Signal handlers

The LeakSanitizer adds a few signal handlers to your program.

Signal handlers installed by your program take precedence over the LeakSanitizer's handlers.

Deadly signals

Upon receipt of a deadly signal, the program is terminated and the callstack of the receiving point is printed. The faulty address is also printed if available.

Tip

Example:

Segmentation fault (SIGSEGV) on address 0x0!
Address not existent (MAPERR).
In: (fdf) get_next_line (bonus/get_next_line_bonus.c:0:37)
at: (fdf) generate_read_file (model/generate.c:79:9)
at: (fdf) generate_parse_arguments (model/generate.c:21:17)
at: (fdf) main (main.c:24:10)
at: (/usr/lib/dyld) start + 1903

Caught deadly signals

• SIGSEGV
• SIGABRT
• SIGTERM
• SIGALRM
• SIGPIPE
• SIGFPE
• SIGILL
• SIGQUIT
• SIGHUP
• SIGBUS
• SIGXFSZ
• SIGXCPU
• SIGSYS
• SIGVTALRM
• SIGPROF
• SIGTRAP

SIGUSR1

The SIGUSR1 causes the current memory statistics to be printed. It shows you the amount of the currently allocated objects and the amount of the currently allocated bytes as well as their peek values.

Tip

Example:

Stats of the memory usage so far:
297 objects in the heap, peek 661, 485 deleted objects.

7.72 MiB currently used, peek 7.72 MiB.
[====================================================================================================] of 7.72 MiB peek

297 objects currently in the heap, peek 661 objects.
[=============================================.......................................................] of 661 objects peek

SIGUSR2

The SIGUSR2 causes the callstack of the signal handler to be printed. One can easily see what the application is currently doing using that callstack.

Tip

Example:

The current callstack:
In: (fdf) renderer_draw_line (renderer/renderer_draw.c:46:6)
at: (fdf) renderer_draw_core (renderer/renderer_draw.c:97:3)
at: (fdf) renderer_draw (renderer/renderer_draw.c:24:4)
at: (fdf) delegate_render_frame (renderer/renderer.c:14:2)
at: (libmlx.dylib) do_loop_hook2 (mlx_init_loop.m:16:3)
at: (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation) __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
at: (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation) __CFRunLoopDoTimer + 807
at: (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation) __CFRunLoopDoTimers + 285
at: (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation) __CFRunLoopRun + 2206
at: (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation) CFRunLoopRunSpecific + 560
at: (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox) RunCurrentEventLoopInMode + 292
at: (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox) ReceiveNextEventCommon + 657
at: (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A/HIToolbox) _BlockUntilNextEventMatchingListInModeWithFilter + 64
at: (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit) _DPSNextEvent + 858
at: (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit) -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1214
at: (/System/Library/Frameworks/AppKit.framework/Versions/C/AppKit) -[NSApplication run] + 586
at: (libmlx.dylib) mlx_loop (mlx_init_loop.m:104:3)
at: (fdf) onApplicationFinishedLaunching (delegate/app_delegate.c:36:2)
at: (fdf) main (main.c:32:10)
at: (/usr/lib/dyld) start + 1903