From 78a5dd69c9ed1749f2ad4fd24151e4aa784b1cba Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Thu, 10 Oct 2013 12:11:29 +0200 Subject: trapping lists and tuples --- erts/emulator/beam/external.c | 153 +++++++++++++++++++++++++++++++++++------- 1 file changed, 127 insertions(+), 26 deletions(-) (limited to 'erts/emulator/beam/external.c') diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c index b1cdad1343..48536d610b 100644 --- a/erts/emulator/beam/external.c +++ b/erts/emulator/beam/external.c @@ -1125,7 +1125,18 @@ BIF_RETTYPE term_to_binary_2(BIF_ALIST_2) } -enum B2TState { /*B2TUncompress,*/ B2TSize, B2TDecodeInit, B2TDecode, B2TDecodeFail, B2TBadArg, B2TDone }; +enum B2TState { + /*B2TUncompress,*/ + B2TSize, + B2TDecodeInit, + B2TDecode, + B2TDecodeList, + B2TDecodeTuple, + + B2TDone, + B2TDecodeFail, + B2TBadArg +}; typedef struct { } B2TSizeContext; @@ -1137,6 +1148,10 @@ typedef struct { Eterm* hp_start; Eterm* hp; Eterm* hp_end; + int remaining_n; +#ifdef DEBUG + Eterm* container_start; +#endif } B2TDecodeContext; typedef struct { @@ -1153,7 +1168,7 @@ typedef struct B2TContext_t { byte* aligned_alloc; ErtsBinary2TermState b2ts; //Uint ext_size; - Uint reds; + SWord reds; Eterm trap_bin; enum B2TState state; union { @@ -1309,6 +1324,12 @@ BIF_RETTYPE binary_to_term_1(BIF_ALIST_1) #define B2T_BYTES_PER_REDUCTION 100 +static unsigned sverk_rand(void) +{ + static unsigned prev = 17; + prev = (prev * 214013 + 2531011); + return prev; +} static Eterm binary_to_term_int(Process* p, Eterm bin, Binary* context_b) { @@ -1326,7 +1347,7 @@ static Eterm binary_to_term_int(Process* p, Eterm bin, Binary* context_b) } else { ctx = ERTS_MAGIC_BIN_DATA(context_b); } - ctx->reds = 1; /*(Uint)(ERTS_BIF_REDS_LEFT(p) * B2T_BYTES_PER_REDUCTION);*/ + ctx->reds = 1 + sverk_rand() % 4; /*(Uint)(ERTS_BIF_REDS_LEFT(p) * B2T_BYTES_PER_REDUCTION);*/ do { switch (ctx->state) { @@ -1360,6 +1381,10 @@ static Eterm binary_to_term_int(Process* p, Eterm bin, Binary* context_b) /*fall through*/ case B2TDecodeInit: if (context_b == NULL && ctx->b2ts.extsize > ctx->reds) { + /*SVERK Can we do a better prediction that is still safe + OR is there a way to do HAlloc after result some how... + ... support for mutiple HReleases maybe? + */ /* dec_term will probably trap, allocate space for magic bin before result term to make it easy to trim with HRelease. */ @@ -1374,7 +1399,9 @@ static Eterm binary_to_term_int(Process* p, Eterm bin, Binary* context_b) ctx->u.dc.hp_end = ctx->u.dc.hp_start + ctx->heap_size; ctx->state = B2TDecode; /*fall through*/ - case B2TDecode: + case B2TDecode: + case B2TDecodeList: + case B2TDecodeTuple: dec_term(NULL, NULL, NULL, &MSO(p), NULL, ctx); break; @@ -1404,7 +1431,7 @@ static Eterm binary_to_term_int(Process* p, Eterm bin, Binary* context_b) return ctx->u.dc.res; } - }while (ctx->reds); + }while (ctx->reds || ctx->state >= B2TDone); if (context_b == NULL) { ASSERT(ctx->trap_bin == THE_NON_VALUE); @@ -1415,7 +1442,7 @@ static Eterm binary_to_term_int(Process* p, Eterm bin, Binary* context_b) sys_memcpy(ctx, &c_buff, sizeof(B2TContext)); if (!magic_space) { - ASSERT(ctx->state != B2TDecode); + ASSERT(ctx->state < B2TDecode); magic_space = HAlloc(p, PROC_BIN_SIZE); } ctx->trap_bin = erts_mk_magic_binary_term(&magic_space, &MSO(p), context_b); @@ -2778,28 +2805,81 @@ dec_term(ErtsDistExternal *edep, Eterm** hpp, byte* ep, ErlOffHeap* off_heap, ErtsAtomEncoding char_enc; register Eterm* hp; /* Please don't take the address of hp */ Eterm* next; - byte* ep_trap_limit; + SWord reds; if (ctx) { + reds = ctx->reds; + next = ctx->u.dc.next; + + if (ctx->state != B2TDecode) { + n = ctx->u.dc.remaining_n; + if (reds < n) { + ctx->u.dc.remaining_n -= reds; + n = reds; + } + else { + ctx->u.dc.remaining_n = 0; + } + reds -= n; + + switch (ctx->state) { + case B2TDecodeList: + objp = next - 2; + while (n > 0) { + objp[0] = (Eterm) COMPRESS_POINTER(next); + objp[1] = make_list(next); + next = objp; + objp -= 2; + n--; + } + break; + + case B2TDecodeTuple: + objp = next - 1; + while (n-- > 0) { + objp[0] = (Eterm) COMPRESS_POINTER(next); + next = objp; + objp--; + } + break; + + default: + ASSERT(!"Unknown state"); + } + if (ctx->u.dc.remaining_n) { + ctx->u.dc.next = next; + ctx->reds = 0; + return NULL; + } + ASSERT(next == ctx->u.dc.container_start); + ctx->state = B2TDecode; + } + hp_saved = ctx->u.dc.hp_start; ep = ctx->u.dc.ep; - ep_trap_limit = ep + ctx->reds; - if (ep_trap_limit < ep) { - ep_trap_limit = (byte*)ERTS_UWORD_MAX; /*SVERK Is there a safe way to create a "largest ptr" */ - } - next = ctx->u.dc.next; hpp = &ctx->u.dc.hp; } else { hp_saved = *hpp; - ep_trap_limit = (byte*)ERTS_UWORD_MAX; /*SVERK - " - */ + reds = ERTS_SWORD_MAX; next = objp; *next = (Eterm) (UWord) NULL; } - ASSERT(ep < ep_trap_limit); hp = *hpp; while (next != NULL) { + + if (reds <= 0) { + if (ctx) { + ctx->u.dc.ep = ep; + ctx->u.dc.next = next; + ctx->u.dc.hp = hp; + ctx->reds = 0; + return NULL; + } + reds = ERTS_SWORD_MAX; + } + objp = next; next = (Eterm *) EXPAND_POINTER(*objp); @@ -2918,8 +2998,20 @@ dec_term_atom_common: tuple_loop: *objp = make_tuple(hp); *hp++ = make_arityval(n); + #ifdef DEBUG + if (ctx) ctx->u.dc.container_start = hp; + #endif hp += n; - objp = hp - 1; + objp = hp - 1; + if (ctx) { + if (reds < n) { + ASSERT(reds > 0); + ctx->state = B2TDecodeTuple; + ctx->u.dc.remaining_n = n - reds; + n = reds; + } + reds -= n; + } while (n-- > 0) { objp[0] = (Eterm) COMPRESS_POINTER(next); next = objp; @@ -2937,17 +3029,30 @@ dec_term_atom_common: break; } *objp = make_list(hp); - hp += 2*n; + #ifdef DEBUG + if (ctx) ctx->u.dc.container_start = hp; + #endif + hp += 2 * n; objp = hp - 2; objp[0] = (Eterm) COMPRESS_POINTER((objp+1)); objp[1] = (Eterm) COMPRESS_POINTER(next); next = objp; objp -= 2; - while (--n > 0) { + n--; + if (ctx) { + if (reds < n) { + ctx->state = B2TDecodeList; + ctx->u.dc.remaining_n = n - reds; + n = reds; + } + reds -= n; + } + while (n > 0) { objp[0] = (Eterm) COMPRESS_POINTER(next); - objp[1] = make_list(objp + 2); + objp[1] = make_list(next); next = objp; objp -= 2; + n--; } break; case STRING_EXT: @@ -3494,20 +3599,16 @@ dec_term_atom_common: *hpp = hp_saved; if (ctx) { ctx->state = B2TDecodeFail; + ctx->reds = reds; } return NULL; } - if (ep > ep_trap_limit) { - ASSERT(ctx); - ctx->u.dc.ep = ep; - ctx->u.dc.next = next; - ctx->u.dc.hp = hp; - ctx->reds = 0; - return NULL; - } + + --reds; } if (ctx) { ctx->state = B2TDone; + ctx->reds = reds; } *hpp = hp; return ep; -- cgit v1.2.3