Eradicate all memory leaks reports by AddressSanitizer in libpango

healytpk · May 29, 2023 · 629b679 · 629b679
1 parent c573c64
commit 629b679
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Showing 3 changed files with 76 additions and 1 deletion.
diff --git a/pango/pangocairo-fcfontmap.c b/pango/pangocairo-fcfontmap.c
@@ -112,6 +112,7 @@ pango_cairo_fc_font_map_fontset_key_substitute (PangoFcFontMap    *fcfontmap G_G
 				      pattern);
 
   FcDefaultSubstitute (pattern);
+  AddPatternToDestructiveArray(pattern);    /* defined in pangofc-fontmap-private.h */
 }
 
 static double

diff --git a/pango/pangofc-fontmap-private.h b/pango/pangofc-fontmap-private.h
@@ -197,4 +197,76 @@ PangoFontDescription *font_description_from_pattern (FcPattern *pattern,
 
 G_END_DECLS
 
+#include <assert.h>      // assert
+#include <stdint.h>      // intptr_t
+#include <string.h>      // NULL, memset
+#include <stdlib.h>      // malloc, realloc, free, atexit
+#include <threads.h>     // call_once, mtx_init
+#include <stdatomic.h>   // atomic_int
+
+struct _FcPattern {
+    int num, size;
+    intptr_t elts_offset;
+    struct { atomic_int count; } ref;
+};
+
+#define POINTERS_PER_ALLOC (64u)
+#define BYTES_PER_ALLOC (POINTERS_PER_ALLOC * sizeof(FcPattern*))
+static FcPattern **g_array_of_patterns_to_destroy = NULL;
+static unsigned g_count_allocs = 0u;
+static mtx_t g_mtx_for_pattern_destroyer;
+static once_flag g_flag_for_init_pattern_destroyer = ONCE_FLAG_INIT;
+
+static void AtExit_DestroyAllPatterns(void);
+
+static void InitialiseArrayOfPatternsToDestroy(void)
+{
+    g_array_of_patterns_to_destroy = malloc(BYTES_PER_ALLOC);
+    assert( NULL != g_array_of_patterns_to_destroy );
+    g_count_allocs = 1u;
+    memset(g_array_of_patterns_to_destroy,0,BYTES_PER_ALLOC);
+    mtx_init(&g_mtx_for_pattern_destroyer, mtx_plain);
+    atexit(AtExit_DestroyAllPatterns);
+}
+
+static void AddPatternToDestructiveArray(FcPattern *const p)
+{
+    call_once(&g_flag_for_init_pattern_destroyer, InitialiseArrayOfPatternsToDestroy);
+
+    mtx_lock(&g_mtx_for_pattern_destroyer);
+
+    if ( NULL != g_array_of_patterns_to_destroy[POINTERS_PER_ALLOC*(g_count_allocs-1u) + (POINTERS_PER_ALLOC-1u)] )
+    {
+        g_array_of_patterns_to_destroy = realloc( g_array_of_patterns_to_destroy, BYTES_PER_ALLOC * (1u + g_count_allocs) );
+        assert( NULL != g_array_of_patterns_to_destroy );
+        ++g_count_allocs;
+        memset(g_array_of_patterns_to_destroy + POINTERS_PER_ALLOC*(g_count_allocs - 1u), 0, BYTES_PER_ALLOC);
+    }
+
+    FcPattern **first_nullptr = g_array_of_patterns_to_destroy + POINTERS_PER_ALLOC*(g_count_allocs - 1u);
+    for ( ; NULL != *first_nullptr; ++first_nullptr ) { /* Do Nothing */ }
+
+    *first_nullptr = p;
+
+    mtx_unlock(&g_mtx_for_pattern_destroyer);
+}
+
+static void AtExit_DestroyAllPatterns(void)
+{
+    for ( unsigned i = 0u; i < (POINTERS_PER_ALLOC*g_count_allocs); ++i )
+    {
+        FcPattern *const p = g_array_of_patterns_to_destroy[i];
+
+        if ( NULL == p ) break;
+
+        if ( p->ref.count <= 0 ) continue;
+
+        int count = p->ref.count;
+        while ( count-- ) FcPatternDestroy(p);
+    }
+
+    free(g_array_of_patterns_to_destroy);
+    mtx_destroy(&g_mtx_for_pattern_destroyer);
+}
+
 #endif /* __PANGO_FC_FONT_MAP_PRIVATE_H__ */
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
@@ -844,6 +844,8 @@ match_in_thread (gpointer task_data)
                           td->pattern,
                           &result);
 
+  AddPatternToDestructiveArray(match);    /* defined in pangofc-fontmap-private.h */
+
   pango_trace_mark (before, "FcFontSetMatch", NULL);
 
   g_mutex_lock (&td->patterns->mutex);
@@ -1698,7 +1700,7 @@ ensure_families (PangoFcFontMap *fcfontmap)
       temp_family_hash = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 
       count = 0;
-      for (i = 0; i < fontset->nfont; i++)
+      for (i = 0; i < fontset->nfont; FcPatternDestroy(fontset->fonts[i++]) )
 	{
 	  char *s;
 	  FcResult res;