First and foremost, apologies for any cross-posting. Hope I m not repeating an issue here, but I was unable to find this elsewhere (via Google and Stack Overflow).
Here s the gist of the error. If I call printf
, sprintf
or fprintf
anywhere within my code, to display a float, I get a SIGSEGV (EXC_BAD_ACCESS)
error. Let me give an example.
The following throws the error:
float f = 0.5f;
printf("%f
",f);
This code does not:
float f = 0.5f;
printf("%d
",f);
I realize there s an implicit conversion there, but I m not concerned with that. I just can t fathom why printing a float vs. printing an integer would throw an error.
Note: Part of the code uses malloc
to create some very large multidimensional arrays. However, these arrays are not being referenced in any way for these print statements. Here s an example how I m declaring these arrays.
#define X_LEN 20
#define XDOT_LEN 20
#define THETA_LEN 20
#define THETADOT_LEN 20
#define NUM_STATES (X_LEN+1) * (XDOT_LEN+1) * (THETA_LEN+1) * (THETADOT_LEN+1)
#define NUM_ACTS 100
float *states = (float *)malloc(NUM_STATES * sizeof(float));
// as opposed to float states[NUM_STATES] (more memory effecient)
float **q = (float**)malloc(NUM_STATES * sizeof(float*));
for(int i=0; i < NUM_STATES; i++) {
float *a = (float*)malloc(NUM_ACTS * sizeof(float));
for(int j=0; j < NUM_ACTS; j++) {
a[j] = 0.0f;
}
q[i] = a;
}
And then the above printf
statements occur later in the code.
The reason I included the malloc
stuff is because from what I understand, SIGSEGV
is related to poorly formed malloc
calls. So, if the array initializations are what s causing the problem, I would like to know:
- why?
- how can I change the
malloc
code to solve this problem?
I ve included the crash log generated by OS X, just in case that helps anybody out.
Process: pole [5453] Path: {REDACTED} Identifier: pole Version: ??? (???) Code Type: X86-64 (Native) Parent Process: bash [5441] Date/Time: 2009-12-08 11:38:38.358 -0600 OS Version: Mac OS X 10.6.2 (10C540) Report Version: 6 Interval Since Last Report: 130074 sec Crashes Since Last Report: 68 Per-App Crashes Since Last Report: 63 Anonymous UUID: CA20CF15-8C46-4C85-A793-6C69F9F40140 Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x0000000100074f3b Crashed Thread: 0 Dispatch queue: com.apple.main-thread Thread 0 Crashed: Dispatch queue: com.apple.main-thread 0 libSystem.B.dylib 0x00007fff828d489e __Balloc_D2A + 164 1 libSystem.B.dylib 0x00007fff828d49b8 __d2b_D2A + 45 2 libSystem.B.dylib 0x00007fff828e8c74 __dtoa + 320 3 libSystem.B.dylib 0x00007fff828aa960 __vfprintf + 4980 4 libSystem.B.dylib 0x00007fff828ec7db vfprintf_l + 111 5 libSystem.B.dylib 0x00007fff828ec75e fprintf + 196 6 pole 0x00000001000028b5 Balance::sarsa() + 187 7 pole 0x0000000100002e54 main + 49 8 pole 0x00000001000010a8 start + 52 Thread 0 crashed with X86 Thread State (64-bit): rax: 0x0000000000000001 rbx: 0x000000010042cca0 rcx: 0x000000010042cca8 rdx: 0x0000000100074f3b rdi: 0x000000000000000e rsi: 0x00007fff5fbfecbc rbp: 0x00007fff5fbfeba0 rsp: 0x00007fff5fbfeb90 r8: 0x00007fff5fbff0b0 r9: 0x0000000000000000 r10: 0x00000000ffffffff r11: 0x000000010083a40b r12: 0x0000000000000001 r13: 0x00007fff5fbfecb8 r14: 0x00007fff5fbfecbc r15: 0x000000010000363e rip: 0x00007fff828d489e rfl: 0x0000000000010202 cr2: 0x0000000100074f3b Binary Images: 0x100000000 - 0x100003fff +pole ??? (???) {REDACTED} 0x7fff5fc00000 - 0x7fff5fc3bdef dyld 132.1 (???) /usr/lib/dyld 0x7fff81697000 - 0x7fff8169bff7 libmathCommon.A.dylib ??? (???) /usr/lib/system/libmathCommon.A.dylib 0x7fff8289c000 - 0x7fff82a5aff7 libSystem.B.dylib ??? (???) /usr/lib/libSystem.B.dylib 0x7fff83c4c000 - 0x7fff83cc9fef libstdc++.6.dylib ??? (???) /usr/lib/libstdc++.6.dylib 0x7fffffe00000 - 0x7fffffe01fff libSystem.B.dylib ??? (???) /usr/lib/libSystem.B.dylib Model: MacBookPro4,1, BootROM MBP41.00C1.B03, 2 processors, Intel Core 2 Duo, 2.4 GHz, 2 GB, SMC 1.27f2 Graphics: NVIDIA GeForce 8600M GT, GeForce 8600M GT, PCIe, 256 MB Memory Module: global_name AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x8C), Broadcom BCM43xx 1.0 (5.10.91.19) Bluetooth: Version 2.2.4f3, 2 service, 1 devices, 1 incoming serial ports Network Service: AirPort, AirPort, en1 Serial ATA Device: Hitachi HTS542520K9SA00, 186.31 GB Parallel ATA Device: MATSHITADVD-R UJ-867 USB Device: Built-in iSight, 0x05ac (Apple Inc.), 0x8502, 0xfd400000 USB Device: Apple Internal Keyboard / Trackpad, 0x05ac (Apple Inc.), 0x0230, 0x5d200000 USB Device: IR Receiver, 0x05ac (Apple Inc.), 0x8242, 0x5d100000 USB Device: BRCM2046 Hub, 0x0a5c (Broadcom Corp.), 0x4500, 0x1a100000 USB Device: Bluetooth USB Host Controller, 0x05ac (Apple Inc.), 0x820f, 0x1a110000
Thanks.