December 2014 - Darwin-dev - lists.apple.com

libmalloc: forget to free something in nano_try_madvise in nano_malloc?
by cee1 23 Dec '14

23 Dec '14

Hi all, I'm interesting to the internal of malloc in OS X and learning some code snippets of it, and I find it seems forget to free page_bitarray in nano_try_madvise() (http://www.opensource.apple.com/source/libmalloc/libmalloc-53.1.1/src/nano_…, line 1395): """ bitarray_t slot_bitarray = bitarray_create(log_size); bitarray_t page_bitarray = bitarray_create(log_page_count); if (!slot_bitarray) { /******* Shouldn't we free(page_bitarray) here？*******/ return bytes_toward_goal; } if (!page_bitarray) { free(slot_bitarray); return bytes_toward_goal; } """ BTW, in segregated_band_grow(), does it miss an unmap call if return another vm area that's not what asked for? """ kern_return_t kr = mach_vm_map(mach_task_self(), &vm_addr, BAND_SIZE, 0, VM_MAKE_TAG(VM_MEMORY_MALLOC_NANO), MEMORY_OBJECT_NULL, 0, FALSE, VM_PROT_DEFAULT, VM_PROT_ALL, VM_INHERIT_DEFAULT); void *q = (uintptr_t)vm_addr; if (kr || q != (void *)(p & ~((uintptr_t)(BAND_SIZE - 1)))) // Must get exactly what we asked for return FALSE; """ -- Regards, - cee1 _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: OS X 10.10 Libc-1044.1.2 missing some parts
by cee1 12 Dec '14

12 Dec '14

2014-12-12 23:43 GMT+08:00 Jean-Daniel Dupas <dev(a)xenonium.com>: > On OS X, libc is split into many independents projects. > > Check the libmalloc project for the malloc implementation. Got it, thanks! -- Regards, - cee1 _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: OS X 10.10 Libc-1044.1.2 missing some parts
by Jean-Daniel Dupas 12 Dec '14

12 Dec '14

On OS X, libc is split into many independents projects. Check the libmalloc project for the malloc implementation. > Le 12 déc. 2014 à 16:37, cee1 <fykcee1(a)gmail.com> a écrit : > > Hey Guys, > > Just curious about the implementation of malloc in OS X, and I tried > to download Libc from > http://www.opensource.apple.com/release/os-x-1010/, but didn't find it > there. > > After googling, I find a similar mail in > http://markmail.org/message/33wdzu533lzjydr3 > > So, the source code is still not available? > > BTW, iOS uses the same malloc implementation as OS X? > > > > -- > Regards, > > - cee1 > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/darwin-dev/mailing%40xenonium.com > > This email sent to mailing(a)xenonium.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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OS X 10.10 Libc-1044.1.2 missing some parts
by cee1 12 Dec '14

12 Dec '14

Hey Guys, Just curious about the implementation of malloc in OS X, and I tried to download Libc from http://www.opensource.apple.com/release/os-x-1010/, but didn't find it there. After googling, I find a similar mail in http://markmail.org/message/33wdzu533lzjydr3 So, the source code is still not available? BTW, iOS uses the same malloc implementation as OS X? -- Regards, - cee1 _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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forkpty/select timeout issue
by Kevin Wojniak 12 Dec '14

12 Dec '14

I have some small code that calls forkpty, then in the child writes to stdout, and in the parent waits with select() for data to be available and then reads it all. When testing on a 10.8 virtual machine and running the code repeatedly, I can get the select() to timeout about every other time I run the shell script. Also, sometimes the data is not read in the parent at all, read() just returns 0. Here is the code: =================== #include <stdio.h> #include <util.h> #include <errno.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <sys/wait.h> #include <assert.h> int main() { int fd; pid_t pid = forkpty(&fd, NULL, NULL, NULL); if (pid == -1) { printf("forkpty failed: %s\n", strerror(errno)); return -1; } else if (pid == 0) { if (write(STDOUT_FILENO, "hello", 5) != 5) { _Exit(1); } _Exit(0); } // parent int flags = fcntl(fd, F_GETFL, 0); assert(flags != -1); assert(fcntl(fd, F_SETFL, flags | O_NONBLOCK) == 0); char output[1024]; bzero(output, sizeof(output)); for (;;) { // Wait for data to become available fd_set readfd; FD_ZERO(&readfd); FD_SET(fd, &readfd); struct timeval tv; tv.tv_sec = 1; tv.tv_usec = 0; printf("select...\n"); int sel = select(fd+1, &readfd, NULL, NULL, &tv); if (sel == -1) { if (errno == EINTR) { printf("select EINTR\n"); continue; } printf("select failed: %s\n", strerror(errno)); return 1; } else if (sel == 0) { printf("select timed out\n"); return 1; } // good assert(FD_ISSET(fd, &readfd)); char foo[1024]; bzero(foo, sizeof(foo)); ssize_t num; for (;;) { num = read(fd, foo, sizeof(foo)-1); if (num == -1 && errno == EINTR) { printf("read EINTR\n"); continue; } break; } printf("read: %d\n", (int)num); assert(num <= 5); if (num == -1) { printf("read failed: %s\n", strerror(errno)); return 1; } if (num == 0) { // done break; } foo[num] = 0; strcat(output, foo); } printf("output: ->%s<-\n", output); assert(strcmp(output, "hello") == 0); int status; assert(waitpid(pid, &status, 0) > 0); assert(close(fd) == 0); assert(WIFEXITED(status) == 1); assert(WEXITSTATUS(status) == 0); return 0; } =================== Compile: cc test.c -o test Here is the shell script to run repeatedly: =================== set -e for i in `seq 200`; do echo $i ./test done =================== This was stripped down from a larger code base to try and figure out what’s going on, but I don’t understand why it occasionally times out. I also reproduced on a 10.9 VM. I have reproduced the timeout on my native 10.10 system, but it is more rare (possibly due to being faster and more cores?). Is there something I’m missing? I’ve been studying a lot of example code and cannot find anything that I should be doing extra. Any help would be appreciated! Kevin _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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VFS/KAuth changes in 10.9.x and later?
by Stéphane Sudre 09 Dec '14

09 Dec '14

Is there a document that lists the changes eventually made in OS X 10.9.x and later when it comes to VFS or KAuth? I've looked for one on the Developer site and did not find any. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: Apple contacts?
by Shantonu Sen 02 Dec '14

02 Dec '14

_______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Apple contacts?
by Benjamin Huntsman 02 Dec '14

02 Dec '14

Hello! Are there many folks still on this list? Does anyone know who the current contact is at Apple for their open source stuff? It used to be Bill Siegrist, but I haven't seen any posts by him in ages, nor have I been able to reach him via e-mail... Thanks! -Ben _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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