- COPYRIGHT AND LICENSE
pixalloc.c Custom memory storage with allocator and deallocator l_int32 pmsCreate() void pmsDestroy() void *pmsCustomAlloc() void pmsCustomDealloc() void *pmsGetAlloc() l_int32 pmsGetLevelForAlloc() l_int32 pmsGetLevelForDealloc() void pmsLogInfo()
l_int32 pmsCreate ( size_t minsize, size_t smallest, NUMA *numalloc, const char *logfile )
pmsCreate() Input: minsize (of data chunk that can be supplied by pms) smallest (bytes of the smallest pre-allocated data chunk. numalloc (array with the number of data chunks for each size that are in the memory store) logfile (use for debugging; null otherwise) Return: 0 if OK, 1 on error Notes: (1) This computes the size of the block of memory required and allocates it. Each chunk starts on a 32-bit word boundary. The chunk sizes are in powers of 2, starting at @smallest, and the number of levels and chunks at each level is specified by @numalloc. (2) This is intended to manage the image data for a small number of relatively large pix. The system malloc is expected to handle very large numbers of small chunks efficiently. (3) Important: set the allocators and call this function before any pix have been allocated. Destroy all the pix in the normal way before calling pmsDestroy(). (4) The pms struct is stored in a static global, so this function is not thread-safe. When used, there must be only one thread per process.
void * pmsCustomAlloc ( size_t nbytes )
pmsCustomAlloc() Input: nbytes (min number of bytes in the chunk to be retrieved) Return: data (ptr to chunk) Notes: (1) This attempts to find a suitable pre-allocated chunk. If not found, it dynamically allocates the chunk. (2) If logging is turned on, the allocations that are not taken from the memory store, and are at least as large as the minimum size the store can handle, are logged to file.
void pmsCustomDealloc ( void *data )
pmsCustomDealloc() Input: data (to be freed or returned to the storage) Return: void
void pmsDestroy ( )
pmsDestroy() Input: (none) Return: void Notes: (1) Important: call this function at the end of the program, after the last pix has been destroyed.
void * pmsGetAlloc ( size_t nbytes )
pmsGetAlloc() Input: nbytes Return: data Notes: (1) This is called when a request for pix data cannot be obtained from the preallocated memory store. After use it is freed like normal memory. (2) If logging is on, only write out allocs that are as large as the minimum size handled by the memory store. (3) size_t is %lu on 64 bit platforms and %u on 32 bit platforms. The C99 platform-independent format specifier for size_t is %zu, but windows hasn't conformed, so we are forced to go back to C89, use %lu, and cast to get platform-independence. Ugh.
l_int32 pmsGetLevelForAlloc ( size_t nbytes, l_int32 *plevel )
pmsGetLevelForAlloc() Input: nbytes (min number of bytes in the chunk to be retrieved) &level (<return>; -1 if either too small or too large) Return: 0 if OK, 1 on error
l_int32 pmsGetLevelForDealloc ( void *data, l_int32 *plevel )
pmsGetLevelForDealloc() Input: data (ptr to memory chunk) &level (<return> level in memory store; -1 if allocated outside the store) Return: 0 if OK, 1 on error
void pmsLogInfo ( )
pmsLogInfo() Input: (none) Return: void
Zakariyya Mughal <firstname.lastname@example.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2014 by Zakariyya Mughal.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.