android中的Signal.docx

Android中的Signal信号What is signalHow many kind signal,General signalHow to send signalHow to handle signalHow to generally use signal Signal and system callsignal handle Reentrant Functionssignal setsignal queuesigprocmask FunctionSignals are a limited form of inter-process communication used in Unix, Unix-like, and other POSIX-compliant operating systems. A signal is an asynchronous notification sent to a process or to a specific thread within the same process in order to notify it of an event that occurred. Signals originated in 1970s Bell Labs Unix and have been more recently specified in the POSIX standard.When a signal is sent, the operating system interrupts the target process normal flow of execution to deliver the signal. Execution can be interrupted during any non-atomic instruction. If the process has previously registered a signal handler, that routine is executed. Otherwise, the default signal handler is executed.Embedded programs may find signals useful for interprocess communications, as the computational and memory footprint for signals is small.[1] signal中文描述列表Signal Description SIGABRT 由调用abort函数产生，进程非正常退出SIGALRM 用alarm函数设置的timer超时或setitimer函数设置的interval timer超时SIGBUS 某种特定的硬件异常，通常由内存访问引起SIGCANCEL 由Solaris Thread Library内部使用，通常不会使用SIGCHLD 进程Terminate或Stop的时候，SIGCHLD会发送给它的父进程。缺省情况下该Signal会被忽略SIGCONT 当被stop的进程恢复运行的时候，自动发送SIGEMT 和实现相关的硬件异常SIGFPE 数学相关的异常，如被0除，浮点溢出，等等SIGFREEZE Solaris专用，Hiberate或者Suspended时候发送SIGHUP 发送给具有Terminal的Controlling Process，当terminal被disconnect时候发送SIGILL 非法指令异常SIGINFO BSD signal。由Status Key产生，通常是CTRL+T。发送给所有Foreground Group的进程SIGINT 由Interrupt Key产生，通常是CTRL+C或者DELETE。发送给所有ForeGround Group的进程SIGIO 异步IO事件SIGIOT 实现相关的硬件异常，一般对应SIGABRT SIGKILL 无法处理和忽略。中止某个进程SIGLWP 由Solaris Thread Libray内部使用SIGPIPE 在reader中止之后写Pipe的时候发送SIGPOLL 当某个事件发送给Pollable Device的时候发送SIGPROF Setitimer指定的Profiling Interval Timer所产生SIGPWR 和系统相关。和UPS相关。SIGQUIT 输入Quit Key的时候（CTRL+\）发送给所有Foreground Group的进程SIGSEGV 非法内存访问SIGSTKFLT Linux专用，数学协处理器的栈异常SIGSTOP 中止进程。无法处理和忽略。SI