138 lines · cpp
1//===-- lib/runtime/unit-map.cpp --------------------------------*- 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-exception6//7//===----------------------------------------------------------------------===//8 9#include "unit-map.h"10#include "flang/Common/optional.h"11 12namespace Fortran::runtime::io {13 14void UnitMap::Initialize() {15 if (!isInitialized_) {16 freeNewUnits_.InitializeState();17 // Unit number -1 is reserved.18 // The unit numbers are pushed in reverse order so that the first19 // ones to be popped will be small and suitable for use as kind=120 // integers.21 for (int j{freeNewUnits_.maxValue}; j > 1; --j) {22 freeNewUnits_.Add(j);23 }24 isInitialized_ = true;25 }26}27 28// See 12.5.6.12 in Fortran 2018. NEWUNIT= unit numbers are negative,29// and not equal to -1 (or ERROR_UNIT, if it were negative, which it isn't.)30ExternalFileUnit &UnitMap::NewUnit(const Terminator &terminator) {31 CriticalSection critical{lock_};32 Initialize();33 common::optional<int> n{freeNewUnits_.PopValue()};34 if (!n) {35 n = emergencyNewUnit_++;36 }37 return Create(-*n, terminator);38}39 40ExternalFileUnit *UnitMap::LookUpForClose(int n) {41 CriticalSection critical{lock_};42 Chain *previous{nullptr};43 int hash{Hash(n)};44 for (Chain *p{bucket_[hash].get()}; p; previous = p, p = p->next.get()) {45 if (p->unit.unitNumber() == n) {46 if (previous) {47 previous->next.swap(p->next);48 } else {49 bucket_[hash].swap(p->next);50 }51 // p->next.get() == p at this point; the next swap pushes p on closing_52 closing_.swap(p->next);53 return &p->unit;54 }55 }56 return nullptr;57}58 59void UnitMap::DestroyClosed(ExternalFileUnit &unit) {60 Chain *p{nullptr};61 {62 CriticalSection critical{lock_};63 Chain *previous{nullptr};64 for (p = closing_.get(); p; previous = p, p = p->next.get()) {65 if (&p->unit == &unit) {66 int n{unit.unitNumber()};67 if (n <= -2) {68 freeNewUnits_.Add(-n);69 }70 if (previous) {71 previous->next.swap(p->next);72 } else {73 closing_.swap(p->next);74 }75 break;76 }77 }78 }79 if (p) {80 p->unit.~ExternalFileUnit();81 FreeMemory(p);82 }83}84 85void UnitMap::CloseAll(IoErrorHandler &handler) {86 // Extract units from the map so they can be closed87 // without holding lock_.88 OwningPtr<Chain> closeList;89 {90 CriticalSection critical{lock_};91 for (int j{0}; j < buckets_; ++j) {92 while (Chain * p{bucket_[j].get()}) {93 bucket_[j].swap(p->next); // pops p from head of bucket list94 closeList.swap(p->next); // pushes p to closeList95 }96 }97 }98 while (Chain * p{closeList.get()}) {99 closeList.swap(p->next); // pops p from head of closeList100 p->unit.CloseUnit(CloseStatus::Keep, handler);101 p->unit.~ExternalFileUnit();102 FreeMemory(p);103 }104}105 106void UnitMap::FlushAll(IoErrorHandler &handler) {107 CriticalSection critical{lock_};108 for (int j{0}; j < buckets_; ++j) {109 for (Chain *p{bucket_[j].get()}; p; p = p->next.get()) {110 p->unit.FlushOutput(handler);111 }112 }113}114 115ExternalFileUnit *UnitMap::Find(const char *path, std::size_t pathLen) {116 if (path) {117 // TODO: Faster data structure118 for (int j{0}; j < buckets_; ++j) {119 for (Chain *p{bucket_[j].get()}; p; p = p->next.get()) {120 if (p->unit.path() && p->unit.pathLength() == pathLen &&121 runtime::memcmp(p->unit.path(), path, pathLen) == 0) {122 return &p->unit;123 }124 }125 }126 }127 return nullptr;128}129 130ExternalFileUnit &UnitMap::Create(int n, const Terminator &terminator) {131 Chain &chain{*New<Chain>{terminator}(n).release()};132 chain.next.reset(&chain);133 bucket_[Hash(n)].swap(chain.next); // pushes new node as list head134 return chain.unit;135}136 137} // namespace Fortran::runtime::io138