]> git.proxmox.com Git - mirror_qemu.git/blobdiff - replay/replay.c
replay: simplify async event processing
[mirror_qemu.git] / replay / replay.c
index 5cc25bd2f8c3adbfad347bdf380bfc55d6acfdf3..4c396bb3761b22ee2a838cb41e8807457823001f 100644 (file)
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
+#include "sysemu/cpu-timers.h"
 #include "sysemu/replay.h"
 #include "sysemu/runstate.h"
 #include "replay-internal.h"
-#include "qemu/timer.h"
 #include "qemu/main-loop.h"
 #include "qemu/option.h"
 #include "sysemu/cpus.h"
@@ -22,7 +22,7 @@
 
 /* Current version of the replay mechanism.
    Increase it when file format changes. */
-#define REPLAY_VERSION              0xe02008
+#define REPLAY_VERSION              0xe0200c
 /* Size of replay log header */
 #define HEADER_SIZE                 (sizeof(uint32_t) + sizeof(uint64_t))
 
@@ -34,6 +34,10 @@ static char *replay_filename;
 ReplayState replay_state;
 static GSList *replay_blockers;
 
+/* Replay breakpoints */
+uint64_t replay_break_icount = -1ULL;
+QEMUTimer *replay_break_timer;
+
 bool replay_next_event_is(int event)
 {
     bool res = false;
@@ -64,7 +68,7 @@ bool replay_next_event_is(int event)
 
 uint64_t replay_get_current_icount(void)
 {
-    return cpu_get_icount_raw();
+    return icount_get_raw();
 }
 
 int replay_get_instructions(void)
@@ -73,6 +77,13 @@ int replay_get_instructions(void)
     replay_mutex_lock();
     if (replay_next_event_is(EVENT_INSTRUCTION)) {
         res = replay_state.instruction_count;
+        if (replay_break_icount != -1LL) {
+            uint64_t current = replay_get_current_icount();
+            assert(replay_break_icount >= current);
+            if (current + res > replay_break_icount) {
+                res = replay_break_icount - current;
+            }
+        }
     }
     replay_mutex_unlock();
     return res;
@@ -83,22 +94,7 @@ void replay_account_executed_instructions(void)
     if (replay_mode == REPLAY_MODE_PLAY) {
         g_assert(replay_mutex_locked());
         if (replay_state.instruction_count > 0) {
-            int count = (int)(replay_get_current_icount()
-                              - replay_state.current_icount);
-
-            /* Time can only go forward */
-            assert(count >= 0);
-
-            replay_state.instruction_count -= count;
-            replay_state.current_icount += count;
-            if (replay_state.instruction_count == 0) {
-                assert(replay_state.data_kind == EVENT_INSTRUCTION);
-                replay_finish_event();
-                /* Wake up iothread. This is required because
-                   timers will not expire until clock counters
-                   will be read from the log. */
-                qemu_notify_event();
-            }
+            replay_advance_current_icount(replay_get_current_icount());
         }
     }
 }
@@ -175,63 +171,49 @@ void replay_shutdown_request(ShutdownCause cause)
 
 bool replay_checkpoint(ReplayCheckpoint checkpoint)
 {
-    bool res = false;
-    static bool in_checkpoint;
     assert(EVENT_CHECKPOINT + checkpoint <= EVENT_CHECKPOINT_LAST);
 
-    if (!replay_file) {
-        return true;
-    }
-
-    if (in_checkpoint) {
-        /* If we are already in checkpoint, then there is no need
-           for additional synchronization.
-           Recursion occurs when HW event modifies timers.
-           Timer modification may invoke the checkpoint and
-           proceed to recursion. */
-        return true;
-    }
-    in_checkpoint = true;
-
     replay_save_instructions();
 
     if (replay_mode == REPLAY_MODE_PLAY) {
         g_assert(replay_mutex_locked());
         if (replay_next_event_is(EVENT_CHECKPOINT + checkpoint)) {
             replay_finish_event();
-        } else if (replay_state.data_kind != EVENT_ASYNC) {
-            res = false;
-            goto out;
+        } else {
+            return false;
         }
-        replay_read_events(checkpoint);
-        /* replay_read_events may leave some unread events.
-           Return false if not all of the events associated with
-           checkpoint were processed */
-        res = replay_state.data_kind != EVENT_ASYNC;
     } else if (replay_mode == REPLAY_MODE_RECORD) {
         g_assert(replay_mutex_locked());
         replay_put_event(EVENT_CHECKPOINT + checkpoint);
-        /* This checkpoint belongs to several threads.
-           Processing events from different threads is
-           non-deterministic */
-        if (checkpoint != CHECKPOINT_CLOCK_WARP_START
-            /* FIXME: this is temporary fix, other checkpoints
-                      may also be invoked from the different threads someday.
-                      Asynchronous event processing should be refactored
-                      to create additional replay event kind which is
-                      nailed to the one of the threads and which processes
-                      the event queue. */
-            && checkpoint != CHECKPOINT_CLOCK_VIRTUAL) {
-            replay_save_events(checkpoint);
-        }
-        res = true;
     }
-out:
-    in_checkpoint = false;
-    return res;
+    return true;
+}
+
+void replay_async_events(void)
+{
+    static bool processing = false;
+    /*
+     * If we are already processing the events, recursion may occur
+     * in case of incorrect implementation when HW event modifies timers.
+     * Timer modification may invoke the icount warp, event processing,
+     * and cause the recursion.
+     */
+    g_assert(!processing);
+    processing = true;
+
+    replay_save_instructions();
+
+    if (replay_mode == REPLAY_MODE_PLAY) {
+        g_assert(replay_mutex_locked());
+        replay_read_events();
+    } else if (replay_mode == REPLAY_MODE_RECORD) {
+        g_assert(replay_mutex_locked());
+        replay_save_events();
+    }
+    processing = false;
 }
 
-bool replay_has_checkpoint(void)
+bool replay_has_event(void)
 {
     bool res = false;
     if (replay_mode == REPLAY_MODE_PLAY) {
@@ -239,6 +221,8 @@ bool replay_has_checkpoint(void)
         replay_account_executed_instructions();
         res = EVENT_CHECKPOINT <= replay_state.data_kind
               && replay_state.data_kind <= EVENT_CHECKPOINT_LAST;
+        res = res || (EVENT_ASYNC <= replay_state.data_kind
+                     && replay_state.data_kind <= EVENT_ASYNC_LAST);
     }
     return res;
 }
@@ -345,7 +329,7 @@ void replay_start(void)
         error_reportf_err(replay_blockers->data, "Record/replay: ");
         exit(1);
     }
-    if (!use_icount) {
+    if (!icount_enabled()) {
         error_report("Please enable icount to use record/replay");
         exit(1);
     }
@@ -366,6 +350,11 @@ void replay_finish(void)
     /* finalize the file */
     if (replay_file) {
         if (replay_mode == REPLAY_MODE_RECORD) {
+            /*
+             * Can't do it in the signal handler, therefore
+             * add shutdown event here for the case of Ctrl-C.
+             */
+            replay_shutdown_request(SHUTDOWN_CAUSE_HOST_SIGNAL);
             /* write end event */
             replay_put_event(EVENT_END);
 
@@ -385,12 +374,16 @@ void replay_finish(void)
     g_free(replay_snapshot);
     replay_snapshot = NULL;
 
-    replay_mode = REPLAY_MODE_NONE;
-
     replay_finish_events();
+    replay_mode = REPLAY_MODE_NONE;
 }
 
 void replay_add_blocker(Error *reason)
 {
     replay_blockers = g_slist_prepend(replay_blockers, reason);
 }
+
+const char *replay_get_filename(void)
+{
+    return replay_filename;
+}