Add low level event recording support

Add low level event recording infrastructure for system and user
defined events.  The infrastructure is able to record high frequency
events such as

 * SMP lock acquire/release,
 * interrupt entry/exit,
 * thread switches,
 * UMA zone allocate/free, and
 * Ethernet packet input/output, etc.

It allows post-mortem analysis in fatal error handlers, e.g. the last
events are in the record buffer, the newest event overwrites the oldest
event.  It is possible to detect record buffer overflows for consumers
that expect a continuous stream of events, e.g. to display the system
state in real-time.

The implementation supports high-end SMP machines (more than 1GHz
processor frequency, more than four processors).

Add a new API instead. The implementation uses per-processor data
structures and no atomic read-modify-write operations.  It is uses
per-processor ring buffers to record the events.

The CPU counter is used to get the time of events. It is combined with
periodic uptime events to synchronize it with CLOCK_REALTIME.

The existing capture engine tries to solve this problem also, but its
performance is not good enough for high-end production systems.  The
main issues are the variable-size buffers and the use of SMP locks for
synchronization.  To fix this, the API would change significantly.

Update #3665.

1 files changed, 290 insertions, 0 deletions

diff --git a/cpukit/libtrace/record/record-server.c b/cpukit/libtrace/record/record-server.c
new file mode 100644
index 0000000000..3f34b5d075
--- /dev/null
+++ b/cpukit/libtrace/record/record-server.c
@@ -0,0 +1,290 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (C) 2018, 2019 embedded brains GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/record.h>
+#include <rtems.h>
+
+#include <sys/endian.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+
+#include <string.h>
+#include <unistd.h>
+
+#include <netinet/in.h>
+
+#ifdef RTEMS_SMP
+#define CHUNKS (3 * CPU_MAXIMUM_PROCESSORS)
+#else
+#define CHUNKS 4
+#endif
+
+typedef struct {
+  int           available;
+  struct iovec *current;
+  struct iovec  iov[CHUNKS];
+} writev_visitor_context;
+
+static void writev_visitor(
+  const rtems_record_item *items,
+  size_t                   count,
+  void                    *arg
+)
+{
+  writev_visitor_context *ctx;
+
+  ctx = arg;
+
+  if ( ctx->available > 0 ) {
+    ctx->current->iov_base = RTEMS_DECONST( rtems_record_item *, items );
+    ctx->current->iov_len = count * sizeof( *items );
+    --ctx->available;
+    ++ctx->current;
+  }
+}
+
+ssize_t rtems_record_writev( int fd, bool *written )
+{
+  writev_visitor_context ctx;
+  int n;
+
+  ctx.available = CHUNKS;
+  ctx.current = &ctx.iov[ 0 ];
+  rtems_record_drain( writev_visitor, &ctx );
+  n = CHUNKS - ctx.available;
+
+  if ( n > 0 ) {
+    *written = true;
+    return writev( fd, &ctx.iov[ 0 ], n );
+  } else {
+    *written = false;
+    return 0;
+  }
+}
+
+#define WAKEUP_EVENT RTEMS_EVENT_0
+
+static void wakeup( rtems_id task )
+{
+  (void) rtems_event_send( task, WAKEUP_EVENT );
+}
+
+static void wait( rtems_option options )
+{
+  rtems_event_set events;
+
+  (void) rtems_event_receive(
+    WAKEUP_EVENT,
+    RTEMS_EVENT_ANY | options,
+    RTEMS_NO_TIMEOUT,
+    &events
+  );
+}
+
+static void wakeup_timer( rtems_id timer, void *arg )
+{
+  rtems_id *server;
+
+  server = arg;
+  wakeup( *server );
+  (void) rtems_timer_reset( timer );
+}
+
+void _Record_Stream_header_initialize( Record_Stream_header *header )
+{
+#if BYTE_ORDER == LITTLE_ENDIAN
+#if __INTPTR_WIDTH__ == 32
+  header->format = RTEMS_RECORD_FORMAT_LE_32,
+#elif __INTPTR_WIDTH__ == 64
+  header->format = RTEMS_RECORD_FORMAT_LE_64,
+#else
+#error "unexpected __INTPTR_WIDTH__"
+#endif
+#elif BYTE_ORDER == BIG_ENDIAN
+#if __INTPTR_WIDTH__ == 32
+  header->format = RTEMS_RECORD_FORMAT_BE_32,
+#elif __INTPTR_WIDTH__ == 64
+  header->format = RTEMS_RECORD_FORMAT_BE_64,
+#else
+#error "unexpected __INTPTR_WIDTH__"
+#endif
+#else
+#error "unexpected BYTE_ORDER"
+#endif
+
+  header->magic = RTEMS_RECORD_MAGIC;
+
+  header->Version.event = RTEMS_RECORD_TIME_EVENT( 0, RTEMS_RECORD_VERSION );
+  header->Version.data = RTEMS_RECORD_THE_VERSION;
+
+  header->Processor_maximum.event =
+    RTEMS_RECORD_TIME_EVENT( 0, RTEMS_RECORD_PROCESSOR_MAXIMUM );
+  header->Processor_maximum.data = rtems_get_processor_count() - 1;
+
+  header->Count.event = RTEMS_RECORD_TIME_EVENT( 0, RTEMS_RECORD_COUNT );
+  header->Count.data = _Record_Item_count;
+
+  header->Frequency.event =
+    RTEMS_RECORD_TIME_EVENT( 0, RTEMS_RECORD_FREQUENCY );
+  header->Frequency.data = rtems_counter_frequency();
+}
+
+static void send_header( int fd )
+{
+  Record_Stream_header header;
+
+  _Record_Stream_header_initialize( &header );
+  (void) write( fd, &header, sizeof( header ) );
+}
+
+void rtems_record_server( uint16_t port, rtems_interval period )
+{
+  rtems_status_code sc;
+  rtems_id self;
+  rtems_id timer;
+  struct sockaddr_in addr;
+  int sd;
+  int rv;
+
+  sd = -1;
+  self = rtems_task_self();
+
+  sc = rtems_timer_create( rtems_build_name( 'R', 'C', 'R', 'D' ), &timer );
+  if ( sc != RTEMS_SUCCESSFUL ) {
+    return;
+  }
+
+  sd = socket( PF_INET, SOCK_STREAM, 0 );
+  if (sd < 0) {
+    goto error;
+  }
+
+  memset( &addr, 0, sizeof( addr ) );
+  addr.sin_family = AF_INET;
+  addr.sin_port = htons( port );
+  addr.sin_addr.s_addr = htonl( INADDR_ANY );
+
+  rv = bind( sd, (const struct sockaddr *) &addr, sizeof( addr ) );
+  if (rv != 0) {
+    goto error;
+  }
+
+  rv = listen( sd, 0 );
+  if (rv != 0) {
+    goto error;
+  }
+
+  while ( true ) {
+    int cd;
+    bool written;
+    ssize_t n;
+
+    cd = accept( sd, NULL, NULL );
+
+    if ( cd < 0 ) {
+      break;
+    }
+
+    wait( RTEMS_NO_WAIT );
+    (void) rtems_timer_fire_after( timer, period, wakeup_timer, &self );
+    send_header( cd );
+
+    while ( true ) {
+      n = rtems_record_writev( cd, &written );
+
+      if ( written && n <= 0 ) {
+        break;
+      }
+
+      wait( RTEMS_WAIT );
+    }
+
+    (void) rtems_timer_cancel( timer );
+    (void) close( cd );
+  }
+
+error:
+
+  (void) close( sd );
+  (void) rtems_timer_delete( timer );
+}
+
+typedef struct {
+  rtems_id       task;
+  uint16_t       port;
+  rtems_interval period;
+} server_arg;
+
+static void server( rtems_task_argument arg )
+{
+  server_arg     *sarg;
+  uint16_t        port;
+  rtems_interval  period;
+
+  sarg = (server_arg *) arg;
+  port = sarg->port;
+  period = sarg->period;
+  wakeup(sarg->task);
+  rtems_record_server( port, period );
+  rtems_task_exit();
+}
+
+rtems_status_code rtems_record_start_server(
+  rtems_task_priority priority,
+  uint16_t            port,
+  rtems_interval      period
+)
+{
+  rtems_status_code sc;
+  rtems_id          id;
+  server_arg        sarg;
+
+  sarg.port = port;
+  sarg.period = period;
+  sarg.task = rtems_task_self();
+
+  sc = rtems_task_create(
+    rtems_build_name( 'R', 'C', 'R', 'D' ),
+    priority,
+    RTEMS_MINIMUM_STACK_SIZE,
+    RTEMS_DEFAULT_MODES,
+    RTEMS_DEFAULT_ATTRIBUTES,
+    &id
+  );
+  if ( sc != RTEMS_SUCCESSFUL ) {
+    return sc;
+  }
+
+  (void) rtems_task_start( id, server, (rtems_task_argument) &sarg );
+  wait( RTEMS_WAIT );
+
+  return RTEMS_SUCCESSFUL;
+}