1 //===-- Implementation of hcreate -------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/search/hcreate.h" 10 #include "src/__support/HashTable/randomness.h" 11 #include "src/__support/HashTable/table.h" 12 #include "src/errno/libc_errno.h" 13 #include "src/search/hsearch/global.h" 14 15 namespace LIBC_NAMESPACE { 16 LLVM_LIBC_FUNCTION(int, hcreate, (size_t capacity)) { 17 // We follow FreeBSD's implementation here. If the global_hash_table is 18 // already initialized, this function will do nothing and return 1. 19 // https://cgit.freebsd.org/src/tree/lib/libc/stdlib/hcreate.c 20 if (internal::global_hash_table != nullptr) 21 return 1; 22 23 uint64_t randomness = internal::randomness::next_random_seed(); 24 internal::HashTable *table = 25 internal::HashTable::allocate(capacity, randomness); 26 if (table == nullptr) { 27 libc_errno = ENOMEM; 28 return 0; 29 } 30 internal::global_hash_table = table; 31 return 1; 32 } 33 34 } // namespace LIBC_NAMESPACE 35