Chapter 20: Signals: Fundamental Concepts

Table of Contents

• Exercise 20-1
  • Exercise 20-1 Without Sleeping
  • Exercise 20-1 With Sleeping
• Exercise 20-2
• Exercise 20-3
  • Exercise 20-3 with SA_NODEFER
  • Exercise 20-3 with SA_RESETHAND
• Exercise 20-4

Exercise 20-1

Exercise 20-1 Without Sleeping

To run the solution without sleeping, use:

make test_1_n

The logs/test1/receiver.log file shows:

sig_receiver: PID=21035
sig_receiver: signal  10 caught 499865 time(s)

The logs/test1/sender.log file shows:

sig_sender: 1000000 signals (signal=10) are to be sent to process (PID=21035) with a last signal of 2.
sig_sender: Completed.

To get verbose output, use:

make test_1_n_v

Exercise 20-1 With Sleeping

To run the solution with sleeping, use:

make test_1_s

The logs/test1/receiver.log file shows:

sig_receiver: PID=21713
sig_receiver: sleeping for 5 seconds.
sig_receiver: pending signals are:
		 10 (User defined signal 1)
sig_receiver: signal  10 caught      1 time(s)

The logs/test1/sender.log file shows:

sig_sender: 1000000 signals (signal=10) are to be sent to process (PID=21713) with a last signal of 2.
sig_sender: Completed.

To get verbose output, use:

make test_1_s_v

Exercise 20-2

To run the solution with sleeping, use:

make test_2

The logs/test2/sender.log file shows:

sig_sender: 1000000 signals (signal=10) are to be sent to process (PID=13960) with a last signal of 2.
sig_sender: Completed.

The logs/test2/receiver.log file shows:

sig_receiver: PID=13960
sig_receiver: signal (10) will be ignored.
sig_receiver: sleeping for 5 seconds.
sig_receiver: pending signals are:
		 10 (User defined signal 1)
sig_receiver: No signals were caught.

To get verbose output, use:

make test_2_v

Exercise 20-3

Test SA_NODEFER

To run tests with the SA_NODEFER set:

make test_3_n

Sample output (from test/logs/test3/sig_receiver.log) is:

sig_receiver: PID=37910
sig_receiver: signals are handled with SA_NODEFER.
sig_receiver: No signals will be ignored.
sig_receiver: signal  10 caught      1 time(s)

Test SA_RESETHAND

To run tests with the SA_RESETHAND set:

make test_3_r

Sample output (from test/logs/test3/sig_receiver.log) is:

sig_receiver: PID=38239
sig_receiver: signals are handled with SA_RESETHAND.
sig_receiver: No signals will be ignored.
sig_receiver: signal  10 caught      1 time(s)

Exercise 20-4

To run the solution, type:

make test_4

Sample output is:

make test_4
gcc -o sig_interrupt sig_interrupt.c 
./run_test_4.sh 
sig_interrupt: Enable signal handler for SIGUSR1
sig_interrupt: Send SIGUSR1 to self
sig_interrupt: signal was received.
sig_interrupt: setting of signal handler (signal_handler) through siginterrupt(10,0)
sig_interrupt: Send SIGUSR1 to self
sig_interrupt: signal was received.
sig_interrupt: setting of signal handler (signal_handler) through siginterrupt(10,1)
sig_interrupt: Send SIGUSR1 to self
sig_interrupt: signal was received.
sig_interrupt: Exit.