a3292e8924
When `pthread_join` returns, the target thread signals its internal semaphore, but the underlying Mach thread hasn't been removed from the task yet with `thread_terminate`. The flakiness is the result of the debugger stopping the process halts the dying thread mid-termination. There is no Mach API to distinguish a dying thread from a live one: it appears as `TH_STATE_STOPPED`, like any other suspended thread. This PR adds a helper (`wait_for_thread_cleanup`) that polls `task_threads` to ensure the Mach thread is actually gone before the breakpoint. Since there might be other tests that are affected by this race, I put it in a common location so it can be reused.
66 lines
1.5 KiB
C++
66 lines
1.5 KiB
C++
// This test verifies the correct handling of child thread exits.
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#include "mach_thread.h"
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#include "pseudo_barrier.h"
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#include <thread>
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pseudo_barrier_t g_barrier1;
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pseudo_barrier_t g_barrier2;
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pseudo_barrier_t g_barrier3;
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void *thread1() {
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// Synchronize with the main thread.
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pseudo_barrier_wait(g_barrier1);
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// Synchronize with the main thread and thread2.
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pseudo_barrier_wait(g_barrier2);
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// Return
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return NULL; // Set second breakpoint here
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}
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void *thread2() {
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// Synchronize with thread1 and the main thread.
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pseudo_barrier_wait(g_barrier2);
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// Synchronize with the main thread.
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pseudo_barrier_wait(g_barrier3);
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// Return
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return NULL;
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}
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int main() {
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pseudo_barrier_init(g_barrier1, 2);
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pseudo_barrier_init(g_barrier2, 3);
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pseudo_barrier_init(g_barrier3, 2);
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// Create a thread.
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std::thread thread_1(thread1);
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// Wait for thread1 to start.
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pseudo_barrier_wait(g_barrier1);
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// Create another thread.
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std::thread thread_2(thread2); // Set first breakpoint here
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// Wait for thread2 to start.
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pseudo_barrier_wait(g_barrier2);
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// Wait for the first thread to finish
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mach_port_t mach_thread_1 = get_mach_thread(thread_1);
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thread_1.join();
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wait_for_thread_cleanup(mach_thread_1);
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// Synchronize with the remaining thread
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int dummy = 47; // Set third breakpoint here
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pseudo_barrier_wait(g_barrier3);
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// Wait for the second thread to finish
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mach_port_t mach_thread_2 = get_mach_thread(thread_2);
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thread_2.join();
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wait_for_thread_cleanup(mach_thread_2);
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return 0; // Set fourth breakpoint here
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}
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