coroutine: move into libqemuutil.a library

The coroutine files are currently referenced by the block-obj-y
variable. The coroutine functionality though is already used by
more than just the block code. eg migration code uses coroutine
yield. In the future the I/O channel code will also use the
coroutine yield functionality. Since the coroutine code is nicely
self-contained it can be easily built as part of the libqemuutil.a
library, making it widely available.

The headers are also moved into include/qemu, instead of the
include/block directory, since they are now part of the util
codebase, and the impl was never in the block/ directory
either.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

1 files changed, 0 insertions, 194 deletions

diff --git a/coroutine-ucontext.c b/coroutine-ucontext.c
deleted file mode 100644
index 259fcb48a4..0000000000
--- a/coroutine-ucontext.c
+++ /dev/null
@@ -1,194 +0,0 @@
-/*
- * ucontext coroutine initialization code
- *
- * Copyright (C) 2006  Anthony Liguori <anthony@codemonkey.ws>
- * Copyright (C) 2011  Kevin Wolf <kwolf@redhat.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.0 of the License, or (at your option) any later version.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, see <http://www.gnu.org/licenses/>.
- */
-
-/* XXX Is there a nicer way to disable glibc's stack check for longjmp? */
-#ifdef _FORTIFY_SOURCE
-#undef _FORTIFY_SOURCE
-#endif
-#include <stdlib.h>
-#include <setjmp.h>
-#include <stdint.h>
-#include <ucontext.h>
-#include "qemu-common.h"
-#include "block/coroutine_int.h"
-
-#ifdef CONFIG_VALGRIND_H
-#include <valgrind/valgrind.h>
-#endif
-
-typedef struct {
-    Coroutine base;
-    void *stack;
-    sigjmp_buf env;
-
-#ifdef CONFIG_VALGRIND_H
-    unsigned int valgrind_stack_id;
-#endif
-
-} CoroutineUContext;
-
-/**
- * Per-thread coroutine bookkeeping
- */
-static __thread CoroutineUContext leader;
-static __thread Coroutine *current;
-
-/*
- * va_args to makecontext() must be type 'int', so passing
- * the pointer we need may require several int args. This
- * union is a quick hack to let us do that
- */
-union cc_arg {
-    void *p;
-    int i[2];
-};
-
-static void coroutine_trampoline(int i0, int i1)
-{
-    union cc_arg arg;
-    CoroutineUContext *self;
-    Coroutine *co;
-
-    arg.i[0] = i0;
-    arg.i[1] = i1;
-    self = arg.p;
-    co = &self->base;
-
-    /* Initialize longjmp environment and switch back the caller */
-    if (!sigsetjmp(self->env, 0)) {
-        siglongjmp(*(sigjmp_buf *)co->entry_arg, 1);
-    }
-
-    while (true) {
-        co->entry(co->entry_arg);
-        qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE);
-    }
-}
-
-Coroutine *qemu_coroutine_new(void)
-{
-    const size_t stack_size = 1 << 20;
-    CoroutineUContext *co;
-    ucontext_t old_uc, uc;
-    sigjmp_buf old_env;
-    union cc_arg arg = {0};
-
-    /* The ucontext functions preserve signal masks which incurs a
-     * system call overhead.  sigsetjmp(buf, 0)/siglongjmp() does not
-     * preserve signal masks but only works on the current stack.
-     * Since we need a way to create and switch to a new stack, use
-     * the ucontext functions for that but sigsetjmp()/siglongjmp() for
-     * everything else.
-     */
-
-    if (getcontext(&uc) == -1) {
-        abort();
-    }
-
-    co = g_malloc0(sizeof(*co));
-    co->stack = g_malloc(stack_size);
-    co->base.entry_arg = &old_env; /* stash away our jmp_buf */
-
-    uc.uc_link = &old_uc;
-    uc.uc_stack.ss_sp = co->stack;
-    uc.uc_stack.ss_size = stack_size;
-    uc.uc_stack.ss_flags = 0;
-
-#ifdef CONFIG_VALGRIND_H
-    co->valgrind_stack_id =
-        VALGRIND_STACK_REGISTER(co->stack, co->stack + stack_size);
-#endif
-
-    arg.p = co;
-
-    makecontext(&uc, (void (*)(void))coroutine_trampoline,
-                2, arg.i[0], arg.i[1]);
-
-    /* swapcontext() in, siglongjmp() back out */
-    if (!sigsetjmp(old_env, 0)) {
-        swapcontext(&old_uc, &uc);
-    }
-    return &co->base;
-}
-
-#ifdef CONFIG_VALGRIND_H
-#ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
-/* Work around an unused variable in the valgrind.h macro... */
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-but-set-variable"
-#endif
-static inline void valgrind_stack_deregister(CoroutineUContext *co)
-{
-    VALGRIND_STACK_DEREGISTER(co->valgrind_stack_id);
-}
-#ifdef CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE
-#pragma GCC diagnostic pop
-#endif
-#endif
-
-void qemu_coroutine_delete(Coroutine *co_)
-{
-    CoroutineUContext *co = DO_UPCAST(CoroutineUContext, base, co_);
-
-#ifdef CONFIG_VALGRIND_H
-    valgrind_stack_deregister(co);
-#endif
-
-    g_free(co->stack);
-    g_free(co);
-}
-
-/* This function is marked noinline to prevent GCC from inlining it
- * into coroutine_trampoline(). If we allow it to do that then it
- * hoists the code to get the address of the TLS variable "current"
- * out of the while() loop. This is an invalid transformation because
- * the sigsetjmp() call may be called when running thread A but
- * return in thread B, and so we might be in a different thread
- * context each time round the loop.
- */
-CoroutineAction __attribute__((noinline))
-qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
-                      CoroutineAction action)
-{
-    CoroutineUContext *from = DO_UPCAST(CoroutineUContext, base, from_);
-    CoroutineUContext *to = DO_UPCAST(CoroutineUContext, base, to_);
-    int ret;
-
-    current = to_;
-
-    ret = sigsetjmp(from->env, 0);
-    if (ret == 0) {
-        siglongjmp(to->env, action);
-    }
-    return ret;
-}
-
-Coroutine *qemu_coroutine_self(void)
-{
-    if (!current) {
-        current = &leader.base;
-    }
-    return current;
-}
-
-bool qemu_in_coroutine(void)
-{
-    return current && current->caller;
-}