add a in memory trace log with processor timestamps. closes #1042

git-svn-id: file:///svn/tokudb@5318 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/Makefile

@@ -72,6 +72,7 @@ BRT_SOURCES = \
   roll \
   toku_assert \
   ybt \
+  trace_mem \
 # keep this line so I can ha vea \ on the previous line
 
 OFILES = newbrt.o

newbrt/trace_mem.c

+#include <stdio.h>
+#include "../include/rdtsc.h"
+
+// customize this as required
+#define NTRACE 1000
+#if NTRACE
+static struct toku_trace {
+    const char *str;
+    int n;
+    unsigned long long ts;
+} toku_trace[NTRACE];
+
+static int toku_next_trace = 0;
+#endif
+
+void toku_add_trace_mem(const char *str, int n) __attribute__((__visibility__("default")));
+void toku_add_trace_mem(const char *str __attribute__((unused)), 
+                        int n __attribute__((unused))) {
+#if USE_RDTSC && NTRACE
+    int i = toku_next_trace++;
+    if (toku_next_trace >= NTRACE) toku_next_trace = 0;
+    toku_trace[i].ts = rdtsc();
+    toku_trace[i].str = str;
+    toku_trace[i].n = n;
+#endif
+}
+
+void toku_print_trace_mem() __attribute__((__visibility__("default")));
+void toku_print_trace_mem() {
+#if NTRACE
+    int i = toku_next_trace;
+    do {
+        if (toku_trace[i].str) 
+            printf("%llu %s:%d\n", toku_trace[i].ts, toku_trace[i].str, toku_trace[i].n);
+        i++;
+        if (i >= NTRACE) i = 0;
+    } while (i != toku_next_trace);
+#endif
+}

newbrt/trace_mem.h

+// a circular log of trace entries is maintained in memory. the trace
+// entry consists of a string pointer, an integer, and the processor
+// timestamp. there are functions to add an entry to the end of the
+// trace log, and to print the trace log.
+// example: one can use the __FUNCTION__ and __LINE__ macros as
+// the arguments to the toku_add_trace function.
+// performance: we trade speed for size by not compressing the trace
+// entries.
+
+void toku_add_trace_mem(const char *str, int n);
+// add an entry to the end of the trace which consists of a string
+// pointer, a number, and the processor timestamp
+
+void toku_print_trace_mem();
+// print the trace 

src/export.map

@@ -13,6 +13,9 @@
    toku_set_trace_file;
    toku_close_trace_file;
 
+   toku_add_trace_mem;
+   toku_print_trace_mem;
+
  local: *;
 };