1LAM_KSIGNAL(2) LAM LOCAL LIBRARY LAM_KSIGNAL(2)
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6 lam_ksignal - Specify a signal handler for a LAM signal.
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9 #include <lam_ksignal.h>
10 void (*lam_ksignal (int signum, void (*func)())) ();
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14 lam_ksignal() exchanges a current signal handler for a new signal han‐
15 dler. When a process is signalled, execution control passes immedi‐
16 ately to the handler function. Control passes back to the previous
17 location when the handler function returns. Each signal begins with a
18 default handler when the process is initialized.
19 LAM signals are completely separate from the signal facilities of the
21 host operating system. While the syntax and functionality are similar,
22 signal(3) cannot affect LAM signals and vice versa.
23 The following is a list of LAM signals as they appear in <lam_ksig‐
25 nal.h>.
26 LAM_SIGTRACE 1 unload trace data
28 LAM_SIGUDIE 4 terminate
29 LAM_SIGARREST 5 suspend execution
30 LAM_SIGRELEASE 6 continue execution
31 LAM_SIGA 7 user defined
32 LAM_SIGB 8 user defined
33 LAM_SIGFUSE 9 node about to die
34 LAM_SIGSHRINK 10 another node has died
35 By default, LAM_SIGA and LAM_SIGB are ignored. They are reserved for
37 application programmers LAM_SIGUDIE causes the signalled process to
38 exit. LAM_SIGARREST causes the signalled process to indefinitely block
39 and LAM_SIGRELEASE reschedules it.
40 LAM_SIGTRACE causes the current contents of the trace buffer to be
42 flushed to the local trace daemon.
43 LAM_SIGFUSE and LAM_SIGSHRINK are fault tolerant signals. The former
45 indicates that the local node and all its processes will terminate
46 imminently. The process receiving LAM_SIGFUSE should take immediate
47 action to clean up. By default, LAM_SIGFUSE is ignored. LAM_SIGSHRINK
48 indicates that another node has died or been forcefully terminated.
49 The default action is to flush the route cache so that subsequent
50 remote service calls to the dead node will fail with EBADNODE (in <ter‐
51 ror.h>). If the application decides to trap this signal, the signal
52 handler should call the old handler (the default which will be returned
53 by lam_ksignal()) before returning.
54 The new signal handler must be the address of a function. The special
56 value LAM_KSIG_IGN ignores the given signal. (A function that does
57 nothing is called when the signal occurs.) Another special value,
58 LAM_KSIG_DFL, returns the signal handler to the default function.
59 When a signal handler is called, the signal number that caused the
61 invocation is passed as the sole parameter to the handler.
62 While an signal handler is running, further signals on the same number
64 are blocked. Interrupts do not form queues. A second signal will
65 overwrite the first (thus two appear as one) if the first has not yet
66 been handled, either due to scheduling or signal blocking.
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69 Upon successful completion, the address of the previously installed
70 signal handler, which may be reinstated later, is returned. Otherwise,
71 -1 is returned and the global variable errno is set to indicate the
72 error.
73
75 EINVAL The signal number is invalid or privileged.
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78 MPIL_Signal(2), lam_ksigblock(2)
79LAM 7.1.2 March, 2006 LAM_KSIGNAL(2)