Switch to a single malloc call

bitcoin-core · Oct 22, 2018 · f24aa9c · f24aa9c
1 parent e7c5e26
commit f24aa9c
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Showing 5 changed files with 37 additions and 22 deletions.
diff --git a/src/ecmult.h b/src/ecmult.h
@@ -22,7 +22,7 @@ typedef struct {
 
 static size_t secp256k1_ecmult_context_prealloc_size(void);
 static void secp256k1_ecmult_context_init(secp256k1_ecmult_context *ctx);
-static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, const secp256k1_callback *cb);
+static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, void **prealloc);
 static void secp256k1_ecmult_context_clone(secp256k1_ecmult_context *dst,
  const secp256k1_ecmult_context *src, const secp256k1_callback *cb);
 static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context *ctx);

diff --git a/src/ecmult_gen.h b/src/ecmult_gen.h
@@ -30,7 +30,7 @@ typedef struct {
 
 static size_t secp256k1_ecmult_gen_context_prealloc_size(void);
 static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context* ctx);
-static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context* ctx, const secp256k1_callback* cb);
+static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context* ctx, void **prealloc);
 static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context *dst,
  const secp256k1_ecmult_gen_context* src, const secp256k1_callback* cb);
 static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context* ctx);

diff --git a/src/ecmult_gen_impl.h b/src/ecmult_gen_impl.h
@@ -28,19 +28,20 @@ static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context *ctx)
  ctx->prec = NULL;
 }
 
-static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context *ctx, const secp256k1_callback* cb) {
+static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context *ctx, void **prealloc) {
 #ifndef USE_ECMULT_STATIC_PRECOMPUTATION
  secp256k1_ge prec[1024];
  secp256k1_gej gj;
  secp256k1_gej nums_gej;
  int i, j;
+ size_t ctx_size = secp256k1_ecmult_gen_context_prealloc_size();
 #endif
 
  if (ctx->prec != NULL) {
  return;
  }
 #ifndef USE_ECMULT_STATIC_PRECOMPUTATION
- ctx->prec = (secp256k1_ge_storage (*)[64][16])checked_malloc(cb, sizeof(*ctx->prec));
+ ctx->prec = (secp256k1_ge_storage (*)[64][16])manual_alloc(prealloc, ctx_size, *prealloc, ctx_size);
 
  /* get the generator */
  secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g);
@@ -95,7 +96,7 @@ static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context *ctx
  }
  }
 #else
- (void)cb;
+ (void)prealloc;
  ctx->prec = (secp256k1_ge_storage (*)[64][16])secp256k1_ecmult_static_context;
 #endif
  secp256k1_ecmult_gen_blind(ctx, NULL);
@@ -123,9 +124,6 @@ static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context *dst
 }
 
 static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context *ctx) {
-#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
- free(ctx->prec);
-#endif
  secp256k1_scalar_clear(&ctx->blind);
  secp256k1_gej_clear(&ctx->initial);
  ctx->prec = NULL;

diff --git a/src/ecmult_impl.h b/src/ecmult_impl.h
@@ -269,8 +269,10 @@ static void secp256k1_ecmult_context_init(secp256k1_ecmult_context *ctx) {
 #endif
 }
 
-static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, const secp256k1_callback *cb) {
+static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, void **prealloc) {
  secp256k1_gej gj;
+ void* const base = *prealloc;
+ size_t const prealloc_size = secp256k1_ecmult_context_prealloc_size();
 
  if (ctx->pre_g != NULL) {
  return;
@@ -279,7 +281,7 @@ static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, const
  /* get the generator */
  secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g);
 
- ctx->pre_g = (secp256k1_ge_storage (*)[])checked_malloc(cb, sizeof((*ctx->pre_g)[0]) * ECMULT_TABLE_SIZE(WINDOW_G));
+ ctx->pre_g = (secp256k1_ge_storage (*)[])manual_alloc(prealloc, sizeof((*ctx->pre_g)[0]) * ECMULT_TABLE_SIZE(WINDOW_G), base, prealloc_size);
 
  /* precompute the tables with odd multiples */
  secp256k1_ecmult_odd_multiples_table_storage_var(ECMULT_TABLE_SIZE(WINDOW_G), *ctx->pre_g, &gj);
@@ -289,7 +291,7 @@ static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, const
  secp256k1_gej g_128j;
  int i;
 
- ctx->pre_g_128 = (secp256k1_ge_storage (*)[])checked_malloc(cb, sizeof((*ctx->pre_g_128)[0]) * ECMULT_TABLE_SIZE(WINDOW_G));
+ ctx->pre_g_128 = (secp256k1_ge_storage (*)[])manual_alloc(prealloc, sizeof((*ctx->pre_g_128)[0]) * ECMULT_TABLE_SIZE(WINDOW_G), base, prealloc_size);
 
  /* calculate 2^128*generator */
  g_128j = gj;
@@ -326,10 +328,6 @@ static int secp256k1_ecmult_context_is_built(const secp256k1_ecmult_context *ctx
 }
 
 static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context *ctx) {
- free(ctx->pre_g);
-#ifdef USE_ENDOMORPHISM
- free(ctx->pre_g_128);
-#endif
  secp256k1_ecmult_context_init(ctx);
 }
 

diff --git a/src/secp256k1.c b/src/secp256k1.c
@@ -83,29 +83,43 @@ size_t secp256k1_context_prealloc_size(unsigned int flags) {
  return ret;
 }
 
-secp256k1_context* secp256k1_context_create(unsigned int flags) {
- secp256k1_context* ret = (secp256k1_context*)checked_malloc(&default_error_callback, sizeof(secp256k1_context));
+secp256k1_context* secp256k1_context_prealloc_create(void* prealloc, unsigned int flags) {
+ void* const base = prealloc;
+ size_t const ctx_size = secp256k1_context_prealloc_size(flags);
+ secp256k1_context* ret = (secp256k1_context*)manual_alloc(&prealloc, sizeof(secp256k1_context), base, ctx_size);
+
  ret->illegal_callback = default_illegal_callback;
  ret->error_callback = default_error_callback;
 
  if (EXPECT((flags & SECP256K1_FLAGS_TYPE_MASK) != SECP256K1_FLAGS_TYPE_CONTEXT, 0)) {
  secp256k1_callback_call(&ret->illegal_callback,
  "Invalid flags");
- free(ret);
+ /* Unreachable */
  return NULL;
  }
 
  secp256k1_ecmult_context_init(&ret->ecmult_ctx);
  secp256k1_ecmult_gen_context_init(&ret->ecmult_gen_ctx);
 
  if (flags & SECP256K1_FLAGS_BIT_CONTEXT_SIGN) {
- secp256k1_ecmult_gen_context_build(&ret->ecmult_gen_ctx, &ret->error_callback);
+ secp256k1_ecmult_gen_context_build(&ret->ecmult_gen_ctx, &prealloc);
  }
  if (flags & SECP256K1_FLAGS_BIT_CONTEXT_VERIFY) {
- secp256k1_ecmult_context_build(&ret->ecmult_ctx, &ret->error_callback);
+ secp256k1_ecmult_context_build(&ret->ecmult_ctx, &prealloc);
  }
 
- return ret;
+ return (secp256k1_context*) ret;
+}
+
+secp256k1_context* secp256k1_context_create(unsigned int flags) {
+ size_t ctx_size = secp256k1_context_prealloc_size(flags);
+ secp256k1_context* ctx = (secp256k1_context*) checked_malloc(&default_error_callback, ctx_size);
+ if (secp256k1_context_prealloc_create(ctx, flags) == NULL) {
+ free(ctx);
+ return NULL;
+ }
+
+ return ctx;
 }
 
 secp256k1_context* secp256k1_context_clone(const secp256k1_context* ctx) {
@@ -117,11 +131,16 @@ secp256k1_context* secp256k1_context_clone(const secp256k1_context* ctx) {
  return ret;
 }
 
-void secp256k1_context_destroy(secp256k1_context* ctx) {
+void secp256k1_context_prealloc_destroy(secp256k1_context* ctx) {
  if (ctx != NULL) {
  secp256k1_ecmult_context_clear(&ctx->ecmult_ctx);
  secp256k1_ecmult_gen_context_clear(&ctx->ecmult_gen_ctx);
+ }
+}
 
+void secp256k1_context_destroy(secp256k1_context* ctx) {
+ if (ctx != NULL) {
+ secp256k1_context_prealloc_destroy(ctx);
  free(ctx);
  }
 }