static
void thread_func(co_thread_t * self) {
args_t & args = * (args_t*) co_get_user(self);
for (uint32_t to=999999;to;--to) {
if (--args.val_) {
uint32_t next = rand64() % num_threads;
co_yield(self, args.thread_[next]);
}
else {
co_yield(self, args.host_);
}
}
}
static int
timing_yield(lua_State *L) {
#ifdef DEBUG_LOG
lua_State *from = lua_tothread(L, -1);
#endif
lua_rawget(L, lua_upvalueindex(2)); // check total time
if (lua_isnil(L, -1)) {
lua_pop(L,1);
} else {
double ti = lua_tonumber(L, -1);
lua_pop(L,1);
lua_pushthread(L);
lua_rawget(L, lua_upvalueindex(1));
double starttime = lua_tonumber(L, -1);
lua_pop(L,1);
double diff = diff_time(starttime);
ti += diff;
#ifdef DEBUG_LOG
fprintf(stderr, "PROFILE [%p] yield (%lf/%lf)\n", from, diff, ti);
#endif
lua_pushthread(L);
lua_pushnumber(L, ti);
lua_rawset(L, lua_upvalueindex(2));
}
lua_CFunction co_yield = lua_tocfunction(L, lua_upvalueindex(3));
return co_yield(L);
}
static
void thread_a(co_thread_t * self) {
assert(co_get_user(self));
args_t & args = * (args_t*) co_get_user(self);
co_yield(self, args.b_);
assert(!"Should not get here");
}
static int
timing_yield(lua_State *L) {
// printf("%s(%d): %d\n", __FUNCTION__, __LINE__, lua_gettop(L));
#ifdef DEBUG_LOG
lua_State *from = lua_tothread(L, -1);
#endif
lua_rawget(L, lua_upvalueindex(2)); // check total time， 当前函数第二个upvalue指向的index，该index指向一个table，栈顶为key，key为一个协程，从lyield传入，取table[key]压栈
if (lua_isnil(L, -1)) {
lua_pop(L,1);
// printf("%s(%d): %d\n", __FUNCTION__, __LINE__, lua_gettop(L));
} else {
double ti = lua_tonumber(L, -1); // total time
lua_pop(L,1);
lua_pushthread(L); // 协程压入
lua_rawget(L, lua_upvalueindex(1)); // 当前函数的第一个upvalue指向的index，该index指向的table，以上面的协程为索引，取得starttime
double starttime = lua_tonumber(L, -1); // start time
lua_pop(L,1);
double diff = diff_time(starttime); // now - start time
ti += diff; // 更新时间开销
#ifdef DEBUG_LOG
fprintf(stderr, "PROFILE [%p] yield (%lf/%lf)\n", from, diff, ti);
// printf("%s(%d): %d\n", __FUNCTION__, __LINE__, lua_gettop(L));
#endif
lua_pushthread(L); // 协程入栈作为key
lua_pushnumber(L, ti); // 更新后的ti入栈作为value
lua_rawset(L, lua_upvalueindex(2)); // 更新当前函数第二个upvalue指向的index指向的table，t[key]=value
}
lua_CFunction co_yield = lua_tocfunction(L, lua_upvalueindex(3)); // lua_CFuntion是一个c函数指针类型，面向lua调用的一个接口，取出当前函数的第三个upvalue指向的index指向的函数指针
return co_yield(L); // 执行这个函数
}
static coroutine_fn int ssh_read(BDRVSSHState *s, BlockDriverState *bs,
int64_t offset, size_t size,
QEMUIOVector *qiov)
{
ssize_t r;
size_t got;
char *buf, *end_of_vec;
struct iovec *i;
DPRINTF("offset=%" PRIi64 " size=%zu", offset, size);
ssh_seek(s, offset, SSH_SEEK_READ);
/* This keeps track of the current iovec element ('i'), where we
* will write to next ('buf'), and the end of the current iovec
* ('end_of_vec').
*/
i = &qiov->iov[0];
buf = i->iov_base;
end_of_vec = i->iov_base + i->iov_len;
/* libssh2 has a hard-coded limit of 2000 bytes per request,
* although it will also do readahead behind our backs. Therefore
* we may have to do repeated reads here until we have read 'size'
* bytes.
*/
for (got = 0; got < size; ) {
again:
DPRINTF("sftp_read buf=%p size=%zu", buf, end_of_vec - buf);
r = libssh2_sftp_read(s->sftp_handle, buf, end_of_vec - buf);
DPRINTF("sftp_read returned %zd", r);
if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
co_yield(s, bs);
goto again;
}
if (r < 0) {
sftp_error_report(s, "read failed");
s->offset = -1;
return -EIO;
}
if (r == 0) {
/* EOF: Short read so pad the buffer with zeroes and return it. */
qemu_iovec_memset(qiov, got, 0, size - got);
return 0;
}
got += r;
buf += r;
s->offset += r;
if (buf >= end_of_vec && got < size) {
i++;
buf = i->iov_base;
end_of_vec = i->iov_base + i->iov_len;
}
}
return 0;
}
int32_t test_unchained() {
args_t args;
args.host_ = co_init(nullptr);
args.val_ = 100000;
for (uint32_t i = 0; i < num_threads; ++i) {
args.thread_[i] = co_create (args.host_, thread_func, 1024, nullptr);
assert(args.thread_[i]);
co_set_user(args.thread_[i], &args);
}
co_yield(args.host_, args.thread_[0]);
assert(args.val_ == 0);
return 0;
}
int32_t test_yieldmain() {
args_t args;
args.host_ = co_init(nullptr);
args.a_ = co_create (args.host_, thread_a, 1024, nullptr, &args);
args.b_ = co_create (args.host_, thread_b, 1024, nullptr, &args);
co_yield(args.host_, args.a_);
co_delete(args.a_);
co_delete(args.b_);
co_delete(args.host_);
return 0;
}
static coroutine_fn int ssh_flush(BDRVSSHState *s, BlockDriverState *bs)
{
int r;
DPRINTF("fsync");
again:
r = libssh2_sftp_fsync(s->sftp_handle);
if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
co_yield(s, bs);
goto again;
}
if (r == LIBSSH2_ERROR_SFTP_PROTOCOL &&
libssh2_sftp_last_error(s->sftp) == LIBSSH2_FX_OP_UNSUPPORTED) {
unsafe_flush_warning(s, "OpenSSH >= 6.3");
return 0;
}
if (r < 0) {
sftp_error_report(s, "fsync failed");
return -EIO;
}
return 0;
}
static int ssh_write(BDRVSSHState *s, BlockDriverState *bs,
int64_t offset, size_t size,
QEMUIOVector *qiov)
{
ssize_t r;
size_t written;
char *buf, *end_of_vec;
struct iovec *i;
DPRINTF("offset=%" PRIi64 " size=%zu", offset, size);
ssh_seek(s, offset, SSH_SEEK_WRITE);
/* This keeps track of the current iovec element ('i'), where we
* will read from next ('buf'), and the end of the current iovec
* ('end_of_vec').
*/
i = &qiov->iov[0];
buf = i->iov_base;
end_of_vec = i->iov_base + i->iov_len;
for (written = 0; written < size; ) {
again:
DPRINTF("sftp_write buf=%p size=%zu", buf, end_of_vec - buf);
r = libssh2_sftp_write(s->sftp_handle, buf, end_of_vec - buf);
DPRINTF("sftp_write returned %zd", r);
if (r == LIBSSH2_ERROR_EAGAIN || r == LIBSSH2_ERROR_TIMEOUT) {
co_yield(s, bs);
goto again;
}
if (r < 0) {
sftp_error_report(s, "write failed");
s->offset = -1;
return -EIO;
}
/* The libssh2 API is very unclear about this. A comment in
* the code says "nothing was acked, and no EAGAIN was
* received!" which apparently means that no data got sent
* out, and the underlying channel didn't return any EAGAIN
* indication. I think this is a bug in either libssh2 or
* OpenSSH (server-side). In any case, forcing a seek (to
* discard libssh2 internal buffers), and then trying again
* works for me.
*/
if (r == 0) {
ssh_seek(s, offset + written, SSH_SEEK_WRITE|SSH_SEEK_FORCE);
co_yield(s, bs);
goto again;
}
written += r;
buf += r;
s->offset += r;
if (buf >= end_of_vec && written < size) {
i++;
buf = i->iov_base;
end_of_vec = i->iov_base + i->iov_len;
}
if (offset + written > s->attrs.filesize)
s->attrs.filesize = offset + written;
}
return 0;
}
void CoYield(void * pCoID)
{
co_yield((stCoRoutine_t *)pCoID);
}
