riscv/qemu - qemu - Gitea: Git with a cup of tea

26034 Commits

68 Branches

448 Tags

581 MiB

Tree: 380cd056ec

Commit Graph

Author	SHA1	Message	Date
Paolo Bonzini	402397843e	coroutine: move pooling to common code The coroutine pool code is duplicated between the ucontext and sigaltstack backends, and absent from the win32 backend. But the code can be shared easily by moving it to qemu-coroutine.c. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>	13 years ago
Paolo Bonzini	737e150e89	block: move include files to include/block/ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>	13 years ago
Kevin Wolf	00dccaf1f8	coroutine: introduce coroutines Asynchronous code is becoming very complex. At the same time synchronous code is growing because it is convenient to write. Sometimes duplicate code paths are even added, one synchronous and the other asynchronous. This patch introduces coroutines which allow code that looks synchronous but is asynchronous under the covers. A coroutine has its own stack and is therefore able to preserve state across blocking operations, which traditionally require callback functions and manual marshalling of parameters. Creating and starting a coroutine is easy: coroutine = qemu_coroutine_create(my_coroutine); qemu_coroutine_enter(coroutine, my_data); The coroutine then executes until it returns or yields: void coroutine_fn my_coroutine(void opaque) { MyData my_data = opaque; /* do some work / qemu_coroutine_yield(); / do some more work */ } Yielding switches control back to the caller of qemu_coroutine_enter(). This is typically used to switch back to the main thread's event loop after issuing an asynchronous I/O request. The request callback will then invoke qemu_coroutine_enter() once more to switch back to the coroutine. Note that if coroutines are used only from threads which hold the global mutex they will never execute concurrently. This makes programming with coroutines easier than with threads. Race conditions cannot occur since only one coroutine may be active at any time. Other coroutines can only run across yield. This coroutines implementation is based on the gtk-vnc implementation written by Anthony Liguori <anthony@codemonkey.ws> but it has been significantly rewritten by Kevin Wolf <kwolf@redhat.com> to use setjmp()/longjmp() instead of the more expensive swapcontext() and by Paolo Bonzini <pbonzini@redhat.com> for Windows Fibers support. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>	15 years ago

Author

SHA1

Message

Date

Paolo Bonzini

402397843e

coroutine: move pooling to common code

The coroutine pool code is duplicated between the ucontext and
sigaltstack backends, and absent from the win32 backend.  But the
code can be shared easily by moving it to qemu-coroutine.c.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

13 years ago

Paolo Bonzini

737e150e89

block: move include files to include/block/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

13 years ago

Kevin Wolf

00dccaf1f8

coroutine: introduce coroutines

Asynchronous code is becoming very complex.  At the same time
synchronous code is growing because it is convenient to write.
Sometimes duplicate code paths are even added, one synchronous and the
other asynchronous.  This patch introduces coroutines which allow code
that looks synchronous but is asynchronous under the covers.

A coroutine has its own stack and is therefore able to preserve state
across blocking operations, which traditionally require callback
functions and manual marshalling of parameters.

Creating and starting a coroutine is easy:

  coroutine = qemu_coroutine_create(my_coroutine);
  qemu_coroutine_enter(coroutine, my_data);

The coroutine then executes until it returns or yields:

  void coroutine_fn my_coroutine(void *opaque) {
      MyData *my_data = opaque;

      /* do some work */

      qemu_coroutine_yield();

      /* do some more work */
  }

Yielding switches control back to the caller of qemu_coroutine_enter().
This is typically used to switch back to the main thread's event loop
after issuing an asynchronous I/O request.  The request callback will
then invoke qemu_coroutine_enter() once more to switch back to the
coroutine.

Note that if coroutines are used only from threads which hold the global
mutex they will never execute concurrently.  This makes programming with
coroutines easier than with threads.  Race conditions cannot occur since
only one coroutine may be active at any time.  Other coroutines can only
run across yield.

This coroutines implementation is based on the gtk-vnc implementation
written by Anthony Liguori <anthony@codemonkey.ws> but it has been
significantly rewritten by Kevin Wolf <kwolf@redhat.com> to use
setjmp()/longjmp() instead of the more expensive swapcontext() and by
Paolo Bonzini <pbonzini@redhat.com> for Windows Fibers support.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

15 years ago

3 Commits (380cd056ec0e7fc8bbd553cdcb061d3ca612bb82)