source: src/Concurrency/Waitfor.cc@ ee858bf

//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Waitfor.cc --
//
// Author           : Thierry Delisle
// Created On       : Mon Aug 28 11:06:52 2017
// Last Modified By :
// Last Modified On :
// Update Count     : 12
//

#include "Concurrency/Keywords.h"

#include <cassert>                 // for assert
#include <string>                  // for string, operator==

using namespace std::string_literals;

#include "Common/PassVisitor.h"    // for PassVisitor
#include "Common/SemanticError.h"  // for SemanticError
#include "Common/UniqueName.h"     // for UniqueName
#include "Common/utility.h"        // for deleteAll, map_range
#include "CodeGen/OperatorTable.h" // for isConstructor
#include "InitTweak/InitTweak.h"   // for getPointerBase
#include "ResolvExpr/Resolver.h"   // for findVoidExpression
#include "SynTree/LinkageSpec.h"   // for Cforall
#include "SynTree/Constant.h"      // for Constant
#include "SynTree/Declaration.h"   // for StructDecl, FunctionDecl, ObjectDecl
#include "SynTree/Expression.h"    // for VariableExpr, ConstantExpr, Untype...
#include "SynTree/Initializer.h"   // for SingleInit, ListInit, Initializer ...
#include "SynTree/Label.h"         // for Label
#include "SynTree/Statement.h"     // for CompoundStmt, DeclStmt, ExprStmt
#include "SynTree/Type.h"          // for StructInstType, Type, PointerType
#include "SynTree/Visitor.h"       // for Visitor, acceptAll

class Attribute;
/*
void foo() {
        while( true ) {
                when( a < 1 ) waitfor( f : a ) { bar(); }
                or timeout( swagl() );
                or waitfor( g : a ) { baz(); }
                or waitfor( ^?{} : a ) { break; }
                or waitfor( ^?{} ) { break; }
        }
}

void f(int i, float f, A & mutex b, struct foo *  );
void f(int );


                      |  |
                      |  |
                            |  |
                      |  |
                      |  |
                    \ |  | /
                     \    /
                      \  /
                       \/


void foo() {
        while( true ) {
                {
                        acceptable_t acceptables[3];
                        if( a < 1 ) {
                                acceptables[0].func = f;
                                acceptables[0].mon = a;
                        }
                        acceptables[1].func = g;
                        acceptables[1].mon = a;

                        acceptables[2].func = f;
                        acceptables[2].mon = a;
                        acceptables[2].is_dtor = true;

                        int ret = waitfor_internal( acceptables, swagl() );

                        switch( ret ) {
                                case 0:
                                {
                                        bar();
                                }
                                case 1:
                                {
                                        baz();
                                }
                                case 2:
                                        signal(a);
                                        {
                                                break;
                                        }
                        }
                }
        }
}*/

namespace Concurrency {
        //=============================================================================================
        // Pass declarations
        //=============================================================================================

        class GenerateWaitForPass final : public WithIndexer {
          public:

                void premutate( FunctionDecl * decl );
                void premutate( StructDecl   * decl );

                Statement * postmutate( WaitForStmt * stmt );

                static void generate( std::list< Declaration * > & translationUnit ) {
                        PassVisitor< GenerateWaitForPass > impl;
                        acceptAll( translationUnit, impl );
                }

                ObjectDecl * declare( unsigned long count, CompoundStmt * stmt );
                ObjectDecl * declareFlag( CompoundStmt * stmt );
                Statement  * makeSetter( ObjectDecl * flag );
                ObjectDecl * declMon( WaitForStmt::Clause & clause, CompoundStmt * stmt );
                void         init( ObjectDecl * acceptables, int index, WaitForStmt::Clause & clause, Statement * settter, CompoundStmt * stmt );
                Expression * init_timeout( Expression *& time, Expression *& time_cond, bool has_else, Expression *& else_cond, Statement * settter, CompoundStmt * stmt );
                Expression * call(size_t count, ObjectDecl * acceptables, Expression * timeout, CompoundStmt * stmt);
                void         choose( WaitForStmt * waitfor, Expression  * result, CompoundStmt * stmt );

                static void implement( std::list< Declaration * > & translationUnit ) {
                        PassVisitor< GenerateWaitForPass > impl;
                        mutateAll( translationUnit, impl );
                }


          private:
                FunctionDecl        * decl_waitfor    = nullptr;
                StructDecl          * decl_mask       = nullptr;
                StructDecl          * decl_acceptable = nullptr;
                StructDecl          * decl_monitor    = nullptr;

                static std::unique_ptr< Type > generic_func;

                UniqueName namer_acc = "__acceptables_"s;
                UniqueName namer_idx = "__index_"s;
                UniqueName namer_flg = "__do_run_"s;
                UniqueName namer_msk = "__mask_"s;
                UniqueName namer_mon = "__monitors_"s;
                UniqueName namer_tim = "__timeout_"s;
        };

        //=============================================================================================
        // General entry routine
        //=============================================================================================
        void generateWaitFor( std::list< Declaration * > & translationUnit ) {
                GenerateWaitForPass     ::implement( translationUnit );
        }

        //=============================================================================================
        // Generic helper routine
        //=============================================================================================

        namespace {
                Expression * makeOpIndex( DeclarationWithType * array, unsigned long index ) {
                        return new UntypedExpr(
                                new NameExpr( "?[?]" ),
                                {
                                        new VariableExpr( array ),
                                        new ConstantExpr( Constant::from_ulong( index ) )
                                }
                        );
                }

                Expression * makeOpAssign( Expression * lhs, Expression * rhs ) {
                        return new UntypedExpr(
                                        new NameExpr( "?=?" ),
                                        { lhs, rhs }
                        );
                }

                Expression * makeOpMember( Expression * sue, const std::string & mem ) {
                        return new UntypedMemberExpr( new NameExpr( mem ), sue );
                }

                Statement * makeAccStatement( DeclarationWithType * object, unsigned long index, const std::string & member, Expression * value, const SymTab::Indexer & indexer ) {
                        Expression * expr = makeOpAssign(
                                makeOpMember(
                                        makeOpIndex(
                                                object,
                                                index
                                        ),
                                        member
                                ),
                                value
                        );

                        ResolvExpr::findVoidExpression( expr, indexer );

                        return new ExprStmt( expr );
                }

                Expression * safeCond( Expression * expr, bool ifnull = true ) {
                        if( expr ) return expr;

                        return new ConstantExpr( Constant::from_bool( ifnull ) );
                }

                VariableExpr * extractVariable( Expression * func ) {
                        if( VariableExpr * var = dynamic_cast< VariableExpr * >( func ) ) {
                                return var;
                        }

                        CastExpr * cast = strict_dynamic_cast< CastExpr * >( func );
                        return strict_dynamic_cast< VariableExpr * >( cast->arg );
                }

                Expression * detectIsDtor( Expression * func ) {
                        VariableExpr * typed_func = extractVariable( func );
                        bool is_dtor = InitTweak::isDestructor( typed_func->var );
                        return new ConstantExpr( Constant::from_bool( is_dtor ) );
                }
        };


        //=============================================================================================
        // Generate waitfor implementation
        //=============================================================================================

        void GenerateWaitForPass::premutate( FunctionDecl * decl) {
                if( decl->name != "__waitfor_internal" ) return;

                decl_waitfor = decl;
        }

        void GenerateWaitForPass::premutate( StructDecl   * decl ) {
                if( ! decl->body ) return;

                if( decl->name == "__acceptable_t" ) {
                        assert( !decl_acceptable );
                        decl_acceptable = decl;
                }
                else if( decl->name == "__waitfor_mask_t" ) {
                        assert( !decl_mask );
                        decl_mask = decl;
                }
                else if( decl->name == "$monitor" ) {
                        assert( !decl_monitor );
                        decl_monitor = decl;
                }
        }

        Statement * GenerateWaitForPass::postmutate( WaitForStmt * waitfor ) {
                if( !decl_monitor || !decl_acceptable || !decl_mask )
                        SemanticError( waitfor, "waitfor keyword requires monitors to be in scope, add #include <monitor.hfa>" );

                CompoundStmt * stmt = new CompoundStmt();

                ObjectDecl * acceptables = declare( waitfor->clauses.size(), stmt );
                ObjectDecl * flag        = declareFlag( stmt );
                Statement  * setter      = makeSetter( flag );

                int index = 0;
                for( auto & clause : waitfor->clauses ) {
                        init( acceptables, index, clause, setter, stmt );

                        index++;
                }

                Expression * timeout = init_timeout(
                        waitfor->timeout.time,
                        waitfor->timeout.condition,
                        waitfor->orelse .statement,
                        waitfor->orelse .condition,
                        setter,
                        stmt
                );

                CompoundStmt * compound = new CompoundStmt();
                stmt->push_back( new IfStmt(
                        safeCond( new VariableExpr( flag ) ),
                        compound,
                        nullptr
                ));

                Expression * result = call( waitfor->clauses.size(), acceptables, timeout, compound );

                choose( waitfor, result, compound );

                return stmt;
        }

        ObjectDecl * GenerateWaitForPass::declare( unsigned long count, CompoundStmt * stmt )
        {
                ObjectDecl * acceptables = ObjectDecl::newObject(
                        namer_acc.newName(),
                        new ArrayType(
                                noQualifiers,
                                new StructInstType(
                                        noQualifiers,
                                        decl_acceptable
                                ),
                                new ConstantExpr( Constant::from_ulong( count ) ),
                                false,
                                false
                        ),
                        nullptr
                );

                stmt->push_back( new DeclStmt( acceptables) );

                Expression * set = new UntypedExpr(
                        new NameExpr( "__builtin_memset" ),
                        {
                                new VariableExpr( acceptables ),
                                new ConstantExpr( Constant::from_int( 0 ) ),
                                new SizeofExpr( new VariableExpr( acceptables ) )
                        }
                );

                ResolvExpr::findVoidExpression( set, indexer );

                stmt->push_back( new ExprStmt( set ) );

                return acceptables;
        }

        ObjectDecl * GenerateWaitForPass::declareFlag( CompoundStmt * stmt ) {
                ObjectDecl * flag = ObjectDecl::newObject(
                        namer_flg.newName(),
                        new BasicType(
                                noQualifiers,
                                BasicType::Bool
                        ),
                        new SingleInit( new ConstantExpr( Constant::from_ulong( 0 ) ) )
                );

                stmt->push_back( new DeclStmt( flag) );

                return flag;
        }

        Statement * GenerateWaitForPass::makeSetter( ObjectDecl * flag ) {
                Expression * expr = new UntypedExpr(
                        new NameExpr( "?=?" ),
                        {
                                new VariableExpr( flag ),
                                new ConstantExpr( Constant::from_ulong( 1 ) )
                        }
                );

                ResolvExpr::findVoidExpression( expr, indexer );

                return new ExprStmt( expr );
        }

        ObjectDecl * GenerateWaitForPass::declMon( WaitForStmt::Clause & clause, CompoundStmt * stmt ) {

                ObjectDecl * mon = ObjectDecl::newObject(
                        namer_mon.newName(),
                        new ArrayType(
                                noQualifiers,
                                new PointerType(
                                        noQualifiers,
                                        new StructInstType(
                                                noQualifiers,
                                                decl_monitor
                                        )
                                ),
                                new ConstantExpr( Constant::from_ulong( clause.target.arguments.size() ) ),
                                false,
                                false
                        ),
                        new ListInit(
                                map_range < std::list<Initializer*> > ( clause.target.arguments, [this](Expression * expr ){
                                        Expression * init = new CastExpr(
                                                new UntypedExpr(
                                                        new NameExpr( "get_monitor" ),
                                                        { expr }
                                                ),
                                                new PointerType(
                                                        noQualifiers,
                                                        new StructInstType(
                                                                noQualifiers,
                                                                decl_monitor
                                                        )
                                                ),
                                                false
                                        );

                                        ResolvExpr::findSingleExpression( init, indexer );
                                        return new SingleInit( init );
                                })
                        )
                );

                stmt->push_back( new DeclStmt( mon) );

                return mon;
        }

        void GenerateWaitForPass::init( ObjectDecl * acceptables, int index, WaitForStmt::Clause & clause, Statement * setter, CompoundStmt * stmt ) {

                ObjectDecl * monitors = declMon( clause, stmt );

                Type * fptr_t = new PointerType( noQualifiers, new FunctionType( noQualifiers, true ) );

                stmt->push_back( new IfStmt(
                        safeCond( clause.condition ),
                        new CompoundStmt({
                                makeAccStatement( acceptables, index, "is_dtor", detectIsDtor( clause.target.function )                                    , indexer ),
                                makeAccStatement( acceptables, index, "func"   , new CastExpr( clause.target.function, fptr_t, false )                     , indexer ),
                                makeAccStatement( acceptables, index, "data"   , new VariableExpr( monitors )                                              , indexer ),
                                makeAccStatement( acceptables, index, "size"   , new ConstantExpr( Constant::from_ulong( clause.target.arguments.size() ) ), indexer ),
                                setter->clone()
                        }),
                        nullptr
                ));

                clause.target.function = nullptr;
                clause.target.arguments.empty();
                clause.condition = nullptr;
        }

        Expression * GenerateWaitForPass::init_timeout(
                Expression *& time,
                Expression *& time_cond,
                bool has_else,
                Expression *& else_cond,
                Statement * setter,
                CompoundStmt * stmt
        ) {
                ObjectDecl * timeout = ObjectDecl::newObject(
                        namer_tim.newName(),
                        new BasicType(
                                noQualifiers,
                                BasicType::LongLongUnsignedInt
                        ),
                        new SingleInit(
                                new ConstantExpr( Constant::from_int( -1 ) )
                        )
                );

                stmt->push_back( new DeclStmt( timeout ) );

                if( time ) {
                        stmt->push_back( new IfStmt(
                                safeCond( time_cond ),
                                new CompoundStmt({
                                        new ExprStmt(
                                                makeOpAssign(
                                                        new VariableExpr( timeout ),
                                                        time
                                                )
                                        ),
                                        setter->clone()
                                }),
                                nullptr
                        ));

                        time = time_cond = nullptr;
                }

                if( has_else ) {
                        stmt->push_back( new IfStmt(
                                safeCond( else_cond ),
                                new CompoundStmt({
                                        new ExprStmt(
                                                makeOpAssign(
                                                        new VariableExpr( timeout ),
                                                        new ConstantExpr( Constant::from_ulong( 0 ) )
                                                )
                                        ),
                                        setter->clone()
                                }),
                                nullptr
                        ));

                        else_cond = nullptr;
                }

                delete setter;

                return new VariableExpr( timeout );
        }

        Expression * GenerateWaitForPass::call(
                size_t count,
                ObjectDecl * acceptables,
                Expression * timeout,
                CompoundStmt * stmt
        ) {
                ObjectDecl * index = ObjectDecl::newObject(
                        namer_idx.newName(),
                        new BasicType(
                                noQualifiers,
                                BasicType::ShortSignedInt
                        ),
                        new SingleInit(
                                new ConstantExpr( Constant::from_int( -1 ) )
                        )
                );

                stmt->push_back( new DeclStmt( index ) );

                ObjectDecl * mask = ObjectDecl::newObject(
                        namer_msk.newName(),
                        new StructInstType(
                                noQualifiers,
                                decl_mask
                        ),
                        new ListInit({
                                new SingleInit( new AddressExpr( new VariableExpr( index ) ) ),
                                new ListInit({
                                        new SingleInit( new VariableExpr( acceptables ) ),
                                        new SingleInit( new ConstantExpr( Constant::from_ulong( count ) ) )
                                })
                        })
                );

                stmt->push_back( new DeclStmt( mask ) );

                stmt->push_back( new ExprStmt(
                        new ApplicationExpr(
                                VariableExpr::functionPointer( decl_waitfor ),
                                {
                                        new CastExpr(
                                                new VariableExpr( mask ),
                                                new ReferenceType(
                                                        noQualifiers,
                                                        new StructInstType(
                                                                noQualifiers,
                                                                decl_mask
                                                        )
                                                ),
                                                false
                                        ),
                                        timeout
                                }
                        )
                ));

                return new VariableExpr( index );
        }

        void GenerateWaitForPass::choose(
                WaitForStmt * waitfor,
                Expression  * result,
                CompoundStmt * stmt
        ) {
                SwitchStmt * swtch = new SwitchStmt(
                        result,
                        std::list<Statement *>()
                );

                unsigned long i = 0;
                for( auto & clause : waitfor->clauses ) {
                        swtch->statements.push_back(
                                new CaseStmt(
                                        new ConstantExpr( Constant::from_ulong( i++ ) ),
                                        {
                                                new CompoundStmt({
                                                        clause.statement,
                                                        new BranchStmt(
                                                                "",
                                                                BranchStmt::Break
                                                        )
                                                })
                                        }
                                )
                        );
                }

                if(waitfor->timeout.statement) {
                        swtch->statements.push_back(
                                new CaseStmt(
                                        new ConstantExpr( Constant::from_int( -2 ) ),
                                        {
                                                new CompoundStmt({
                                                        waitfor->timeout.statement,
                                                        new BranchStmt(
                                                                "",
                                                                BranchStmt::Break
                                                        )
                                                })
                                        }
                                )
                        );
                }

                if(waitfor->orelse.statement) {
                        swtch->statements.push_back(
                                new CaseStmt(
                                        new ConstantExpr( Constant::from_int( -1 ) ),
                                        {
                                                new CompoundStmt({
                                                        waitfor->orelse.statement,
                                                        new BranchStmt(
                                                                "",
                                                                BranchStmt::Break
                                                        )
                                                })
                                        }
                                )
                        );
                }

                stmt->push_back( swtch );
        }
};

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