framework/java/jdwp/helpers.go

// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package jdwp

import (
	"fmt"

	"android.googlesource.com/platform/tools/gpu/framework/log"
)

// GetClassBySignature returns the single loaded class matching the requested
// signature from the server. If there are no, or more than one class found,
// then an error is returned.
func (c *Connection) GetClassBySignature(signature string) (ClassInfo, error) {
	classes, err := c.GetClassesBySignature(signature)
	if err != nil {
		return ClassInfo{}, err
	}
	if len(classes) != 1 {
		err := fmt.Errorf("%d classes found with the signature '%v'", len(classes), signature)
		return ClassInfo{}, err
	}
	return classes[0], nil
}

// GetLocationMethodName returns the name of the method from the location.
func (c *Connection) GetLocationMethodName(l Location) (string, error) {
	methods, err := c.GetMethods(ReferenceTypeID(l.Class))
	if err != nil {
		return "", err
	}
	method := methods.FindByID(l.Method)
	if method == nil {
		return "", fmt.Errorf("Method not found with ID %v", l.Method)
	}
	return method.Name, nil
}

// GetClassMethod looks up the method with the specified signature on class.
func (c *Connection) GetClassMethod(class ClassID, name, signature string) (Method, error) {
	methods, err := c.GetMethods(ReferenceTypeID(class))
	if err != nil {
		return Method{}, err
	}
	method := methods.FindBySignature(name, signature)
	if method == nil {
		return Method{}, fmt.Errorf("Method '%s' not found", signature)
	}
	return *method, nil
}

// WaitForClassPrepare blocks until a class with a name that matches the pattern
// is prepared, and then returns the thread that prepared the class.
func (c *Connection) WaitForClassPrepare(ctx log.Context, pattern string) (ThreadID, error) {
	id, err := c.SetEvent(ClassPrepare, SuspendEventThread, ClassMatchEventModifier(pattern))
	if err != nil {
		return 0, err
	}
	defer c.ClearEvent(ClassPrepare, id)

	var thread ThreadID
	c.WatchEvents(ctx, func(event Event, _ SuspendPolicy) bool {
		if event, ok := event.(*EventClassPrepare); ok {
			if event.Request == id {
				thread = event.Thread
				return false
			}
		}
		return true
	})
	return thread, nil
}

// WaitForMethodEntry blocks until the method on class is entered, and then
// returns the method entry event. The thread is suspended when the method
// returns. If wakeup is not 0, then the given thread is resumed before
// we wait for the method.
func (c *Connection) WaitForMethodEntry(ctx log.Context, class ClassID, method MethodID, wakeup ThreadID) (*EventMethodEntry, error) {
	id, err := c.SetEvent(MethodEntry, SuspendEventThread, ClassOnlyEventModifier(class))
	if err != nil {
		return nil, err
	}
	if wakeup != 0 {
		c.Resume(wakeup)
	}

	defer c.ClearEvent(MethodEntry, id)

	var out *EventMethodEntry
	c.WatchEvents(ctx, func(event Event, _ SuspendPolicy) bool {
		if event, ok := event.(*EventMethodEntry); ok {
			if event.Location.Method == method {
				out = event
				return false
			}
			c.Resume(event.Thread)
		}
		return true
	})

	return out, nil
}