[Tarantool-patches] [PATCH v2] refactoring: drop excess 16Kb bss buffer

[Sergey Kaplun]

We already have 12Kb thread-safe static buffer
in `lib/small/small/static.h`, that can be used instead of 16Kb
bss buffer in `src/lib/core/backtrace.cc` for backtrace payload.

Closes #4650
---

branch: https://github.com/tarantool/tarantool/tree/skaplun/drop-bss-buff
issue: https://github.com/tarantool/tarantool/issues/4650

 src/lib/core/backtrace.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/lib/core/backtrace.cc b/src/lib/core/backtrace.cc
index 77f77b05c..c70576b53 100644
--- a/src/lib/core/backtrace.cc
+++ b/src/lib/core/backtrace.cc
@@ -33,6 +33,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <assert.h>
 
 #include <cxxabi.h>
 
@@ -47,6 +48,7 @@
 #include <libunwind.h>
 
 #include "small/region.h"
+#include "small/static.h"
 /*
  * We use a global static buffer because it is too late to do any
  * allocation when we are printing backtrace and fiber stack is
@@ -55,8 +57,6 @@
 
 #define BACKTRACE_NAME_MAX 200
 
-static char backtrace_buf[4096 * 4];
-
 static __thread struct region cache_region;
 static __thread struct mh_i64ptr_t *proc_cache = NULL;
 
@@ -140,8 +140,10 @@ backtrace()
 	unw_getcontext(&unw_context);
 	unw_cursor_t unw_cur;
 	unw_init_local(&unw_cur, &unw_context);
+	char *backtrace_buf = (char *)static_alloc(SMALL_STATIC_SIZE);
+	assert(backtrace_buf);
 	char *p = backtrace_buf;
-	char *end = p + sizeof(backtrace_buf) - 1;
+	char *end = p + SMALL_STATIC_SIZE - 1;
 	int unw_status;
 	*p = '\0';
 	while ((unw_status = unw_step(&unw_cur)) > 0) {
-- 
2.24.1