On 6/20/22 11:32, Richard Biener wrote:
> On Thu, Jun 16, 2022 at 9:01 AM Martin Liška <mli...@suse.cz> wrote:
>>
>> lto-plugin/ChangeLog:
>>
>> * lto-plugin.c (plugin_lock): New lock.
>> (claim_file_handler): Use mutex for critical section.
>> (onload): Initialize mutex.
>> ---
>> lto-plugin/lto-plugin.c | 16 +++++++++++++++-
>> 1 file changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
>> index 00b760636dc..13118c4983c 100644
>> --- a/lto-plugin/lto-plugin.c
>> +++ b/lto-plugin/lto-plugin.c
>> @@ -55,6 +55,7 @@ along with this program; see the file COPYING3. If not see
>> #include <unistd.h>
>> #include <fcntl.h>
>> #include <sys/types.h>
>> +#include <pthread.h>
>
> Not sure if we support any non-pthread target for building the LTO
> plugin, but it
> seems we have
>
> # Among non-ELF, only Windows platforms support the lto-plugin so far.
> # Build it unless LTO was explicitly disabled.
> case $target in
> *-cygwin* | *-mingw*) build_lto_plugin=$enable_lto ;;
>
> which suggests that at least build validating the above with --enable-lto
Verified that it's fine.
>
> IIRC we have gthr-*.h in libgcc/, not sure if that's usable in a
> host linker plugin.
>
>> #ifdef HAVE_SYS_WAIT_H
>> #include <sys/wait.h>
>> #endif
>> @@ -157,6 +158,9 @@ enum symbol_style
>> ss_uscore, /* Underscore prefix all symbols. */
>> };
>>
>> +/* Plug-in mutex. */
>> +static pthread_mutex_t plugin_lock;
>> +
>> static char *arguments_file_name;
>> static ld_plugin_register_claim_file register_claim_file;
>> static ld_plugin_register_all_symbols_read register_all_symbols_read;
>> @@ -1262,15 +1266,18 @@ claim_file_handler (const struct
>> ld_plugin_input_file *file, int *claimed)
>> lto_file.symtab.syms);
>> check (status == LDPS_OK, LDPL_FATAL, "could not add symbols");
>>
>> + pthread_mutex_lock (&plugin_lock);
>> num_claimed_files++;
>> claimed_files =
>> xrealloc (claimed_files,
>> num_claimed_files * sizeof (struct plugin_file_info));
>> claimed_files[num_claimed_files - 1] = lto_file;
>> + pthread_mutex_unlock (&plugin_lock);
>>
>> *claimed = 1;
>> }
>>
>> + pthread_mutex_lock (&plugin_lock);
>> if (offload_files == NULL)
>> {
>> /* Add dummy item to the start of the list. */
>> @@ -1333,11 +1340,12 @@ claim_file_handler (const struct
>> ld_plugin_input_file *file, int *claimed)
>> offload_files_last_lto = ofld;
>> num_offload_files++;
>> }
>> + pthread_mutex_unlock (&plugin_lock);
>>
>> goto cleanup;
>>
>> err:
>> - non_claimed_files++;
>> + __atomic_fetch_add (&non_claimed_files, 1, __ATOMIC_RELAXED);
>
> is it worth "optimizing" this with yet another need for target specific
> support
> (just use pthread_mutex here as well?)
Sure.
May I install the patch with the change?
Cheers,
Martin
>
>> free (lto_file.name);
>>
>> cleanup:
>> @@ -1415,6 +1423,12 @@ onload (struct ld_plugin_tv *tv)
>> struct ld_plugin_tv *p;
>> enum ld_plugin_status status;
>>
>> + if (pthread_mutex_init (&plugin_lock, NULL) != 0)
>> + {
>> + fprintf (stderr, "mutex init failed\n");
>> + abort ();
>> + }
>> +
>> p = tv;
>> while (p->tv_tag)
>> {
>> --
>> 2.36.1
>>
>>
From 12fb5f8fbb283313f9d5bcadb24c45904128804d Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Mon, 16 May 2022 14:18:41 +0200
Subject: [PATCH 1/2] lto-plugin: make claim_file_handler thread-safe
lto-plugin/ChangeLog:
* lto-plugin.c (plugin_lock): New lock.
(claim_file_handler): Use mutex for critical section.
(onload): Initialize mutex.
---
lto-plugin/lto-plugin.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/lto-plugin/lto-plugin.c b/lto-plugin/lto-plugin.c
index 00b760636dc..2d95b7b3803 100644
--- a/lto-plugin/lto-plugin.c
+++ b/lto-plugin/lto-plugin.c
@@ -55,6 +55,7 @@ along with this program; see the file COPYING3. If not see
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
+#include <pthread.h>
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
@@ -157,6 +158,9 @@ enum symbol_style
ss_uscore, /* Underscore prefix all symbols. */
};
+/* Plug-in mutex. */
+static pthread_mutex_t plugin_lock;
+
static char *arguments_file_name;
static ld_plugin_register_claim_file register_claim_file;
static ld_plugin_register_all_symbols_read register_all_symbols_read;
@@ -1262,15 +1266,18 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed)
lto_file.symtab.syms);
check (status == LDPS_OK, LDPL_FATAL, "could not add symbols");
+ pthread_mutex_lock (&plugin_lock);
num_claimed_files++;
claimed_files =
xrealloc (claimed_files,
num_claimed_files * sizeof (struct plugin_file_info));
claimed_files[num_claimed_files - 1] = lto_file;
+ pthread_mutex_unlock (&plugin_lock);
*claimed = 1;
}
+ pthread_mutex_lock (&plugin_lock);
if (offload_files == NULL)
{
/* Add dummy item to the start of the list. */
@@ -1333,11 +1340,14 @@ claim_file_handler (const struct ld_plugin_input_file *file, int *claimed)
offload_files_last_lto = ofld;
num_offload_files++;
}
+ pthread_mutex_unlock (&plugin_lock);
goto cleanup;
err:
+ pthread_mutex_lock (&plugin_lock);
non_claimed_files++;
+ pthread_mutex_unlock (&plugin_lock);
free (lto_file.name);
cleanup:
@@ -1415,6 +1425,12 @@ onload (struct ld_plugin_tv *tv)
struct ld_plugin_tv *p;
enum ld_plugin_status status;
+ if (pthread_mutex_init (&plugin_lock, NULL) != 0)
+ {
+ fprintf (stderr, "mutex init failed\n");
+ abort ();
+ }
+
p = tv;
while (p->tv_tag)
{
--
2.36.1
