2012-03-08 Stan Shebs <stan@codesourcery.com>

	    Hafiz Abid Qadeer  <abidh@codesourcery.com>

	gdb/
	* NEWS: Mention set and show trace-buffer-size commands.
	Mention new packet.
	* target.h (struct target_ops): New method
	to_set_trace_buffer_size.
	(target_set_trace_buffer_size): New macro.
	* target.c (update_current_target): Set up new method.
	* tracepoint.c (trace_buffer_size): New global.
	(start_tracing): Send it to the target.
	(set_trace_buffer_size): New function.
	(_initialize_tracepoint): Add new setshow for trace-buffer-size.
	* remote.c (remote_set_trace_buffer_size): New function.
	(_initialize_remote): Use it.
	(QTBuffer:size) New remote command.
	(PACKET_QTBuffer_size): New enum.
	(remote_protocol_features): Add an entry for
	PACKET_QTBuffer_size.

	gdb/gdbserver/
	* tracepoint.c (trace_buffer_size): New global.
	(DEFAULT_TRACE_BUFFER_SIZE): New define.
	(init_trace_buffer): Change to one-argument function. Allocate
	trace buffer memory.
	(handle_tracepoint_general_set): Call cmd_bigqtbuffer_size to
	handle QTBuffer:size packet.
	(cmd_bigqtbuffer_size): New function.
	(initialize_tracepoint): Call init_trace_buffer with
	DEFAULT_TRACE_BUFFER_SIZE.
	* server.c (handle_query): Add QTBuffer:size in the
	supported packets.

	gdb/doc/
	* gdb.texinfo (Starting and Stopping Trace Experiments): Document
	trace-buffer-size set and show commands.
	(Tracepoint Packets): Document QTBuffer:size.
	(General Query Packets): Document QTBuffer:size.

	gdb/testsuite/
	* gdb.trace/trace-buffer-size.exp: New file.
	* gdb.trace/trace-buffer-size.c: New file.

1 files changed, 50 insertions, 6 deletions

diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
index 632ee14..dcc2e78 100644
--- a/gdb/gdbserver/tracepoint.c
+++ b/gdb/gdbserver/tracepoint.c
@@ -30,6 +30,8 @@
 
 #include "ax.h"
 
+#define DEFAULT_TRACE_BUFFER_SIZE 5242880 /* 5*1024*1024 */
+
 /* This file is built for both GDBserver, and the in-process
    agent (IPA), a shared library that includes a tracing agent that is
    loaded by the inferior to support fast tracepoints.  Fast
@@ -992,6 +994,10 @@ int current_traceframe = -1;
 static int circular_trace_buffer;
 #endif
 
+/* Size of the trace buffer.  */
+
+static LONGEST trace_buffer_size;
+
 /* Pointer to the block of memory that traceframes all go into.  */
 
 static unsigned char *trace_buffer_lo;
@@ -1478,9 +1484,13 @@ clear_inferior_trace_buffer (void)
 #endif
 
 static void
-init_trace_buffer (unsigned char *buf, int bufsize)
+init_trace_buffer (LONGEST bufsize)
 {
-  trace_buffer_lo = buf;
+  trace_buffer_size = bufsize;
+
+  /* If we already have a trace buffer, try realloc'ing.  */
+  trace_buffer_lo = xrealloc (trace_buffer_lo, bufsize);
+
   trace_buffer_hi = trace_buffer_lo + bufsize;
 
   clear_trace_buffer ();
@@ -4020,6 +4030,37 @@ cmd_bigqtbuffer_circular (char *own_buf)
 }
 
 static void
+cmd_bigqtbuffer_size (char *own_buf)
+{
+  ULONGEST val;
+  LONGEST sval;
+  char *packet = own_buf;
+
+  /* Can't change the size during a tracing run.  */
+  if (tracing)
+    {
+      write_enn (own_buf);
+      return;
+    }
+
+  packet += strlen ("QTBuffer:size:");
+
+  /* -1 is sent as literal "-1".  */
+  if (strcmp (packet, "-1") == 0)
+    sval = DEFAULT_TRACE_BUFFER_SIZE;
+  else
+    {
+      unpack_varlen_hex (packet, &val);
+      sval = (LONGEST) val;
+    }
+
+  init_trace_buffer (sval);
+  trace_debug ("Trace buffer is now %s bytes",
+	       plongest (trace_buffer_size));
+  write_ok (own_buf);
+}
+
+static void
 cmd_qtnotes (char *own_buf)
 {
   size_t nbytes;
@@ -4143,6 +4184,11 @@ handle_tracepoint_general_set (char *packet)
       cmd_bigqtbuffer_circular (packet);
       return 1;
     }
+  else if (strncmp ("QTBuffer:size:", packet, strlen ("QTBuffer:size:")) == 0)
+    {
+      cmd_bigqtbuffer_size (packet);
+      return 1;
+    }
   else if (strncmp ("QTNotes:", packet, strlen ("QTNotes:")) == 0)
     {
       cmd_qtnotes (packet);
@@ -7228,10 +7274,8 @@ get_timestamp (void)
 void
 initialize_tracepoint (void)
 {
-  /* There currently no way to change the buffer size.  */
-  const int sizeOfBuffer = 5 * 1024 * 1024;
-  unsigned char *buf = xmalloc (sizeOfBuffer);
-  init_trace_buffer (buf, sizeOfBuffer);
+  /* Start with the default size.  */
+  init_trace_buffer (DEFAULT_TRACE_BUFFER_SIZE);
 
   /* Wire trace state variable 1 to be the timestamp.  This will be
      uploaded to GDB upon connection and become one of its trace state