)
I'm trying to port an application to the NeXT computer that uses the sbrk() UNIX system call. I got a memory allocation error when trying to run the program; and the man page says: The UNIX system calls `brk' and `sbrk' are not supported on the NeXT computer. Does anyone know of an alternative call that would have the same functionality (assuming there is one). Thanks in advance. -- _ _ | |_ ___ ___ __ _| |_ Brent Benson - University of Rochester | .\| _\/ ._\| \|_ _| e-mail: bwbe_ltd@uhura.cc.rochester.edu |___/|_| \___/|_|_| |_| ..!rochester!ur-cc!bwbe_ltd
bph@buengc.BU.EDU (Blair P. Houghton) (03/03/90)
In article <5538@ur-cc.UUCP> bwbe_c52@uhura.cc.rochester.edu (Brent Benson) writes: >I'm trying to port an application to the NeXT computer that uses the >sbrk() UNIX system call. I got a memory allocation error when >trying to run the program; and the man page says: > > The UNIX system calls `brk' and `sbrk' are not supported > on the NeXT computer. > >Does anyone know of an alternative call that would have the same >functionality (assuming there is one). malloc(). Really. The NeXT box should be doing ANSI C, so malloc() and calloc() are the only portable methods of getting bytes from the system. Or maybe the program was rewriting its own malloc()... Or maybe it was system software rather than an application... --Blair "Sometimes, Unix reminds me of Australian movies that feature lots of post-armageddon automotive resourcefulness...and sometimes it reminds me of the Ford Pinto."
gwyn@smoke.BRL.MIL (Doug Gwyn) (03/03/90)
In article <5538@ur-cc.UUCP> bwbe_c52@uhura.cc.rochester.edu (Brent Benson) writes: > The UNIX system calls `brk' and `sbrk' are not supported > on the NeXT computer. Try the following emulation; you may need to add an initial call sbrk(0) at the beginning of main() just to make sure things are set up properly, although I've attempted to automate that for you. If this emulation doesn't work, the system architecture is probably unsuitable for use of brk()/sbrk() and you'll need to rework the application code accordingly. /* sbrk(), brk() emulation based on calloc() last edit: 02-Mar-1990 D A Gwyn */ #include <errno.h> /* for errno, ENOMEM */ #if __STDC__ #include <stdlib.h> /* for calloc */ #else extern char *calloc(); #endif #ifndef HEAP_SIZE /* with 32-bit ints, 0x200000 is recommended */ #define HEAP_SIZE 0x8000 /* size of simulated heap, in bytes */ #endif #define BRK_OK 0 #define BRK_ERR (-1) #define SBRK_ERR ((char *)-1) /* horrible interface design */ static char *bottom = 0; /* bottom of calloc()ed pseudo-heap */ static char *brkval = 0; /* current value of simulated break */ int brk( endds ) char *endds; { int offset; if ( bottom == 0 ) if ( (bottom = (char *)calloc( HEAP_SIZE, 1 )) == 0 ) return BRK_ERR; /* unable to set up pseudo-heap */ else brkval = bottom; if ( (offset = endds - bottom) < 0 || offset > HEAP_SIZE ) { errno = ENOMEM; return BRK_ERR; /* attempt to set break out of heap */ } else { brkval = endds; return BRK_OK; } } char * sbrk( incr ) int incr; { int offset; if ( bottom == 0 ) if ( (bottom = (char *)calloc( HEAP_SIZE, 1 )) == 0 ) return SBRK_ERR; /* unable to set up heap */ else brkval = bottom; if ( (offset = (brkval - bottom) + incr) < 0 || offset > HEAP_SIZE ) { errno = ENOMEM; return SBRK_ERR; /* attempt to set break out of heap */ } else { char *oldbrk = brkval; brkval += incr; return oldbrk; } }