Java example source code file (shmemBase.c)
The shmemBase.c Java example source code
/*
* Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include "sysShmem.h"
#include "shmemBase.h"
#include "jdwpTransport.h" /* for Packet, TransportCallback */
#define MIN(x,y) ((x)<(y)?(x):(y))
/*
* This is the base shared memory transport implementation that is used
* by both front-end transports (through com.sun.tools.jdi) and
* back-end transports (through JDWP_OnLoad and the function tables
* it requires). It supports multiple connections for the benefit of the
* front-end client; the back end interface assumes only a single connection.
*/
#define MAX_IPC_PREFIX 50 /* user-specified or generated name for */
/* shared memory seg and prefix for other IPC */
#define MAX_IPC_SUFFIX 25 /* suffix to shmem name for other IPC names */
#define MAX_IPC_NAME (MAX_IPC_PREFIX + MAX_IPC_SUFFIX)
#define MAX_GENERATION_RETRIES 20
#define SHARED_BUFFER_SIZE 5000
#define CHECK_ERROR(expr) do { \
jint error = (expr); \
if (error != SYS_OK) { \
setLastError(error); \
return error; \
} \
} while (0)
/*
* The following assertions should hold anytime the stream's mutex is not held
*/
#define STREAM_INVARIANT(stream) \
do { \
SHMEM_ASSERT((stream->shared->readOffset < SHARED_BUFFER_SIZE) \
&& (stream->shared->readOffset >= 0)); \
SHMEM_ASSERT((stream->shared->writeOffset < SHARED_BUFFER_SIZE) \
&& (stream->shared->writeOffset >= 0)); \
} while (0)
/*
* Transports are duplex, so carve the shared memory into "streams",
* one used to send from client to server, the other vice versa.
*/
typedef struct SharedMemoryListener {
char mutexName[MAX_IPC_NAME];
char acceptEventName[MAX_IPC_NAME];
char attachEventName[MAX_IPC_NAME];
jboolean isListening;
jboolean isAccepted;
jlong acceptingPID;
jlong attachingPID;
} SharedListener;
typedef struct SharedMemoryTransport {
char name[MAX_IPC_PREFIX];
sys_ipmutex_t mutex;
sys_event_t acceptEvent;
sys_event_t attachEvent;
sys_shmem_t sharedMemory;
SharedListener *shared;
} SharedMemoryTransport;
/*
* Access must be syncronized. Holds one shared
* memory buffer and its state.
*/
typedef struct SharedStream {
char mutexName[MAX_IPC_NAME];
char hasDataEventName[MAX_IPC_NAME];
char hasSpaceEventName[MAX_IPC_NAME];
int readOffset;
int writeOffset;
jboolean isFull;
jbyte buffer[SHARED_BUFFER_SIZE];
} SharedStream;
/*
* The two shared streams: client to server and
* server to client.
*/
typedef struct SharedMemory {
SharedStream toClient;
SharedStream toServer;
} SharedMemory;
/*
* Local (to process) access to the shared memory
* stream. access to hasData and hasSpace synchronized
* by OS.
*/
typedef struct Stream {
sys_ipmutex_t mutex;
sys_event_t hasData;
sys_event_t hasSpace;
SharedStream *shared;
jint state;
} Stream;
/*
* Values for Stream.state field above.
*/
#define STATE_CLOSED 0xDEAD
#define STATE_OPEN (STATE_CLOSED -1)
/*
* State checking macro. We compare against the STATE_OPEN value so
* that STATE_CLOSED and any other value will be considered closed.
* This catches a freed Stream as long as the memory page is still
* valid. If the memory page is gone, then there is little that we
* can do.
*/
#define IS_STATE_CLOSED(state) (state != STATE_OPEN)
typedef struct SharedMemoryConnection {
char name[MAX_IPC_NAME];
SharedMemory *shared;
sys_shmem_t sharedMemory;
Stream incoming;
Stream outgoing;
sys_process_t otherProcess;
sys_event_t shutdown; /* signalled to indicate shutdown */
} SharedMemoryConnection;
static jdwpTransportCallback *callback;
static JavaVM *jvm;
static int tlsIndex;
typedef jint (*CreateFunc)(char *name, void *arg);
/*
* Set the per-thread error message (if not already set)
*/
static void
setLastErrorMsg(char *newmsg) {
char *msg;
msg = (char *)sysTlsGet(tlsIndex);
if (msg == NULL) {
msg = (*callback->alloc)((int)strlen(newmsg)+1);
if (msg != NULL) {
strcpy(msg, newmsg);
}
sysTlsPut(tlsIndex, (void *)msg);
}
}
/*
* Clear last per-thread error message
*/
static void
clearLastError() {
char* msg = (char *)sysTlsGet(tlsIndex);
if (msg != NULL) {
(*callback->free)(msg);
sysTlsPut(tlsIndex, NULL);
}
}
/*
* Set the per-thread error message to the textual representation
* of the last system error (if not already set)
*/
static void
setLastError(jint error) {
char buf[128];
switch (error) {
case SYS_OK : return; /* no-op */
case SYS_DIED : strcpy(buf, "Other process terminated"); break;
case SYS_TIMEOUT : strcpy(buf, "Timed out"); break;
default : sysGetLastError(buf, sizeof(buf));
}
setLastErrorMsg(buf);
}
jint
shmemBase_initialize(JavaVM *vm, jdwpTransportCallback *cbPtr)
{
jvm = vm;
callback = cbPtr;
tlsIndex = sysTlsAlloc();
return SYS_OK;
}
static jint
createWithGeneratedName(char *prefix, char *nameBuffer, CreateFunc func, void *arg)
{
jint error;
jint i = 0;
do {
strcpy(nameBuffer, prefix);
if (i > 0) {
char buf[10];
sprintf(buf, ".%d", i+1);
strcat(nameBuffer, buf);
}
error = func(nameBuffer, arg);
i++;
} while ((error == SYS_INUSE) && (i < MAX_GENERATION_RETRIES));
if (error != SYS_OK) {
setLastError(error);
}
return error;
}
typedef struct SharedMemoryArg {
jint size;
sys_shmem_t memory;
void *start;
} SharedMemoryArg;
static jint
createSharedMem(char *name, void *ptr)
{
SharedMemoryArg *arg = ptr;
return sysSharedMemCreate(name, arg->size, &arg->memory, &arg->start);
}
static jint
createMutex(char *name, void *arg)
{
sys_ipmutex_t *retArg = arg;
return sysIPMutexCreate(name, retArg);
}
/*
* Creates named or unnamed event that is automatically reset
* (in other words, no need to reset event after it has signalled
* a thread).
*/
static jint
createEvent(char *name, void *arg)
{
sys_event_t *retArg = arg;
return sysEventCreate(name, retArg, JNI_FALSE);
}
#define ADD_OFFSET(o1, o2) ((o1 + o2) % SHARED_BUFFER_SIZE)
#define FULL(stream) (stream->shared->isFull)
#define EMPTY(stream) ((stream->shared->writeOffset == stream->shared->readOffset) \
&& !stream->shared->isFull)
static jint
leaveMutex(Stream *stream)
{
return sysIPMutexExit(stream->mutex);
}
/* enter the stream's mutex and (optionally) check for a closed stream */
static jint
enterMutex(Stream *stream, sys_event_t event)
{
jint ret = sysIPMutexEnter(stream->mutex, event);
if (ret != SYS_OK) {
if (IS_STATE_CLOSED(stream->state)) {
setLastErrorMsg("stream closed");
}
return ret;
}
if (IS_STATE_CLOSED(stream->state)) {
setLastErrorMsg("stream closed");
(void)leaveMutex(stream);
return SYS_ERR;
}
return SYS_OK;
}
/*
* Enter/exit with stream mutex held.
* On error, does not hold the stream mutex.
*/
static jint
waitForSpace(SharedMemoryConnection *connection, Stream *stream)
{
jint error = SYS_OK;
/* Assumes mutex is held on call */
while ((error == SYS_OK) && FULL(stream)) {
CHECK_ERROR(leaveMutex(stream));
error = sysEventWait(connection->otherProcess, stream->hasSpace, 0);
if (error == SYS_OK) {
CHECK_ERROR(enterMutex(stream, connection->shutdown));
} else {
setLastError(error);
}
}
return error;
}
static jint
signalSpace(Stream *stream)
{
return sysEventSignal(stream->hasSpace);
}
/*
* Enter/exit with stream mutex held.
* On error, does not hold the stream mutex.
*/
static jint
waitForData(SharedMemoryConnection *connection, Stream *stream)
{
jint error = SYS_OK;
/* Assumes mutex is held on call */
while ((error == SYS_OK) && EMPTY(stream)) {
CHECK_ERROR(leaveMutex(stream));
error = sysEventWait(connection->otherProcess, stream->hasData, 0);
if (error == SYS_OK) {
CHECK_ERROR(enterMutex(stream, connection->shutdown));
} else {
setLastError(error);
}
}
return error;
}
static jint
signalData(Stream *stream)
{
return sysEventSignal(stream->hasData);
}
static jint
closeStream(Stream *stream, jboolean linger)
{
/*
* Lock stream during close - ignore shutdown event as we are
* closing down and shutdown should be signalled.
*/
CHECK_ERROR(enterMutex(stream, NULL));
/* mark the stream as closed */
stream->state = STATE_CLOSED;
/* wake up waitForData() if it is in sysEventWait() */
sysEventSignal(stream->hasData);
sysEventClose(stream->hasData);
/* wake up waitForSpace() if it is in sysEventWait() */
sysEventSignal(stream->hasSpace);
sysEventClose(stream->hasSpace);
/*
* If linger requested then give the stream a few seconds to
* drain before closing it.
*/
if (linger) {
int attempts = 10;
while (!EMPTY(stream) && attempts>0) {
CHECK_ERROR(leaveMutex(stream));
sysSleep(200);
CHECK_ERROR(enterMutex(stream, NULL));
attempts--;
}
}
CHECK_ERROR(leaveMutex(stream));
sysIPMutexClose(stream->mutex);
return SYS_OK;
}
/*
* Server creates stream.
*/
static int
createStream(char *name, Stream *stream)
{
jint error;
char prefix[MAX_IPC_PREFIX];
sprintf(prefix, "%s.mutex", name);
error = createWithGeneratedName(prefix, stream->shared->mutexName,
createMutex, &stream->mutex);
if (error != SYS_OK) {
return error;
}
sprintf(prefix, "%s.hasData", name);
error = createWithGeneratedName(prefix, stream->shared->hasDataEventName,
createEvent, &stream->hasData);
if (error != SYS_OK) {
(void)closeStream(stream, JNI_FALSE);
return error;
}
sprintf(prefix, "%s.hasSpace", name);
error = createWithGeneratedName(prefix, stream->shared->hasSpaceEventName,
createEvent, &stream->hasSpace);
if (error != SYS_OK) {
(void)closeStream(stream, JNI_FALSE);
return error;
}
stream->shared->readOffset = 0;
stream->shared->writeOffset = 0;
stream->shared->isFull = JNI_FALSE;
stream->state = STATE_OPEN;
return SYS_OK;
}
/*
* Initialization for the stream opened by the other process
*/
static int
openStream(Stream *stream)
{
jint error;
CHECK_ERROR(sysIPMutexOpen(stream->shared->mutexName, &stream->mutex));
error = sysEventOpen(stream->shared->hasDataEventName,
&stream->hasData);
if (error != SYS_OK) {
setLastError(error);
(void)closeStream(stream, JNI_FALSE);
return error;
}
error = sysEventOpen(stream->shared->hasSpaceEventName,
&stream->hasSpace);
if (error != SYS_OK) {
setLastError(error);
(void)closeStream(stream, JNI_FALSE);
return error;
}
stream->state = STATE_OPEN;
return SYS_OK;
}
/********************************************************************/
static SharedMemoryConnection *
allocConnection(void)
{
/*
* TO DO: Track all allocated connections for clean shutdown?
*/
SharedMemoryConnection *conn = (*callback->alloc)(sizeof(SharedMemoryConnection));
if (conn != NULL) {
memset(conn, 0, sizeof(SharedMemoryConnection));
}
return conn;
}
static void
freeConnection(SharedMemoryConnection *connection)
{
(*callback->free)(connection);
}
static void
closeConnection(SharedMemoryConnection *connection)
{
/*
* Signal all threads accessing this connection that we are
* shutting down.
*/
if (connection->shutdown) {
sysEventSignal(connection->shutdown);
}
(void)closeStream(&connection->outgoing, JNI_TRUE);
(void)closeStream(&connection->incoming, JNI_FALSE);
if (connection->sharedMemory) {
sysSharedMemClose(connection->sharedMemory, connection->shared);
}
if (connection->otherProcess) {
sysProcessClose(connection->otherProcess);
}
/*
* Ideally we should close the connection->shutdown event and
* free the connection structure. However as closing the
* connection is asynchronous it means that other threads may
* still be accessing the connection structure. On Win32 this
* means we leak 132 bytes and one event per connection. This
* memory will be reclaim at process exit.
*
* if (connection->shutdown)
* sysEventClose(connection->shutdown);
* freeConnection(connection);
*/
}
/*
* For client: connect to the shared memory. Open incoming and
* outgoing streams.
*/
static jint
openConnection(SharedMemoryTransport *transport, jlong otherPID,
SharedMemoryConnection **connectionPtr)
{
jint error;
SharedMemoryConnection *connection = allocConnection();
if (connection == NULL) {
return SYS_NOMEM;
}
sprintf(connection->name, "%s.%ld", transport->name, sysProcessGetID());
error = sysSharedMemOpen(connection->name, &connection->sharedMemory,
&connection->shared);
if (error != SYS_OK) {
closeConnection(connection);
return error;
}
/* This process is the client */
connection->incoming.shared = &connection->shared->toClient;
connection->outgoing.shared = &connection->shared->toServer;
error = openStream(&connection->incoming);
if (error != SYS_OK) {
closeConnection(connection);
return error;
}
error = openStream(&connection->outgoing);
if (error != SYS_OK) {
closeConnection(connection);
return error;
}
error = sysProcessOpen(otherPID, &connection->otherProcess);
if (error != SYS_OK) {
setLastError(error);
closeConnection(connection);
return error;
}
/*
* Create an event that signals that the connection is shutting
* down. The event is unnamed as it's process local, and is
* manually reset (so that signalling the event will signal
* all threads waiting on it).
*/
error = sysEventCreate(NULL, &connection->shutdown, JNI_TRUE);
if (error != SYS_OK) {
setLastError(error);
closeConnection(connection);
return error;
}
*connectionPtr = connection;
return SYS_OK;
}
/*
* For server: create the shared memory. Create incoming and
* outgoing streams.
*/
static jint
createConnection(SharedMemoryTransport *transport, jlong otherPID,
SharedMemoryConnection **connectionPtr)
{
jint error;
char streamPrefix[MAX_IPC_NAME];
SharedMemoryConnection *connection = allocConnection();
if (connection == NULL) {
return SYS_NOMEM;
}
sprintf(connection->name, "%s.%ld", transport->name, otherPID);
error = sysSharedMemCreate(connection->name, sizeof(SharedMemory),
&connection->sharedMemory, &connection->shared);
if (error != SYS_OK) {
closeConnection(connection);
return error;
}
memset(connection->shared, 0, sizeof(SharedMemory));
/* This process is the server */
connection->incoming.shared = &connection->shared->toServer;
connection->outgoing.shared = &connection->shared->toClient;
strcpy(streamPrefix, connection->name);
strcat(streamPrefix, ".ctos");
error = createStream(streamPrefix, &connection->incoming);
if (error != SYS_OK) {
closeConnection(connection);
return error;
}
strcpy(streamPrefix, connection->name);
strcat(streamPrefix, ".stoc");
error = createStream(streamPrefix, &connection->outgoing);
if (error != SYS_OK) {
closeConnection(connection);
return error;
}
error = sysProcessOpen(otherPID, &connection->otherProcess);
if (error != SYS_OK) {
setLastError(error);
closeConnection(connection);
return error;
}
/*
* Create an event that signals that the connection is shutting
* down. The event is unnamed as it's process local, and is
* manually reset (so that a signalling the event will signal
* all threads waiting on it).
*/
error = sysEventCreate(NULL, &connection->shutdown, JNI_TRUE);
if (error != SYS_OK) {
setLastError(error);
closeConnection(connection);
return error;
}
*connectionPtr = connection;
return SYS_OK;
}
/********************************************************************/
static SharedMemoryTransport *
allocTransport(void)
{
/*
* TO DO: Track all allocated transports for clean shutdown?
*/
return (*callback->alloc)(sizeof(SharedMemoryTransport));
}
static void
freeTransport(SharedMemoryTransport *transport)
{
(*callback->free)(transport);
}
static void
closeTransport(SharedMemoryTransport *transport)
{
sysIPMutexClose(transport->mutex);
sysEventClose(transport->acceptEvent);
sysEventClose(transport->attachEvent);
sysSharedMemClose(transport->sharedMemory, transport->shared);
freeTransport(transport);
}
static int
openTransport(const char *address, SharedMemoryTransport **transportPtr)
{
jint error;
SharedMemoryTransport *transport;
transport = allocTransport();
if (transport == NULL) {
return SYS_NOMEM;
}
memset(transport, 0, sizeof(*transport));
if (strlen(address) >= MAX_IPC_PREFIX) {
char buf[128];
sprintf(buf, "Error: address strings longer than %d characters are invalid\n", MAX_IPC_PREFIX);
setLastErrorMsg(buf);
closeTransport(transport);
return SYS_ERR;
}
error = sysSharedMemOpen(address, &transport->sharedMemory, &transport->shared);
if (error != SYS_OK) {
setLastError(error);
closeTransport(transport);
return error;
}
strcpy(transport->name, address);
error = sysIPMutexOpen(transport->shared->mutexName, &transport->mutex);
if (error != SYS_OK) {
setLastError(error);
closeTransport(transport);
return error;
}
error = sysEventOpen(transport->shared->acceptEventName,
&transport->acceptEvent);
if (error != SYS_OK) {
setLastError(error);
closeTransport(transport);
return error;
}
error = sysEventOpen(transport->shared->attachEventName,
&transport->attachEvent);
if (error != SYS_OK) {
setLastError(error);
closeTransport(transport);
return error;
}
*transportPtr = transport;
return SYS_OK;
}
static jint
createTransport(const char *address, SharedMemoryTransport **transportPtr)
{
SharedMemoryTransport *transport;
jint error;
char prefix[MAX_IPC_PREFIX];
transport = allocTransport();
if (transport == NULL) {
return SYS_NOMEM;
}
memset(transport, 0, sizeof(*transport));
if ((address == NULL) || (address[0] == '\0')) {
SharedMemoryArg arg;
arg.size = sizeof(SharedListener);
error = createWithGeneratedName("javadebug", transport->name,
createSharedMem, &arg);
transport->shared = arg.start;
transport->sharedMemory = arg.memory;
} else {
if (strlen(address) >= MAX_IPC_PREFIX) {
char buf[128];
sprintf(buf, "Error: address strings longer than %d characters are invalid\n", MAX_IPC_PREFIX);
setLastErrorMsg(buf);
closeTransport(transport);
return SYS_ERR;
}
strcpy(transport->name, address);
error = sysSharedMemCreate(address, sizeof(SharedListener),
&transport->sharedMemory, &transport->shared);
}
if (error != SYS_OK) {
setLastError(error);
closeTransport(transport);
return error;
}
memset(transport->shared, 0, sizeof(SharedListener));
transport->shared->acceptingPID = sysProcessGetID();
sprintf(prefix, "%s.mutex", transport->name);
error = createWithGeneratedName(prefix, transport->shared->mutexName,
createMutex, &transport->mutex);
if (error != SYS_OK) {
closeTransport(transport);
return error;
}
sprintf(prefix, "%s.accept", transport->name);
error = createWithGeneratedName(prefix, transport->shared->acceptEventName,
createEvent, &transport->acceptEvent);
if (error != SYS_OK) {
closeTransport(transport);
return error;
}
sprintf(prefix, "%s.attach", transport->name);
error = createWithGeneratedName(prefix, transport->shared->attachEventName,
createEvent, &transport->attachEvent);
if (error != SYS_OK) {
closeTransport(transport);
return error;
}
*transportPtr = transport;
return SYS_OK;
}
jint
shmemBase_listen(const char *address, SharedMemoryTransport **transportPtr)
{
int error;
clearLastError();
error = createTransport(address, transportPtr);
if (error == SYS_OK) {
(*transportPtr)->shared->isListening = JNI_TRUE;
}
return error;
}
jint
shmemBase_accept(SharedMemoryTransport *transport,
long timeout,
SharedMemoryConnection **connectionPtr)
{
jint error;
SharedMemoryConnection *connection;
clearLastError();
CHECK_ERROR(sysEventWait(NULL, transport->attachEvent, timeout));
error = createConnection(transport, transport->shared->attachingPID,
&connection);
if (error != SYS_OK) {
/*
* Reject the attacher
*/
transport->shared->isAccepted = JNI_FALSE;
sysEventSignal(transport->acceptEvent);
freeConnection(connection);
return error;
}
transport->shared->isAccepted = JNI_TRUE;
error = sysEventSignal(transport->acceptEvent);
if (error != SYS_OK) {
/*
* No real point trying to reject it.
*/
closeConnection(connection);
return error;
}
*connectionPtr = connection;
return SYS_OK;
}
static jint
doAttach(SharedMemoryTransport *transport, long timeout)
{
transport->shared->attachingPID = sysProcessGetID();
CHECK_ERROR(sysEventSignal(transport->attachEvent));
CHECK_ERROR(sysEventWait(NULL, transport->acceptEvent, timeout));
return SYS_OK;
}
jint
shmemBase_attach(const char *addressString, long timeout, SharedMemoryConnection **connectionPtr)
{
int error;
SharedMemoryTransport *transport;
jlong acceptingPID;
clearLastError();
error = openTransport(addressString, &transport);
if (error != SYS_OK) {
return error;
}
/* lock transport - no additional event to wait on as no connection yet */
error = sysIPMutexEnter(transport->mutex, NULL);
if (error != SYS_OK) {
setLastError(error);
closeTransport(transport);
return error;
}
if (transport->shared->isListening) {
error = doAttach(transport, timeout);
if (error == SYS_OK) {
acceptingPID = transport->shared->acceptingPID;
}
} else {
/* Not listening: error */
error = SYS_ERR;
}
sysIPMutexExit(transport->mutex);
if (error != SYS_OK) {
closeTransport(transport);
return error;
}
error = openConnection(transport, acceptingPID, connectionPtr);
closeTransport(transport);
return error;
}
void
shmemBase_closeConnection(SharedMemoryConnection *connection)
{
clearLastError();
closeConnection(connection);
}
void
shmemBase_closeTransport(SharedMemoryTransport *transport)
{
clearLastError();
closeTransport(transport);
}
jint
shmemBase_sendByte(SharedMemoryConnection *connection, jbyte data)
{
Stream *stream = &connection->outgoing;
SharedStream *shared = stream->shared;
int offset;
clearLastError();
CHECK_ERROR(enterMutex(stream, connection->shutdown));
CHECK_ERROR(waitForSpace(connection, stream));
SHMEM_ASSERT(!FULL(stream));
offset = shared->writeOffset;
shared->buffer[offset] = data;
shared->writeOffset = ADD_OFFSET(offset, 1);
shared->isFull = (shared->readOffset == shared->writeOffset);
STREAM_INVARIANT(stream);
CHECK_ERROR(leaveMutex(stream));
CHECK_ERROR(signalData(stream));
return SYS_OK;
}
jint
shmemBase_receiveByte(SharedMemoryConnection *connection, jbyte *data)
{
Stream *stream = &connection->incoming;
SharedStream *shared = stream->shared;
int offset;
clearLastError();
CHECK_ERROR(enterMutex(stream, connection->shutdown));
CHECK_ERROR(waitForData(connection, stream));
SHMEM_ASSERT(!EMPTY(stream));
offset = shared->readOffset;
*data = shared->buffer[offset];
shared->readOffset = ADD_OFFSET(offset, 1);
shared->isFull = JNI_FALSE;
STREAM_INVARIANT(stream);
CHECK_ERROR(leaveMutex(stream));
CHECK_ERROR(signalSpace(stream));
return SYS_OK;
}
static jint
sendBytes(SharedMemoryConnection *connection, const void *bytes, jint length)
{
Stream *stream = &connection->outgoing;
SharedStream *shared = stream->shared;
jint fragmentStart;
jint fragmentLength;
jint index = 0;
jint maxLength;
clearLastError();
CHECK_ERROR(enterMutex(stream, connection->shutdown));
while (index < length) {
CHECK_ERROR(waitForSpace(connection, stream));
SHMEM_ASSERT(!FULL(stream));
fragmentStart = shared->writeOffset;
if (fragmentStart < shared->readOffset) {
maxLength = shared->readOffset - fragmentStart;
} else {
maxLength = SHARED_BUFFER_SIZE - fragmentStart;
}
fragmentLength = MIN(maxLength, length - index);
memcpy(shared->buffer + fragmentStart, (jbyte *)bytes + index, fragmentLength);
shared->writeOffset = ADD_OFFSET(fragmentStart, fragmentLength);
index += fragmentLength;
shared->isFull = (shared->readOffset == shared->writeOffset);
STREAM_INVARIANT(stream);
CHECK_ERROR(signalData(stream));
}
CHECK_ERROR(leaveMutex(stream));
return SYS_OK;
}
/*
* Send packet header followed by data.
*/
jint
shmemBase_sendPacket(SharedMemoryConnection *connection, const jdwpPacket *packet)
{
jint data_length;
clearLastError();
CHECK_ERROR(sendBytes(connection, &packet->type.cmd.id, sizeof(jint)));
CHECK_ERROR(sendBytes(connection, &packet->type.cmd.flags, sizeof(jbyte)));
if (packet->type.cmd.flags & JDWPTRANSPORT_FLAGS_REPLY) {
CHECK_ERROR(sendBytes(connection, &packet->type.reply.errorCode, sizeof(jshort)));
} else {
CHECK_ERROR(sendBytes(connection, &packet->type.cmd.cmdSet, sizeof(jbyte)));
CHECK_ERROR(sendBytes(connection, &packet->type.cmd.cmd, sizeof(jbyte)));
}
data_length = packet->type.cmd.len - 11;
SHMEM_GUARANTEE(data_length >= 0);
CHECK_ERROR(sendBytes(connection, &data_length, sizeof(jint)));
if (data_length > 0) {
CHECK_ERROR(sendBytes(connection, packet->type.cmd.data, data_length));
}
return SYS_OK;
}
static jint
receiveBytes(SharedMemoryConnection *connection, void *bytes, jint length)
{
Stream *stream = &connection->incoming;
SharedStream *shared = stream->shared;
jint fragmentStart;
jint fragmentLength;
jint index = 0;
jint maxLength;
clearLastError();
CHECK_ERROR(enterMutex(stream, connection->shutdown));
while (index < length) {
CHECK_ERROR(waitForData(connection, stream));
SHMEM_ASSERT(!EMPTY(stream));
fragmentStart = shared->readOffset;
if (fragmentStart < shared->writeOffset) {
maxLength = shared->writeOffset - fragmentStart;
} else {
maxLength = SHARED_BUFFER_SIZE - fragmentStart;
}
fragmentLength = MIN(maxLength, length - index);
memcpy((jbyte *)bytes + index, shared->buffer + fragmentStart, fragmentLength);
shared->readOffset = ADD_OFFSET(fragmentStart, fragmentLength);
index += fragmentLength;
shared->isFull = JNI_FALSE;
STREAM_INVARIANT(stream);
CHECK_ERROR(signalSpace(stream));
}
CHECK_ERROR(leaveMutex(stream));
return SYS_OK;
}
/*
* Read packet header and insert into packet structure.
* Allocate space for the data and fill it in.
*/
jint
shmemBase_receivePacket(SharedMemoryConnection *connection, jdwpPacket *packet)
{
jint data_length;
jint error;
clearLastError();
CHECK_ERROR(receiveBytes(connection, &packet->type.cmd.id, sizeof(jint)));
CHECK_ERROR(receiveBytes(connection, &packet->type.cmd.flags, sizeof(jbyte)));
if (packet->type.cmd.flags & JDWPTRANSPORT_FLAGS_REPLY) {
CHECK_ERROR(receiveBytes(connection, &packet->type.reply.errorCode, sizeof(jshort)));
} else {
CHECK_ERROR(receiveBytes(connection, &packet->type.cmd.cmdSet, sizeof(jbyte)));
CHECK_ERROR(receiveBytes(connection, &packet->type.cmd.cmd, sizeof(jbyte)));
}
CHECK_ERROR(receiveBytes(connection, &data_length, sizeof(jint)));
if (data_length < 0) {
return SYS_ERR;
} else if (data_length == 0) {
packet->type.cmd.len = 11;
packet->type.cmd.data = NULL;
} else {
packet->type.cmd.len = data_length + 11;
packet->type.cmd.data = (*callback->alloc)(data_length);
if (packet->type.cmd.data == NULL) {
return SYS_ERR;
}
error = receiveBytes(connection, packet->type.cmd.data, data_length);
if (error != SYS_OK) {
(*callback->free)(packet->type.cmd.data);
return error;
}
}
return SYS_OK;
}
jint
shmemBase_name(struct SharedMemoryTransport *transport, char **name)
{
*name = transport->name;
return SYS_OK;
}
jint
shmemBase_getlasterror(char *msg, jint size) {
char *errstr = (char *)sysTlsGet(tlsIndex);
if (errstr != NULL) {
strcpy(msg, errstr);
return SYS_OK;
} else {
return SYS_ERR;
}
}
void
exitTransportWithError(char *message, char *fileName,
char *date, int lineNumber)
{
JNIEnv *env;
jint error;
char buffer[500];
sprintf(buffer, "Shared Memory Transport \"%s\" (%s), line %d: %s\n",
fileName, date, lineNumber, message);
error = (*jvm)->GetEnv(jvm, (void **)&env, JNI_VERSION_1_2);
if (error != JNI_OK) {
/*
* We're forced into a direct call to exit()
*/
fprintf(stderr, "%s", buffer);
exit(-1);
} else {
(*env)->FatalError(env, buffer);
}
}
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