[Mesa-dev] [PATCH 06/10] i965: attach to a listening debugger

[Ben Widawsky]

Use unix domain sockets to connect to a debugger and send the
information the debugger will use to properly handle debug events.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 src/mesa/drivers/dri/i965/brw_wm_debug.c |   85 ++++++++++++++++++++++++++++-
 1 files changed, 82 insertions(+), 3 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_wm_debug.c b/src/mesa/drivers/dri/i965/brw_wm_debug.c
index cacb24a..a231d87 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_debug.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_debug.c
@@ -175,12 +175,82 @@ void brw_wm_print_program( struct brw_wm_compile *c,
 }
 
 #define SCRATCH_SIZE (512 * 1024)
+#ifndef NO_DEBUGGER_LISTENING
+#include <unistd.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#include "intel_debug.h"
+
+static int
+attach_to_debugger()
+{
+   struct sockaddr_un addr;
+   int fd, ret;
+
+   fd = socket(AF_UNIX, SOCK_STREAM, 0);
+   if (fd == -1)
+      return -1;
+
+   memset(&addr, 0, sizeof(addr));
+   addr.sun_family = AF_UNIX;
+   strncpy(addr.sun_path, SHADER_DEBUG_SOCKET, sizeof(addr.sun_path) - 1);
+
+   ret = connect(fd, &addr, sizeof(addr));
+   if (ret)
+      return ret;
+
+   return fd;
+}
+
+static int
+start_debugger(int fd, int flink_handle)
+{
+   struct debug_handshake dh;
+   int reply, ret;
+
+   dh.version = DEBUG_HANDSHAKE_VERSION;
+   dh.flink_handle = flink_handle;
+   dh.per_thread_scratch = SCRATCH_SIZE;
+   ret = write(fd, &dh, sizeof(dh));
+   if (ret != sizeof(dh)) {
+      ret = -1;
+      goto done;
+   }
+
+   ret = read(fd, &reply, sizeof(reply));
+   if (ret != sizeof(reply)) {
+      ret = -1;
+      goto done;
+   }
+
+   if (strncmp(DEBUG_HANDSHAKE_ACK, (char *)&reply, strlen(DEBUG_HANDSHAKE_ACK))) {
+      ret = 1;
+      goto done;
+   }
+
+   ret = 0;
+
+done:
+   close(fd);
+   return ret;
+}
+#endif
+
 void brw_wm_init_debug( struct brw_context *brw )
 {
    struct intel_context *intel = &brw->intel;
    uint32_t name;
+   int debugger_fd;
    int ret;
 
+   /* Simple system routines do not need a debugger present */
+   #ifndef NO_DEBUGGER_LISTENING
+   if ((debugger_fd = attach_to_debugger()) < 0) {
+      fprintf(stderr, "Failed to attach to debugger\n");
+      return;
+   }
+   #endif
+
    /* In the debug case, we allocate the buffer now because we'll need to attach
     * with the debugger at a later time when flink will not work (the ring /
     * struct_mutex are likely to be frozen). If we make the buffer visible early
@@ -192,12 +262,21 @@ void brw_wm_init_debug( struct brw_context *brw )
 					   4096);
    assert(brw->wm.scratch_bo);
 
+   ret = drm_intel_bo_flink(brw->wm.scratch_bo, &name);
+   assert(ret == 0);
+
+   #ifndef NO_DEBUGGER_LISTENING
+   ret = start_debugger(debugger_fd, name);
+   if (ret != 0) {
+      drm_intel_bo_unreference(brw->wm.scratch_bo);
+      return;
+   }
+   #endif
+
+   /* Put a nice pattern in the buffer to hopefully help detect errors */
    drm_intel_bo_map(brw->wm.scratch_bo, 0);
    memset(brw->wm.scratch_bo->virtual, 0xa5, SCRATCH_SIZE * brw->wm_max_threads);
    drm_intel_bo_unmap(brw->wm.scratch_bo);
 
-   ret = drm_intel_bo_flink(brw->wm.scratch_bo, &name);
-   assert(ret == 0);
-
    brw->wm.debugging = true;
 }
-- 
1.7.6