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-rw-r--r--include/block/aio-wait.h61
-rw-r--r--include/qemu/log-for-trace.h35
-rw-r--r--include/qemu/log.h18
3 files changed, 69 insertions, 45 deletions
diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
index f7a3972200..8c90a2e66e 100644
--- a/include/block/aio-wait.h
+++ b/include/block/aio-wait.h
@@ -50,8 +50,8 @@
  *   }
  */
 typedef struct {
-    /* Is the main loop waiting for a kick?  Accessed with atomic ops. */
-    bool need_kick;
+    /* Number of waiting AIO_WAIT_WHILE() callers. Accessed with atomic ops. */
+    unsigned num_waiters;
 } AioWait;
 
 /**
@@ -71,35 +71,34 @@ typedef struct {
  * wait on conditions between two IOThreads since that could lead to deadlock,
  * go via the main loop instead.
  */
-#define AIO_WAIT_WHILE(wait, ctx, cond) ({                  \
-    bool waited_ = false;                                   \
-    bool busy_ = true;                                      \
-    AioWait *wait_ = (wait);                                \
-    AioContext *ctx_ = (ctx);                               \
-    if (in_aio_context_home_thread(ctx_)) {                 \
-        while ((cond) || busy_) {                           \
-            busy_ = aio_poll(ctx_, (cond));                 \
-            waited_ |= !!(cond) | busy_;                    \
-        }                                                   \
-    } else {                                                \
-        assert(qemu_get_current_aio_context() ==            \
-               qemu_get_aio_context());                     \
-        assert(!wait_->need_kick);                          \
-        /* Set wait_->need_kick before evaluating cond.  */ \
-        atomic_mb_set(&wait_->need_kick, true);             \
-        while (busy_) {                                     \
-            if ((cond)) {                                   \
-                waited_ = busy_ = true;                     \
-                aio_context_release(ctx_);                  \
-                aio_poll(qemu_get_aio_context(), true);     \
-                aio_context_acquire(ctx_);                  \
-            } else {                                        \
-                busy_ = aio_poll(ctx_, false);              \
-                waited_ |= busy_;                           \
-            }                                               \
-        }                                                   \
-        atomic_set(&wait_->need_kick, false);               \
-    }                                                       \
+#define AIO_WAIT_WHILE(wait, ctx, cond) ({                         \
+    bool waited_ = false;                                          \
+    bool busy_ = true;                                             \
+    AioWait *wait_ = (wait);                                       \
+    AioContext *ctx_ = (ctx);                                      \
+    if (in_aio_context_home_thread(ctx_)) {                        \
+        while ((cond) || busy_) {                                  \
+            busy_ = aio_poll(ctx_, (cond));                        \
+            waited_ |= !!(cond) | busy_;                           \
+        }                                                          \
+    } else {                                                       \
+        assert(qemu_get_current_aio_context() ==                   \
+               qemu_get_aio_context());                            \
+        /* Increment wait_->num_waiters before evaluating cond. */ \
+        atomic_inc(&wait_->num_waiters);                           \
+        while (busy_) {                                            \
+            if ((cond)) {                                          \
+                waited_ = busy_ = true;                            \
+                aio_context_release(ctx_);                         \
+                aio_poll(qemu_get_aio_context(), true);            \
+                aio_context_acquire(ctx_);                         \
+            } else {                                               \
+                busy_ = aio_poll(ctx_, false);                     \
+                waited_ |= busy_;                                  \
+            }                                                      \
+        }                                                          \
+        atomic_dec(&wait_->num_waiters);                           \
+    }                                                              \
     waited_; })
 
 /**
diff --git a/include/qemu/log-for-trace.h b/include/qemu/log-for-trace.h
new file mode 100644
index 0000000000..2f0a5b080e
--- /dev/null
+++ b/include/qemu/log-for-trace.h
@@ -0,0 +1,35 @@
+/* log-for-trace.h: logging basics required by the trace.h generated
+ * by the log trace backend.
+ *
+ * This should not be included directly by any .c file: if you
+ * need to use the logging functions include "qemu/log.h".
+ *
+ * The purpose of splitting these parts out into their own header
+ * is to catch the easy mistake where a .c file includes trace.h
+ * but forgets to include qemu/log.h. Without this split, that
+ * would result in the .c file compiling fine when the default
+ * trace backend is in use but failing to compile with any other
+ * backend.
+ *
+ * This code is licensed under the GNU General Public License,
+ * version 2 or (at your option) any later version.
+ */
+
+#ifndef QEMU_LOG_FOR_TRACE_H
+#define QEMU_LOG_FOR_TRACE_H
+
+/* Private global variable, don't use */
+extern int qemu_loglevel;
+
+#define LOG_TRACE          (1 << 15)
+
+/* Returns true if a bit is set in the current loglevel mask */
+static inline bool qemu_loglevel_mask(int mask)
+{
+    return (qemu_loglevel & mask) != 0;
+}
+
+/* main logging function */
+int GCC_FMT_ATTR(1, 2) qemu_log(const char *fmt, ...);
+
+#endif
diff --git a/include/qemu/log.h b/include/qemu/log.h
index a50e994c21..ff92a8b86a 100644
--- a/include/qemu/log.h
+++ b/include/qemu/log.h
@@ -1,10 +1,11 @@
 #ifndef QEMU_LOG_H
 #define QEMU_LOG_H
 
+/* A small part of this API is split into its own header */
+#include "qemu/log-for-trace.h"
 
-/* Private global variables, don't use */
+/* Private global variable, don't use */
 extern FILE *qemu_logfile;
-extern int qemu_loglevel;
 
 /* 
  * The new API:
@@ -41,16 +42,9 @@ static inline bool qemu_log_separate(void)
 #define CPU_LOG_MMU        (1 << 12)
 #define CPU_LOG_TB_NOCHAIN (1 << 13)
 #define CPU_LOG_PAGE       (1 << 14)
-#define LOG_TRACE          (1 << 15)
+/* LOG_TRACE (1 << 15) is defined in log-for-trace.h */
 #define CPU_LOG_TB_OP_IND  (1 << 16)
 
-/* Returns true if a bit is set in the current loglevel mask
- */
-static inline bool qemu_loglevel_mask(int mask)
-{
-    return (qemu_loglevel & mask) != 0;
-}
-
 /* Lock output for a series of related logs.  Since this is not needed
  * for a single qemu_log / qemu_log_mask / qemu_log_mask_and_addr, we
  * assume that qemu_loglevel_mask has already been tested, and that
@@ -69,10 +63,6 @@ static inline void qemu_log_unlock(void)
 
 /* Logging functions: */
 
-/* main logging function
- */
-int GCC_FMT_ATTR(1, 2) qemu_log(const char *fmt, ...);
-
 /* vfprintf-like logging function
  */
 static inline void GCC_FMT_ATTR(1, 0)