// See comments above for open_ckpt_to_read()
int dmtcp::CkptSerializer::openDmtcpCheckpointFile(const dmtcp::string& path,
int *offset,
int skipBytes)
{
char buf[1024];
// Function also sets dmtcp::ext_decomp_pid::ConnectionToFds
int fd = open_ckpt_to_read(path.c_str());
// The rest of this function is for compatibility with original definition.
JASSERT(fd >= 0) (path) .Text("Failed to open file.");
const int len = strlen(DMTCP_FILE_HEADER);
JASSERT(_real_read(fd, buf, len) == len)(path) .Text("_real_read() failed");
if (strncmp(buf, DMTCP_FILE_HEADER, len) == 0) {
JTRACE("opened checkpoint file [uncompressed]")(path);
} else {
close_ckpt_to_read(fd);
fd = open_ckpt_to_read(path.c_str()); /* Re-open from beginning */
JASSERT(fd >= 0) (path) .Text("Failed to open file.");
}
if (offset != NULL) {
*offset = strlen(DMTCP_FILE_HEADER);
}
skipBytes -= strlen(DMTCP_FILE_HEADER);
if (skipBytes > 0) {
JASSERT(dmtcp::Util::skipBytes(fd, skipBytes) == skipBytes) (skipBytes);
}
return fd;
}
int dmtcp::CkptSerializer::loadFromFile(const dmtcp::string& path,
dmtcp::ConnectionToFds *conToFds,
dmtcp::ProcessInfo *processInfo)
{
int fd = openDmtcpCheckpointFile(path);
JASSERT(fd != -1);
jalib::JBinarySerializeReaderRaw rdr(path, fd);
conToFds->serialize(rdr);
processInfo->serialize(rdr);
close_ckpt_to_read(fd);
return rdr.bytes() + strlen(DMTCP_FILE_HEADER);
}
// Copied from mtcp/mtcp_restart.c.
// Let's keep this code close to MTCP code to avoid maintenance problems.
// MTCP code in: mtcp/mtcp_restart.c:open_ckpt_to_read()
// A previous version tried to replace this with popen, causing a regression:
// (no call to pclose, and possibility of using a wrong fd).
// Returns fd; sets ext_decomp_pid, if checkpoint was compressed.
static int open_ckpt_to_read(const char *filename)
{
int fd;
int fds[2];
char fc;
const char *decomp_path;
const char **decomp_args;
const char *gzip_path = "gzip";
static const char * gzip_args[] = { "gzip", "-d", "-", NULL };
#ifdef HBICT_DELTACOMP
const char *hbict_path = "hbict";
static const char *hbict_args[] = { "hbict", "-r", NULL };
#endif
pid_t cpid;
fc = first_char(filename);
fd = open(filename, O_RDONLY);
JASSERT(fd>=0)(filename).Text("Failed to open file.");
if(fc == DMTCP_MAGIC_FIRST) /* no compression */
return fd;
#ifdef HBICT_DELTACOMP
else if (fc == GZIP_FIRST || fc == HBICT_FIRST){ /* External compression */
#else
else if(fc == GZIP_FIRST){ /* gzip */
#endif
if( fc == GZIP_FIRST ){
decomp_path = gzip_path;
decomp_args = gzip_args;
}
#ifdef HBICT_DELTACOMP
else{
decomp_path = hbict_path;
decomp_args = hbict_args;
}
#endif
JASSERT(pipe(fds) != -1)(filename).Text("Cannot create pipe to execute gunzip to decompress checkpoint file!");
cpid = _real_fork();
JASSERT(cpid != -1).Text("ERROR: Cannot fork to execute gunzip to decompress checkpoint file!");
if(cpid > 0) /* parent process */
{
JTRACE ( "created child process to uncompress checkpoint file")(cpid);
ext_decomp_pid = cpid;
close(fd);
close(fds[1]);
return fds[0];
}
else /* child process */
{
JTRACE ( "child process, will exec into external de-compressor");
fd = dup(dup(dup(fd)));
fds[1] = dup(fds[1]);
close(fds[0]);
JASSERT(fd != -1);
JASSERT(dup2(fd, STDIN_FILENO) == STDIN_FILENO);
close(fd);
JASSERT(dup2(fds[1], STDOUT_FILENO) == STDOUT_FILENO);
close(fds[1]);
_real_execvp(decomp_path, (char **)decomp_args);
JASSERT(decomp_path!=NULL)(decomp_path).Text("Failed to launch gzip.");
/* should not get here */
JASSERT(false)("ERROR: Decompression failed! No restoration will be performed! Cancelling now!");
abort();
}
} else /* invalid magic number */
JASSERT(false).Text("ERROR: Invalid magic number in this checkpoint file!");
// NOT_REACHED
return -1;
}
// See comments above for open_ckpt_to_read()
int dmtcp::CkptSerializer::openDmtcpCheckpointFile(const dmtcp::string& path){
// Function also sets dmtcp::ext_decomp_pid::ConnectionToFds
int fd = open_ckpt_to_read( path.c_str() );
// The rest of this function is for compatibility with original definition.
JASSERT(fd>=0)(path).Text("Failed to open file.");
char buf[512];
const int len = strlen(DMTCP_FILE_HEADER);
JASSERT(_real_read(fd, buf, len)==len)(path).Text("_real_read() failed");
if(strncmp(buf, DMTCP_FILE_HEADER, len)==0){
JTRACE("opened checkpoint file [uncompressed]")(path);
}else{
close_ckpt_to_read(fd);
fd = open_ckpt_to_read( path.c_str() ); /* Re-open from beginning */
}
return fd;
}
void dmtcp::CkptSerializer::closeDmtcpCheckpointFile(int fd)
{
JASSERT(fd >= 0);
close_ckpt_to_read(fd);
}
