add winfsp-tests and ext/tlib

ext/tlib/injection.c

@@ -0,0 +1,144 @@
+/**
+ * @file tlib/injection.c
+ *
+ * @copyright 2014-2015 Bill Zissimopoulos
+ */
+
+#include <tlib/injection.h>
+#include <tlib/callstack.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+#undef NDEBUG
+#include <assert.h>
+
+#define NBUCKETS                        256
+struct injection_cond_s
+{
+    struct injection_cond_s *cnext;
+    char *sym;
+    unsigned trigger, count;
+};
+struct injection_entry_s
+{
+    struct injection_entry_s *hnext;
+    char *name;
+    struct injection_cond_s *clist;
+};
+struct injection_htab_s
+{
+    struct injection_entry_s **buckets;
+};
+
+static inline size_t hash_chars(const char *s, size_t length)
+{
+    /* djb2: see http://www.cse.yorku.ca/~oz/hash.html */
+    size_t h = 5381;
+    for (const char *t = s + length; t > s; ++s)
+        h = 33 * h + *s;
+    return h;
+}
+static struct injection_htab_s *injection_htab()
+{
+    static struct injection_htab_s *htab;
+    if (0 == htab)
+    {
+        htab = calloc(1, sizeof *htab);
+        assert(0 != htab);
+        htab->buckets = calloc(NBUCKETS, sizeof(struct injection_entry_s *));
+    }
+    return htab;
+}
+static struct injection_entry_s *injection_lookup(const char *name)
+{
+    struct injection_htab_s *htab = injection_htab();
+    size_t i = hash_chars(name, strlen(name)) & (NBUCKETS - 1);
+    for (struct injection_entry_s *entry = htab->buckets[i]; entry; entry = entry->hnext)
+        if (0 == strcmp(entry->name, name))
+            return entry;
+    return 0;
+}
+static struct injection_entry_s *injection_insert(const char *name)
+{
+    struct injection_htab_s *htab = injection_htab();
+    size_t i = hash_chars(name, strlen(name)) & (NBUCKETS - 1);
+    struct injection_entry_s *entry = calloc(1, sizeof *entry);
+    assert(0 != entry);
+    entry->name = strdup(name);
+    entry->hnext = htab->buckets[i];
+    htab->buckets[i] = entry;
+    return entry;
+}
+static struct injection_cond_s *injection_cond_get(struct injection_entry_s *entry, const char **syms)
+{
+    struct injection_cond_s *deinjection_centry = 0;
+    for (struct injection_cond_s *centry = entry->clist; centry; centry = centry->cnext)
+        if ('*' == centry->sym[0] && '\0' == centry->sym[1])
+            deinjection_centry = centry;
+        else
+        {
+            for (const char *sym; 0 != (sym = *syms); syms++)
+                if (0 == strcmp(centry->sym, sym))
+                    return centry;
+        }
+    return deinjection_centry;
+}
+static void injection_cond_set(struct injection_entry_s *entry, const char *sym, unsigned trigger)
+{
+    for (struct injection_cond_s *centry = entry->clist; centry; centry = centry->cnext)
+        if (0 == strcmp(centry->sym, sym))
+        {
+            centry->trigger = trigger;
+            return;
+        }
+    struct injection_cond_s *centry = calloc(1, sizeof *centry);
+    assert(0 != centry);
+    centry->sym = strdup(sym);
+    centry->trigger = trigger;
+    centry->cnext = entry->clist;
+    entry->clist = centry;
+}
+static void injection_cond_remove(struct injection_entry_s *entry, const char *sym)
+{
+    struct injection_cond_s **p = &entry->clist;
+    for (; *p; p = &(*p)->cnext)
+        if (0 == strcmp((*p)->sym, sym))
+            break;
+    if (*p) /* did we find the condition? */
+    {
+        struct injection_cond_s *q = *p;
+        *p = q->cnext;
+        free(q->sym);
+        free(q);
+    }
+}
+
+void *tlib_injection(const char *name)
+{
+    struct injection_entry_s *entry = injection_lookup(name);
+    if (0 == entry)
+        entry = injection_insert(name);
+    return entry;
+}
+int tlib_injection_trace(void *injection)
+{
+    if (0 == ((struct injection_entry_s *)injection)->clist)
+        return 0;
+    struct tlib_callstack_s stack;
+    tlib_callstack(2, TLIB_MAX_SYMRET, &stack);
+    struct injection_cond_s *centry = injection_cond_get(injection, stack.syms);
+    if (0 == centry)
+        return 0;
+    return centry->count++ == centry->trigger || ~0 == centry->trigger;
+}
+void tlib_injection_enable(const char *name, const char *sym, unsigned trigger)
+{
+    struct injection_entry_s *entry = tlib_injection(name);
+    injection_cond_set(entry, sym, trigger);
+}
+void tlib_injection_disable(const char *name, const char *sym)
+{
+    struct injection_entry_s *entry = tlib_injection(name);
+    injection_cond_remove(entry, sym);
+}