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/****************************************************************************** Welcome to GDB Online. GDB online is an online compiler and debugger tool for C, C++, Python, PHP, Ruby, C#, VB, Perl, Swift, Prolog, Javascript, Pascal, HTML, CSS, JS Code, Compile, Run and Debug online from anywhere in world. Gabriel Staples 26 Sept. 2020 empirically_determine_max_thread_stack_size You can run this as a C OR C++ program! References: 1. 1. Originally by Bruno Haible, here, 24 Oct. 2009 I've added some minor changes to it for readability, clarity, and efficiency. *******************************************************************************/ // =============== Program for determining the default thread stack size ========= // Modified by Gabriel Staples, 26 Sept. 2020 // Originally by Bruno Haible // 24 Oct. 2009 // Source: #include <alloca.h> #include <pthread.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <unistd.h> // sleep /// Thread function to repeatedly allocate memory within a thread, printing /// the total memory allocated each time, until the program crashes. The last /// value printed before the crash indicates how big a thread's stack size is. void* threadfunc(void* bytes_to_allocate_each_loop) { const uint32_t BYTES_TO_ALLOCATE_EACH_LOOP = *(uint32_t*)bytes_to_allocate_each_loop; uint32_t bytes_allocated = 0; while (true) { printf("bytes_allocated = %u\n", bytes_allocated); fflush(stdout); // NB: it appears that you don't necessarily need `volatile` here, // but you DO definitely need to actually use (ex: write to) the // memory allocated by `alloca()`, as we do below, or else the // `alloca()` call does seem to get optimized out on some systems, // making this whole program just run infinitely forever without // ever hitting the expected segmentation fault. volatile uint8_t * byte_buff = (volatile uint8_t *)alloca(BYTES_TO_ALLOCATE_EACH_LOOP); byte_buff[0] = 0; bytes_allocated += BYTES_TO_ALLOCATE_EACH_LOOP; } } int main() { const uint32_t BYTES_TO_ALLOCATE_EACH_LOOP = 128; pthread_t thread; pthread_create(&thread, NULL, threadfunc, (void*)(&BYTES_TO_ALLOCATE_EACH_LOOP)); while (true) { const unsigned int SLEEP_SEC = 10000; sleep(SLEEP_SEC); } return 0; } /* Sample output: bytes_allocated = 7449856 bytes_allocated = 7449984 bytes_allocated = 7450112 bytes_allocated = 7450240 bytes_allocated = 7450368 bytes_allocated = 7450496 bytes_allocated = 7450624 bytes_allocated = 7450752 bytes_allocated = 7450880 Segmentation fault (core dumped) */

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