usage: allow pluggable die-recursion checks
When any git code calls die or die_errno, we use a counter
to detect recursion into the die functions from any of the
helper functions. However, such a simple counter is not good
enough for threaded programs, which may call die from a
sub-thread, killing only the sub-thread (but incrementing
the counter for everyone).
Rather than try to deal with threads ourselves here, let's
just allow callers to plug in their own recursion-detection
function. This is similar to how we handle the die routine
(the caller plugs in a die routine which may kill only the
sub-thread).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git-compat-util.h b/git-compat-util.h
index 9c01e9b..6aee9df 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -301,6 +301,7 @@
extern void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params));
extern void set_error_routine(void (*routine)(const char *err, va_list params));
+extern void set_die_is_recursing_routine(int (*routine)(void));
extern int prefixcmp(const char *str, const char *prefix);
extern int suffixcmp(const char *str, const char *suffix);
diff --git a/usage.c b/usage.c
index 8eab281..9d2961e 100644
--- a/usage.c
+++ b/usage.c
@@ -6,8 +6,6 @@
#include "git-compat-util.h"
#include "cache.h"
-static int dying;
-
void vreportf(const char *prefix, const char *err, va_list params)
{
char msg[4096];
@@ -49,12 +47,19 @@
vreportf("warning: ", warn, params);
}
+static int die_is_recursing_builtin(void)
+{
+ static int dying;
+ return dying++;
+}
+
/* If we are in a dlopen()ed .so write to a global variable would segfault
* (ugh), so keep things static. */
static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
static void (*error_routine)(const char *err, va_list params) = error_builtin;
static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
+static int (*die_is_recursing)(void) = die_is_recursing_builtin;
void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
{
@@ -66,6 +71,11 @@
error_routine = routine;
}
+void set_die_is_recursing_routine(int (*routine)(void))
+{
+ die_is_recursing = routine;
+}
+
void NORETURN usagef(const char *err, ...)
{
va_list params;
@@ -84,11 +94,10 @@
{
va_list params;
- if (dying) {
+ if (die_is_recursing()) {
fputs("fatal: recursion detected in die handler\n", stderr);
exit(128);
}
- dying = 1;
va_start(params, err);
die_routine(err, params);
@@ -102,12 +111,11 @@
char str_error[256], *err;
int i, j;
- if (dying) {
+ if (die_is_recursing()) {
fputs("fatal: recursion detected in die_errno handler\n",
stderr);
exit(128);
}
- dying = 1;
err = strerror(errno);
for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
