Fix the C library initialization to avoid calling static C++ constructors twice.
The problem was due to the fact that, in the case of dynamic executables,
the dynamic linker calls the DT_PREINIT_ARRAY, DT_INIT and DT_INIT_ARRAY
constructors when loading shared libraries and dynamic executables,
*before* calling the executable's entry point (i.e. arch-$ARCH/bionic/crtbegin_dynamic.c)
which in turns call __libc_init() in libc.so, as defined by bionic/libc_init_dynamic.c
The latter did call these constructors array again, mistakenly.
The patch also updates the documentation of many related functions.
Also adds a new section to linker/README.TXT explaining restrictions on
C library usage.
The patch has been tested on a Dream for stability issues with
proprietary blobs:
- H264 decoding works
- Camera + Video recording works
- GPS works
- Sensors work
The tests in system/extra/tests/bionic/libc/common/test_static_cpp_mutex.cpp has been
run and shows the static C++ constructor being called only once.
diff --git a/linker/linker.c b/linker/linker.c
index e398f82..e7d5ab4 100644
--- a/linker/linker.c
+++ b/linker/linker.c
@@ -44,7 +44,7 @@
#include <sys/atomics.h>
/* special private C library header - see Android.mk */
-#include <bionic_tls.h>
+#include <bionic_preinit.h>
#include "linker.h"
#include "linker_debug.h"
@@ -1691,6 +1691,7 @@
#define ANDROID_TLS_SLOTS BIONIC_TLS_SLOTS
static void * __tls_area[ANDROID_TLS_SLOTS];
+static pthread_internal_t __main_thread;
unsigned __linker_init(unsigned **elfdata)
{
@@ -1709,8 +1710,7 @@
gettimeofday(&t0, 0);
#endif
- __set_tls(__tls_area);
- ((unsigned *)__get_tls())[TLS_SLOT_THREAD_ID] = gettid();
+ __libc_preinit(&__main_thread, __tls_area);
debugger_init();