109 lines
3.1 KiB
C++
109 lines
3.1 KiB
C++
/*
|
|
* Copyright (C) 2005 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.
|
|
*/
|
|
|
|
//
|
|
// FIFO I/O.
|
|
//
|
|
#ifndef _LIBS_UTILS_PIPE_H
|
|
#define _LIBS_UTILS_PIPE_H
|
|
|
|
#ifdef HAVE_ANDROID_OS
|
|
#error DO NOT USE THIS FILE IN THE DEVICE BUILD
|
|
#endif
|
|
|
|
namespace android {
|
|
|
|
/*
|
|
* Simple anonymous unidirectional pipe.
|
|
*
|
|
* The primary goal is to create an implementation with minimal overhead
|
|
* under Linux. Making Windows, Mac OS X, and Linux all work the same way
|
|
* is a secondary goal. Part of this goal is to have something that can
|
|
* be fed to a select() call, so that the application can sleep in the
|
|
* kernel until something interesting happens.
|
|
*/
|
|
class Pipe {
|
|
public:
|
|
Pipe(void);
|
|
virtual ~Pipe(void);
|
|
|
|
/* Create the pipe */
|
|
bool create(void);
|
|
|
|
/* Create a read-only pipe, using the supplied handle as read handle */
|
|
bool createReader(unsigned long handle);
|
|
/* Create a write-only pipe, using the supplied handle as write handle */
|
|
bool createWriter(unsigned long handle);
|
|
|
|
/* Is this object ready to go? */
|
|
bool isCreated(void);
|
|
|
|
/*
|
|
* Read "count" bytes from the pipe. Returns the amount of data read,
|
|
* or 0 if no data available and we're non-blocking.
|
|
* Returns -1 on error.
|
|
*/
|
|
int read(void* buf, int count);
|
|
|
|
/*
|
|
* Write "count" bytes into the pipe. Returns number of bytes written,
|
|
* or 0 if there's no room for more data and we're non-blocking.
|
|
* Returns -1 on error.
|
|
*/
|
|
int write(const void* buf, int count);
|
|
|
|
/* Returns "true" if data is available to read */
|
|
bool readReady(void);
|
|
|
|
/* Enable or disable non-blocking I/O for reads */
|
|
bool setReadNonBlocking(bool val);
|
|
/* Enable or disable non-blocking I/O for writes. Only works on Linux. */
|
|
bool setWriteNonBlocking(bool val);
|
|
|
|
/*
|
|
* Get the handle. Only useful in some platform-specific situations.
|
|
*/
|
|
unsigned long getReadHandle(void);
|
|
unsigned long getWriteHandle(void);
|
|
|
|
/*
|
|
* Modify inheritance, i.e. whether or not a child process will get
|
|
* copies of the descriptors. Systems with fork+exec allow us to close
|
|
* the descriptors before launching the child process, but Win32
|
|
* doesn't allow it.
|
|
*/
|
|
bool disallowReadInherit(void);
|
|
bool disallowWriteInherit(void);
|
|
|
|
/*
|
|
* Close one side or the other. Useful in the parent after launching
|
|
* a child process.
|
|
*/
|
|
bool closeRead(void);
|
|
bool closeWrite(void);
|
|
|
|
private:
|
|
bool mReadNonBlocking;
|
|
bool mWriteNonBlocking;
|
|
|
|
unsigned long mReadHandle;
|
|
unsigned long mWriteHandle;
|
|
};
|
|
|
|
}; // android
|
|
|
|
#endif // _LIBS_UTILS_PIPE_H
|