#! /usr/bin/env python import random from optparse import OptionParser class malloc: def __init__(self, size, start, headerSize, policy, order, coalesce, align): # size of space self.size = size # info about pretend headers self.headerSize = headerSize # init free list self.freelist = [] self.freelist.append((start, size)) # keep track of ptr to size mappings self.sizemap = {} # policy self.policy = policy assert(self.policy in ['FIRST', 'BEST', 'WORST']) # list ordering self.returnPolicy = order assert(self.returnPolicy in ['ADDRSORT', 'SIZESORT+', 'SIZESORT-', 'INSERT-FRONT', 'INSERT-BACK']) # this does a ridiculous full-list coalesce, but that is ok self.coalesce = coalesce # alignment (-1 if no alignment) self.align = align assert(self.align == -1 or self.align > 0) def addToMap(self, addr, size): assert(addr not in self.sizemap) self.sizemap[addr] = size # print 'adding', addr, 'to map of size', size def malloc(self, size): if self.align != -1: left = size % self.align if left != 0: diff = self.align - left else: diff = 0 # print 'aligning: adding %d to %d' % (diff, size) size += diff size += self.headerSize bestIdx = -1 if self.policy == 'BEST': bestSize = self.size + 1 elif self.policy == 'WORST' or self.policy == 'FIRST': bestSize = -1 count = 0 for i in range(len(self.freelist)): eaddr, esize = self.freelist[i][0], self.freelist[i][1] count += 1 if esize >= size and ((self.policy == 'BEST' and esize < bestSize) or (self.policy == 'WORST' and esize > bestSize) or (self.policy == 'FIRST')): bestAddr = eaddr bestSize = esize bestIdx = i if self.policy == 'FIRST': break if bestIdx != -1: if bestSize > size: # print 'SPLIT', bestAddr, size self.freelist[bestIdx] = (bestAddr + size, bestSize - size) self.addToMap(bestAddr, size) elif bestSize == size: # print 'PERFECT MATCH (no split)', bestAddr, size self.freelist.pop(bestIdx) self.addToMap(bestAddr, size) else: abort('should never get here') return (bestAddr, count) # print '*** FAILED TO FIND A SPOT', size return (-1, count) def free(self, addr): # simple back on end of list, no coalesce if addr not in self.sizemap: return -1 size = self.sizemap[addr] if self.returnPolicy == 'INSERT-BACK': self.freelist.append((addr, size)) elif self.returnPolicy == 'INSERT-FRONT': self.freelist.insert(0, (addr, size)) elif self.returnPolicy == 'ADDRSORT': self.freelist.append((addr, size)) self.freelist = sorted(self.freelist, key=lambda e: e[0]) elif self.returnPolicy == 'SIZESORT+': self.freelist.append((addr, size)) self.freelist = sorted(self.freelist, key=lambda e: e[1], reverse=False) elif self.returnPolicy == 'SIZESORT-': self.freelist.append((addr, size)) self.freelist = sorted(self.freelist, key=lambda e: e[1], reverse=True) # not meant to be an efficient or realistic coalescing... if self.coalesce == True: self.newlist = [] self.curr = self.freelist[0] for i in range(1, len(self.freelist)): eaddr, esize = self.freelist[i] if eaddr == (self.curr[0] + self.curr[1]): self.curr = (self.curr[0], self.curr[1] + esize) else: self.newlist.append(self.curr) self.curr = eaddr, esize self.newlist.append(self.curr) self.freelist = self.newlist del self.sizemap[addr] return 0 def dump(self): print 'Free List [ Size %d ]: ' % len(self.freelist), for e in self.freelist: print '[ addr:%d sz:%d ]' % (e[0], e[1]), print '' # # main program # parser = OptionParser() parser.add_option('-s', '--seed', default=0, help='the random seed', action='store', type='int', dest='seed') parser.add_option('-S', '--size', default=100, help='size of the heap', action='store', type='int', dest='heapSize') parser.add_option('-b', '--baseAddr', default=1000, help='base address of heap', action='store', type='int', dest='baseAddr') parser.add_option('-H', '--headerSize', default=0, help='size of the header', action='store', type='int', dest='headerSize') parser.add_option('-a', '--alignment', default=-1, help='align allocated units to size; -1->no align', action='store', type='int', dest='alignment') parser.add_option('-p', '--policy', default='BEST', help='list search (BEST, WORST, FIRST)', action='store', type='string', dest='policy') parser.add_option('-l', '--listOrder', default='ADDRSORT', help='list order (ADDRSORT, SIZESORT+, SIZESORT-, INSERT-FRONT, INSERT-BACK)', action='store', type='string', dest='order') parser.add_option('-C', '--coalesce', default=False, help='coalesce the free list?', action='store_true', dest='coalesce') parser.add_option('-n', '--numOps', default=10, help='number of random ops to generate', action='store', type='int', dest='opsNum') parser.add_option('-r', '--range', default=10, help='max alloc size', action='store', type='int', dest='opsRange') parser.add_option('-P', '--percentAlloc',default=50, help='percent of ops that are allocs', action='store', type='int', dest='opsPAlloc') parser.add_option('-A', '--allocList', default='', help='instead of random, list of ops (+10,-0,etc)', action='store', type='string', dest='opsList') parser.add_option('-c', '--compute', default=False, help='compute answers for me', action='store_true', dest='solve') (options, args) = parser.parse_args() m = malloc(int(options.heapSize), int(options.baseAddr), int(options.headerSize), options.policy, options.order, options.coalesce, options.alignment) percent = int(options.opsPAlloc) / 100.0 random.seed(int(options.seed)) p = {} L = [] assert(percent > 0) if options.opsList == '': c = 0 j = 0 while j < int(options.opsNum): pr = False if random.random() < percent: size = int(random.random() * int(options.opsRange)) + 1 ptr, cnt = m.malloc(size) if ptr != -1: p[c] = ptr L.append(c) print 'ptr[%d] = Alloc(%d)' % (c, size), if options.solve == True: print ' returned %d (searched %d elements)' % (ptr + options.headerSize, cnt) else: print ' returned ?' c += 1 j += 1 pr = True else: if len(p) > 0: # pick random one to delete d = int(random.random() * len(L)) rc = m.free(p[L[d]]) print 'Free(ptr[%d])' % L[d], if options.solve == True: print 'returned %d' % rc else: print 'returned ?' del p[L[d]] del L[d] # print 'DEBUG p', p # print 'DEBUG L', L pr = True j += 1 if pr: if options.solve == True: m.dump() else: print 'List? ' print '' else: c = 0 for op in options.opsList.split(','): if op[0] == '+': # allocation! size = int(op.split('+')[1]) ptr, cnt = m.malloc(size) if ptr != -1: p[c] = ptr print 'ptr[%d] = Alloc(%d)' % (c, size), if options.solve == True: print ' returned %d (searched %d elements)' % (ptr, cnt) else: print ' returned ?' c += 1 elif op[0] == '-': # free index = int(op.split('-')[1]) if index >= len(p): print 'Invalid Free: Skipping' continue print 'Free(ptr[%d])' % index, rc = m.free(p[index]) if options.solve == True: print 'returned %d' % rc else: print 'returned ?' else: abort('badly specified operand: must be +Size or -Index') if options.solve == True: m.dump() else: print 'List?' print ''