[PATCH v2 1/2] usage: allow pluggable die-recursion checks
- From
Jeff King <peff@peff.net>
- Date
- Apr 16, 2013, 19:46 UTC
- Message-ID
- <20130416194621.GA11185@sigill.intra.peff.net>
- In-Reply-To
- <20130416194418.GA7187@sigill.intra.peff.net>
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> --- git-compat-util.h | 1 + usage.c | 20 ++++++++++++++------ 2 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/git-compat-util.h b/git-compat-util.h index cde442f..e955bb5 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -331,6 +331,7 @@ extern void set_error_routine(void (*routine)(const char *err, va_list params)); 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 40b3de5..ed14645 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 @@ static void (*warn_routine)(const char *err, va_list params) = warn_builtin; 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 @@ void set_error_routine(void (*routine)(const char *err, va_list params)) 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 @@ void NORETURN die(const char *err, ...) { 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 @@ void NORETURN die_errno(const char *fmt, ...) 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; ) {
-- 1.8.2.8.g44e4c28