MaxOS::processes::SharedMessageEndpoint Class Reference

A endpoint that allows processes to queue messages on. More...

#include <ipc.h>

Inheritance diagram for MaxOS::processes::SharedMessageEndpoint:

Public Member Functions
	SharedMessageEndpoint (const string &name, size_t size, resources::resource_type_t type)
	Creates a new shared message endpoint.
	~SharedMessageEndpoint () final
	Destroys the shared message endpoint and frees all messages.
void	send (const ipc_iovec_t *vec, size_t count)
	Combines a multipart message and sends it to the endpoint.
int	read (void *buffer, size_t size, size_t flags) final
	Reads the first message from the endpoint or will yield until a message has been written.
int	write (const void *buffer, size_t size, size_t flags) final
	Handles writing to the message endpoint resource by writing the buffer as a message.

Detailed Description

A endpoint that allows processes to queue messages on.

Definition at line 70 of file ipc.h.

Constructor & Destructor Documentation

SharedMessageEndpoint()

SharedMessageEndpoint::SharedMessageEndpoint	(	const string &	name,
		size_t	size,
		resources::resource_type_t	type
	)

Creates a new shared message endpoint.

Parameters

name	The name of the endpoint
size	The size of messages that can be sent
type	The type of resource

Definition at line 112 of file ipc.cpp.

: Resource(name, size, type)
{
 
}

~SharedMessageEndpoint()

SharedMessageEndpoint::~SharedMessageEndpoint ( )

final

Destroys the shared message endpoint and frees all messages.

Definition at line 121 of file ipc.cpp.

                                              {
 
    // Free the messages
    for(auto& message : m_queue)
        delete message;
}

Member Function Documentation

read()

int SharedMessageEndpoint::read ( void *  buffer, size_t  size, size_t  flags  )

final

Reads the first message from the endpoint or will yield until a message has been written.

Parameters

buffer	Where to write the message to
size	Max size of the message to be read
flags	0 to block, 1 for async

Returns

The amount of bytes read (0 means no messages available for async)

Todo:

int here to size_t in syscall - fix

Definition at line 165 of file ipc.cpp.

                                                                       {
 
    // Wait for a message
    while(m_queue.empty()) {
        if (flags)
            return 0;
 
        // Block
        GlobalScheduler::current_thread()->yield();
    }
 
    // Read the message into the buffer
    buffer_t* message = m_queue.pop_front();
    size_t readable = size > message->capacity() ? message->capacity() : size;
    memcpy(buffer, message -> raw(), readable);
 
    //@todo free the message mem here now aswell?
 
    return readable;
}

References MaxOS::processes::GlobalScheduler::current_thread(), and MaxOS::processes::Thread::yield().

send()

void SharedMessageEndpoint::send	(	const ipc_iovec_t *	vec,
		size_t	count
	)

Combines a multipart message and sends it to the endpoint.

Parameters

vec	The io vector containing the parts
count	How many entries the vector has

Todo:

validate stuff

Definition at line 135 of file ipc.cpp.

                                                                     {
 
    m_message_lock.lock();
 
    // Parse the message parts
    size_t size = 0;
    for (size_t i = 0; i < count; ++i)
        size += vec[i].length;
 
    // Create the message
    auto* new_message = new buffer_t(size);
    for (size_t i = 0; i < count; ++i)
        new_message->copy_from(vec[i].address, vec[i].length);
 
    // Send the message
    m_queue.push_back(new_message);
    m_message_lock.unlock();
 
}

References MaxOS::processes::BlockingLock::lock(), and MaxOS::processes::BlockingLock::unlock().

Referenced by write().

write()

int SharedMessageEndpoint::write ( const void *  buffer, size_t  size, size_t  flags  )

final

Handles writing to the message endpoint resource by writing the buffer as a message.

Parameters

buffer	The message to write to the endpoint
size	The size of the message
flags	Unused

Returns

The amount of bytes written

Definition at line 194 of file ipc.cpp.

                                                                              {
 
    // Send the buffer as the entire message
    ipc_iovec_t message = {buffer, size};
    send(&message, 1);
 
    return size;
}

References send().

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The documentation for this class was generated from the following files:

• /home/runner/work/MaxOS/MaxOS/kernel/include/processes/ipc.h
• /home/runner/work/MaxOS/MaxOS/kernel/src/processes/ipc.cpp