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Diffstat (limited to 'sysdeps/mach/hurd/profil.c')
| -rw-r--r-- | sysdeps/mach/hurd/profil.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/profil.c b/sysdeps/mach/hurd/profil.c new file mode 100644 index 0000000000..4032219a9e --- /dev/null +++ b/sysdeps/mach/hurd/profil.c @@ -0,0 +1,164 @@ +/* Low-level statistical profiling support function. Mach/Hurd version. +Copyright (C) 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <sys/types.h> +#include <unistd.h> +#include <errno.h> +#include <hurd.h> +#include <mach/mach4.h> +#include <mach/pc_sample.h> +#include <cthreads.h> +#include <assert.h> + +static thread_t profile_thread = MACH_PORT_NULL; +static u_short *samples; +static size_t maxsamples; +static size_t pc_offset; +static size_t sample_scale; +static sampled_pc_seqno_t seqno; +static struct mutex lock = MUTEX_INITIALIZER; + +/* Enable statistical profiling, writing samples of the PC into at most + SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling + is enabled, the system examines the user PC and increments + SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero, + disable profiling. Returns zero on success, -1 on error. */ + +static error_t +update_waiter (u_short *sample_buffer, size_t size, size_t offset, u_int scale) +{ + error_t err; + + if (profile_thread == MACH_PORT_NULL) + { + /* Set up the profiling collector thread. */ + static void profile_waiter (void); + err = __thread_create (__mach_task_self (), &profile_thread); + if (! err) + err = __mach_setup_thread (__mach_task_self (), profile_thread, + &profile_waiter, NULL, NULL); + } + else + err = 0; + + if (! err) + { + if (sample_scale == 0) + err = __thread_resume (profile_thread); + if (! err) + { + samples = sample_buffer; + maxsamples = size / sizeof *sample_buffer; + pc_offset = offset; + sample_scale = scale; + } + } + + return err; +} + +int +profil (u_short *sample_buffer, size_t size, size_t offset, u_int scale) +{ + error_t err; + + __mutex_lock (&lock); + + if (scale == 0) + { + /* Disable profiling. */ + int count; + __thread_suspend (profile_thread); + err = __task_disable_pc_sampling (__mach_task_self (), &count); + sample_scale = 0; + seqno = 0; + } + else + err = update_waiter (sample_buffer, size, offset, scale); + + __mutex_unlock (&lock); + + return err ? __hurd_fail (err) : 0; +} + +static void +profile_waiter (void) +{ + sampled_pc_t pc_samples[512]; + mach_msg_type_number_t nsamples = 512, i; + mach_port_t rcv = __mach_reply_port (); + mach_msg_header_t msg; + const mach_msg_timeout_t timeout = 17; /* ??? XXX */ + error_t err; + + while (1) + { + __mutex_lock (&lock); + + err = __task_get_sampled_pcs (__mach_task_self (), &seqno, + pc_samples, &nsamples); + assert_perror (err); + + for (i = 0; i < nsamples; ++i) + { + size_t idx = (((pc_samples[i].pc - pc_offset) / 2) * + sample_scale / 65536); + if (idx < maxsamples) + ++samples[idx]; + } + + __vm_deallocate (__mach_task_self (), + (vm_address_t) pc_samples, + nsamples * sizeof *pc_samples); + + __mutex_unlock (&lock); + + __mach_msg (&msg, MACH_RCV_MSG|MACH_RCV_TIMEOUT, 0, sizeof msg, + rcv, timeout, MACH_PORT_NULL); + } +} + +data_set_element (_hurd_fork_locks, lock); + +static void +fork_profil (void) +{ + u_short *sb; + size_t n, o, ss; + error_t err; + + if (profile_thread != MACH_PORT_NULL) + { + __mach_port_deallocate (__mach_task_self (), profile_thread); + profile_thread = MACH_PORT_NULL; + } + + sb = samples; + samples = NULL; + n = maxsamples; + maxsamples = 0; + o = pc_offset; + pc_offset = 0; + ss = sample_scale; + sample_scale = 0; + + err = update_waiter (sb, n * sizeof *sb, o, ss); + assert_perror (err); +} +text_set_element (_hurd_fork_child_hook, fork_profil); |