ref: 600bbfe4aaa9ad0f73d8d73eef1b7670e5f7d3a3
dir: /os/port/alloc.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "interp.h" #define left u.s.bhl #define right u.s.bhr #define fwd u.s.bhf #define prev u.s.bhv #define parent u.s.bhp #define RESERVED 512*1024 struct Pool { char* name; int pnum; uintptr maxsize; int quanta; int chunk; uintptr ressize; uintptr cursize; uintptr arenasize; uintptr hw; Lock l; Bhdr* root; Bhdr* chain; uintptr nalloc; uintptr nfree; int nbrk; int lastfree; int warn; void (*move)(void*, void*); }; /* keep the quanta above the size of 5 pointers and 2 longs else the next block will be getting overwritten by the header -- starts a corruption hunt when pointer size = 8 bytes, then 63 = 2^q -1 for 4 bytes, 31 TODO make this a macro? for allocpc and reallocpc, 2 * 8 = 16 bytes get added so, minimum size = 2*4 + 2*8 + 5*8 = 64, using 127 to satisfy 2^q -1 */ static struct { int n; Pool pool[MAXPOOL]; // Lock l; } table = { 3, { { "main", 0, 32*1024*1024, 127, 512*1024, 0, 31*1024*1024 }, { "heap", 1, 32*1024*1024, 127, 512*1024, 0, 31*1024*1024 }, { "image", 2, 64*1024*1024+256, 127, 4*1024*1024, 1, 63*1024*1024 }, } }; Pool* mainmem = &table.pool[0]; Pool* heapmem = &table.pool[1]; Pool* imagmem = &table.pool[2]; static void _auditmemloc(char *, void *); void (*auditmemloc)(char *, void *) = _auditmemloc; static void _poolfault(void *, char *, uintptr); void (*poolfault)(void *, char *, uintptr) = _poolfault; int memusehigh(void) { return mainmem->cursize > mainmem->ressize || heapmem->cursize > heapmem->ressize || imagmem->cursize > imagmem->ressize; } void poolimmutable(void *v) { Bhdr *b; D2B(b, v); b->magic = MAGIC_I; } void poolmutable(void *v) { Bhdr *b; D2B(b, v); b->magic = MAGIC_A; ((Heap*)v)->color = mutator; } char* poolname(Pool *p) { return p->name; } Bhdr* poolchain(Pool *p) { return p->chain; } void pooldel(Pool *p, Bhdr *t) { Bhdr *s, *f, *rp, *q; if(t->parent == nil && p->root != t) { t->prev->fwd = t->fwd; t->fwd->prev = t->prev; return; } if(t->fwd != t) { f = t->fwd; s = t->parent; f->parent = s; if(s == nil) p->root = f; else { if(s->left == t) s->left = f; else s->right = f; } rp = t->left; f->left = rp; if(rp != nil) rp->parent = f; rp = t->right; f->right = rp; if(rp != nil) rp->parent = f; t->prev->fwd = t->fwd; t->fwd->prev = t->prev; return; } if(t->left == nil) rp = t->right; else { if(t->right == nil) rp = t->left; else { f = t; rp = t->right; s = rp->left; while(s != nil) { f = rp; rp = s; s = rp->left; } if(f != t) { s = rp->right; f->left = s; if(s != nil) s->parent = f; s = t->right; rp->right = s; if(s != nil) s->parent = rp; } s = t->left; rp->left = s; s->parent = rp; } } q = t->parent; if(q == nil) p->root = rp; else { if(t == q->left) q->left = rp; else q->right = rp; } if(rp != nil) rp->parent = q; } void pooladd(Pool *p, Bhdr *q) { int size; Bhdr *tp, *t; q->magic = MAGIC_F; q->left = nil; q->right = nil; q->parent = nil; q->fwd = q; q->prev = q; t = p->root; if(t == nil) { p->root = q; return; } size = q->size; tp = nil; while(t != nil) { if(size == t->size) { q->prev = t->prev; q->prev->fwd = q; q->fwd = t; t->prev = q; return; } tp = t; if(size < t->size) t = t->left; else t = t->right; } q->parent = tp; if(size < tp->size) tp->left = q; else tp->right = q; } void poolsummary(void) { int x = 0; char buf[400]; print("\n"); print(" cursize maxsize hw nalloc nfree nbrk max name\n"); x=poolread( buf, sizeof buf - 1, x ); buf[x] = 0; putstrn(buf, x); print("\n"); } void* poolalloc(Pool *p, uintptr asize) { Bhdr *q, *t; intptr alloc, ldr, ns, frag; intptr osize, size; Prog *prog; // if(asize >= 1024*1024*1024) /* for sanity and to avoid overflow */ // return nil; if(p->cursize > p->ressize && (prog = currun()) != nil && prog->flags&Prestricted){ print("poolalloc exception\n"); return nil; } size = asize; osize = size; size = (size + BHDRSIZE + p->quanta) & ~(p->quanta); ilock(&p->l); p->nalloc++; t = p->root; q = nil; while(t) { if(t->size == size) { t = t->fwd; pooldel(p, t); t->magic = MAGIC_A; p->cursize += t->size; if(p->cursize > p->hw) p->hw = p->cursize; iunlock(&p->l); return B2D(t); } if(size < t->size) { q = t; t = t->left; } else t = t->right; } if(q != nil) { pooldel(p, q); q->magic = MAGIC_A; frag = q->size - size; if(frag < (size>>2) && frag < 0x8000) { p->cursize += q->size; if(p->cursize > p->hw) p->hw = p->cursize; iunlock(&p->l); return B2D(q); } /* Split */ ns = q->size - size; q->size = size; B2T(q)->hdr = q; t = B2NB(q); t->size = ns; B2T(t)->hdr = t; pooladd(p, t); p->cursize += q->size; if(p->cursize > p->hw) p->hw = p->cursize; iunlock(&p->l); return B2D(q); } ns = p->chunk; if(size > ns) ns = size; ldr = p->quanta+1; alloc = ns+ldr+ldr; p->arenasize += alloc; if(p->arenasize > p->maxsize) { p->arenasize -= alloc; ns = p->maxsize-p->arenasize-ldr-ldr; ns &= ~p->quanta; if (ns < size) { if(poolcompact(p)) { iunlock(&p->l); return poolalloc(p, osize); } iunlock(&p->l); if(p->warn) return nil; p->warn = 1; if (p != mainmem || ns > 512) print("arena too large: %s size %zd cursize %zud arenasize %zud maxsize %zud, alloc = %zd\n", p->name, osize, p->cursize, p->arenasize, p->maxsize, alloc); return nil; } alloc = ns+ldr+ldr; p->arenasize += alloc; } p->nbrk++; t = xalloc(alloc); if(t == nil) { p->nbrk--; iunlock(&p->l); return nil; } /* Double alignment */ t = (Bhdr *)(((uintptr)t + 7) & ~7); /* TBS xmerge */ if(0 && p->chain != nil && (char*)t-(char*)B2LIMIT(p->chain)-ldr == 0){ /* can merge chains */ if(0)print("merging chains %p and %p in %s\n", p->chain, t, p->name); q = B2LIMIT(p->chain); q->magic = MAGIC_A; q->size = alloc; B2T(q)->hdr = q; t = B2NB(q); t->magic = MAGIC_E; p->chain->csize += alloc; p->cursize += alloc; iunlock(&p->l); poolfree(p, B2D(q)); /* for backward merge */ return poolalloc(p, osize); } t->magic = MAGIC_E; /* Make a leader */ t->size = ldr; t->csize = ns+ldr; t->clink = p->chain; p->chain = t; B2T(t)->hdr = t; t = B2NB(t); t->magic = MAGIC_A; /* Make the block we are going to return */ t->size = size; B2T(t)->hdr = t; q = t; ns -= size; /* Free the rest */ if(ns > 0) { q = B2NB(t); q->size = ns; B2T(q)->hdr = q; pooladd(p, q); } B2NB(q)->magic = MAGIC_E; /* Mark the end of the chunk */ p->cursize += t->size; if(p->cursize > p->hw) p->hw = p->cursize; iunlock(&p->l); return B2D(t); } void poolfree(Pool *p, void *v) { Bhdr *b, *c; extern Bhdr *ptr; D2B(b, v); ilock(&p->l); p->nfree++; p->cursize -= b->size; c = B2NB(b); if(c->magic == MAGIC_F) { /* Join forward */ if(c == ptr) ptr = b; pooldel(p, c); c->magic = 0; b->size += c->size; B2T(b)->hdr = b; } c = B2PT(b)->hdr; if(c->magic == MAGIC_F) { /* Join backward */ if(b == ptr) ptr = c; pooldel(p, c); b->magic = 0; c->size += b->size; b = c; B2T(b)->hdr = b; } pooladd(p, b); iunlock(&p->l); } void * poolrealloc(Pool *p, void *v, uintptr size) { Bhdr *b; void *nv; intptr osize; //if(size >= 1024*1024*1024) /* for sanity and to avoid overflow */ // return nil; if(size == 0){ poolfree(p, v); return nil; } SET(osize); if(v != nil){ ilock(&p->l); D2B(b, v); osize = b->size - BHDRSIZE; iunlock(&p->l); if(osize >= size) return v; } nv = poolalloc(p, size); if(nv != nil && v != nil){ memmove(nv, v, osize); poolfree(p, v); } return nv; } uintptr poolmsize(Pool *p, void *v) { Bhdr *b; uintptr size; if(v == nil) return 0; ilock(&p->l); D2B(b, v); size = b->size - BHDRSIZE; iunlock(&p->l); return size; } static uintptr poolmax(Pool *p) { Bhdr *t; uintptr size; ilock(&p->l); size = p->maxsize - p->cursize; t = p->root; if(t != nil) { while(t->right != nil) t = t->right; if(size < t->size) size = t->size; } if(size >= BHDRSIZE) size -= BHDRSIZE; iunlock(&p->l); return size; } int poolread(char *va, int count, u64 offset) { Pool *p; int n, i, signed_off; n = 0; signed_off = offset; for(i = 0; i < table.n; i++) { p = &table.pool[i]; n += snprint(va+n, count-n, "%11zud %11zud %11zud %11zud %11zud %11d %11zud %s\n", p->cursize, p->maxsize, p->hw, p->nalloc, p->nfree, p->nbrk, poolmax(p), p->name); if(signed_off > 0) { signed_off -= n; if(signed_off < 0) { memmove(va, va+n+signed_off, -signed_off); n = -signed_off; } else n = 0; } } return n; } /* this function signature is tied to the system's libc.h */ void* malloc(ulong size) { void *v; v = poolalloc(mainmem, size); if(v != nil){ setmalloctag(v, getcallerpc(&size)); setrealloctag(v, 0); memset(v, 0, size); } return v; } void* smalloc(uintptr size) { void *v; for(;;) { v = poolalloc(mainmem, size); if(v != nil) break; tsleep(&up->sleep, return0, 0, 100); } setmalloctag(v, getcallerpc(&size)); setrealloctag(v, 0); memset(v, 0, size); return v; } void* mallocz(ulong size, int clr) { void *v; v = poolalloc(mainmem, size); if(v != nil){ setmalloctag(v, getcallerpc(&size)); setrealloctag(v, 0); if(clr) memset(v, 0, size); } return v; } /* on 9front, mallocalign() returns a pointer to a buffer that satisfies the alignment, offset and span requirements. As inferno keeps track of buffers at a lesser granularity, it is harder to keep track of the small memory areas that will have to be skipped for alignment. Instead of taking the responsibility of accounting for those memory areas, this function returns a buffer which will have a pointer that satisfies the size, alignment, offset and span requirements. It will be upto the caller to use it is wants. When free'ing, it needs to ensure that it frees using the Bhdr.u.data pointer and not any other pointer in that buffer. Alternate implementation: The free() function finds the Bhdr that contains the pointer being free'ed and frees that Bhdr. This breaks the assumption that the pointer passed to free() is always Bhdr.u.data. 12:25 < joe7> cinap_lenrek: any comments on this? http://okturing.com/src/11617/body 12:26 < joe7> I have 2 ways of implementing mallocalign on inferno. The second (alternative implementation) approach lies closer to what 9front does.(I think). 12:27 < joe7> just want to run it by you.. 12:27 < cinap_lenrek> joe7: obviously you want it to be symmetic 12:27 < cinap_lenrek> like dont push that extra complexity to the caller 12:27 < cinap_lenrek> the rest is just implementation detail 12:28 < joe7> izaki, there is a way to read nvram and secstore keys automatically in the boot process. 12:29 < joe7> cinap_lenrek: so, making the free more robust seems the obvious choice. Instead of assuming that free will always receive the data pointer, we make the assumption that the pointer being freed can be any where in a buffer's data space. 12:30 < cinap_lenrek> no. 12:30 < cinap_lenrek> free needs to be called exactly on the pointer returned from mallocalign 12:30 < joe7> so, someone needs to record the pointer returned by mallocalign.. 12:31 < joe7> the allocator only keeps track of the Bhdr's in the Pool structure now. 12:31 < cinap_lenrek> or mark it with a header to find the Bhdr 12:31 < cinap_lenrek> or some padding bytes 12:31 < joe7> good idea, thanks, will think through. 12:32 < cinap_lenrek> i think pool has align magic for this 12:32 < cinap_lenrek> so free is kind of search for the Bhdr 12:32 < cinap_lenrek> but thats an implementation details 12:33 < cinap_lenrek> but calling free() on something other than the pointer returned by mallocalign should be undefined 12:33 < cinap_lenrek> and you shouldnt rely on it */ static void* alignptr(void *v, u32 align, s32 offset) { char *c; u32 off; c = v; if(align){ off = ((u32)(uintptr)c) % align; if(off != offset){ offset -= off; if(offset < 0) offset += align; c += offset; } } return c; } void* mallocalign(uintptr dsize, u32 align, s32 offset, u32 span) { uintptr asize; void *v; char *c; int skip; Balign *ba; Bhdr *b; /* * allocate block * dsize bytes * addr == offset (modulo align) * does not cross span-byte block boundary * * to satisfy alignment, just allocate an extra * align bytes and then shift appropriately. * * to satisfy span, try once and see if we're * lucky. the second time, allocate 2x asize * so that we definitely get one not crossing * the boundary. */ if(align){ if(offset < 0) offset = align - ((-offset)%align); offset %= align; } asize = dsize+align+sizeof(Balign); v = mallocz(asize, 1); if(v == nil) return nil; if(span && (uintptr)v/span != ((uintptr)v+asize)/span){ /* try again */ free(v); v = mallocz(2*asize, 1); if(v == nil) return nil; } /* * figure out what pointer we want to return */ c = alignptr(v, align, offset); if(span && (uintptr)c/span != (uintptr)(c+dsize-1)/span){ c += span - (uintptr)c%span; c = alignptr(c, align, offset); if((uintptr)c/span != (uintptr)(c+dsize-1)/span){ free(v); werrstr("cannot satisfy dsize %lud span %lud with align %lud+%ld", dsize, span, align, offset); return nil; } } skip = c - (char*)v; if(skip == 0){ /* perfect match, Hallelujah */ return c; }else if (skip < sizeof(Balign)){ /* TODO this situation should be handled, error for now */ werrstr("skip %d < sizeof(Balign) %d cannot satisfy dsize %lud span %lud with align %lud+%ld", skip, sizeof(Balign), dsize, span, align, offset); return nil; }else{ /* add the Balign header to point back to the header */ ba = (Balign*)(c-sizeof(Balign)); D2B(b,v); ba->hdr = b; setmalloctag(v, getcallerpc(&dsize)); if(0)print("mallocalign dsize %zd align %d 0x%x offset %d span %d\n" " b 0x%p b->magic 0x%x b->size %zd\n" " ba 0x%p ba->hdr 0x%p v 0x%p c 0x%p\n", dsize, align, align, offset, span, b, b->magic, b->size, ba, ba->hdr, v, c); return c; } } void free(void *v) { Bhdr *b; if(v != nil) { D2B(b, v); poolfree(mainmem, v); } } /* this function signature is tied to emu which is tied to the system's libc.h */ void* realloc(void *v, ulong size) { void *nv; if(size == 0) return malloc(size); /* temporary change until realloc calls can be checked */ nv = poolrealloc(mainmem, v, size); if(nv != nil) { nv = (uintptr*)nv; setrealloctag(nv, getcallerpc(&v)); if(v == nil) setmalloctag(v, getcallerpc(&v)); } return nv; } void setmalloctag(void *v, uintptr pc) { Bhdr *b; if(v != nil){ D2B(b, v); b->allocpc = pc; } } uintptr getmalloctag(void *v) { Bhdr *b; if(v == nil) return ~0; D2B(b, v); return b->allocpc; } void setrealloctag(void *v, uintptr pc) { Bhdr *b; if(v != nil){ D2B(b, v); b->reallocpc = pc; } } uintptr getrealloctag(void *v) { Bhdr *b; if(v == nil) return ~0; D2B(b, v); return b->reallocpc; } ulong msize(void *v) { if(v == nil) return 0; return poolmsize(mainmem, v); } /* this function signature is tied to emu which is tied to the system's libc.h */ void* calloc(ulong n, ulong szelem) { return malloc(n*szelem); } void pooldump(Bhdr *b, int d, int c) { Bhdr *t; if(b == nil) return; print("%.8p %.8p %.8p %c %4d %zud (f %.8p p %.8p)\n", b, b->left, b->right, c, d, b->size, b->fwd, b->prev); d++; for(t = b->fwd; t != b; t = t->fwd) print("\t%.8p %.8p %.8p\n", t, t->prev, t->fwd); pooldump(b->left, d, 'l'); pooldump(b->right, d, 'r'); } void poolshow(void) { int i; for(i = 0; i < table.n; i++) { print("Arena: %s root=%.8p\n", table.pool[i].name, table.pool[i].root); pooldump(table.pool[i].root, 0, 'R'); } } void poolsetcompact(Pool *p, void (*move)(void*, void*)) { p->move = move; } int poolcompact(Pool *pool) { Bhdr *base, *limit, *ptr, *end, *next; int compacted, nb; if(pool->move == nil || pool->lastfree == pool->nfree) return 0; pool->lastfree = pool->nfree; base = pool->chain; ptr = B2NB(base); /* First Block in arena has clink */ limit = B2LIMIT(base); compacted = 0; pool->root = nil; end = ptr; while(base != nil) { next = B2NB(ptr); if(ptr->magic == MAGIC_A || ptr->magic == MAGIC_I) { if(ptr != end) { memmove(end, ptr, ptr->size); pool->move(B2D(ptr), B2D(end)); compacted = 1; } end = B2NB(end); } if(next >= limit) { nb = (uchar*)limit - (uchar*)end; if(nb > 0){ if(nb < pool->quanta+1) panic("poolcompact: leftover too small\n"); end->size = nb; B2T(end)->hdr = end; pooladd(pool, end); } base = base->clink; if(base == nil) break; ptr = B2NB(base); end = ptr; /* could do better by copying between chains */ limit = B2LIMIT(base); } else ptr = next; } return compacted; } void poolsize(Pool *p, uintptr max, int contig) { void *x; print("poolsize max %llud contig %d\n", max, contig); p->maxsize = max; if(max == 0) p->ressize = max; else if(max < RESERVED) p->ressize = max; else p->ressize = max-RESERVED; if (contig && max > 0) { p->chunk = max-1024; x = poolalloc(p, p->chunk); if(x == nil) panic("poolsize: don't have %d bytes\n", p->chunk); poolfree(p, x); p->hw = 0; } } static void _poolfault(void *v, char *msg, uintptr c) { setpanic(); auditmemloc(msg, v); panic("%s %p (from %p/%zux)", msg, v, getcallerpc(&v), c); } static void dumpvl(char *msg, uintptr *v, int n) { int i, l; l = print("%s at %p: ", msg, v); for(i = 0; i < n; i++) { if(l >= 60) { print("\n"); l = print(" %p: ", v); } l += print(" %zux", *v++); } print("\n"); USED(l); } static void corrupted(char *str, char *msg, Pool *p, Bhdr *b, void *v) { print("%s(%p): pool %s CORRUPT: %s at %p'%zud(magic=%ux)\n", str, v, p->name, msg, b, b->size, b->magic); dumpvl("bad Bhdr", (uintptr *)((uintptr)b & ~3)-4, 10); } static void _auditmemloc(char *str, void *v) { Pool *p; Bhdr *bc, *ec, *b, *nb, *fb = nil; char *fmsg, *msg; uintptr fsz; SET(fsz, fmsg); for (p = &table.pool[0]; p < &table.pool[nelem(table.pool)]; p++) { ilock(&p->l); for (bc = p->chain; bc != nil; bc = bc->clink) { if (bc->magic != MAGIC_E) { iunlock(&p->l); corrupted(str, "chain hdr!=MAGIC_E", p, bc, v); goto nextpool; } ec = B2LIMIT(bc); if (((Bhdr*)v >= bc) && ((Bhdr*)v < ec)){ goto found; } } iunlock(&p->l); nextpool: ; } print("%s: %lux not in pools\n", str, v); return; found: for (b = bc; b < ec; b = nb) { switch(b->magic) { case MAGIC_F: msg = "free blk"; break; case MAGIC_I: msg = "immutable block"; break; case MAGIC_A: msg = "block"; break; default: if (b == bc && b->magic == MAGIC_E) { msg = "pool hdr"; break; } iunlock(&p->l); corrupted(str, "bad magic", p, b, v); goto badchunk; } if (b->size <= 0 || (b->size & p->quanta)) { iunlock(&p->l); corrupted(str, "bad size", p, b, v); goto badchunk; } if (fb != nil) break; nb = B2NB(b); if ((Bhdr*)v < nb) { fb = b; fsz = b->size; fmsg = msg; } } iunlock(&p->l); if (b >= ec) { if (b > ec) corrupted(str, "chain size mismatch", p, b, v); else if (b->magic != MAGIC_E) corrupted(str, "chain end!=MAGIC_E", p, b, v); } badchunk: if (fb != nil) { print("%s: %p in %s:", str, v, p->name); if (fb == v) print(" is %s '%zux\n", fmsg, fsz); else print(" in %s at %p B2D 0x%p size %zux ec 0x%p next block 0x%p searched address 0x%p\n", fmsg, fb, B2D(fb), fsz, ec, nb, v); dumpvl("area", (uintptr *)((uintptr)v & ~3)-4, 20); } } char * poolaudit(char*(*audit)(int, Bhdr *)) { Pool *p; Bhdr *bc, *ec, *b; char *r = nil; for (p = &table.pool[0]; p < &table.pool[nelem(table.pool)]; p++) { ilock(&p->l); for (bc = p->chain; bc != nil; bc = bc->clink) { if (bc->magic != MAGIC_E) { iunlock(&p->l); return "bad chain hdr"; } ec = B2LIMIT(bc); for (b = bc; b < ec; b = B2NB(b)) { if (b->size <= 0 || (b->size & p->quanta)) r = "bad size in bhdr"; else switch(b->magic) { case MAGIC_E: if (b != bc) { r = "unexpected MAGIC_E"; break; } case MAGIC_F: case MAGIC_A: case MAGIC_I: r = audit(p->pnum, b); break; default: r = "bad magic"; } if (r != nil) { iunlock(&p->l); return r; } } if (b != ec || b->magic != MAGIC_E) { iunlock(&p->l); return "bad chain ending"; } } iunlock(&p->l); } return r; } void poolinit(void) { debugkey('m', "memory pools", poolsummary, 0); }