#include <signal.h>
#include <pthread.h>
#endif
-#include "qemu-timer.h"
+#include "qemu/timer.h"
#include "trace.h"
#include "trace/control.h"
#define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
/** Trace file version number, bump if format changes */
-#define HEADER_VERSION 0
+#define HEADER_VERSION 2
/** Records were dropped event ID */
#define DROPPED_EVENT_ID (~(uint64_t)0 - 1)
/** Trace record is valid */
#define TRACE_RECORD_VALID ((uint64_t)1 << 63)
-/** Trace buffer entry */
-typedef struct {
- uint64_t event;
- uint64_t timestamp_ns;
- uint64_t x1;
- uint64_t x2;
- uint64_t x3;
- uint64_t x4;
- uint64_t x5;
- uint64_t x6;
-} TraceRecord;
-
-enum {
- TRACE_BUF_LEN = 4096,
- TRACE_BUF_FLUSH_THRESHOLD = TRACE_BUF_LEN / 4,
-};
-
/*
* Trace records are written out by a dedicated thread. The thread waits for
* records to become available, writes them out, and then waits again.
*/
static GStaticMutex trace_lock = G_STATIC_MUTEX_INIT;
+
+/* g_cond_new() was deprecated in glib 2.31 but we still need to support it */
+#if GLIB_CHECK_VERSION(2, 31, 0)
+static GCond the_trace_available_cond;
+static GCond the_trace_empty_cond;
+static GCond *trace_available_cond = &the_trace_available_cond;
+static GCond *trace_empty_cond = &the_trace_empty_cond;
+#else
static GCond *trace_available_cond;
static GCond *trace_empty_cond;
+#endif
+
static bool trace_available;
static bool trace_writeout_enabled;
-static TraceRecord trace_buf[TRACE_BUF_LEN];
-static unsigned int trace_idx;
+enum {
+ TRACE_BUF_LEN = 4096 * 64,
+ TRACE_BUF_FLUSH_THRESHOLD = TRACE_BUF_LEN / 4,
+};
+
+uint8_t trace_buf[TRACE_BUF_LEN];
+static volatile gint trace_idx;
+static unsigned int writeout_idx;
+static volatile gint dropped_events;
static FILE *trace_fp;
-static char *trace_file_name = NULL;
+static char *trace_file_name;
+/* * Trace buffer entry */
+typedef struct {
+ uint64_t event; /* TraceEventID */
+ uint64_t timestamp_ns;
+ uint32_t length; /* in bytes */
+ uint32_t reserved; /* unused */
+ uint64_t arguments[];
+} TraceRecord;
+
+typedef struct {
+ uint64_t header_event_id; /* HEADER_EVENT_ID */
+ uint64_t header_magic; /* HEADER_MAGIC */
+ uint64_t header_version; /* HEADER_VERSION */
+} TraceLogHeader;
+
+
+static void read_from_buffer(unsigned int idx, void *dataptr, size_t size);
+static unsigned int write_to_buffer(unsigned int idx, void *dataptr, size_t size);
+
+static void clear_buffer_range(unsigned int idx, size_t len)
+{
+ uint32_t num = 0;
+ while (num < len) {
+ if (idx >= TRACE_BUF_LEN) {
+ idx = idx % TRACE_BUF_LEN;
+ }
+ trace_buf[idx++] = 0;
+ num++;
+ }
+}
/**
* Read a trace record from the trace buffer
*
*
* Returns false if the record is not valid.
*/
-static bool get_trace_record(unsigned int idx, TraceRecord *record)
+static bool get_trace_record(unsigned int idx, TraceRecord **recordptr)
{
- if (!(trace_buf[idx].event & TRACE_RECORD_VALID)) {
+ uint64_t event_flag = 0;
+ TraceRecord record;
+ /* read the event flag to see if its a valid record */
+ read_from_buffer(idx, &record, sizeof(event_flag));
+
+ if (!(record.event & TRACE_RECORD_VALID)) {
return false;
}
- __sync_synchronize(); /* read memory barrier before accessing record */
-
- *record = trace_buf[idx];
- record->event &= ~TRACE_RECORD_VALID;
+ smp_rmb(); /* read memory barrier before accessing record */
+ /* read the record header to know record length */
+ read_from_buffer(idx, &record, sizeof(TraceRecord));
+ *recordptr = malloc(record.length); /* dont use g_malloc, can deadlock when traced */
+ /* make a copy of record to avoid being overwritten */
+ read_from_buffer(idx, *recordptr, record.length);
+ smp_rmb(); /* memory barrier before clearing valid flag */
+ (*recordptr)->event &= ~TRACE_RECORD_VALID;
+ /* clear the trace buffer range for consumed record otherwise any byte
+ * with its MSB set may be considered as a valid event id when the writer
+ * thread crosses this range of buffer again.
+ */
+ clear_buffer_range(idx, record.length);
return true;
}
static gpointer writeout_thread(gpointer opaque)
{
- TraceRecord record;
- unsigned int writeout_idx = 0;
- unsigned int num_available, idx;
+ TraceRecord *recordptr;
+ union {
+ TraceRecord rec;
+ uint8_t bytes[sizeof(TraceRecord) + sizeof(uint64_t)];
+ } dropped;
+ unsigned int idx = 0;
+ int dropped_count;
size_t unused __attribute__ ((unused));
for (;;) {
wait_for_trace_records_available();
- num_available = trace_idx - writeout_idx;
- if (num_available > TRACE_BUF_LEN) {
- record = (TraceRecord){
- .event = DROPPED_EVENT_ID,
- .x1 = num_available,
- };
- unused = fwrite(&record, sizeof(record), 1, trace_fp);
- writeout_idx += num_available;
+ if (g_atomic_int_get(&dropped_events)) {
+ dropped.rec.event = DROPPED_EVENT_ID,
+ dropped.rec.timestamp_ns = get_clock();
+ dropped.rec.length = sizeof(TraceRecord) + sizeof(uint64_t),
+ dropped.rec.reserved = 0;
+ do {
+ dropped_count = g_atomic_int_get(&dropped_events);
+ } while (!g_atomic_int_compare_and_exchange(&dropped_events,
+ dropped_count, 0));
+ dropped.rec.arguments[0] = dropped_count;
+ unused = fwrite(&dropped.rec, dropped.rec.length, 1, trace_fp);
}
- idx = writeout_idx % TRACE_BUF_LEN;
- while (get_trace_record(idx, &record)) {
- trace_buf[idx].event = 0; /* clear valid bit */
- unused = fwrite(&record, sizeof(record), 1, trace_fp);
- idx = ++writeout_idx % TRACE_BUF_LEN;
+ while (get_trace_record(idx, &recordptr)) {
+ unused = fwrite(recordptr, recordptr->length, 1, trace_fp);
+ writeout_idx += recordptr->length;
+ free(recordptr); /* dont use g_free, can deadlock when traced */
+ idx = writeout_idx % TRACE_BUF_LEN;
}
fflush(trace_fp);
return NULL;
}
-static void trace(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
- uint64_t x4, uint64_t x5, uint64_t x6)
+void trace_record_write_u64(TraceBufferRecord *rec, uint64_t val)
{
- unsigned int idx;
- uint64_t timestamp;
-
- if (!trace_list[event].state) {
- return;
- }
-
- timestamp = get_clock();
-
- idx = g_atomic_int_exchange_and_add((gint *)&trace_idx, 1) % TRACE_BUF_LEN;
- trace_buf[idx] = (TraceRecord){
- .event = event,
- .timestamp_ns = timestamp,
- .x1 = x1,
- .x2 = x2,
- .x3 = x3,
- .x4 = x4,
- .x5 = x5,
- .x6 = x6,
- };
- __sync_synchronize(); /* write barrier before marking as valid */
- trace_buf[idx].event |= TRACE_RECORD_VALID;
-
- if ((idx + 1) % TRACE_BUF_FLUSH_THRESHOLD == 0) {
- flush_trace_file(false);
- }
+ rec->rec_off = write_to_buffer(rec->rec_off, &val, sizeof(uint64_t));
}
-void trace0(TraceEventID event)
+void trace_record_write_str(TraceBufferRecord *rec, const char *s, uint32_t slen)
{
- trace(event, 0, 0, 0, 0, 0, 0);
+ /* Write string length first */
+ rec->rec_off = write_to_buffer(rec->rec_off, &slen, sizeof(slen));
+ /* Write actual string now */
+ rec->rec_off = write_to_buffer(rec->rec_off, (void*)s, slen);
}
-void trace1(TraceEventID event, uint64_t x1)
+int trace_record_start(TraceBufferRecord *rec, TraceEventID event, size_t datasize)
{
- trace(event, x1, 0, 0, 0, 0, 0);
-}
+ unsigned int idx, rec_off, old_idx, new_idx;
+ uint32_t rec_len = sizeof(TraceRecord) + datasize;
+ uint64_t event_u64 = event;
+ uint64_t timestamp_ns = get_clock();
+
+ do {
+ old_idx = g_atomic_int_get(&trace_idx);
+ smp_rmb();
+ new_idx = old_idx + rec_len;
+
+ if (new_idx - writeout_idx > TRACE_BUF_LEN) {
+ /* Trace Buffer Full, Event dropped ! */
+ g_atomic_int_inc(&dropped_events);
+ return -ENOSPC;
+ }
+ } while (!g_atomic_int_compare_and_exchange(&trace_idx, old_idx, new_idx));
-void trace2(TraceEventID event, uint64_t x1, uint64_t x2)
-{
- trace(event, x1, x2, 0, 0, 0, 0);
-}
+ idx = old_idx % TRACE_BUF_LEN;
-void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3)
-{
- trace(event, x1, x2, x3, 0, 0, 0);
+ rec_off = idx;
+ rec_off = write_to_buffer(rec_off, &event_u64, sizeof(event_u64));
+ rec_off = write_to_buffer(rec_off, ×tamp_ns, sizeof(timestamp_ns));
+ rec_off = write_to_buffer(rec_off, &rec_len, sizeof(rec_len));
+
+ rec->tbuf_idx = idx;
+ rec->rec_off = (idx + sizeof(TraceRecord)) % TRACE_BUF_LEN;
+ return 0;
}
-void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4)
+static void read_from_buffer(unsigned int idx, void *dataptr, size_t size)
{
- trace(event, x1, x2, x3, x4, 0, 0);
+ uint8_t *data_ptr = dataptr;
+ uint32_t x = 0;
+ while (x < size) {
+ if (idx >= TRACE_BUF_LEN) {
+ idx = idx % TRACE_BUF_LEN;
+ }
+ data_ptr[x++] = trace_buf[idx++];
+ }
}
-void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5)
+static unsigned int write_to_buffer(unsigned int idx, void *dataptr, size_t size)
{
- trace(event, x1, x2, x3, x4, x5, 0);
+ uint8_t *data_ptr = dataptr;
+ uint32_t x = 0;
+ while (x < size) {
+ if (idx >= TRACE_BUF_LEN) {
+ idx = idx % TRACE_BUF_LEN;
+ }
+ trace_buf[idx++] = data_ptr[x++];
+ }
+ return idx; /* most callers wants to know where to write next */
}
-void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4, uint64_t x5, uint64_t x6)
+void trace_record_finish(TraceBufferRecord *rec)
{
- trace(event, x1, x2, x3, x4, x5, x6);
+ TraceRecord record;
+ read_from_buffer(rec->tbuf_idx, &record, sizeof(TraceRecord));
+ smp_wmb(); /* write barrier before marking as valid */
+ record.event |= TRACE_RECORD_VALID;
+ write_to_buffer(rec->tbuf_idx, &record, sizeof(TraceRecord));
+
+ if (((unsigned int)g_atomic_int_get(&trace_idx) - writeout_idx)
+ > TRACE_BUF_FLUSH_THRESHOLD) {
+ flush_trace_file(false);
+ }
}
void st_set_trace_file_enabled(bool enable)
flush_trace_file(true);
if (enable) {
- static const TraceRecord header = {
- .event = HEADER_EVENT_ID,
- .timestamp_ns = HEADER_MAGIC,
- .x1 = HEADER_VERSION,
+ static const TraceLogHeader header = {
+ .header_event_id = HEADER_EVENT_ID,
+ .header_magic = HEADER_MAGIC,
+ /* Older log readers will check for version at next location */
+ .header_version = HEADER_VERSION,
};
trace_fp = fopen(trace_file_name, "wb");
{
st_set_trace_file_enabled(false);
- free(trace_file_name);
+ g_free(trace_file_name);
if (!file) {
- if (asprintf(&trace_file_name, CONFIG_TRACE_FILE, getpid()) < 0) {
- trace_file_name = NULL;
- return false;
- }
+ trace_file_name = g_strdup_printf(CONFIG_TRACE_FILE, getpid());
} else {
- if (asprintf(&trace_file_name, "%s", file) < 0) {
- trace_file_name = NULL;
- return false;
- }
+ trace_file_name = g_strdup_printf("%s", file);
}
st_set_trace_file_enabled(true);
trace_file_name, trace_fp ? "on" : "off");
}
-void st_print_trace(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...))
-{
- unsigned int i;
-
- for (i = 0; i < TRACE_BUF_LEN; i++) {
- TraceRecord record;
-
- if (!get_trace_record(i, &record)) {
- continue;
- }
- stream_printf(stream, "Event %" PRIu64 " : %" PRIx64 " %" PRIx64
- " %" PRIx64 " %" PRIx64 " %" PRIx64 " %" PRIx64 "\n",
- record.event, record.x1, record.x2,
- record.x3, record.x4, record.x5,
- record.x6);
- }
-}
-
void st_flush_trace_buffer(void)
{
flush_trace_file(true);
{
unsigned int i;
- for (i = 0; i < NR_TRACE_EVENTS; i++) {
+ for (i = 0; i < trace_event_count(); i++) {
+ TraceEvent *ev = trace_event_id(i);
stream_printf(stream, "%s [Event ID %u] : state %u\n",
- trace_list[i].tp_name, i, trace_list[i].state);
+ trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
}
}
-bool trace_event_set_state(const char *name, bool state)
+void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state)
{
- unsigned int i;
-
- for (i = 0; i < NR_TRACE_EVENTS; i++) {
- if (!strcmp(trace_list[i].tp_name, name)) {
- trace_list[i].state = state;
- return true;
- }
- }
- return false;
+ ev->dstate = state;
}
/* Helper function to create a thread with signals blocked. Use glib's
sigfillset(&set);
pthread_sigmask(SIG_SETMASK, &set, &oldset);
#endif
- thread = g_thread_create(writeout_thread, NULL, FALSE, NULL);
+
+#if GLIB_CHECK_VERSION(2, 31, 0)
+ thread = g_thread_new("trace-thread", fn, NULL);
+#else
+ thread = g_thread_create(fn, NULL, FALSE, NULL);
+#endif
+
#ifndef _WIN32
pthread_sigmask(SIG_SETMASK, &oldset, NULL);
#endif
GThread *thread;
if (!g_thread_supported()) {
+#if !GLIB_CHECK_VERSION(2, 31, 0)
g_thread_init(NULL);
+#else
+ fprintf(stderr, "glib threading failed to initialize.\n");
+ exit(1);
+#endif
}
+#if !GLIB_CHECK_VERSION(2, 31, 0)
trace_available_cond = g_cond_new();
trace_empty_cond = g_cond_new();
+#endif
thread = trace_thread_create(writeout_thread);
if (!thread) {
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