我有一个stackshot文件，我正在试图弄清楚它里面发生了什么。这是来自其中一个进程的线程（来自WindowServer）：
Thread 0xf09 1000 samples (1-1000) priority 79 (base 79) cpu time 0.044s
1000 thread_start + 13 (libsystem_pthread.dylib + 4981) [0x7fff952b3375]
1000 _pthread_start + 168 (libsystem_pthread.dylib + 15248) [0x7fff952b5b90]
1000 _pthread_body + 131 (libsystem_pthread.dylib + 15379) [0x7fff952b5c13]
1000 thread_fun + 25 (QuartzCore + 129849) [0x7fff816e1b39]
993 CA::Render::Server::server_thread(void*) + 257 (QuartzCore + 130113) [0x7fff816e1c41]
993 mach_msg_trap + 10 (libsystem_kernel.dylib + 70534) [0x7fff8f639386]
*992 ipc_mqueue_receive_continue + 0 (kernel + 828992) [0xffffff80002ca640]
*1 Thread_continue + 8 (kernel + 1879576) [0xffffff80003cae18]
*1 thread_continue + 67 (kernel + 1001955) [0xffffff80002f49e3] (running)
7 CA::Render::Server::server_thread(void*) + 563 (QuartzCore + 130419) [0x7fff816e1d73]
7 CA::Render::Server::ReceivedMessage::dispatch() + 31 (QuartzCore + 1031139) [0x7fff817bdbe3]
6 CA::Render::Server::ReceivedMessage::run_command_stream() + 567 (QuartzCore + 1032931) [0x7fff817be2e3]
5 CA::Render::decode_commands(CA::Render::Decoder*) + 2276 (QuartzCore + 1030108) [0x7fff817bd7dc]
3 CA::Render::Context::did_commit(bool, bool) + 76 (QuartzCore + 750372) [0x7fff81779324]
2 CA::Render::post_notification(CA::Render::NotificationName, CA::Render::Object*, void*, bool) + 249 (QuartzCore + 104465) [0x7fff816db811]
2 contextChanged + 127 (CoreGraphics + 5099842) [0x7fff91bf3142]
2 mach_msg_trap + 10 (libsystem_kernel.dylib + 70534) [0x7fff8f639386]
*2 hndl_mach_scall64 + 22 (kernel + 2030166) [0xffffff80003efa56]
*2 mach_call_munger64 + 410 (kernel + 1817898) [0xffffff80003bbd2a]
*2 mach_msg_overwrite_trap + 197 (kernel + 877285) [0xffffff80002d62e5]
*2 ipc_kmsg_send + 307 (kernel + 813363) [0xffffff80002c6933]
*2 ipc_mqueue_send + 599 (kernel + 827767) [0xffffff80002ca177]
*2 ipc_mqueue_post + 932 (kernel + 828756) [0xffffff80002ca554] (running)
1 CA::Render::post_notification(CA::Render::NotificationName, CA::Render::Object*, void*, bool) + 99 (QuartzCore + 104315) [0x7fff816db77b] (running)
1 CA::Render::post_notification(CA::Render::NotificationName, CA::Render::Object*, void*, bool) + 94 (QuartzCore + 104310) [0x7fff816db776] (running)
1 CA::Render::post_notification(CA::Render::NotificationName, CA::Render::Object*, void*, bool) + 249 (QuartzCore + 104465) [0x7fff816db811]
1 contextDidCommit + 125 (CoreGraphics + 5100116) [0x7fff91bf3254] (running)
1 CA::Render::decode_commands(CA::Render::Decoder*) + 61 (QuartzCore + 1027893) [0x7fff817bcf35]
1 CA::Render::Context::will_commit() + 30 (QuartzCore + 163728) [0x7fff816e9f90]
1 CA::Render::post_notification(CA::Render::NotificationName, CA::Render::Object*, void*, bool) + 94 (QuartzCore + 104310) [0x7fff816db776] (running)
1 CA::Render::Server::ReceivedMessage::run_command_stream() + 683 (QuartzCore + 1033047) [0x7fff817be357]
1 x_mem_dealloc_chain + 35 (QuartzCore + 54163) [0x7fff816cf393] (running)
标题行声明1000 samples，所以我猜猜堆栈帧前面的数字是采样器在快照中找到该帧的次数的计数？这也可以解释缩进。样本号旁边的*是什么意思？例如，hndle_mach_scall64旁边有*2。这是什么意思？
答案 0 :(得分：1)
再看一遍，似乎*表示系统调用另一端的代码。