include/lttng/ust-libc-wrapper.h

   1 // SPDX-FileCopyrightText: 2020 Michael Jeanson <mjeanson@efficios.com>
   2 //
   3 // SPDX-License-Identifier: MIT
   4
   5 /*
   6  * Public symbols of liblttng-ust-libc-wrapper.so
   7  */
   8
   9 #ifndef _LTTNG_UST_LIBC_WRAPPER_H
  10 #define _LTTNG_UST_LIBC_WRAPPER_H
  11
  12 /*
  13  * This is the constructor for the malloc part of the libc wrapper. It is
  14  * publicly exposed because the malloc override needs to be initialized before
  15  * the process becomes multithreaded and thus must happen before the main
  16  * constructor of liblttng-ust starts threads. Since there is no reliable way
  17  * to guarantee the execution order of constructors across shared library, the
  18  * liblttng-ust constructor has to call the malloc constructor before starting
  19  * any thread. This is achieved by having a weak public version of this
  20  * function in liblttng-ust that is overridden by the one in
  21  * liblttng-ust-wrapper-libc when it's preloaded.
  22  */
  23 void lttng_ust_libc_wrapper_malloc_ctor(void)
  24         __attribute__((constructor));
  25
  26 #endif