Use var_InheritString for --decklink-video-connection.

[vlc] / bin / override.c

diff --git a/bin/override.c b/bin/override.c
index 60bee0ce3eebfa21a527a5359bbc9a82da79f087..ac9e14cddd5bf98be6ad55e8726dc007a53868fd 100644 (file)
--- a/bin/override.c
+++ b/bin/override.c
@@ -23,16 +23,18 @@
 #endif
 
 #include <stdbool.h>
+#define MAX_ERRORS 5
 
 void vlc_enable_override (void);
 
-#if defined (__GNUC__) /* typeof and statement-expression */ \
+#if defined (__GNUC__) \
  && (defined (__ELF__) && !defined (__sun__))
 /* Solaris crashes on printf("%s", NULL); which is legal, but annoying. */
 
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <dlfcn.h>
 #include <pthread.h>
 #ifdef HAVE_EXECINFO_H
@@ -55,32 +57,37 @@ void vlc_enable_override (void)
     pthread_atfork (NULL, NULL, vlc_reset_override);
 }
 
-static void vlogbug (const char *level, const char *func, const char *fmt,
-                     va_list ap)
+static void vlogbug (unsigned *pc, const char *level, const char *func,
+                     const char *fmt, va_list ap)
 {
 #ifdef HAVE_BACKTRACE
-    const size_t framec = 4;
+    const size_t framec = 5;
     void *framev[framec];
 
     backtrace (framev, framec);
 #endif
     flockfile (stderr);
-    fprintf (stderr, "%s: call to %s(", level, func);
-    vfprintf (stderr, fmt, ap);
-    fputs (")\n", stderr);
-    fflush (stderr);
+    if (*pc < MAX_ERRORS)
+    {
+        (*pc)++;
+        fprintf (stderr, "%s: call to %s(", level, func);
+        vfprintf (stderr, fmt, ap);
+        fputs (")\n", stderr);
+        fflush (stderr);
 #ifdef HAVE_BACKTRACE
-    backtrace_symbols_fd (framev + 2, framec - 2, fileno (stderr));
+        backtrace_symbols_fd (framev + 2, framec - 2, fileno (stderr));
 #endif
+    }
     funlockfile (stderr);
 }
 
-static void logbug (const char *level, const char *func, const char *fmt, ...)
+static void logbug (unsigned *pc, const char *level, const char *func,
+                    const char *fmt, ...)
 {
     va_list ap;
 
     va_start (ap, fmt);
-    vlogbug (level, func, fmt, ap);
+    vlogbug (pc, level, func, fmt, ap);
     va_end (ap);
 }
 
@@ -96,9 +103,29 @@ static void *getsym (const char *name)
     return sym;
 }
 
-#define LOG(level, ...) logbug(level, __func__, __VA_ARGS__)
+#define LOG(level, ...) \
+    do { \
+        static unsigned counter = 0; \
+        logbug(&counter, level, __func__, __VA_ARGS__); \
+    } while (0)
+
+/* Evil non-standard GNU C macro ;)
+ *  typeof keyword,
+ *  statement-expression,
+ *  nested function...
+ */
 #define CALL(func, ...) \
-    ({ typeof (func) *sym = getsym ( # func); sym (__VA_ARGS__); })
+({ \
+    static typeof (func) *sym = NULL; \
+    static pthread_once_t once = PTHREAD_ONCE_INIT; \
+    auto void getsym_once (void); \
+    void getsym_once (void) \
+    { \
+        sym = getsym ( # func); \
+    } \
+    pthread_once (&once, getsym_once); \
+    sym (__VA_ARGS__); \
+})
 
 
 /*** Environment ***
@@ -148,52 +175,85 @@ int unsetenv (const char *name)
  * preserve reproducibility of the number sequence (which usually does not
  * matter).
  **/
-static pthread_mutex_t prng_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct
+{
+    pthread_mutex_t lock;
+    unsigned int seed;
+} prng = { PTHREAD_MUTEX_INITIALIZER, 0, };
 
 void srand (unsigned int seed)
 {
-    pthread_mutex_lock (&prng_lock);
+    pthread_mutex_lock (&prng.lock);
     LOG("Warning", "%d", seed);
-    CALL(srand, seed);
-    pthread_mutex_unlock (&prng_lock);
+    prng.seed = seed;
+    pthread_mutex_unlock (&prng.lock);
 }
 
 int rand (void)
 {
     int ret;
 
-    pthread_mutex_lock (&prng_lock);
+    pthread_mutex_lock (&prng.lock);
     LOG("Warning", "");
-    ret = CALL(rand);
-    pthread_mutex_unlock (&prng_lock);
+    ret = rand_r (&prng.seed);
+    pthread_mutex_unlock (&prng.lock);
     return ret;
 }
 
 
+#if 0
 /** Signals **/
 #include <signal.h>
 
+static bool blocked_signal (int num)
+{
+    switch (num)
+    {
+        case SIGINT:
+        case SIGHUP:
+        case SIGQUIT:
+        case SIGTERM:
+        case SIGPIPE:
+        case SIGCHLD:
+            return true;
+    }
+    return false;
+}
+
 void (*signal (int signum, void (*handler) (int))) (int)
 {
     if (override)
     {
-        const char *msg = "Error";
-
-        if ((signum == SIGPIPE && handler == SIG_IGN)
-         || (signum != SIGPIPE && handler == SIG_DFL))
-            /* Same settings we already use */
-            msg = "Warning";
-        LOG(msg, "%d, %p", signum, handler);
+        if (handler != SIG_IGN && handler != SIG_DFL)
+            goto error;
+        if (!blocked_signal (signum))
+            goto error;
+        /* For our blocked signals, the handler won't matter much... */
+        if (handler == SIG_DFL)
+            LOG("Warning", "%d, SIG_DFL", signum, handler);
     }
     return CALL(signal, signum, handler);
+error:
+    LOG("Blocked", "%d, %p", signum, handler);
+    return SIG_DFL;
 }
 
 int sigaction (int signum, const struct sigaction *act, struct sigaction *old)
 {
-    if (act != NULL)
-        LOG("Error", "%d, %p, %p", signum, act, old);
+    if (override && act != NULL)
+    {
+        if ((act->sa_flags & SA_SIGINFO)
+         || (act->sa_handler != SIG_IGN && act->sa_handler != SIG_DFL))
+            goto error;
+        if (act->sa_handler == SIG_DFL)
+            LOG("Warning", "%d, %p, SIG_DFL", signum, act);
+    }
     return CALL(sigaction, signum, act, old);
+error:
+    LOG("Blocked", "%d, %p, %p", signum, act, old);
+    return -1;
 }
+#endif
 
 
 /*** Locales ***
@@ -214,6 +274,20 @@ char *setlocale (int cat, const char *locale)
 }
 
 
+/* strerror() is not thread-safe in theory (POSIX), nor in practice (glibc).
+ * This caused quite nasty crashes in the history of VLC/Linux. */
+char *strerror (int val)
+{
+    if (override)
+    {
+        static const char msg[] =
+            "Error message unavailable (use strerror_r instead of strerror)!";
+        LOG("Blocked", "%d", val);
+        return (char *)msg;
+    }
+    return CALL(strerror, val);
+}
+
 /*** Xlib ****/
 #ifdef HAVE_X11_XLIB_H
 # include <X11/Xlib.h>